Charles Q. Choi
Space.com
Tue, 01 Jan 2008 15:07 EST
The farthest reaches of our solar system remain the most mysterious areas around the sun. Solving the mysteries of the outer solar system could shed light on how the whole thing emerged - as well as how life on Earth was born.
Why the rainbow of colors in the Kuiper belt?
For instance, the Kuiper belt past Neptune is currently the suspected home of comets that only take a few decades or at most centuries to complete their solar orbits - so-called "short-period comets." Surprisingly, Kuiper belt objects "show a wide range of colors - neutral or even slightly blue all the way to very red," said University of Hawaii astrophysicist David Jewitt.
The color of an object helps reveal details about its surface composition. It remains a mystery why Kuiper belt objects show a much wider range of color - and thus surface composition - than other planetoids, such as the asteroids.
Some researchers had suggested volcanic activity could have led to all these colors - "absurd in the context of 100-kilometer-sized (60-mile) bodies," Jewitt said, as volcanism needs something bigger.
Jewitt and his colleagues had suggested that cosmic rays could have made Kuiper belt objects redder, while impacts with rocks could have dug up more pristine matter that made them less red. Nowadays Jewitt thinks there must be another explanation for this rainbow, but it remains unknown.
What is ultra-red matter?
There appears to be a material dubbed "ultra-red matter" that exists only on about half of all Kuiper belt objects and their immediate progeny, known as centaurs - icy planetoids orbiting between Jupiter and Neptune that very recently escaped from the Kuiper belt.
This ultra-red matter does not exist in the inner solar system, "not even on the comets which come from the Kuiper belt. This suggests that the ultra-red matter is somehow unstable at the higher temperatures close to the sun," Jewitt explained.
The red colors suggest this substance might contain organic molecules. Comets and other planetoids are often thought to have helped bring organic molecules to Earth.
"In the Kuiper belt objects, organics might have been 'cooked' by cosmic ray radiation, giving them dark red surfaces, but there is no proof," Jewitt said. Ideally spacecraft could go out there and find out, he added.
Has the Kuiper belt shrunk?
Theoretical calculations suggest the Kuiper belt was once hundreds or maybe even thousands of times more populated than it is now. "How was 99 percent or 99.9 percent of the mass lost, and when?" Jewitt asked.
One conjecture suggests when Saturn and Jupiter shifted their orbits roughly 4 billion years ago, their gravitational pulls slung Kuiper belt objects out of the solar system. Another says the Kuiper belt objects pulverized themselves to dust, which then was swept away by the sun's radiation. Yet another possibility "is that we are missing something crucial and the conclusion that the belt is heavily depleted is wrong," Jewitt said. "All these possibilities are comparably hard to swallow, but would each be amazing, if true."
Secrets in the Oort cloud?
A distant reservoir of trillions of comets known as the Oort cloud theoretically lies up to 100,000 astronomical units from the sun - an astronomical unit or AU being about 93 million miles (150 million kilometers). This means the Oort cloud is a fifth of the way to the nearest star, so far away that objects within it have never been seen directly, only inferred - but it must exist, given all the comets seen over the years.
The Oort cloud is the conjectured source of comets that require centuries or millennia to complete their long journeys around the sun. Since these "long-period comets" come from all directions, the Oort cloud is often thought to be spherical. However, while comets such as Halley's do not come from the Kuiper belt, their orbits also do not jibe with a spherical Oort cloud, Jewitt explained. This suggests there may be an "inner Oort cloud" shaped kind of like a doughnut.
Astrophysicists think the Oort cloud is a remnant of the protoplanetary disk that formed around the sun roughly 4.6 billion years ago. Learning more about the Oort cloud could shed light on how our solar system - and Earth - were born, Jewitt said.
Are there more dwarf planets?
So far, three dwarf planets are recognized - Ceres, Pluto and Eris. The Kuiper belt, which lies about 50 AU from the sun, could hold some 200 more. Beyond that there could be scores of dwarf-planet-sized bodies beyond roughly 100 AU from the sun "that nobody had seen before due to their faintness and slow motion," said astronomer Chad Trujillo at Gemini Observatory in Hawaii. "Even a body as big as Mars could be missed in our current surveys if it were moved beyond a couple hundred AU."�
Trujillo noted projects such as Pan-STARRS (Panoramic Survey Telescope And Rapid Response System) and the LSST (Large Synoptic Survey Telescope) "should fill this gap in our knowledge in the coming decade."
Where do the dwarf planets come from?
There are theories that the dwarf planets of the outer solar system may have dwelt in the inner solar system billions of years ago, based on their current orbital trajectories. If so, "why are there so many ices on their surfaces?" Trujillo asked. Bodies in the inner solar system are generally expected to lose their ice due to sunlight.
Trujillo and his colleagues suspect the ice now seen on these dwarf planets is relatively new, with such replacement ice coming perhaps from within these worlds, erupting out during "cryovolcanism." Of course, further research is needed to see if such ice renewal would be enough to cover the dwarf planet after they voyaged from the inner to the outer solar system, he added.
Do cosmic rays come from a bubble around the solar system?
When the supersonic wind of charged particles that flows from our sun collides with the thin gas found between the stars, the solar wind essentially blows a bubble in this interstellar medium - a ball known as the heliosphere.
Scientists have thought unusually weak cosmic rays - energetic particles that zip from space at Earth - come from the heliosphere. Specifically, these rays are thought to come from the "termination shock" - a shock wave of compressed, hot particles that results when the solar wind abruptly brakes against interstellar gas. (The termination shock appears to be about 75 to 85 AU from the sun.)
However, Voyager 1 saw no sign these anomalous cosmic rays were produced at the termination shock. "Perhaps it crossed the shock at the wrong time or place," said MIT astrophysicist John Richardson, or perhaps the standard view on how these anomalous cosmic rays are generated is wrong. Voyager 2 crossed the termination shock in 2007 about 10 billion miles away from where Voyager 1 crossed it in 2004, and its data, which is still being analyzed, "may help us understand where these particle are produced," he explained.
"Cosmic rays have been reported to affect Earth's weather so understanding their source is important," Richardson added. Moreover, high-energy particles from shock waves triggered by huge eruptions from the sun known as coronal mass ejections can damage spacecraft and astronauts, and better understanding the termination shock could help understand these other, potentially dangerous particles.
Leonard David and Tariq Malik
Space.com
Thu, 03 Jan 2008 16:17 EST
The possibility of an asteroid walloping the planet Mars this month is whetting the appetites of Earth-bound scientists, even as they further refine the space rock's trajectory.
The space rock in question - Asteroid 2007 WD5 - is similar in size to the object that carved Meteor Crater into northern Arizona some 50,000 years ago and is approaching Mars at about 30,000 miles per hour (48,280 kph).
Whether the asteroid will actually hit Mars or not is still uncertain.
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| ©space.com |
Such an impact, researchers said, would prove an awesome blow for planetary science since NASA's Mars Reconnaissance Orbiter (MRO) and a flotilla of other spacecraft are already in position to follow up any impact from orbit.
"An impact that we could witness/follow-up with MRO would be truly spectacular, and could tell us much about the hidden subsurface that could help direct a search for life or life-related molecules," said John Rummel, NASA's senior scientist for astrobiology at the agency's Washington, D.C., headquarters.
Observations of the asteroid between Dec. 29 and Jan. 2 allowed astronomers to slightly lower the space rock's odds of striking Mars to about 3.6 percent (down from 3.9), giving the object a 1 in 28 chance of hitting the planet, according to Tuesday report from NASA's Near Earth-Object program office at the Jet Propulsion Laboratory in Pasadena, Calif.
More observations may further reduce the asteroid's impact chances to nil, NEO officials said. The space rock's refined course stems from observations by astronomers at New Mexico Tech's Magdalena Ridge Observatory.
But if WD5 does smack into Mars, some astronomers have a fair idea of what havoc it may spawn. The likely strike zone would be near the equator, but to the north of the current position of NASA's Opportunity rover at Victoria Crater, NASA officials have said.
Mark Boslough, a collision dynamics expert at New Mexico's Sandia National Laboratory, said the atmosphere at Mars' surface is similar to that of Earth at an altitude of 12 miles (20 km). Some space rocks that target Earth explode under the pressure created as they stream into our atmosphere. But they tend not to explode until much below the 12-mile mark.
"So this won't be an airburst," Boslough said. "It will either hit the ground intact and make a single crater, or break up and generate a cluster of craters."
The collision, were it to occur, could also create a visible dust plume as ejecta is lofted high into the martian atmosphere, he said.
The resulting crater could reach more than a half-mile (0.8-km) in diameter, or about the size of the Opportunity rover's Victoria home, NASA added.
Boslough's break-up scenario is reminiscent of Comet P/Shoemaker-Levy 9, which broke into more than 20 fragments as it neared Jupiter in 1994, then repeatedly pummeled the gas giant over the course of six days. The resulting impact scars were visible to telescopes on Earth, in orbit and NASA's Galileo probe, which was circling Jupiter at the time of the collision.
Like Galileo at Jupiter, NASA's MRO probe and its High-Resolution Imaging Experiment (HiRISE) camera would be in prime position for a martian collision. With its ability to resolve objects three feet (one meter) across, HiRISE as been billed as the most powerful camera ever sent to study Mars.
"If the asteroid hits Mars, we'll get a great look at the crater within a few days of impact," said HiRISE principal investigator Alfred McEwen of the University of Arizona's Lunar and Planetary Laboratory in Tucson.
Ary Hermawan and Yuli Tri Suwarni
The Jakarta Post
Thu, 03 Jan 2008 09:33 EST
Gianyar, Bandung - Residents in Sukawati village in Gianyar regency, around 20 kilometers north of Denpasar, reported the appearance of a mysterious crater in the middle of a paddy field Wednesday.
The hole was allegedly caused by a falling meteorite fragment.
One meter wide and around 30 centimeters deep, the cavity has turned into a large puddle in the heavy rains that have showered the area since New Year's Eve.
Disregarding slippery paths leading to the site, hundreds of people came to see the crater with their own eyes, and take photographs of it with cameras and mobile phones.
"Residents heard an extremely loud gun-like explosion Tuesday evening around 1 a.m. At the same time, a number of residents saw a bright object falling from the sky," Made Tekek Arimbawa, a neighborhood leader, told reporters.
The hole first noticed Tuesday morning by I Wayan Miasa, 60, the owner of the field.
Made said he ordered the owner to wait for an explanation from the authorities before using the field again.
"We don't know for sure what it is," he said.
Sukawati police chief Comr. Ida Bagus Bedanajati said pieces of rock were found in the alleged meteorite crater.
"The rocks we found resembled pumice but didn't float -- it sank in water," he said.
He said the impact had not altered the structure of the soil or killed any plants or animals in the surrounding area.
"There were no casualties or material losses. What we do next is wait for the experts," he said.
The police had secured the area with a police line.
Bali is home to many mystic beliefs where odd and supernatural occurrences like flying fire balls are not unheard of.
The Balinese describe the occurrences as niskala which refers to the world of "unseen" phenomena.
Bandung Flight and Space Institute sun and space researcher Thomas Djamaludin said Wednesday he believed the unidentified object was a meteoric fragment.
He said he suspected a larger fragment had created the hole as it was impossible for small fragments to create the loud noise heard by residents.
The fragment would not cause radiation effects dangerous to humans, Djamaludin said.
Fragments were "only dangerous at the time of their explosive impact, with a fallout of hot debris ... After that they are harmless," he said in Bandung.
CBC News
Fri, 04 Jan 2008 08:34 EST
Mammoth fossils around the Yukon are offering evidence that ancient meteor explosions may have wiped out entire species there thousands of years ago, a California-based researcher says.
A team led by Richard Firestone, a nuclear scientist at the Lawrence Berkeley National Laboratory in Berkeley, Calif., made the discovery while testing thousands of samples of fossilized Alaskan mammoth ivory from a suspected meteor impact that occurred about 13,000 years ago.
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| ©R. Firestone |
"You would see round circles with little holes in them," Firestone told CBC News in an interview Thursday, referring to hundreds of circular burn marks he saw on some mastadon tusks.
X-ray analysis showed tiny rock fragments deep inside those holes, and metallurgical tests confirmed the fragments did come from meteors.
Firestone said he believes meteorites exploded over parts of Beringia - the Ice Age-era region that includes parts of modern-day Alaska, Yukon and Siberia - creating showers of fragments, or "micrometeorites," that struck and killed many of the prehistoric creatures that roamed the area.
Furthermore, Firestone's team uncovered a surprise: The sample tusks dated back to about 35,000 years ago, meaning they were older than the blast from 13,000 years ago that they were initially studying.
"It turns out that there was an impact event, probably a meteor, that exploded over Alaska and probably over Siberia ... around that time and embedded these particles into the tusks," he said.
"They probably came in under very high velocities, hundreds of kilometres a second almost. It must have exploded and just embedded these things in the tusks in large quantities, as many as 100 or more in one tusk."
The small holes with meteorite fragments were found in about one out of every 1,000 pieces of mastodon ivory pieces Firestone's team has tested. They also found similar fragments in one Siberian bison skull that appeared to have survived the blast, he said.
"In the bison skull, since that was bone, we could see renewed growth around these particles after they had been impacted. So presumably the bison - that particular individual, at least - survived the impact."
Now, Firestone is asking Yukoners for any mammoth fossil samples they may have. He is asking anyone who has found fossilized bone or ivory with circular discolorations to try and collect soil samples in the area where they found the fossil, then contact him at the California laboratory.
"We think they came from your area around the Yukon somewhere," he said. "So presumably [Yukoners] are going to be finding these things if they look for them."
Firestone's findings were presented last month at a meeting of the American Geophysical Union in San Francisco.
Times of India
Fri, 04 Jan 2008 14:35 EST
Washington: An asteroid that has a one in 20 chance of striking Mars on January 30, might just fly past, which would probably make it target Earth at some point in future.
Designated 2007 WD5, the 160-foot wide asteroid was originally identified as a possible risk to Earth, though later analysis showed that it actually might be on a collision course with Mars.
According to a report in Discovery News, Donald Yeomans, a planetary scientist at NASA's Jet Propulsion Laboratory in Pasadena, California, has said that the odds are that the asteroid is going to fly right past Mars.
In the long run, that may not be good news for Earth, which could find itself in the asteroid's path at some point in the future. "Something of this size could take out a fairly large metropolitan area," said Yeomans.
But unlike the 1908 Tunguska event, when a large asteroid exploded over central Siberia with the force of a large nuclear bomb, now there would be advance warning of a possible strike, as well as the tools and knowledge to divert the threat.
Comment: From the information available, it is evident that we are not prepared nor have the knowledge on how to divert such a thread. It was only this last year that the mainstream media began even talking about the possibility of a strike. Nope, no matter how reassuring the last sentence of the article, it just ain't true folks!
Stephen Battersby
New Scientist
Thu, 03 Jan 2008 16:17 EST
The most intense meteor shower of the year hits Earth tonight. If the skies are clear and you live at high northern latitudes, then you could see dozens of Quadrantid meteors streaking over the pole.
Or you might spot a plane full of astronomers racing northward, trying to find out how this unusual meteor shower was created, and whether it is the shrapnel of a celestial explosion witnessed in the 15th century.
Like other meteor showers, the Quadrantids appear when Earth moves through an interplanetary stream of debris, which hits the upper atmosphere at more than 40 kilometres a second, vaporising to become the brilliant trails we see as shooting stars.
"It is our strongest annual shower, but one that is frustratingly difficult to observe," says Peter Jenniskens of NASA's Ames Research Center in Moffett Field, California, US. That's partly because of bad weather in the northern hemisphere at this time of year. And unless you live in the far north, the shower's radiant - the point in the sky from which the meteors appear to radiate - is below the horizon.
This year Jenniskens will be joining other astronomers on a plane festooned with cameras, which will get above the clouds and fly from Ames to the North Pole, keeping the Quadrantids in clear sight for 9 hours. By tracking the arrival rate of meteors over that time, they are hoping to discover when this stream of meteoroids was born.
Dormant comet
Some meteoroid streams are created and maintained by active comets, which throw off bits of rock and soot as the Sun gradually evaporates their ices. But there is no active comet to supply fresh material to the Quadrantids.
In fact, no parent body was known at all until 2003, when Jenniskens discovered that there is an asteroid following the same orbit as the stream. Jenniskens thinks that this object, 2003 EH1, is the remnant of a dormant comet that spawned the Quadrantids in a single violent event - perhaps an internal convulsion or an impact with another object.
Observers in China, Korea and Japan saw a comet in 1490 moving in
roughly the same path as the Quadrantids. Could it have been a cloud of
dust surrounding the newly shattered 2003 EH1?
Mixed prospects
If the meteoroid stream was created so recently, it will have had little time to disperse, and indeed observations suggest that the stream is narrow.
Jenniskens realised that Jupiter's gravity should deflect such a narrow stream, and he calculates that this year it would push the stream towards Earth. So if it really is narrow, we should hit it a few hours earlier than if it is old, broad and undeflected.
If the shower was created in 1490, Jenniskens calculates it should peak around 0200 GMT on Friday, making it ideal for European observers. If it is much older and more spread out, it should remain relatively unaffected by Jupiter's gravity, and the peak should occur around 0700 GMT - a good time for observers in North America.
For those of us stuck on the ground, viewing prospects are mixed. The rate of visible meteors could be as high as 120 per hour - if you happen to be standing on a mountaintop in Norway. If you're in southern California, however, it drops to only 2 per hour. To see Jenniskens' predictions for your location, visit the "Fluxtimator".
Comets and Asteroids - Learn more in our special report.
Laura Knight-Jadczyk
sott.net
Mon, 07 Jan 2008 11:15 EST
Having recently written a review of New Light on the Black Death: The Cosmic Connection by dendrochronologist Mike Baillie of Queen's University, Belfast, Ireland, I decided to go deeper into the subject. Over the past few weeks a whole case of books I ordered have been arriving and getting piled on my desk after a quick thumb-through... so much to do, so little time.
In the meantime, a friend of mine (who is a climate scientist at a major U.S. research facility) turned me on to an interesting find, a paper addressed to the European Office of Aerospace Research and development, dated June 4, 1996, entitled: The Hazard to Civilization from Fireballs and Comets by S.V.M. Clube. (For the uninitiated, Clube is an astrophysicist at the University of Oxford).
In this short (4 pages) letter and summary statement, Clube writes (emphases in the original, make of them what you will):
Asteroids which pass close to the Earth have been fully recognized by mankind for only about 20 years. Previously, the idea that substantial unobserved objects might be close enough to be a potential hazard to the Earth was treated with as much derision as the unobserved aether. Scientists of course are in business to establish broad principles (eg relativity) and the Earth's supposedly uneventful, uniformitarian environment was already very much in place. The result was that scientists who paid more than lip service to objects close enough to encounter the Earth did so in an atmosphere of barely disguised contempt. Even now, it is difficult for laymen to appreciate the enormity of the intellectual blow with which most of the Body Scientific has recently been struck and from which it is now seeking to recover.
I stopped right there and asked myself: Hmmm... just what intellectual blow is he talking about here? After a bit of thought, it occurred to me that he must be talking about the Comet Shoemaker-Levy fragment impacts on Jupiter which produced a huge amount of excitement at the time which was just two years before the date of this letter. To return to Clube's report, he continues:
The present report, then, is concerned with those other celestial bodies recorded by mankind since the dawn of civilization which either miss or impinge upon the Earth and which have also been despised. Now known respectively as comets (>1 kilometre in size) and meteoroids (<10>
That he immediately switched from asteroids to comets seems to confirm my speculation that he was talking about Shoemaker-Levy. But it gets more interesting:
Confronted on many occasions in the past by the prospect of world-end, national elites have often found themselves having to suppress public panic - only to discover, too late, that the usual means of control commonly fail. Thus an institutionalized science is expected to withhold knowledge of the threat; a self-regulated press is expected to make light of any disaster; while an institutionalized religion is expected to oppose predestination and to secure such general belief in a fundamentally benevolent deity as can be mustered. [...]
(B) The present report based on the above grant addresses a variety of issues within the broad context of the hazard to civilization due to fireballs and comets. It consists of:
(1) A brief statement of conclusions arising from a narrative report (3 copies);
(2) A narrative report (with appendix) linking the results of three scientific studies described in papers submitted to mainstream journals (3 copies)
(3) The relevant papers detailing the results which arise through the granted funds due to (a) Clube; (b) Clube & Napier; and (c) Clube, Holye, Napier & Wickramasinghe (3 copies; and
(4) A co-authored foundation paper by Asher & Clube detailing the results from which items (3) and (2) progressed.
It is emphasized here that the present report expresses a viewpoint which is contrary to the mainstream scientific theme currently reinforced through various US agencies in the wake of recent major findings under US leadership...
Despite the importance of this mainstream theme, it is recognized here that the cometary signatures in the terrestrial record are generally stronger than the asteroidal signatures in the case of both long term and short term effects i.e. those affecting biological and geological evolution on the one hand and mankind and civilization on the other..[...]
There are fundamental paradoxes to be assimilated as a result of this unexpected situation. Thus the perceived culture of enterprise and enlightenment which underpins the two centuries culminating with the Space Age and which led mankind to spurn comets and fireballs may now be seen as the prelude to a profound paradigm shift: the restoration of an environmental outlook more in keeping with that which preceded American Independence and which paid serious heed to comets and fireballs.
Clube then thanks the USAF for "its generous and timely injection of funds" and we note that the letter was cc'd to, among others, Edward Teller at the Hoover Institute, S. Fred Singer at Fairfax VA, and Jack A. Goldstone, Davis, CA.
The summary of conclusions accompanying this letter is equally
interesting, but that will have to wait for tomorrow. If you can't
wait, you can read a pdf here: The Hazard to Civilization from Fireballs and Comets.
I should add that, yes, I obtained the whole report and the papers
it refers to (and more besides). The report makes one startling remark
that I'm going to drop just to whet your appetite:
...the Christian, Islamic and Judaic cultures have all moved since the European Renaissance to adopt an unreasoning anti-apocalyptic stance, apparently unaware of the burgeoning science of catastrophes. History, it now seems, is repeating itself: it has taken the Space Age to revive the Platonist voice of reason but it emerges this time within a modern anti-fundamentalist, anti-apocalyptic tradition over which governments may, as before, be unable to exercise control. ... Cynics (or modern sophists), in other words, would say that we do not need the celestial threat to disguise Cold War intentions; rather we need the Cold War to disguise celestial intentions! (emphasis in the original)
Just think about what this might mean, considering when it was written and all that has happened since. One might think the War on Terror was actually a planned cover-up...
With that happy thought, have a look at this: Majesterium and the Tipping Point
Makes one wonder where the REAL hazard to civilization is coming from...
Stephen Battersby
New Scientist
Tue, 08 Jan 2008 12:39 EST
Last week's Quadrantid meteor shower was probably debris from a deep-space explosion that went off in the late 15th century, new observations reveal.
The meteors, which return every January, were observed more closely than ever before when a group of 14 astronomers tracked them for nine hours on a flight from California, US, to the North Pole.
They found that the shower peaked at around 0200 GMT on Friday, matching a prediction made by Peter Jenniskens of NASA.
He based his prediction on the theory that the shower originated in 1490, when observers in China, Japan and Korea saw a comet following a path similar to that of the Quadrantids. Apparently a sudden event caused the dormant comet to flare up - like Comet Holmes in October 2007 - leaving behind a stream of debris.
Jenniskens calculated that such a young stream should be narrow, and thus easily deflected by Jupiter's gravity. That would make it arrive a few hours earlier than if it were an older, more diffuse stream.
Friday's observations confirm the story. A closer analysis of the new data might also give astronomers some clues about what caused the outburst.
The 1490 event left behind at least one larger remnant, a near-Earth asteroid called 2003 EH1.
Laura Knight-Jadczyk
sott.net
Tue, 08 Jan 2008 09:51 EST
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| ©Julian Baum |
Today we are going to look at the Summary of Conclusions about Fireballs and Meteorites that Victor Clube attached to his cover letter to the Chief, Physics and BMD Coordinator of the European Office of Aerospace Research and Development back in 1996, 5 years before September 11, 2001; that, and a few other things.
I often get accused of "fear mongering" because I keep bringing this subject up again and again. I even think that it is fascinating that the big breakthrough in my experiment in Superluminal Communication came on the day that the fragments of Comet Shoemaker-Levy began striking Jupiter - even at the very moment of the first impact - and that this communication with "myself in the future" has focused so much attention on the subject of swarms of comets and comet fragments that repeatedly barrel through the solar system, wreaking havoc and bringing death and destruction to earth. As a result of the research prompted by this communication, I wrote an entire 800 page book that is woven around the issue of cometary explosion type catastrophes that obviously have occurred repeatedly throughout history: The Secret History of The World.
In the early days of publishing the results of this experiment, I was nonplussed by the many attacks I came under from all quarters. I was accused of "channeling aliens" (not true); of wanting to "start a cult" (what is cultic about doing research into scientific subjects and exposing religion for the fraud it is?) and so on. That sort of thing really hurt and puzzled me at first, but I have now seen it for the blessing it was: it has helped me to learn about the kinds of people who are in charge of our world, the kind of people who want to keep secrets so that they can hang onto power: the kind of people who create such things as "The War on Terror" to conceal from the masses of humanity the future that may very well bring our civilization to an end; the kind of people who know that survival of cometary bombardment is possible and who want to be the only ones who do survive, and to hell with everyone else.
Mike Baillie, in his book about the Black Death, writes:
It is increasingly evident that intellectually the world is divided into two. There are those who study the past, in the fields of history and archaeology, and see no evidence for any human populations ever having been affected by impacts from space. In diametric opposition to this stance there are those who study the objects that come close to, and sometimes collide with, this planet. Some serious members of this latter group have no doubt whatsoever that there must have been numerous devastating impacts in the last five millennia; the period of human civilization. In a paper published in 2005, David Asher and colleagues have looked at the objects that are known to have come close to the earth in recent times. They conclude, based on various strands of evidence (for example, the number of meteorites discovered on earth that originated on the moon) that the average time between impacts on earth is no more than 300 years, probably less. [Earth in the Cosmic Shooting Gallery]
Checking the authors Baillie is referring to, we find Bill Napier listed. Napier is a colleague of Victor Clube. This brings us to another division. There is a debate going on about this issue as was mentioned by Clube in the first parts of the letter in question that I quoted yesterday. He wrote:
It is emphasised here that the present report expresses a viewpoint which is contrary to the mainstream scientific theme currently reinforced through various US agencies in the wake of recent major findings under US leadership (eg those of Luis Alvarez, Eugene Shoemaker, David Morrison etc. Despite the importance of this mainstream theme, it is recognized here that the cometary signatures in the terrestrial record are generally stronger than the asteroidal signatures in the case of both long term and short term effects ie those affecting biological and geological evolution on the one hand and mankind and civilization on the other. The raison d'etre behind this situation is a cometary input dominated in the long term by objects > 100 kilometres in size which substantially break up in the short term into objects < 1 kilometre in size, the "window" of significance so far as the average interval between random impacts by comets and asteroids in the intervening size range are concerned being approximately 1- 10 million years. To concentrate, for planetary defence purposes, on catastrophes which occur only within this particularly narrow range of frequencies is patently absurd.
Clube's reference to the "mainstream scientific" ideas about comets and asteroids and so on is only the tip of the iceberg in reference to this debate.
The debate is about asteroids vs. comets. Asteroids are solid bodies of rock and there are about 1000 of them with diameters of 1 km or more that cross the orbit of the earth. They are called "Apollo" or "earth crossing" asteroids. The "American School" of astronomers believe that these objects are the main threat to earth and humanity and they are concerned with finding them, tracking them, and working out their orbits. This school believes that if all these asteroids can be mapped, and any "bad ones" dealt with, Earth will be safe for the foreseeable future. Their estimates are that we only get hit with one of these babies about every 100,000 years or so.
At this point in time, the American school of astronomers has already found and tracked about 700 of the estimated 1000 such asteroids and, so far, none of them are likely to hit the earth anytime soon. By the end of 2008, they expect to have located 90% of these potential threats.
Of course, they aren't talking about objects smaller than 1 km because they are believed to pose much less risk even if they do smack into the earth.
So it is that the "American School" believes that they can, over time and with superior American technology, survey everything around us and keep our space in space "under control."
What they are saying, as Baillie astutely points out is this: There are objects that cross the path of the earth but they hardly ever hit us (only about every 100,000 years), but they are going to make us safe by finding any and all of them and devising methods to take out the ones that MIGHT pose a threat at any point in the future. They assume, of course, that if they figure out that any of them might be a threat by mapping their orbits, they will have time to do this.
In "Asteroid Astronomer World" there have not been any serious impacts in the last few thousand years, for sure, and they are going to see to it that it stays that way!
How typically American! Don't you worry, little Lady, John Wayne and his gang will circle the wagons and shoot up those redskins/outlaws!
It's obvious that Victor Clube is not a member of the American School.
The "Comet Hazard" school is British based and they think very differently from the American "mainstream" asteroid school.
Comets are said to be different from asteroids because they are made up of water ice, frozen gas, organic materials, and odd bits of rock and metal. The standard theory (which may need revision according to those who advocate the electric universe theory) says that comets are heated as they pass through the solar system and this causes outgassing. It is then that we see them as bright objects with long tails.
After a few circuits through the solar system, some comets "outgas" completely and all that is left is a "very black lump" of any size, typically at least a few kilometers in diameter. The reason a worn out comet is so black is possibly due to the poly-aromatic-hydrocarbons that are concentrated onto the comet's surface like a coating of tar. Such objects, unlike asteroids, are very difficult to spot because they do not reflect light.
Comets also leave trails of dust and debris in the inner solar system and the Earth passes through such periodically. When this happens, there are generally meteor showers which are really particles of comets burning up in the atmosphere.
Comets can also break up in to smaller - but still sizable - chunks.
Now, imagine that in a trail of comet dust, there are also some fairly large chunks of black, un-seeable, comet fragments. If you can't see them, you can't do anything about them. And when they do "hit," they tend to burn up and/or explode violently in the atmosphere (eg Tunguska event), so they don't leave long-lasting traces such as craters for archaeologists to find and say "Yes, the fall of this civilization was due to an assault from outer space." No, there is only fire, death and destruction; sometimes total.
What all this means is that the comet problem does not submit itself to an efficient solution.
The Comet Hazard school scientists propose that the Tunguska event was due to a fragment of Comet Encke. These scientists also now have the FACT of the fragments of Comet Shoemaker-Levy hitting Jupiter in July of 1994 to illustrate the problem we face. The Comet Hazard scientists also think, as mentioned above, that impacts are a lot more frequent than many people suppose.
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| ©Unknown |
So, to sum it up: there are two very different schools that study hazards from space. The Asteroid school says that there have been very few impacts and the problem is solvable, and the Comet school says there is evidence that there have been numerous impacts by comet debris that have had profound effects on human civilizations, and will again, probably very soon.
Okay, now let's take a look at Victor Clube's summary of the problem. He writes:
Asteroid strikes, though important, are not the most serious short-term risk to mankind or civilization
Every 5-10 generations or so, for about a generation, mankind is subject to an increased risk of global insult through another kind of cosmic agency.
This cosmic agency is a "Shoemaker-Levy type" train of cometary debris resulting in sequences of terrestrial encounters with sub-km meteoroids.
While the resulting risk is ~ 10%, the global insults take the form of (a) multiple multi-megaton bombardment, (b) climatic deterioration through stratospheric dust-loading, not excluding ice-age, and (c) consequent uncontrolled disease/plague.
The sequence of events affecting involved generations is potentially debilitating because, whether or not the risk is realised, civilization commonly undergoes violent transitions eg revolution, migration and collapse.
Subsequently perceived as pointless, such transitions are commonly an embarrassment to national elites even to the extent that historical and astronomical evidence of the risk are abominated and suppressed.
Upon revival of the risk, however, such "enlightenment" becomes an inducement to violent transition since historical and astronomical evidence are then in demand.
Such change and change about in addition to the insult is evidently self-defeating and calls for a procedure to eliminate the risk.
Our technological ability to counter (a) multiple multi-megaton bombardment and (b) stratospheric dust-loading should therefore be explored.
The very short lead-time commonly associated with the detection of sum-km meteoroids approaching the Earth implies countering procedures which differ from those associated with catalogued km-plus asteroids and comets.
So, the question is: if there is even a 10 % chance that we are facing a Shoemaker-Levy type event, why isn't anybody doing anything about it?
Well... maybe they are. Maybe all this War on Terror business and getting control of resources is, at its root, the psychopath's way of handling a threat to their survival. Maybe it isn't the "Twilight of the Psychopaths" as Kevin Barrett might like to think... but the Twilight of Humanity; if we don't wake up.
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| ©Unknown |
Space rock risk underreported, researchers argue
World Science
Tue, 21 Mar 2006 10:29 EST
A small but growing number of astronomers are arguing that the risks of comets or meteors hitting Earth are much higher than past estimates suggest.
Some of these objects may be going unnoticed in space, the researchers say, and scientists may need to begin new studies tailored to finding them.
But advocates of the earlier estimates are shooting back that the evidence doesn't warrant revising the figures drastically.
The traditional estimates, based on sky surveys and other techniques, vary.
But in general, they conflict with the number of objects actually found to have visited Earth's neighborhood, according to David J. Asher of the Armagh Observatory in Northern Ireland and three colleagues.
These numbers may provide better estimates, they wrote in the October issue of the research journal Observatory, because they "represent observational 'ground truth' so far as impact statistics are concerned."
To re-estimate risks from these limited data, the team made a simple - but to some critics, questionable - assumption.
Basically, if a given type of object struck once in the past two centuries, they assumed it hits once every two centuries on average. A somewhat longer, but essentially similar calculation translated known near-misses into impact probabilities.
They analyzed in this way three well-studied types of object either seen to have passed near Earth or believed to have hit recently. They also took into account other flybys whose occurrence they deduced from meteorites.
Their revised estimates in the Observatory paper were as follows:
* Impacts greater than 10 megatons (about 500 Hiroshima bombs), like a 1908 explosion in remote Siberia widely attributed to a space object, would occur at least every 300 years. That's almost tenfold the rate generally accepted estimates suggest. The blast in Tunguska, Siberia, felled an estimated 60 million trees.
* Strikes of a hundredfold greater destructive energy or more would happen every 3,000 years or so, more than 10 times as often as prevailing estimates.
* Objects known as active comets packing a 100-million-megaton punch - an event like what may have killed off the dinosaurs along with more than half the Earth's other species - would strike once every few tens of millions of years. That's about 100 times more often than a conventional figure of every 3 billion years. The team didn't present revised estimates for another class of comets, inactive comets, thought to hit every 150 million years or so.
"We're not trying to make a precise estimate," Asher said. "We're trying to point out that if you accept all the current estimates, then the three or four single objects we've mentioned," these together don't fit prevailing views.
The work was in part a follow-up on earlier findings by researchers at Cardiff University in Cardiff, U.K., one of whom also co-authored the Observatory paper.
The earlier study, which appeared in the Nov. 2004 issue of the research journal Monthly Notices of the Royal Astronomical Society, proposed that most potentially dangerous comets are unseen because they're too dark.
But some astronomers are skeptical of all this.
Donald K. Yeomans of NASA's Jet Propulsion Laboratory in Pasadena, Calif., wrote in an email that Asher's team employed what he called "the statistics of one," the unreliable practice of drawing statistical conclusions from one object.
Asher countered that although he sometimes used one object to represent a class of objects, he repeated this for several different classes, with similar results. "It seems to be stretching the imagination to say they're all just coincidences," he said.
Yeomans, lead author of a major 2003 NASA report on the impact risks, also said any dark "stealth comets" would emit strong infrared light, a type of light invisible to the eye. Past space surveys would have detected this, he added. Asher said those surveys haven't been extensive enough, and wider ones may be warranted.
In any case, Yeomans said, not all past assessments have been as rosy as the ones Asher's team criticized. His own report, Yeomans argued, contains numbers that aren't as far from those of Asher as other papers are.
Asher conceded at least one point: his study doesn't explain just why all these objects would be going unseen.
Yeomans argued that all known comets have nearly the same reflectivity, which largely determines their brightness, and that these data contradict the dark comet proposal. Asher acknowledged the lack of known dark comets is puzzling in the context of his study, but suggested something else may explain why objects are going unseen.
One possibility is that they're breaking up into smaller, less-noticeable pieces, he added. Either way, he wrote in an email, "there remain unsettling discrepancies in our understanding of these matters."
Reference:
D.J. Asher, M. Bailey, V. Emel'yanenko, B. Napier, 2005. Earth in the Cosmic Shooting Gallery. Observatory, 125, 319-322.
Ray Newburn, Jr., Jet Propulsion Laboratory
Astronomical Society of the Pacific: 'Universe in the Classroom' Issue No. 27 - Spring 1994
Tue, 01 Mar 1994 12:49 EST
These clouds may provide the clearest indication of the impact locations after each event.
Large regular fluctuations of atmospheric temperature and pressure will be created by the shock front of each entering fragment and travel outward from the impact sites, somewhat analogous to the ripples created when a pebble is tossed into a pond. These may be observable near layers of existing clouds in the same way that regular cloud patterns are seen on the leeward side of the mountains. Jupiter's atmosphere will be sequentially raised and lowered. creating a pattern of alternating cloudy areas where ammonia gas freezes into particles (the same way that water condenses into cloud droplets in our own atmosphere) and clear areas where the ice particles warm up and evaporate back into the gas phase.
Whether or not these "wave'' clouds appear, the ripples spreading from the impact sites will produce a wave structure in the temperature at a given level that may be observable in infrared (or thermal) maps. In addition there should be compression waves, alternate compression and rarefaction in the atmospheric pressure, which could reflect and refract within the deeper atmosphere, much as seismic waves reflect and refract due to density changes inside Earth.
The phenomena directly associated with each impact from entry trail to rising fireball will last perhaps three minutes. The fallback of ejecta over a radius of a few thousand kilometers will last for about three hours. Seismic waves from each impact might be detectable for a day, and atmospheric waves for several days. Vortices and atmospheric hazes could conceivably persist for weeks. New material injected into the Jovian ring system might be detectable for years. Changes in the magnetosphere (Jupiter's magnetic field is much stronger than that of Earth and affects an area of space tens of millions of kilometers from the planet) and/or the Io torus (particles ejected from Io's volcanoes are ionized and trapped by Jupiter's magnetic field into a donut-shaped torus completely circling the planet) caused by the sudden influx of large amounts of cometary dust might also persist for some weeks or months. There is the potential to keep planetary observers busy for a long time!
What observations are astronomers planning?
Many large telescopes will be available on Earth with which to observe the phenomena associated with the Shoemaker-Levy 9 impacts on Jupiter in visible, infrared, and radio wavelengths. Apart from the obvious difficulty that the impacts will occur on the back side of Jupiter as seen from Earth, the biggest problem is that Jupiter in July can only be observed usefully for about two hours per night from any given northern hemisphere site. Earlier the sky is still too bright and later the planet is too close to the horizon. Therefore, to keep Jupiter under continuous surveillance would require a dozen observatories equally spaced in longitude around the globe. A dozen observatories is feasible, but equal spacing is not. There will be gaps in the coverage, notably in the Pacific Ocean, where Mauna Kea, Hawaii, is the only astronomical bastion. In the southern hemisphere Jupiter can be observed for longer periods of time for example, at 30 degrees south latitude it will be visible for five hours. but only Australia and Chile offer major observing facilities and it will be mid-winter there.
There are at least four spacecraft -- Galileo, Ulysses, Voyager 2, and Clementine -- with some potential to observe the Jovian impacts from different vantage points than that of Earth. There is also the Hubble Space Telescope (HST) in orbit around Earth, which will view the event with essentially the same geometry as any Earth-based telescope. HST. however, has the advantage of' no atmospheric turbulence, very low scattered light, ultraviolet sensitivity, and the ability to observe much more than two hours each day. HST is scheduled to devote considerable time to the observation of Shoemaker-Levy 9 before as well as during the impacts.
The Galileo spacecraft has the best vantage point from which to observe the impacts. It is on its way to Jupiter and will be only 246 million kilometers away from the planet, less than a third the distance of Earth from Jupiter at the time. All of the impacts will occur directly in the field of view of its high resolution camera. In addition, instruments that study infrared and ultraviolet light will most likely be used.
Using Galileo to make observations will be challenging however. The amount of data the spacecraft can transmit back to Earth is limited by the capability of its low-gain antenna (the spacecraft's high-gain antenna, which could have transmitted large amounts of data in short periods of time, failed after launch and the time available on the receiving antennas of NASA's Deep Space Network here on Earth. A lot of data frames can be stored in the Galileo tape recorder, but only about 5 percent of them can be transmitted back to Earth. so the trick will be to decide which 5 percent of the data are most likely to include the impacts and have the greatest scientific value, without being able to look at any of them first! After the fact, the impact times should be known quite accurately. This knowledge can help to make the decisions about which data to return to Earth.
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| ©D. Seal |
| The impact site of the fragments of Comet Shoemaker-Levy 9 on Jupiter. |
The Ulysses spacecraft was designed for solar study and used a "gravity assist'' for flying close to Jupiter to change its inclination (the tilt of its path relative to the plane of the planets) so it can fly over the poles of the Sun. In July 1994 it will be about 378 million kilometers south of the plane of the planets (the ecliptic) and able to "look'' over the south pole of Jupiter directly at the impact sites. Unfortunately, Ulysses has no camera as a part of its instrument complement. It does have an extremely sensitive radio receiver that may be able to detect thermal radiation from the impact fireballs once they rise sufficiently high above interference from the Jovian ionosphere (upper atmosphere) and to measure a precise time history of their rapid cooling.
The Voyager 2 spacecraft is now far beyond Neptune and is about 6.4 billion kilometers from the Sun. It can look directly back at the dark side of Jupiter, but the whole of Jupiter is now only two picture elements in diameter as seen by its high resolution camera, if that instrument were to be used. In fact the camera has shut down for several years, and the engineers who knew how to control it have new jobs or are retired. It would be very expensive to take the camera "out of mothballs'' and probably of limited scientific value. Voyager does have an ultraviolet spectrometer which is still taking data, and it will probably be used to observe the impact.
A new small spacecraft called Clementine was launched on Jan. 25 of this year, intended to orbit the Moon and then proceed on to study the asteroid Geographos. Clementine has good imaging capabilities, but its viewpoint will not be much different from Earth's. Still. it seems probable that attempts will be made to observe "blips'' of light on the edge of Jupiter from the entering fragments or subsequent fireballs.
Stupendous as these collisions will be, they will occur on the far side of a planet half a million miles from Earth. There will be no display visible to the general public. Amateur astronomers may note a few seconds of brightening of the inner satellites of Jupiter during the impacts, and they might observe minor changes in the Jovian cloud structure during the days following the impacts. In the best of cases, these events will be spectacles for the mind to imagine and big telescopes to observe, not a free fireworks display. The real value of this most unusual event will come from scientific studies of the comet's composition. of the impact phenomena themselves, and of the response of a planetary atmosphere to such a series of "insults.''
Atmospheric phenomena on this scale cannot be reproduced, even by nuclear fusion explosions, and have never before been observed. Sixty-five million years ago the Earth was struck by a large asteroid or comet, an event which may have hastened the extinction of the dinosaurs. Better knowledge of the effects of Comet Shoemaker-Levy 9 on Jupiter may allow scientists to predict more accurately just how serious could be the results of future impacts of various-sized bodies on Earth.
Energy Comparisons & Power Comparisons
| Energy Comparisons | ||
|---|---|---|
| Event | Energy in Joules | Energy Relative |
| Two 3,500-lb. cars colliding head-on at 55 mph | 9.6 X 105 | 1 |
| Explosion of 1 U.S. ton of TNT | 4.2 X 109 | 4,271 |
| Explosion of a 20-megaton fusion bomb | 8.4 X 1016 | 87,500,000,000 |
| Total U.S. annual electric power production, 1990 | 1 X 1019 | 10,400,000,000,000 |
| Energy released in last second of 1013-kg fragment of Comet Shoemaker-Levy 9 | 9 X 1021 | 9,375,000,000,000,000 |
| Total energy released by 1013-kg fragment of Comet Shoemaker-Levy 9 | 1.8 X 1022 | 18,750,000,000,000,000 |
| Total sunlight on Jupiter for one day | 6.6 X 1022 | 68,750,000,000,000,000 |
| + Note: 1 BTU = 252 (small) calories = 1,055 Joules = 2.93 X 104 kWh. | ||
| Power Comparisons | ||
| Power Producer | Power in Megawatts | Power Relative |
| Hoover Dam | 1,345 | 1 |
| Grand Coulee Dam, final plant | 9,700 | 7.2 |
| Annual average, sum of all U.S. power plants | 320,000 | 238 |
| Average, impact of 1013-kg fragment of Comet Shoemaker-Levy 9, final second | 9 X 1015 | 6,700,000,000,000 |
| Sun | 3.8 X 1020 | 280,000,000,000,000,000 |
| + Note: 1 horsepower = 745.7 W = 7.457 X 104 Megawatts (MW) | ||
© 1994, Astronomical Society of the Pacific, 390 Ashton Avenue, San Francisco, CA 94112.
NASA JPL
Tue, 14 Mar 2000 13:33 EST
From July 16 through July 22, 1994, pieces of an object designated as Comet P/Shoemaker-Levy 9 collided with Jupiter. This is the first collision of two solar system bodies ever to be observed, and the effects of the comet impacts on Jupiter's atmosphere have been simply spectacular and beyond expectations. Comet Shoemaker-Levy 9 consisted of at least 21 discernable fragments with diameters estimated at up to 2 kilometers.
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| ©NASA JPL |
Latest Images of Comet Shoemaker-Levy
News Flash (Last Updated March 14, 2000)
* NASA Renames NEAR Spacecraft For Planetary Science Pioneer Gene Shoemaker (NASA - March 14, 2000)
* New CDROMs With Comet Shoemaker-Levy 9 Data Available (Goddard Space Flight Center - July 29, 1999)
* Moon Burial For Eugene Shoemaker (BBC News - July 28, 1999)
* Eugene Shoemaker Ashes Carried on Lunar Prospector (University of Arizona - January 7, 1998)
* Eugene Shoemaker (1928-1997) (Brian Marsden - July 18, 1997)
* Chain of Impact Craters Suggested by Spaceborne Radar Images (NASA - March 20, 1996).
* Comet SL9 Home Page Tops 7 Million Accesses (March 1, 1996).
* Hubble Observes Comet SL9 Effects on Jupiter (February 22-23, 1996).
* Pic du Midi Images of Jupiter (February 3, 1996).
* New Galileo Jupiter Animations Available (JPL - February 2, 1996).
* Comet Schwassmann-Wachmann 3 Splits Again (Sky & Telescope - February 2, 1996).
* Galileo Probe Science Results (NASA - January 22, 1996).
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| ©NASA JPL |
Comet Shoemaker-Levy 9, torn into pieces as a result of a close approach to Jupiter in July 1992, will collide with Jupiter during the third week of July 1994. Of tremendous scientific importance, the impacts of the cometary fragments will release more energy into Jupiter's atmosphere than that of the world's combined nuclear arsenals. Because the impacts will occur on the night side of Jupiter, the explosions will not be directly observable from Earth. However, professional and amateur astronomers may observe the impact light flashes reflected off the inner satellites of Jupiter. Any lasting effects on Jupiter, such as atmospheric clouds, ejecta plumes, or seismic thermal disturbances, may be observable an hour or so later when the rotation of Jupiter brings the impact sites into Earth's view.
Analysis of high-resolution images of the comet taken by the NASA's Hubble Space Telescope in July 1993 suggests that the major cometary fragments range in size from one to a few kilometers. The large fragments are embedded in a cloud of debris with material ranging in size from boulder-sized to microscopic particles. Although comet-like outgassing of the fragments has not been observed, the fragile nature of the object suggests that it is indeed a comet rather than a more compact asteroid.
Comet Shoemaker-Levy 9 was the ninth short-periodic comet discovered by Eugene and Carolyn Shoemaker and David Levy. It was first detected on a photograph taken on the night of March 24, 1993 with the 0.4-meter Schmidt telescope on Palomar Mountain in California. Subsequent observations were forthcoming from observers at the University of Hawaii, the Spacewatch telescope on Kitt Peak in Arizona and McDonald Observatory in Texas. These observations were used to demonstrate that the comet was in orbit about Jupiter, and had made a very close approach (within 1.4 Jupiter radii from Jupiter's center) on July 7, 1992. During this close approach, the unequal Jupiter gravitational attractions on the comet's near and far sides broke apart the fragile object. The disruption of a comet into multiple fragments is an unusual event, the capture of a comet into an orbit about Jupiter is even more unusual, and the collision of a large comet with a planet is an extraordinary, millennial event.
* Comet Freight Train to Collide with Jupiter.
* The Probability of Collisions with Earth.
* The K-T Event.
* Planetary Spacecraft as Observers.
* Comet Team Biographies.
Latest Conclusions of the Comet Collision
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| ©NASA JPL |
This page lists a series of articles on the preliminary conclusions that have been drawn so far on the Comet Shoemaker-Levy 9 collision with Jupiter.
Published Papers about Comet Shoemaker-Levy 9 (May 1995).
Proceedings from ESO SL9-Jupiter Workshop (March 1995).
* Report of the Near-Earth Objects Survey Working Group (June 1995).
* A Comet's Fiery Dance at Jupiter (Galileo Messenger - May 1995).
* Abstracts from IAU Colloquium 156 (May 1995).
* Summary of European SL-9/Jupiter Workshop (Postcript file only) (ESO - February 1995).
* Talk given by Amara Graps at the MacWorld Expo in January 1995.
* The Brilliant Death of Comet SL9 (JPL - December 1994).
* Update on SL9/Jupiter Collision (Richard West - December 15, 1994).
* Galileo Comet SL9 Observations (JPL - October 31, 1994).
* Summary of Comet Day Poster Session (Mark Boslough - October 1994)
* The Great Dark Spots of Jupiter (Sky & Telescope - November 1994).
* Hubble Observations Shed New Light on Jupiter Collision (NASA - September 29, 1994).
* ESO Messenger Article (September 1994).
* http://www2.jpl.nasa.gov/sl9/uni1.html (JPL - July 29, 1994).
Images, Images, Images (1444 Images, 64 Observatories)
* Top 20 Comet SL9 Images
* Most Recent Comet SL9 Images
* Images Sorted By Observatory
* Images Sorted By Fragment Impact
* Miscellaneous Images
Comet Shoemaker-Levy Impact Times
* Impact Times for SL9 (Chodas & Yeomans - March 18, 1995).
* Impact Times for SL9 (Calar Alto - October 25, 1994).
* Post-Crash Impact Times for SL9 (Chodas & Yeomans - August 5, 1994).
* Lastest Table of Impact Times for the remaining comet fragments from Chodas, Yeomans (July 20, 1994).
* Predicted Impact Times of the Lost Fragments (July 11, 1994)
* Best Viewing Locations for the Impacts (June 25, 1994)
* Earth Facing Views of Each Impact.
* Likelihood of Fireball Visibility.
TV Coverage
* Discovery Channel
* NASA TV
* PBS
* CNN
Spacecraft Observations of the Impacts
* Galileo
* Hubble Space Telescope
* Voyager 2
* Ulysses
* International Ultraviolet Explorer (IUE)
* Extreme Ultraviolet Explorer (EUVE)
* Roentgensatellit (ROSAT)
* NASA Sounding Rocket
Ground Based Observations
* Jet Propulsion Laboratory
* Caltech
* Cerro Tololo Interamerican Observatory
* Comet Impact Network Experiment
* Deep Space Network
* European Southern Observatory
* Griffith Observatory
* Infrared Telescope Facility
* IUE Observatory.
* Keck Telescope
* Kitt Peak National Observatory
* Kuiper Airborne Observatory
* Lawrence Livermore National Laboratory
* Lick and Leuschner Observatories
* Lowell Observatory
* McDonald Observatory
* Mount Stromlo and Siding Spring Observatories
* Mt. Wilson Observatory
* National Radio Astronomy Observatory, Very Large Array (VLA)
* National Solar Observatory
* Owens Valley Radio Observatory
* Project BAMBI Amateur Radio Telescope
* South Africa Astronomical Observatory
* Space Telescope Science Institude (STScI)
* University of Hawaii
* University of Oregon
* University of Rochester
* Whately Observatory
Links to Other Comet Shoemaker-Levy Home Pages
* Comet/Jupiter Collision Frequently Asked Questions Home Page (Texas A&M).
* Comet Shoemaker-Levy 9 Bulletin Board (University of Maryland).
* Comet Shoemaker-Levy 9 Collision with Jupiter Home Page (GSFC).
* EUVE/Comet Shoemaker-Levy Home Page (University of California, Berkeley).
* Computer Simulations of the Jupiter-Comet Collision (MIT).
* Shoemaker-Levy9/Jupiter Collision (European Southern Observatory).
* Comet Shoemaker-Levy Home Page (Pittsburgh Supercomputing Center).
Please direct questions and comments about this page to Ron Baalke
ron@jpl.nasa.gov
Joe Rao
Space.com
Fri, 04 Jan 2008 12:53 EST
As we kick off the year 2008, Comet Tuttle is putting on a nice show for backyard skywatchers. It had not been seen since 1994, but you'll have an excellent opportunity to pick it up with binoculars or small telescopes during the next two weeks.
Tuttle can even be glimpsed by sharp-eyed observers under pristine skies without any optical aids, for it is one of the brightest of the short-period comets, those that orbit the sun often enough to be seen again and again from Earth and identified as such.
And speaking of short-period comets, Comet Holmes continues to delight observers more than two months after its stupendous explosion to naked-eye visibility.
Discovery
As we all know, Halley's was the first comet-to be recognized as periodic, but it had been seen on many previous returns before Edmund Halley announced that fact in the year 1705. Similarly, although Encke's comet was discovered in 1786, it was observed on three more returns before Johann Franz Encke determined that it had an orbital period of 3.3-years.
The object that we today call Comet Tuttle had a similar history.
On Jan. 9, 1790, the renowned Parisian comet hunter Pierre Méchain discovered a fairly bright telescopic comet in the western evening sky. His friend and rival Charles Messier described it on the following night as resembling an unresolved star cluster or nebula without a nucleus. It was followed for just over three weeks; just not enough time for a sufficient number of observations to determine an accurate orbit.
Astronomers assumed that the object was traveling in a parabolic orbit and would never be seen again, and entered the literature simply as "Comet 1790 II." It wasn't to be seen again for nearly 70-years.
Tuttle's turn
Horace P. Tuttle, an assistant at Harvard College Observatory, discovered three comets by telescope during the year 1858. Tuttle found the first of them on Jan. 4 in the constellation Andromeda. Still approaching the perihelion point of its orbit (its least distance from the sun), the comet was favorably placed relative to the Earth, and this made possible a long series of positional measurements.
Comet Tuttle was brightest during February at about magnitude 7, meaning it was just below the threshold of naked eye visibility, though a relatively easy object to see with binoculars or a small telescope.
Tuttle himself was among the first to suggest that his object was identical with Comet 1790 II. A 13.7-year period was proposed by several astronomers, and it soon became clear that Comet Tuttle of 1858 had been missed at four intervening apparitions. At three of those returns (1803, 1817, and 1844) it was too close to the sun in the sky to be seen, while conversely, in 1830 it should have been an easy object in the morning sky but was somehow missed.
Comet Tuttle became the eighth comet to be recognized as a periodic object hence it is now designated as 8P/Tuttle.
The perihelion distance of 8P/Tuttle places it just outside of the Earth's orbit at 95.5 million miles (153.6 million kilometers). Also, around Dec. 22 of each year the Earth passes through the dusty trail left behind by the comet from its previous visits. This encounter gives rise to an annual display of meteors known as the Ursids, which appear to diverge from near the bright star Kochab in the bowl of the Little Dipper.
Because 8P/Tuttle was observed at each return following its 1858 rediscovery except in 1953, this time around will go down in the record books as its 12th observed apparition. And as it turns out, this apparition will be among its very best.
Where and when to look
On New Year's Day, 8P/Tuttle passed closest to Earth; a distance of 23.5 million miles (37.8 million kilometers). Although it is now slowly moving away from the Earth, it will continue to slowly approach the sun, passing closest to it on Jan. 27. Comets are most visible when they near the sun, which lights up material that boils off the comet.
So, during these next two weeks, the comet will hold nearly steady in brightness at around magnitude 6. For those blessed with clear, dark skies far from significant light pollution, the comet might be even glimpsed with the unaided eye. But good binoculars or a small telescope will easily bring 8P/Tuttle into view if you know where to train them; it should appear as a small fuzzy star possibly sporting a faint, narrow tail.
The comet will be situated against the rather dim stars that compose the so-called "watery region" of the sky, passing through eastern Pisces (the fishes) into Cetus (the whale) during the night of Jan. 6-7. On that night, it will lie not far to the west from one of the brightest stars in Pisces: fourth magnitude, Al Rischa, located at the point where the two fish are tied. In fact, the name comes from the Arabic word for "cord."
For the next couple of weeks both Pisces and Cetus can be conveniently found well up in the southern sky between 6 to 8 p.m. local standard time.
Comet 8P/Tuttle will appear to skid south in its orbit against the background stars of these two constellations. After moving through Cetus, 8P/Tuttle will pass into the dim, shapeless constellation of Fornax (the furnace) on Jan. 16. It will continue to plunge south thereafter, gradually becoming unfavorably placed for viewers in the Northern Hemisphere, although those living south of the equator will be able to follow the now fading comet right on into February.
A reminder about Comet Holmes!
While the spotlight is now on Comet Tuttle, we should not forget about our old friend, Comet Holmes which continues to be dimly visible to the unaided eye as a diffuse, circular cloud, roughly twice the apparent diameter of the moon against the stars of the constellation Perseus.
This comet was no brighter than magnitude 17 in mid-October - that's about 25,000 times fainter than the faintest star that can normally be seen without any optical aid. But late on Oct. 23, the comet's brightness suddenly rocketed all the way up to magnitude 2.5, brightening nearly one million times in less than 24 hours!
In attempting to explain why Comet Holmes exploded, comet expert, John Bortle suggested that this comet's nucleus consists of low-density material that, over time developed into a large region with a very tenuous structure, like a honeycomb. At some point, the highly fragile bonds connecting the honeycomb of material reached a failing point and a sudden crushing collapse occurred, expelling a gigantic volume of dust into space, making this dim comet suddenly appear impressively bright.
Back in 1892, Comet Holmes suffered two major outbursts separated by about 75 days. This leads to the question as to whether this comet will undergo a similar "cosmic aftershock" in the wake of its recent late October explosion.
Bortle thinks it's a possibility, based on the theory that there may be a large amount of residual instability which might lead to a second major collapse of material on the comet nucleus. If what happens now parallels what happened in 1892, another possible explosive outburst may be imminent, so it might be wise to keep a close watch on Comet Holmes in the coming days ahead.
Michael Goodspeed
Thunderbolts
Sat, 05 Jan 2008 13:31 EST
"Mysteries are due to secrecy."
-Francis Bacon
On December 24, 2007, the website Space.com published a report entitled, "The Enduring Mysteries of Comets." The premise is intriguing, since it is rare for science media to acknowledge that "mysteries" of any real significance exist for conventional theories. Unfortunately, the report mentions few of the recent discoveries that have thrown the popular "dirty snowball" model of comets into disarray.
"We have now had four close encounters with comets, and every one of them has thrown astronomers onto their back foot." -Stuart Clark, New Scientist, September 09, 2005.
The Space.com article begins with the statement, "For millennia, comets were believed to be omens of doom." This itself is a profound anomaly left unanswered by mainstream theorists, but the author makes no inquiry into why this is so. Instead, his next sentence reveals that the veil of discredited theories distorting scientists' view of comets has yet to be lifted. "...Solving the mysteries regarding these 'dirty snowballs' could help reveal the part they played in the birth of life on Earth, as well as secrets concerning the rest of the galaxy." But as we shall see as we continue, one can only hold to the idea of comets as "dirty snowballs" by ignoring all of the recent revelations about comets.
The first item asks, "Did comets help create Earth's seas?" The report reads: "For years scientists thought comets slamming against the newborn Earth helped deliver water to a once dry planet. But roughly a decade ago this view was shaken by the discovery that the water in comets and Earth's oceans did not match up in terms of hydrogen isotopes."
But the mainstream is not yet ready to abandon the notion of primordial comets dumping copious amounts of water onto Earth. The article continues: "In the last two years, however, researchers have discovered comets in the outer part of the asteroid belt. These 'main-belt comets' may have the right levels of hydrogen isotopes, and are perhaps close enough to Earth to have realistically brought us the seas that life emerged from."
In the minds of Electric Universe proponents, most cometologists have a distorted view of cometary water/ice. Cometary comas often exude an abundance of what scientists interpret as "water." In fact, what they measure as "water" is the hydroxyl radical OH, the most abundant cometary radical, which they assume is formed by the breakdown of water from solar UV radiation. It is this radical's presence that leads to their estimates of the amount of water ice sublimating from the comet nucleus.
Electrical theorist Wallace Thornhill offers a different interpretation, consistent with the surprising discoveries of recent years. He notes that space probes have detected the negatively charged oxygen atom, or negative oxygen ion, close to cometary nuclei. Additionally, spectral analysis of neutral oxygen (O) shows a 'forbidden line' indicative of the presence of an 'intense' electric field. Negative ions near a comet nucleus puzzled investigators because such ions are easily destroyed by solar radiation. Thus, investigators reviewing the findings at comet Halley noted, "an efficient production mechanism, so far unidentified, is required to account for the observed densities" of negative ions.
As stated by Thornhill, "...the intense electric field near the comet nucleus is inexplicable if it is merely an inert body plowing through the solar wind." But the electric model resolves the mysteries: "The electric field near the comet nucleus is expected if a comet is a highly negatively charged body, relative to the solar wind. Cathode sputtering of the comet nucleus will strip atoms and molecules directly from solid rock and charge them negatively. So the presence of negative oxygen and other ions close to the comet nucleus is to be expected. Negative oxygen ions will be accelerated away from the comet in the cathode jets and combine with protons from the solar wind to form the observed OH radical at some distance from the nucleus."
If Thornhill is correct, the OH does not require water ice on, or in, the comet. Though it would be irrational to categorically exclude the possibility of ice, our probes have revealed scorched surfaces looking more like burnt rocks than "dirty snowballs." They are, in fact, barely distinguishable from ice-free asteroids.
The Space.com report continues with questions about the origins of comets -- "Where do they come from?," and "Secrets regarding the birth of the solar system?" Astronomers have long told us that comets were born in the theoretical "Oort cloud," about 4.6 trillion miles from the Sun. Until fairly recently it was as simple as that. But a few years ago, cometologists began to adjust the theory, postulating that only long-period comets were born in an ultra-remote cloud. Scientists have not reached a consensus on where they think short-period comets originate. "Maybe there are other reservoirs of comets yet to be discovered," says astrophysicist David Jewitt.
Proponents of standard theory have long claimed comets are "Rosetta stones" that can help us decipher the origins of the solar system. But the notion was dealt a devastating blow by the findings of NASA's Stardust Mission. The tiny fragments of comet dust that the mission brought back to Earth did not accrete in the cold of space, but were formed under "astonishingly" high temperatures. Mineral inclusions ranged from anorthite, which is made up of calcium, sodium, aluminum and silicate, to diopside, made of calcium, magnesium and silicate. Formations of such minerals requires temperatures of thousands of degrees.
NASA curator Michael Zolensky said, "That's a big surprise. People thought comets would just be cold stuff that formed out ... where things are very cold....It was kind of a shock to not just find one but several of these, which implies they are pretty common in the comet."
Researchers were forced to conclude that the enigmatic particle material formed at a superheated region either close to our Sun, or close to an alien star. "In the coldest part of the solar system we've found samples that formed at extremely high temperatures," said Donald Brownlee, Stardust's principal investigator. "When these minerals formed they were either red hot or white hot grains, and yet they were collected in a comet, the Siberia of the Solar System."
Some scientists speculated that perhaps something occurred in or very near the Sun in its formative phase, flinging immense quantities of material out to the periphery of the Sun's domain (far, far beyond the orbit of Pluto), all the way to the Oort cloud. Then the researchers reminded themselves that this would produce a mixing and contradict the zoning that is evident in the asteroid belt. "If this mixing is occurring, as suggested by these results, then how do you preserve any kind of zoning in the solar system," Zolenksy asked. "It raises more mysteries."
But today, a new report states, quite unequivocally, that parts of Wild 2 formed in an area close to the Sun. The spacedaily.com site writes: "The X-ray and isotopic analyses point to gas acquisition in a hot, high-ion flux nebular environment close to the young sun."
The startling bottom-line is that comet scientists cannot give us any reliable story of comet formation. And the glaring contradictions are barely acknowledged, if at all. The "mysteries" of the Stardust mission -- which are not mysterious under an electrical model of comets -- are not even mentioned in the Space.com report. Obviously, the question of comets' origins is profoundly affected by the discovery of abundant minerals that only form under super-hot temperatures.
The Electric Universe puts forth a very different hypothesis on the origins of both comets and asteroids. In an epoch of planetary instability in our solar system, many planets and moons, moving through the electric field of the Sun and immersed in an electrically dynamic environment, experienced electrical interactions with one another. Electric arcs shattered small moons and raked across planetary surfaces, producing the most dramatic scarring features we see on planetary bodies. These electrical scars include Valles Marineris, the stupendous chasm that stretches more than 3000 miles across the Martian surface. In this view the comets and asteroids we observe are leftovers from these violent electric discharge events. And the composition of comets is from the same material that planets and moons were formed.
In fact, this vision of the electrical theorists explains the next "mystery" in the Space.com piece, "Why are comets so close to the Sun?" The report reads, "The main-belt comets are themselves a mystery. Until their discovery, researchers had largely supposed no comets could have lasted that close to the sun without getting baked away after a few centuries or millennia." But then again, if the electrical theorists are correct, comets have not been around for billions of years, not even millions of years. They are the residue of catastrophe in the recent history of the solar system.
The Space.com story concludes by attempting to answer the question of speculative "Interstellar comets." It reads: "As our solar system formed, calculations predict the gravitational pull of the planets would have scattered 90 to 99 percent of all comets that once orbited the sun away toward the stars, never to be seen again. 'If every star does that, you would expect some of their comets to come toward us, but no such object has ever been seen,' Jewitt said."
This admission only reinforces the failure of the standard model, confirming that virtually nothing discovered in recent decades has matched theoretical expectations. But in electrical terms, the idea of comets wandering interstellar space was never a viable concept. If comets are the remnants of electrical discharge activity within the solar system, then their short-term and long-term orbits are the results we should expect.
Space.com considers the above mysteries to be the greatest puzzles for conventional comet theory. We can only urge them to more carefully consider the following comet discoveries, none of which are expected by a "dirty snowball" model, but which are both explicable and predictable by the electrical one:
Cometary Jets
Supersonic jets have been seen exploding from comets' nuclei. From the mainstream perspective, these jets are eruptions of subsurface gas and water from solar heating. But again and again, this theory has been refuted by observation. In the case of Comet Wild 2, some of its nearly two dozen jets emanated from the dark, unheated side of the comet. And as seems to be the case with most comet jets, they remained intact across great distances -- they did not disperse in the fashion of a gas in a vacuum (an anomaly left unresolved, and not even addressed by most mainstream theorists). Consider also the jets of comet Hale-Bopp, which began discharging (seven jets) while it was still too far from the Sun for a "snowball" to melt.
Amazingly, as far as back as the early 20th century, the Norwegian physicist Kristian Birkeland demonstrated experimental evidence for the electric comet theory. He was able to emulate cometary jets from a cathode in a vacuum tube -- Birkeland wrote: "From a cathode of graphite there came long, steady pencils of light, which greatly resembled the so-called eruptions or jets in comets." (See Comets: Kristian Birkeland's Theory)
From the Electric Universe perspective, comet jets arise from the interaction between the electric charge of the comet and the solar discharge plasma. The comet spends most of its time far from the Sun, where the plasma charge density is low. The comet moves slowly and its charge easily comes into balance with that region. On the other hand, as the comet approaches the Sun, the nucleus moves at a furious speed through regions of increasing charge density and varying electrical characteristics. The comet's surface charge and internal polarization, developed in deep space, respond to the new environment by forming cathode jets and a visible plasma sheath, or coma. The jets flare up and move over the nucleus irregularly, and the comet may shed and grow anew several tails. Or the comet may explode like an overstressed capacitor (see below), breaking into separate fragments or simply giving up the ghost and disappearing.
Cometary discharging may also occur due to any disturbances of its electrical plasma sheath as it passes through regions of varying electric potential. This seems to have occurred in the recent "totally surprising" outburst of Comet Holmes 17P as it moved away from the Sun's domain.
Comets Breaking Apart or Exploding
The unexpected break-up of comets, some at considerable distances from the Sun, has long baffled comet investigators. In 1976, Comet West never approached closer than 30 million kilometers from the Sun. So when the comet suddenly split into four fragments, astronomers were shocked.
More recently, the explosive break up of Comet Linear in the summer of 2000 provoked even greater amazement. The event occurred well over a hundred million kilometers from the Sun.
In fact, eighty percent of comets that split do so when they are far from the Sun, according to Carl Sagan and Ann Druyan, authors of the book Comet. Comet Wirtanen fragmented in 1957 a little inside the orbit of Saturn, and something similar occurred to Comet Biela/Bambert.
But other comets have approached much closer to the Sun and not broken apart. The perihelion of the Great Comet of December 1680, studied by both Newton and Halley, was less than 100,000 kilometers from the Sun, but it did not split.
We can also point to the astonishing disintegration of Comet Schwassman-Wachmann 3, whose catastrophic fate remains unexplained by the scientific mainstream. Some proposed that the comet disintegrated due to "thermal stress" resulting from the rapid transfer of heat through thousands of feet of insulating material -- something inconceivable even if one ignores the deep freeze of the vacuum through which the comet is moving, with its sunward face continually changing due to rotation. Other explanations included "the outburst of trapped volatile gases," and the suggestion that the comet flew apart from "rapid rotation of the nucleus." One astronomer even proposed that the comet "was shattered by a hit from a small interplanetary boulder." This is yet another instance where scientists' lack of consideration for an electric model has left them unable to explain what they're seeing.
Many other "mysterious" comet discoveries and observations of comet behavior are best explained as electrical phenomena. These include:
Unexpectedly high temperatures and X-ray emissions from cometary comas (something never anticipated by mainstream theorists);
The sharply carved relief of comets -- the exact opposite of what astronomers expected under the "dirty snowball" model;
The unexplained ability of a relatively minuscule comet nucleus to hold in place a highly spherical coma, up to millions of miles in diamater, against the force of the solar wind;
Ejection of larger particles and "gravel" that was never anticipated under the idea that comets accreted from primordial clouds of ice, gas, and dust;
A short supply or complete absence of water and other volatiles on comets' nuclei;
The predicted occurrence of an advance flash prior to the impact of a projectile into the nucleus of Comet Tempel 1 (Deep Impact.)
Recently, the journal Icarus published a report confirming that the
advance flash did indeed occur, "upstream" (and slightly off-course) of
the projectile -- exactly as one might expect of an electric discharge
just prior to impact.
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This article began with reference to the historic quote, "Mysteries are due to secrecy." If a kind of tacit "conspiracy" exists amongst space scientists, it is to never speak of cosmic electricity, despite the overabundance of evidence for electrical activity in space. Sadly, mainstream astronomy seems still to be guided by the axiom, "If it doesn't fit, you must forget!" But the puzzles will not be solved by ignoring or downplaying them. And in increasing numbers, critics of today's standard theory are coming to agree that the key to resolving these unsolved mysteries is electricity.
Nasa
Wed, 09 Jan 2008 19:23 EST
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| ©NASA/JPL |
| This artist rendering uses an arrow to show the predicted path of the asteroid on Jan. 30, 2008, and the orange swath indicates the area it is expected to pass through. Mars may or may not be in its path. |
UPDATE - As expected, scientists at JPL's Near-Earth Object Office have further refined the trajectory estimate for asteroid 2007 WD5 and ruled out any possibility of a Mars impact on Jan. 30. The latest trajectory plot of the asteroid was made possible by adding to previously obtained data some new data from a round of observations acquired by three observatories on the evenings of Jan. 5 through 8. Based on this latest analysis, the odds for the asteroid impacting Mars on Jan. 30 are 0.0 percent. The latest observations come from the German-Spanish Astronomical Center, Calar Alto, Spain; the Multi-Mirror Telescope, Mt. Hopkins, Ariz.; and the University of Hawaii telescope, Mauna Kea, Hawaii.
For more information, visit the Near-Earth Object site at [link]
Frank Roylance
Maryland Weather
Tue, 08 Jan 2008 17:40 EST
I'm starting to receive reports of a fireball southwest of Baltimore Monday evening. Here are two of them:
From Donna Caudle: "My husband and I were driving last night (1/7/08) through Perry Hall, MD when we spotted a blue-green fall fireball speeding to some site not far from us ... We were traveling near the area of Magdlet Rd in Perry Hall and Joppa was closed for some accident. I would say we were facing north west when we spotted it falling the the direction of Carney or Towson. The time was about 8:50 pm last night ,Monday the 7th of Janurary "
And, from Jeff Ceccola, who has reported before: "Frank,
I was lucky enough to see another fireball tonight (1/7/08). Twice in a
2 months. I fear my friends are going to think I'm fibbing when I tell
them about this one.
This one was to the southwest, in front of the constellation
Cetus. It had a greenish hue, with a magnitude of about a -4, lasting
no more than 3 seconds.
I was in West Chester, Pa., the event occurred about 8:40 PM.
From my POV, it was to the SW at about a 30 degree angle, falling from
SW to W.
Since my first event, I've been doing a lot more star gazing and
have studied sky maps. I'm sure my increased interest is why I was
lucky enough to see yet another fireball..
Let me know if anyone has seen this one. Look for you in the Sun. -Jeff"
If anyone else out there saw this object, please send me a comment. Be sure to include the time you saw it, where you were, which direction it was going relative to your location, any sounds that seemed to accompany the event, and any other descriptive details you have. Here is more on what to include.
You can also file a fireball report with the International Meteor Organization, or the American Meteor Society. Last night's object has not yet turned up on the AMC Fireball Log for 2008.
Never seen a fireball? Well, here's one in a terrific image captured Nov. 2, 2005, by Mark Vornhusen of Germany and published by NASA. It is NOT Monday's object. But if you got a picture of it, send it to me and I'll replace this one with yours.
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| ©Mark Vornhusen |
| Fireball in Germany, Nov. 2, 2005 |
News-Leader
Wed, 09 Jan 2008 08:59 EST
The Greene County Sheriff's Department was investigating Saturday night a series of explosions heard over a 10-mile area west of Springfield.
According to Capt. Randy Gibson of the Greene County Sheriff's Department, the department received "eight or nine calls" of explosions in the area of Greene County EE.
"We got reports from as far away as (Missouri) 266 west of town and north to Willard of explosions and light flashes. Some were loud enough to rattle windows at residences north of I-44 and some were barely audible.
"It's a bit of a mystery to us at this point," said Gibson, who said he heard the explosions himself from his home. "They did not sound like a sonic boom and there shouldn't be any blasting in that area."
He said he heard four very loud explosions and eight smaller ones. He said the first one occurred about 7:45 and they continued for about 25 or 30 minutes.
"Willard Police officers heard them, and the 911 call center in the middle of town."
FOX 35
Wed, 09 Jan 2008 10:33 EST
FOX 35 viewer, Alexandra Gregory captured these spectacular images of an object -- what appears to be a meteor -- streaking through the sky on Tuesday, January 7, as seen from Poinciana.
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| ©Fox 35 |
| FOX 35 viewer, Alexandra Gregory captured these spectacular images of an object streaking through the sky on Tuesday, January 7, as seen from Poinciana. |
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| ©Fox 35 |
According to NASA, beginning each New Year and lasting for nearly a week, the Quadrantid Meteor Shower can be witnessed across the night sky for nearly all viewers around the world, though Monday's sighting in Central Florida has not been confirmed as being related this annual interstellar phenomenon.
The term meteor comes from the Greek meteoron, meaning phenomenon in the sky. Solarviews.com describes a meteor as a streak of light produced as matter in the solar system falls into Earth's atmosphere creating temporary incandescence resulting from atmospheric friction. This typically occurs at heights of 50 to 70 miles above Earth's surface. A meteorite is a meteoroid that reaches the surface of the Earth without being completely vaporized.
The International Meteorite Collectors Association offers extensive records which show occurrences of meteorites striking man-made objects, animals and even people! You can see a list of such events, including one reported strike in Orlando in 2004, by clicking here.
Jonny Muir
The Evening Telegraph
Fri, 11 Jan 2008 08:25 EST
Likened to a scene from an HG Wells novel, the green streak of a meteor has been sighted in the skies above Peterborough and Stamford.
Verified by three separate eye-witness accounts, the meteor - which could have been hundreds of miles above the Earth's surface - may have been no larger than a pea.
The meteor was initially reported to The Evening Telegraph by a reader in Werrington, Peterborough, who spotted the glowing green object at 7pm on Wednesday.
That prompted systems engineer Adam Warr to reveal he had seen sighted something similar as he walked his dogs in Orton Longueville, Peterborough.
He said: "I'm glad someone else saw it, because I thought I was imagining things.
"I saw this object passing over to the north, as if heading towards Ferry Meadows.
"As your Werrington reader indicates, this was a greenish-tinged glowing object that seemed quite large in the night sky.
"I'd say it was football-sized and very bright, with a green halo surrounding it.
"I'm no expert on such things, but would suggest that the meteor had a high copper content, causing the green glow as it burned up.
"Any fan of HG Wells or '70s prog rock would find startling parallels between this and the martian cylinders in the War of the Worlds.
"I was half expecting to see giant metal tripods emerging from Ferry Meadows."
Meanwhile, a third sighting was made in Stamford by Dave Dickens, at precisely the same time.
He said: "I was in my car in Recreation Ground Road when I spotted something travelling seriously fast through the sky.
"It had a 5ft tail and was the size of a football. It was gone in a split second."
Andrew Richens, a member of the Society for Popular Astronomy, said: "The object seen was a meteor. they only become meteorites if they fall to Earth.
"Had the object indeed fallen to Earth, it may well have been football-sized.
"However, the object would have been several hundred miles up in the outer atmosphere when seen, and judging its size with the naked eye may have been somewhat extreme.
"Meteors do occasionally contain small quantities of copper. They do, however, also contain nickel which was the most probable cause for the green flame.
"Most meteors are the size of a pea and burn up as they meet with friction generated from hitting the Earth's atmosphere, at about 17km per second."
Mohammed Aminu
This Day
Fri, 11 Jan 2008 05:14 EST
There was pandemoniun yesterday as a loud explosion emanating from a heavy metal - like object rocked the city of Sokoto.
The object fell from an unknown location and landed at Mana Village, Sokoto South Local Government Council, at about 10:00p.m. Wednesday night, in the compound of one Bello Mohammed, creating extra ordinary lightning across the metropolis.
THISDAY gathered that residents were thrown into confusion when they saw an illuminated object moving before it later exploded.Assistant Commissioner of Police in charge of Criminal Investigations Department, Sir Clement Adoda, who confirmed the incident, said as soon as the incident occured, security personnel moved swiftly to the village and located the shattered house.
He said the object is a Meteorite, which has completely
destroyed the roof of Mohammed's house, and went almost two meters deep
into the ground. Adoda also went with bomb disposal men who took the object to the state police command for further investigation.
He, however, said the police are yet to ascertain where the object came from. No casualty was recorded.
AIAA 2007 Planetary Defense Conference
NASA
Thu, 10 May 2007 09:07 EDT
WHITE PAPER: SUMMARY AND RECOMMENDATIONS
1. Meeting Overview
The 2007 Planetary Defense Conference was held March 5-8, 2007 at the Cloyd Heck Marvin Center at George Washington University in Washington, D.C. The primary objectives of the meeting were: to highlight current capabilities in Near Earth Object (NEO) detection, characterization and mitigation; to advance understanding of the threat posed by asteroids and comets and arrive at possible responses to an asteroid impact; and to consider political, policy, legal and societal issues that would affect our ability to mount an effective defense. The conference followed a format similar to the 2004 Planetary Defense Conference, results of which are summarized in an AIAA Position Paper.
Copies of papers, presentation material, and videos of the presentations themselves are available at the conference web site.
Day 1 of the conference provided an overview of efforts to discover threatening Near Earth Objects (NEOs), defined as asteroids or comets whose orbits have perihelia of less than 1.3 Astronomical Units (AU), and the subset of NEOs that pose a more immediate threat to Earth, called Potentially Hazardous Objects (PHOs). PHOs are defined as asteroids and comets that pass within 0.05 AU of Earth's orbit and are large enough to cause significant damage should one impact Earth (~50 meters in diameter and larger). Day 1 presenters also discussed what we know about the composition and structure of PHOs, how such characteristics are determined, and what has been learned from recent missions to, and observations of, asteroids and comets. Briefings included a summary of the detection and characterization aspects of the recently completed study by NASA in response to congressional direction. Information was also presented on NEO/PHO populations, the potential increases in their rates of discovery, and the variation of impact probability as the number of observations increases.
Presenters in Day 2 discussed techniques that could be used to deflect or otherwise mitigate a threatening asteroid and the design of deflection and mitigation missions. Presentations highlighted how NEO composition and structure influence the effectiveness of mitigation techniques, described slow-push and quick-impulse deflection methods, and proposed techniques that could be used to break a threatening object into small fragments. Presenters also gave an overview of missions that have been proposed to actually test our ability to move an asteroid. Included in Day 2 was the presentation of deflection technique-related highlights of the NASA Report to Congress.4
Day 3 summarized recent work on consequences of an impact, including tsunamis and the overpressure developed during a high-speed entry into Earth's atmosphere. The latter work suggests that treating airbursts as point-source explosions may not provide the most accurate estimates of surface effects from NEO entries. Likely, hypothetical reactions of disaster and emergency response agencies and the public to warnings or to an actual impact were also highlighted using lessons learned from recent hurricane and tsunami-related disasters.
On Day 4, the final day, a panel of experts discussed topics such as legal issues associated with testing and implementing deflection techniques, educational aspects of NEO impact protection, and maintaining funding for an ongoing, long-term level of effort on detection, characterization and deflection. The panel also reported on ongoing efforts to develop an international decision process for NEO deflection. A second panel, made up of session chairs, discussed key points raised in each session. Meeting attendees were invited to address both panels.
After the meeting, key points discussed by presenters and participants were distilled and refined by the conference's steering committee and circulated to all conference attendees for comment and discussion. Resulting consensus findings and recommendations are collected in this document.
2. Findings and Recommendations
While significant scientific and technological advances have been made since the 2004 conference and are ongoing, it is clear that providing effective planetary defense from Near Earth Objects and planning for mitigation of an impact disaster are in their infancy. Specifically, the primary findings of the conference are that:
1. While our search and discovery efforts have successfully found most of the large, "civilization-killer" 1-km and larger objects, we are just beginning to find the much more prevalent and, for that reason, more frequently dangerous objects in the 140- to 300-meter size range. An impact by an object in this size range could occur with little or no warning and could cause serious loss of life and property over a broad area.
2. Earth-based resources such as the Arecibo radar are critical for refining a PHO's orbit and providing basic information required for deflection. Arecibo has an essential role in refining the threat posed by PHOs such as Apophis.
3. Deflection of a threatening object is in the conceptual phase. We are just beginning to identify the options available to deflect an object and have yet to design or test techniques that might be used. Further, we have yet to design complete missions to deliver one or more deflection devices, and have not considered what is required to assure a high probability of success for an overall deflection campaign.
4. There are serious technical, political, policy, legal and societal issues involved in deciding whether and how to respond to a threat of a NEO impact. NEO impacts have the potential to cause disasters that would equal or exceed anything ever faced by recent civilizations. Moreover, this type of threat has never been seriously considered by any agencies that would have responsibility for responding. In addition, it is uncertain where responsibility for coordination of all aspects of the NEO threat lies, from detection to deflection to impact aftermath.
5. Understanding, analyzing, and dealing with a potential NEO threat is an international problem demanding international cooperation. Considerable work is required to develop a foundation for international cooperation and action in all areas related to planetary defense. This foundation may extend beyond defense and include benefits from international manned and unmanned space exploration.
The remainder of this White Paper provides background and recommendations in five areas considered at the conference: Detection and Characterization; Deflection Approaches and Missions; Impact Consequences and Response; Political, Policy, Legal; and Public Perception and Trust.
2.1 Detection and Characterization
Significant progress has been made in detecting and tracking NEOs, with about 4600 currently known compared to ~2700 in 2004. Similarly, the number of known PHOs was about 580 in 2004 and is currently about 850. Presenters estimated that there could be over 100,000 NEOs, including 20,000 PHOs, once the smaller, 140-meter and larger objects are added to the catalog. It was suggested that as many as 10,000 new 140-meter class objects, whose Earth impact probabilities will initially be non-zero, might be discovered in the next 20 years should an effort to discover and catalog these smaller objects proceed. In addition, some NEOs are binary in nature, and accompanying bodies are themselves large enough to pose a hazard; these must also be included in deflection plans.
The 270-meter diameter asteroid 99942 Apophis continues to be an object of interest, and the calculated probability of impact has varied as additional tracking data have been utilized to refine its orbit. Presenters discussed the predicted 2029 close Earth flyby and the associated "keyhole," the small region in space during the 2029 approach where Earth's gravity would perturb the asteroid's trajectory such that the subsequent 2036 encounter would be an Earth impact. A deflection effort for Apophis prior to the 2029 keyhole would require more than four orders-of-magnitude less momentum transfer than after 2029, and good tracking data during the 2012-2013 apparition of Apophis is particularly critical for refining impact probabilities and deciding whether a deflection action is required before the 2029 close approach. As a note, there may be several deflection techniques, including slow-push techniques, that could be applied prior to 2029; after that date, deflection options narrow to more energetic techniques - probably nuclear explosives. The Arecibo radar, which is scheduled for possible closure, is the most powerful instrument available for improving orbital accuracy and physically characterizing many NEOs making close passages to Earth.
A related issue is bringing appropriate assets to bear in a cost-constrained environment. For example, the NASA report to Congress noted that there are civil and U.S. Department of Defense assets that could be leveraged for the NEO detection task. There may also be international resources that should be integrated into these efforts.
One potential requirement for PHOs might be "tagging" the object to permit precise tracking for several years. The Planetary Society is conducting a global competition for a mission design to place a transponder on an asteroid, with a $50,000 privately funded prize. Results from this competition should be studied as a first step for future considerations of tagging. This competition may be a model for encouraging creative ideas for other aspects of planetary defense.
There is continuing scientific uncertainty about the internal structure of NEO objects, with spacecraft imagery indicating that some smaller bodies are not solid, monolithic bodies, but so-called "rubble piles" - accumulations of smaller objects and debris held together by little more than their own self gravity. These physical properties are important for assessing the effects and effectiveness of deflection and mitigation options. Missions to asteroids may be the only way such issues can be resolved.
U.S. and Japanese missions to asteroids and comets are providing invaluable information on these bodies. Presenters detailed results of the Japanese Hayabusa mission to asteroid Itokawa and the proposed European Don Quijote mission. The Hayabusa spacecraft is returning to Earth in 2010, hopefully with small samples of Itokawa obtained when it touched down on the asteroid's surface. Don Quijote is being planned to send an orbiter to an asteroid, where it will observe the effects of a kinetic impact on the object and on its orbit.
Recommendations
2.1.1.Immediately initiate actions to locate threatening objects in the 140-meter to 1-km size range. Objects smaller than 1 km, while certainly not "civilization killers," are large enough to cause local devastation and large loss of life. Perhaps more significantly, objects of this class are much more likely to strike Earth during future decades than are larger objects. The 1908 Tunguska event, caused by the entry of a NEO estimated to be 30-50 meters in diameter, leveled over 2000 sq km of Siberian forest - an area larger than the Washington, D.C. metropolitan area. Current technology limits our ability to detect and track many objects this small, but ground-based telescopes could, if adequately funded, discover and track a high percentage of potentially threatening 140-meter class NEOs in a reasonable time at a relatively low cost. The addition of a space-based infrared survey telescope could significantly increase the discovery rate and provide improved estimates of NEO sizes.
2.1.2.Characterize Apophis and refine its orbit during the 2012-2013 apparition. Asteroid 99942 Apophis is the first known and tracked NEO that will pass close to Earth and present a real threat of impact within the next 30 years. The 2012-2013 apparition presents the opportunity to substantially improve orbital predictions and determine whether the threat warrants future deflection action.
2.1.3.Support the operation of facilities critical to NEO discovery, orbit determination, and tracking. Discovery and precision orbit determination are the critical first steps in characterizing a NEO threat and initiating a mitigation action. Facilities and capabilities for collecting and quickly processing discovery data are essential. The planetary radar at Arecibo is a unique national asset. The facility has the world's best capabilities for determining the orbit of Apophis, as well as estimating its size and spin state, detecting accompanying bodies, helping resolve uncertainties in impact probability and projecting the scope of impact damage. But plans call for this asset to be shut down and rendered unavailable during the 2012-2013 apparition of Apophis. Its use during this period is very important for determining whether Apophis will be a serious threat to Earth in 2036. A similar need for this or an equivalent asset will exist as additional new objects are discovered.
2.1.4.Initiate a program in collaboration with planetary science objectives for the in-situ characterization of PHOs. The effectiveness of deflection techniques is strongly influenced by the physical characteristics of the target NEO, yet we do not have a good understanding of the range of properties with which we might have to deal. Characterization missions, related to both general and specific threats, are required to provide insight into the nature of the objects we may need to deflect. Small and micro-spacecraft technology should be considered to reduce costs and enable multiple characterization missions. International collaborative missions to achieve these goals should be encouraged.
2.1.5.Release the full 272-page "2006 Near-Earth
Object Survey and Deflection Study" to the public. This report contains
more detailed data and analysis supporting the NASA NEO Analysis of
Alternatives Report to Congress4 and is an excellent benchmark for the
current state of knowledge on NEOs and their discovery and deflection
options.
2.2 Deflection Approaches and Missions
Sometime in the future a credible NEO threat will be identified and actions will be required to prevent an impact disaster. As noted, we are very early in the development of technologies and techniques that could be used for such action.
Potential options identified in the NASA Report to Congress and discussed at the conference vary from slow-push techniques such as the gravity tractor and mass driver to more energetic impulsive techniques like kinetic impactors and nuclear explosives. Of course, technological development and verification is required for each, and the nuclear explosive option also requires addressing substantial public and international concerns.
In addition to technology developments related to the implementation of a deflection technique such as a gravity tractor or nuclear explosive, each option also has mission design-related issues that must be addressed. For example, in many cases a kinetic impactor will approach the NEO at a very high relative velocity, and thus will require rapid, accurate, and autonomous trajectory control. Similarly, slow-push techniques require rendezvous and long-term operation either attached, or in close proximity, to the target NEO. All options also have limitations imposed by the availability of launch vehicles and the demand for high reliability.
The 2004 conference discussed mission reliability and it was noted that to achieve the overall objective of deflecting an approaching object away from Earth with high reliability, a deflection campaign might include multiple launches of the same vehicle design. Further, since a common fault might be present in a single mitigation approach, a deflection campaign might actually consist of deflection attempts using two or more independent techniques.
The possibility of synergism between two deflection techniques was discussed from the perspective that a deflection campaign might incorporate both a slow-push and a more energetic technique to increase overall reliability. Some noted, for example, that a deflection campaign might utilize a slow-push technique as primary, with a quick- impulse technique as backup; others suggested a quick-impulse technique as primary, with a slow-push used to "clean up" the results. Of course, the mission timeline, cost effectiveness and overall probability of success of the campaign will factor into related decisions.
In all cases, we must be able to determine a new orbit after (or during, in the case of a slow-push technique) execution of a deflection attempt. The time required for establishing a new orbit must be included in the overall mission design and features that might be used to improve the accuracy of the post-execution orbit, such as placing a transponder on the object or maintaining a spacecraft on station nearby, were proposed.
The possibility was also raised that a deflection action might successfully avert a specific impact, but might increase the possibility of an impact at some future date. Design of a mission for a specific deflection must consider and minimize this possibility.
Recommendations
2.2.1.Research, characterize and demonstrate technologies associated with the most promising impulsive and slow-push techniques. Except for some technologies that might be used for impulsive missions, very little work to characterize deflection techniques has been done. Research is required to move these techniques from concepts to viable options for NEO deflection. Research should identify technologies critical to each method. Research should also consider approaches that might be synergetic and improve the overall certainty of a deflection mission. Included should be microgravity experiments to illustrate the response of NEO materials to impacts or to methods that might be used to attach or couple to the surface of such objects in microgravity conditions (i.e., attaching transponders or other instrument packages).
2.2.2.Identify and pursue opportunities to demonstrate potential deflection technologies during characterization missions that are in formulation or early development. At present, designers of deflection missions must allow for large uncertainties in the response of a target NEO to a deflection attempt, and additional research is required to increase confidence in our ability to predict and control the effectiveness of a deflection attempt. Compatible opportunities during characterization missions should be identified to demonstrate potential deflection technologies (e.g., attaching transponders, testing kinetic impactors, using low-impulse ion engines and slow-push techniques, etc.). The European Space Agency's Don Quijote mission is an example of the type of mission that might be used to characterize a NEO and to test deflection technologies.
2.2.3.Develop and document complete designs of a deflection campaign, including launch vehicle and payload requirements, ground support requirements, overall mission reliability, mission timelines and milestones, and costs. Our ability to deliver a deflection option to a threatening NEO with a high probability of success must also be considered in detail. Results of these studies would feed into an overall NEO deflection plan and help develop a roadmap for the architecture of a deflection campaign using current and near-term technology and capabilities. This plan should be updated on a periodic basis.
2.3 Impact Consequences and Response
Many small objects enter Earth's atmosphere on a daily basis and a few yield fragments that survive to reach the surface as meteorites. While some small object entries lead to airbursts and most are harmless, an otherwise harmless but brilliant bolide (fireball) in the wrong place could be mistaken for an attack, potentially causing a dangerous response. Quick notification of such events, should they be detected, would help avert such consequences.
Larger objects enter less frequently, but the effects increase as size increases. As noted earlier, the 1908 Tunguska event occurred after an airburst of a 30- to 50-meter-diameter object, which caused widespread devastation. The energy released had previously been estimated in the range of 10 to 20 megatons. More recent estimates suggest that the energy released could have been as low as 3 to 5 megatons. An entry of this size is estimated to occur once every 1000 years on average. The statistical likelihood of such an entry this century is 1 in 10.
Based on responses to past disasters, predictions are that an impact would result in initial confusion at all levels of leadership. The lack of understanding of the characteristics of a major impact event and impaired command and control are likely to result in delayed initial response efforts and resulting additional loss of life and suffering. As noted by Michael Chertoff, Secretary, U.S. Department of Homeland Security, in his testimony to the Select Committee Hearing after the Hurricane Katrina disaster: "This tragedy 'once again' emphasized how critical it is that we ensure our planning and response capabilities perform with seamless integrity and efficiency in any type of disaster situation - even one of cataclysmic nature."
Recommendations
2.3.1.Conduct an Impact Response Exercise - a well-scripted and well-designed tabletop exercise, driven by improved gaming, modeling and simulation resources to increase understanding of the evolution of an impact disaster and demands on response agencies and communication systems. For many natural disasters, agencies responsible for assisting those affected conduct simulations involving all segments of disaster response to identify issues and develop solutions. An unexpected NEO impact should be added to the set of disasters simulated. The disaster could be either from an ocean impact, where the effects could be experienced by a long expanse of coastline and possibly affect several or many nations, or from a land impact. The simulation would focus on effects of a 50- to 140-meter class NEO, a size that would likely impact without warning. Ideally, the exercise would involve all stakeholders that would be involved in a response, including local and national governments, military organizations, disaster responders, and members of the press.
2.3.2.Incorporate the NEO hazard into the mandates of agencies, both national and international, that are charged with addressing very large-scale natural and man-made catastrophes. Nations should assess the risk relative to natural and man-made hazards, and encompass the NEO response within existing national and international frameworks that address the more familiar hazards, ensuring that emergency response capabilities are suited to dealing with NEO-related scenarios.
2.3.3.Conduct additional research to advance understanding of the relationship between NEO size and event consequences. This relationship is critical for setting the lower limit of our detection efforts and making the decision to initiate a deflection campaign or other mitigation efforts. Previously, NEO explosions above Earth's surface (events believed typical of a class of smaller NEOs) have been treated as point-source explosions. New information indicates that the shock and flow field generated throughout the entry trajectory may be important contributors to ground effects (tsunamis, etc.). Additionally, an impact could release an electromagnetic pulse that could interrupt communications among disaster responders. We may not yet understand the complete nature of the hazard associated with PHO impacts and the dependence of impact consequences on object size.
2.4 Political, Policy, and Legal
An asteroid impact could occur anywhere on the globe at any time, so planetary defense has implications for all humankind. All nations on Earth should be prepared for this potential calamity and work together to prevent or contain the damage. That said, there is currently very little discussion or coordination of efforts at national or international levels. No single agency in any country has responsibility for moving forward on NEO deflection, and disaster control agencies have not simulated this type of disaster.
Providing funding over the long term was also seen as a challenge. Much of the work in virtually all areas of planetary defense has been done on individuals' own time and initiative. There is a need for ongoing studies and peer-reviewed papers to improve our knowledge in this area, as well as to increase the credibility of the issue and the public's trust in our ability to respond. The reality is that NEO deflection or disaster mitigation efforts may not be required for decades or longer, so governments, which are focused on more immediate concerns, may not be willing to commit sufficient recourses to this type of work. Determining the appropriate level of this work and funding such activities over the long term is seen as a major issue.
In addition, major legal and policy issues related to planetary defense need to be resolved. An example is liability for predictions that prove false or deflection missions that only partially work or fail completely, resulting in an impact. Other examples include:
· A prediction is made that an impact may occur in a specific area, and residents and businesses that might be affected leave. Are there liabilities associated with the loss in property values if the prediction is wrong?
· A nation makes a deflection attempt, but it fails to change the object's orbit enough to miss Earth. Is that nation now responsible for the damage inflicted?
· A NEO threat demands the nuclear option, but public perception is that the possibility of a launch failure and subsequent damage is more acute than the threat from the NEO. What are the liabilities and political and policy implications associated with a launch failure during a deflection mission?
These types of issues should be discussed and resolved before they are raised by a serious threat.
Recommendations
2.4.1.Develop an international protocol for use in situations when critical decisions relating to threat and disaster mitigation are required. Given the global nature of the consequences, it is unlikely that one country will decide on its own whether to take action. There must be international involvement in decision-making and in whatever actions are decided. Discussions on how these decisions will be made should begin while there is no specific threat. Principles and protocols for the process of communication and dissemination of information about potential impacts, and the implementation of necessary mitigation measures should be negotiated and agreed to at an international level. These protocols should identify roles and responsibilities of key players and include a means to notify governments and the public of all hazards of a regional or global nature.
2.4.2.Increase international collaboration on efforts aimed at detection and characterization, mission planning, and research related to deflection. One concept suggested is to establish a Planetary Defense Coordinating Committee (PDCC) where nations can discuss and coordinate research efforts at the technical level. The group might be similar to the current Inter-Agency Space Debris Coordinating Committee (IADC)[1] where space agencies of 11 nations meet to address the issue of man-made debris. The PDCC would be chartered to coordinate NEO research activities and provide technical recommendations supporting legal and policy decisions.
2.4.3.Develop and implement a mechanism to maintain funding for critical technologies and efforts over the long term. Establishment of a trust fund or foundation should be considered to ensure uninterrupted financial support for research related to planetary defense.
2.4.4.Develop a framework for the use of nuclear explosives for NEO deflection before a credible threat is identified. The nuclear option for NEO deflection is sure to raise concerns among the public and governments, but this option would be necessary for the largest NEOs, or for NEOs that don't respond as predicted to non-nuclear techniques, or for those discovered too late to utilize other options.
2.4.5.Develop international agreements limiting the
liability related to making impact predictions or to taking or not
taking action on a NEO threat. In its discussions about NEOs, the
international community should develop agreements regarding specific
limitations of liability for taking or not taking actions, and for
making predictions about NEO threats. At present, there may be
potential liabilities related to specifying a threat and to taking a
deflection action. For example, the mere forecast of an impact could
have tremendous implications for the value of land and for businesses
in the impact zone; a failed or ineffective deflection attempt could
result in a subsequent impact and serious damage to the original threat
area or possibly another area.
2.5 Public Perception and Trust
Low probability disasters come to the attention of policy makers and become part of the national and international agenda as the result of focusing events. These are infrequent, sudden and harmful events that become known to the public and to the government simultaneously. As attention-grabbers, they initiate a push to "do something" about redressing the situation and preventing its recurrence. A hurricane, earthquake, major oil spill or technological catastrophe can generate a "spike" in interest that typically peaks in a few weeks in the media and in a few months in governmental deliberations and then dissipates as other issues come to the fore. Typically it produces a two-year window of opportunity for preparing for similar disasters, a window that closes slowly in the absence of another focusing event.
Progress occurs when there is an organized community of scientists and policy experts who push for new legislation during the window of opportunity. Such "policy entrepreneurs" have been highly successful promoting useful legislation following earthquakes, with the result that construction standards have improved consistently over the past hundred years. For example, earthquake policy entrepreneurs were instrumental in the drafting of the National Earthquake Hazard Reduction Act (NEHRA) of 1977. The key is a motivated and organized group of policy advocates that presses for efforts to mitigate the hazard and not just speed the flow of post-disaster relief.
While no NEO impact disastrous to society has occurred yet, significant NEO detections and even low-level threat warnings provide windows of opportunity for educating the public and decision makers on the nature of this recently recognized problem. Additionally, major projects, such as developing a new NEO warning or mitigation system, may have focusing effects and further our mitigation efforts. In presenting risk, we must treat the threat seriously and act through established protocols that are understandable by the public.
Recommendations
2.5.1.Engage and sustain the interest of professionals and practitioners from the social and behavioral sciences. Even as effective detection and deflection strategies depend upon the best available knowledge from astronomy, physics, and engineering, effective warning and recovery depend upon utilizing the best available knowledge from anthropology, psychology, sociology, political science, risk communication and related disciplines.
2.5.2.Develop a strategy for educating elected and governmental officials and the public on the nature of the NEO threat and what to expect in regards to NEO detections and warnings. The strategy should include ways to present sober, realistic assessments of the facts during periods of potential high risk and subsequent risk reduction efforts after refined orbit determinations are arrived at. The strategy should also consider enhancing understanding of our current abilities to discover threats and the potential for impacts to happen anytime without warning. One suggestion is to provide or enhance Internet sites to show how threats evolve and to illustrate possible action scenarios. A protocol for actions and notifications should be developed for threats that exceed predefined thresholds.
2.5.3.Examine how social factors such as individual and group psychology, culture, and political and religious beliefs might affect the decision to move forward on a NEO deflection effort. Individuals approach problems from a variety of viewpoints, and these factors are likely to be involved in discussions and decisions related to planetary defense and disaster recovery. Experts involved in NEO science and technology must also be aware of these aspects of the problem - particularly when they are informing the public, decision makers or potential funders about their research implications. A periodic survey on issues related to planetary defense may be a way to track progress in public understanding.
3. Summary
The 2007 Planetary Defense Conference focused on the current state-of-the-art of planetary defense-related technologies and legal, policy, political, and public-response issues that would affect the decision to mount a deflection campaign or to respond to a NEO-related disaster. The broad sponsorship of the conference indicates that planetary defense is increasingly being accepted as a legitimate issue and goal internationally and domestically.
The 19 recommendations presented in this White Paper are a result of presentations and discussions at the conference and subsequent interactions among conference participants. The hope of participants is that the recommendations contained herein will encourage serious, long-term efforts to develop and test technologies and to debate and enact policies that support protecting Earth from the threat of Near Earth Objects.
Clube and Napier: Coherent Catastrophism
Phil Burns
pibburns.com
Sun, 06 Jul 2003 11:03 EDT
In 1982, two British astronomers, S. V. M (Victor) Clube and William Napier, published a book entitled The Cosmic Serpent. Clube and Napier suggested that the outer planets occasionally divert giant comets (more than 50 kilometers in diameter) into the inner solar system into short-period orbits. Debris from the resultant disintegration of these giant comets can adversely affect the environment of the Earth. Dusting can block sunlight, resulting in globally cooler conditions. Impact events in the super-Tunguska class may result in not only heavy localized destruction but also the occasional "impact winter" or dust veil with global climatological effects.
Clube and Napier identified the progenitor of the Taurid complex as such a giant comet whose injection into a short-period (about 3.3 year) orbit occurred sometime in the last twenty to thirty thousand years. The Taurid complex currently includes the Taurid meteor atream, Comet Encke (the only known currently active comet in the Taurid complex), "asteroids" such as 2101 Adonis and 2201 Oljato, and copious amounts of dust. All ten of the numbered asteroids in the Taurid complex appear to have associated meteor showers and therefore are likely to be extinct comets masquerading as asteroids.
The effects of the disintegration of the Taurid progenitor object in an Earth-crossing orbit should appear in the geological and climatological record. Clube and Napier marshalled evidence for such effects in "The Cosmic Serpent" as well as their later book Cosmic Winter published in 1990. Clube and Napier, following in the footsteps of earlier catastrophists, also sought evidence of catastrophic events in ancient mythology and history. These authors have also written papers in standard peer-reviewed journals about the role giant comets play in constructing a tenable physical theory of coherent catastrophism.
The giant comets normally reside far beyond the planets, in a spherical cloud surrounding the Sun, called the Oort cloud. There is also evidence for a flattened disk of comets closer to the inner solar system, called the Edgeworth/Kuiper belt. What prompts members of either of these comet repositories to enter the realm of the planets? Clube and Napier suggest a galactic influence. The solar system periodically passes through the plane of the galaxy as the Sun (and the solar system with it) orbits the galactic center. Each passage may dislodge giant comets and divert them closer to the Sun. The outer planets, particularly Jupiter, may then perturb some of these giant comets into orbits which enter the inner solar system. These comets, stressed both by gravity and by heat from the sun, may fragment into a cloud of smaller objects with dynamically similar orbits.
Chiron offers a good example of a giant comet as called for by Clube and Napier's giant comet hypothesis. Chiron is somewhere between 148 and 208 kilometers in diameter. Currently Chiron's unstable "parking orbit" lies mostly between Saturn and Uranus. Chiron may end up injected into the inner solar system within a hundred thousand years, or ejected from the solar system on a similar time scale. It is also possible that Chiron has already visited the inner solar system.
The Taurid complex and the Kreutz sungrazer group are two families of objects which most likely represent the fragmented remains of two giant comets in the current era. SOHO has recently discovered many new members of the Kreutz group which were previously unknown.
The Kreutz progenitor was injected into a retrograde orbit and attained the sungrazing state at a high inclination to the ecliptic. Hence the debris of its "children" does not pose a threat to the Earth. The Taurid progenitor on the other hand ended up in a short-period low-inclination prograde orbit. This is why the Earth can encounter its debris with potentially calamitous results.
What would happen should the Earth pass through the orbit of a disintegrating giant comet just before or after the comet passes that same point? Since larger fragments tend to cluster close to the nucleus of the comet, chances would increase that the Earth would be bombarded by these larger fragments. The severity of this comet fragment shower would far exceed any ordinary meteor shower. Not only would "shooting stars" and bright fireballs caused by small debris appear, but so too would large airbursts and possibly ground impacts. These would result in significant destruction should they occur over an inhabited area. If a large enough fragment struck in the ocean -- say, 200 meters or so in diameter -- it would raise tsunamis even at a great distance that would sweep away coastal habitations.
Duncan Steel, a colleague of Clube and Napier, refers to this process as coherent catastrophism. Widespread destruction derives from the coherent arrival of many impactors within a few days, as opposed to the sporadic arrival of objects spread randomly in space. The shower repeats for a period of years until the cometary orbit precesses so that the Earth no longer encounters the dense part of the debris field. (Of course, sporadic debris unrelated to the disintegrating comet may impact at any time as well.)
I believe that coherent catastrophism, as enunciated by Clube, Napier, Steel, and their colleagues, provides the best physical model for recent astronomical catastrophes, although I do not necessarily agree with all of their historical ideas.
For a contrary viewpoint you should read David Morrison's reviews of recent books and articles on the impact hazard which includes the books by Lewis, Steel, Verschuur, Cox and Chestek, Gribbin and Gribbin, Desonie, and Barnes-Svarney. Also available is a preliminary version of a review of Duncan Steel's book by Clark Chapman. The final version appeared in the journal Meteoritics and Planetary Science, v.31 (1996), pp. 313-314. Morrison and Chapman strongly disagree with the Clube/Napier/Asher/Steel idea of coherent catastrophism.
A common criticism levelled against Clube et al's giant comet hypothesis is that it uses a "Velikovskian" approach to mythological and historical evidence as a primary basis. It does not. Even should every single one of the mythological interpretations offered by Clube and Napier in The Cosmic Serpent or Cosmic Winter prove to be incorrect, this says nothing whatever about the correctness of the giant comet hypothesis and coherent catastrophism. The correctness of these depends solely on physical evidence. Mythological evidence might at best be supporting evidence. The same cannot be said of many other versions of non-orthodox catastrophism, e.g., Velikovsky's, which seek to rewrite physics and astronomy based upon ancient myths.
Bob Kobres's Web Site offers this independent researcher's views on coherent catastrophism. He likes Clube and Napier's ideas. You can find his papers on the role of comets in the Bronze age collapse and on Comet Phaeton's Ride, among other interesting things.
Cambridge Conference Correspondence Menu provides archived messages from this mailing list run by Benny J. Peiser of Liverpool John Moores University. The Cambridge list offers a venue for announcements about current topics and research into near-Earth objects and historical catastrophism.
Tony Smith discusses the Taurid complex, possible timing relationships between Supernovae and comets, and more on his Comets web page. Hale-Bopp was a relatively large comet of twenty-five miles diameter. This is not as large as the purported Taurid progenitor, or comet Sarabat, which reached a magnitude of -3.0 and was visible for over six months in 1729 A.D. Sarabat is estimated to have been 50 km to 100 km in diameter. See my astronomy pages for more links to sites about Hale-Bopp and other comets.
Comets And Disaster In The Bronze Age by Benny J. Peiser was originally published in the December 1997 issue of British Archaeology magazine. Peiser discusses the possible role of cosmic impacts in the widespread collapse of many civilizations around 2300 BC.
The extracts from Victor Clube's paper "Giant Comets and their Role in History " which appeared in The Universe and its Origins edited by S. Fred Singer (Paragon House, New York, 1990) emphasize the potential climatic effects of the Taurid complex.
The Second SIS Cambridge Conference entitled Natural Catastrophes during Bronze Age Civilizations: Archaeological, Geological, and Astronomical Perspectives (sponsored by the Society for Interdisciplinary Studies) was held at Fitzwilliam College, Cambridge, UK, July 11-13, 1997. This conference brought together "historians, archaeologists, climatologists and astronomers in order to discuss whether the 'giant comet' hypothesis brought forward by neo-catastrophist astronomers such as Victor Clube, Bill Napier, Sir Fred Hoyle, David Asher, Mark Bailey, Duncan Steel et al. can be substantiated by the archaeological, climatological and historical record." Includes abstracts of the presentations. See Mark Bailey's review of the conference for more details.
Second SIS Cambridge Conference offers comments by Mark E. Bailey originally published in the November 1997 issue of Meteorite! magazine.
The Dark Ages: Were They Darker Than We Imagined? by Greg Bryant originally appeared in UNIVERSE - Journal of The Astronomical Society of New South Wales Inc.. Bryant reviews the possible relationship between major accretion events from the Taurid complex and the AD 536 onset of the Dark Ages.
Royal Observatory Greenwich Blog
Sun, 13 Jan 2008 12:15 EST
The 27-metre diameter asteroid 2008 AF3 will tonight pass by the Earth as close as the Moon! (see its orbit here)
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| ©NASA/JPL |
In fact, it is passing so close that you can see it for yourself (from a dark site, with a large telescope). At magnitude 14, you will need a 12" diameter telescope to spot it as it passes through Ursa Major (the Plough) this evening (you can plot its position from your locations using Tom's Asteroid Flybys Webpage).
But the worry is that it was only discovered 3 days ago, highlighting the difficulty of finding asteroids that are coming straight for us!
If an asteroid is larger than 100m, and is expected to pass the Earth within 20 times the Earth-Moon separation, then it is considered a potentially hazardous asteroid. Fortunately, none are expected to hit the Earth at the moment, but new ones are being discovered on a regular basis.
According the SpaceWeather.com there are currently 917 potentially hazardous asteroids out there! A full list is maintained by the Centre for Astrophysics at Harvard.
S.V.M. Clube
Vistas in Astronomy, Volume 39, Issue 4, Pages 673-698
Fri, 01 Dec 1995 13:42 EST
Abstract: Mankind's essentially untroubled state of mind in the presence of comets during the last two centuries has been fortified by the overall relative brevity of cometary apparitions and the calculated infrequency of cometary encounters with planets.
During the course of the Space Age, however, the fact of cometary splitting has also become increasingly secure and there is growing appreciation of the fact that mankind's state of mind can never be altogether relaxed. Indeed a watershed in the modern perception of cometary facts has evidently been reached with the most recent and devastating example of cometary splitting, that of the fragmentation of Comet P/Shoemaker-Levy 9 and its subsequent bombardment of planet Jupiter.
Thus there is a recognized tendency now amongst comets, especially those in short-period orbits, due to the occasionally excessive effects of solar irradiation, planetary tides and small body impacts, which gives rise to individual swarms of cometary debris, and it is the resulting repeated penetration of such dispersed swarms by our planet which apparently increases the danger to mankind from time to time.
The danger comprises global coolings, atmospheric pollution and super-Tunguska events, the cometary debris being responsible for both high-level dust insertions and low-level multimegaton explosions in the Earth's atmosphere along with a generally enhanced fireball flux.
Historically, the presence of such danger was drawn to mankind's attention by the observed bombardments over several decades due to "blazing stars threatening the world with famine, plague and war; to princes death; to kingdoms many curses; to all estates many losses; to herdsmen rot; to ploughmen hapless seasons; to sailors storms; to cities civil treasons."
The sense of cosmic destiny aroused by these bombardments evidently involved degrees of fatalism and public anxiety which were deplored by both ecclesiastical authorities and secular administrations with the result that acknowledged dispensers of prognosis and mitigation who endorsed the adverse implications of 'blazing stars' (astrologers, soothsayers etc.) were commonly impugned and censured.
Nowadays, of course, we are able to recognise that the Earth's environment is not only one of essentially uniformitarian calm, as formerly assumed, but one that is also interrupted by 'punctuational crises', each crisis being the sequence of events which arises due to the fragmentation of an individual comet whose orbit intersects the Earth's. That even modest crises can arouse apprehension is known through the circumstances of the nineteenth century break-up of Comet Biela.
Indeed it seems that these crises are rather frequently characterized by relatively violent (paradigm shifting) transmutations of human society such as were originally proposed by Spengler and Toynbee more than sixty years ago on the basis of historical analysis alone.
It would appear, then, that the historical fear of comets which has been with us since the foundation of civilization, far from being the reflection of an astrological perception of the cosmos which was deranged and therefore abandoned, has a perfectly rational basis in occasional cometary fragmentation events. Such events recur and evidently have quite serious implications for society and government today.
Thus when cosmic danger returns and there is growing awareness of the fact, we find that society is capable of becoming uncontrollably convulsed as 'enlightenment' spreads. A revival of millenarian expectations under these circumstances, for example, is not so much an underlying consequence but a deviant manifestation of the violent turmoil into which society falls, often to revolutionary effect.
I. INSPIRATION AND FOREBODING
Today science is more or less unquestioned as the primary body of systematic knowledge reaching us through observation and measurement. However, by making too much of the more passive aspects of this body of knowledge, i.e. its reproducibility through repeated accurate measurement, it is possible to undervalue the significance of its more active aspects, i.e. the inductive insights or connecting links which ultimately give the overall system of knowledge its intrinsic strength.
Scientists, of course, are aware of these countervailing tendencies and while recognising the care, patience and technical skill that are necessary to sustain the reproducibility of systematic knowledge, they do also draw attention to the need for a state of mind in research which brings its practitioners to the point of insight and enlightenment.
Thus a picture for the overall development of knowledge seems now to have emerged in which the network of connections between supposed islands of knowledge may be discontinuously and abruptly rearranged as the islands themselves continuously grow and dissolve. Admittedly any precise description of these discontinuities remains somewhat elusive (Kuhn, 1962 cf. Lindberg, 1992) but there is no lack of archetypes such as Archimedes and his well known cry of Eureka! from the bath as he pondered the problem of the specific gravity of gold.
Our ancestors indeed, who undoubtedly recognised the importance of this not so very subtle aspect of the acquisition of knowledge, would tend to describe an enchanted state of mind which from the very earliest times was believed to have been brought on through the wiles and trickery of a serpent. In fact, a modern dictionary still tells us that to be fascinated, the prerequisite to knowledge, is to be deprived of the power to resist or to escape by the look or presence of a tormentor, possibly a serpent. A mythologist would have little difficulty with such etymology: thus it was the original all-pervading chaos associated with the primeval (cosmic) serpent, whatever this may have been, which served as the principal exemplar down the ages of the turmoil out of which desperate new connections were once forged and which was accepted as naturally illustrating the critical path by which new scientific (mostly astronomical) knowledge was obtained.
In other words, the insights leading to true knowledge have long been thought of as being brought to human attention by some kind of mesmerising process or cunning on the part of nature. That is, we observe natural phenomena as to whose cause we wonder and by whose effect we are astonished. And it is through the perceived enlightenment that comes by joining such cause and effect that a fascination in, say, astronomical phenomena is believed to broaden our cosmic experience and thereby enrich our cultural heritage.
We may be fascinated of course in the sense of being enraptured and heartened, in which case we are in the habit of accepting the cosmic realm as a source of inspiration and our culture as both soothing and ennobling. However, we may also be fascinated in the sense of being agitated and petrified, in which case it can also be that the cosmic realm is a source of foreboding and our culture is both disturbing and intoxicating.
Of the essence here is the injustice to our past if we look back on the sum total of mankind's cosmic experience and fail to recognize how this has ennobled our culture. But equally, there is the unfairness to our future if we look back on this experience and fail to appreciate how it has also overwhelmed our culture from time to time, e.g. through our response to the intermittent incidence of celestial 'signs'. The mistake in fact is to suppose that inspiration and foreboding are uniformitarian and arise in equal measure at all times, rather we should be aware of the possibility of a temporal sequence in the balance of inspiration and foreboding; and of the timescale of variation from one extreme to the other which is tantalizingly beyond the usual reach of direct individual experience. That is, for long periods of time on Earth, generations can follow generations under the impression that our cosmic environment is a continuous source of inspiration only to be succeeded for a while by generations aware of the fact that our cosmic environment can also be an intense source of foreboding.
The point to be noted then is that there are positive and negative, both light and dark, sides to the inspiration provided by astronomical phenomena in the past; and we seriously misunderstand human history if we suppose our celestial environment never impinges adversely upon the Earth.
Quite simply, the enlightened or supposedly uniformitarian view of nature these last two hundred years has diverted attention from adverse celestial inputs and there is now a serious risk, especially from within the fastness of an ivory tower, that inspiration's commonest inducement, the appeal to a sublime principle, will continue to press our cosmic perspective and our cultural endeavour towards some kind of paradisical extreme.
To achieve some kind of balance of course, it is probably necessary to come down from the fastness of the ivory tower and to join the maelstrom in the courtyard below for it is only through grim human contact, it seems, that we are more able to contemplate the punctuational crises which continually threaten and sometimes afflict civilization. There will be optimists, to be sure, who will trivialize such crises and regard such balance as imbalance but, as a well-known yet typical mentor of the last century (Proctor, 1875) once quoted, when troubles were about to befall men, "nation rising against nation, and kingdom against kingdom, with great earthquakes in divers places, and famines, and pestilences, and fearful sights", then "great signs shall there be from heaven".
The point Proctor makes of course is that our cosmic experience has always had both its paradisical and its purgatorial aspects and it is mostly when the latter are in the ascendancy that our cosmic experience rouses us from the opium of culture and plunges us into the politics of despair. Thus it could be a twentieth century indulgence to suppose despondency under uniformitarian conditions cannot be further plumbed for such could be as nothing compared to the depths of despair which have come with the most significant cosmic events during recent millennia.
In this essay, we shall begin with a 'journalistic' perspective on the contemporary politics of punctuational crises and then move on to evaluate the cosmic perspective which now seems to be forced upon us. We shall come to recognize that the great signs from heaven were never primarily the eclipses and random comets which we hang on our supposedly ignorant ancestors, rather they were the fireball flux surges whose nature remains as problematical for us as it was for them.
2. COMETS BY JOVE - A WARNING TO THE PRESIDENT'S MEN?
The unprecedented events on Jupiter during the summer of 1994 served to quicken the pace of developments in space. There was clearly something awesome in those predicted encounters of comet pieces with a planet which, had they occurred on Earth, would have resulted in a mass extinction. Very few could have failed to be moved by the prospect that future comet splittings might suddenly produce a similar impact hazard heading towards the Earth which mankind would be unable to avoid.
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| ©S.V.M. Clube |
| This graph summarizes the flux of large meteors (variously known as 'blazing stars', 'providences' or 'fireballs') during the period 100 BC- 1900 AD as recorded by Chinese imperial astrologers. Note the occasional large surges lasting from decades to centuries indicative of highly entrained cometary/asteroidal debris (a. la Shoemaker-Levy!) in orbit around the Sun and, hence, an increased likelihood of multi- megaton events. While the fear of 'last times' associated with these surges is demonstrably a significant eschatological force, dictating the course of history to a greater extent than is now commonly perceived, (note the surges at the time of Christ and during the European Dark Age), it seems that the events were essentially spurned during the aftermaths of the seventeenth and eighteenth century surges, coinciding with the English and American Enlightenments, respectively. Also, by integrating large meteors according to month and century, (See Figure 1 below) we note that the surges largely take place during the months of July - August and October - November, indicative of a single broad stream (the Taurids) in which most of the observed fragmentations occur. It seems likely that the fear of 'last times' is a long-standing historical problem associated with the disintegration of a single large comet originally at the core of the Taurid stream. |
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| ©SVM Clube |
| Fig. 1 |
Inevitably, so it seemed, there was an added sense of common purpose to mankind's continuing watch on space. Such a sense of purpose in 'spacewatching' has frequently arisen in the past usually in a national context, and can he traced back to the very dawn of civilization: one thinks for example of the Sumerians (e.g. Frankfort et al., 1946), then later the Chinese (e.g. Schafer, 1977) and eventually perhaps the Aztecs (e.g. Sejourne, 1957), all of whom are known to have confronted the cosmos at different epochs for many generations with the same air of realism and foreboding.
Nowadays, of course, it is the American nation which bears the brunt of this watch and ensures that the responsibility is taken seriously. As recently as 1990 for example, Congress was pressing space agencies for an assessment of the impact risk to civilization. Congress however did not count on inertia within the scientific corpus giving rise to a characteristically sanguine interpretation of the brief. Thus there is a kind of mindset afflicting those who put order into the cosmos which also causes them to resent disorderly intrusions. Disintegrating comets which suddenly appear in the Solar System are of this nature and the reaction which is by way of turning a blind eye to unwelcome visitations can often mean that the common purpose is blunted. Those who would have turned us away from Galileo's telescope so many centuries ago were still able to turn us away from the unprecedented events on Jupiter during the summer of 1994!
Even as the comet pieces arrived though there was movement within the corridors of power to revitalize the body scientific. Thus the US Congress or, more specifically, its House Committee on Science, Space and Technology was evidently impelled to recommend an immediate stepping up of the Spaceguard program - NASA's pipeline project to assess the asteroid and comet threat to civilisation from space.
Reflecting what appeared to be a public pressure on dilatory space guardians the Committee's Chairman Representative George Brown, was to comment to the New York Times (Aug 1, 1994) that "you're going to see this thing take off like a rocket. It's going to be easy to sell in Congress".
Later, of course, the excitement receded and we reached a period of more measured reflection. There was then a question mark over NASA's failure to anticipate cometary splittings and a degree of concern whether this organisation's activities should have been oriented so exclusively to single body events. The latter in fact are rare; and to the extent that the currently nominated space guardians may also have had it in mind to exploit asteroids and comets as the largest accessible resource in space, one could readily suppose that the more frequent hazard due to the more numerous debris from cometary splittings had been seriously overlooked.
However, in making its more measured judgement, it was more or less inevitable that the House Committee would reckon in terms of balancing all of NASA's previously approved and currently perceived requirements. This essentially meant a watering down of the more immediate celestial threat. The question for Congress still remained therefore whether Spaceguard provided everything that the American public expected.
To understand what is going on here, we need to examine some of the Spaceguard programme (Morrison, 1992) details which have been tucked away in the fine print. Thus the Spaceguard Catalogue, when it is completed, will be over 90% asteroids. But some of these asteroids will be dormant or dead comets - and herein lies the catch. For, during the next century, the probability of the pure asteroid threat to civilization being realized is only about one in a thousand. Whereas the probability of the dead, dormant or active comet threat being realized during the same period - due to cometary splitting - is more in the region of certainty.
The asteroid threat by itself therefore is not of the kind that will give Congressmen sleepless nights; the comet threat on the other hand could well be of the kind that is a cause of public concern.
The point is that there are crucial physical differences between pure asteroids and comets which are a significant factor when we calculate their respective threats.
Basically, for the asteroid threat to be realised, we need a direct hit on our planet - truly a rare event. For the comet threat to be realised however, given that these objects break up and the debris sprays out around the parent orbit, we need only a relatively close encounter to have some fraction of the original material impact the Earth - a reduced input of mass evidently but impacts nevertheless which are altogether more frequent and by no means negligible in their effect.
The Catalogue then is not the only problem; we need also to consider when comets are going to fragment. Indeed with the benefit of hindsight on the comets by Jove, the situation for the President is now very clear. He may be provided with a map of the world but that does not tell him where and when the next Rwanda is going to arise. Likewise, he may be provided with a catalogue of asteroids and comets in their various orbits but that does not tell him where and when the next earthbound Shoemaker-Levy is going to arise!
There is a very definite sense therefore in which the current NASA plan is deficient in relation to the civilization hazard from space and lulls the American public into a false sense of security. One has to recognize of course that astronomers are trained not to cry wolf in the night and it is a matter of normal common sense that the paymaster is most comfortable if the catalogue on offer appears to provide enough warning whilst keeping down the cost. Unfortunately, this kind of bashful timidity and mutual backscratching amongst scientists and moneyspinners currently results in our not having a policy to deal with the most probable hazard from space, a situation which seems to provide the American public with rather less than it expects!
For what then should we prepare?
First, of course, there is no point in denying the usefulness of Spaceguard for the ferocity of the asteroid threat, when it is realised, is not in doubt - mankind could well be extinguished. It does not follow however that the more frequent cometary threat can therefore be ignored on account of the greater modesty of its effects - for, in this case, it is also worth noting that mankind could well not be extinguished!
Thus governments are not merely confronted with a general fear of global extinction but with that of localized extinctions, or holocausts, as well. In other words, we really need to know about the troubles that arise during the anticipation and the aftermath of any multimegaton events that occur in the wake of a fractured comet (see Section 3.3). These, as we have noted, occur at intervals of a couple of centuries or so and at the very least now we have to consider the possibility of one or more population wipe-outs or Chernobyl-like disasters on the urban to large nation scale, or a mini-ice age of global proportions.
Less frequently, at intervals of a millennium or so, we can expect the incidence of such disasters to be substantially increased.
Obviously these are tantalizing rates for heads of state who feel that there may be a risk and that to be forewarned is to be forearmed. But invariably, so it appears, the general tendency is to discount the risk with the result that civilization and society are usually unprepared. Thus, just as fifteenth and seventeenth century European society apparently broke down in the presence of newly fragmented comets, so it appears the emerging global village of our present epoch could well break down in the presence of yet another newly fragmented comet.
What matters here is the extent to which society is convinced by contemporary 'experts' that the danger is real.
For example, the breakdowns during the centuries preceding Reformation and Enlightenment occurred as apparent historical certainties concerning the incidence of 'providences' or 'blazing stars' were newly translated into the vernacular (i.e. from the Books of Daniel and Revelation) and propagated uncensored from the pulpit (e.g. Thomas, 1971). In the future, it is more likely to be the deeper historical certainties which are gained from the latest scientific understandings of our astronomical past and which are then propagated uncensored through a modern communications network of even greater power!
The problem always with these hazards, like the occasional snowstorm over England, is their rarity - the fact that pragmatic authorities will at present only handle them in accordance with circumstances, as they arise. This wholly reactive mode means that the comet threat is never going to be taken seriously until such post-detection panic as will occur due to the incoming cometary debris is fully recognized for what it may very well be.
Paradoxically though, the more skilled and informed the civilization, the sooner in general the reality is appreciated and the greater the opportunity there is for the subordinate and more reliant elements of society to become seriously unsettled.
Mankind is not extinguished of course and many parts of the globe may even escape physical blemish, but it is a matter of general experience, overlooked apparently by the American scientific community, that sustained public panic is a very effective leveller of civilizations, even to the extent that many societies are capable of becoming seriously unhinged.
Thus it is not obvious that even the most advanced societies will avoid social chaos without the most careful preparation in advance to counter the illusion of 'last times'.
In the past, it has always fallen to individual nations and their administrations to attempt to deal with the illusion through counter-propaganda. In the future it seems more likely that it will fall to the global village to attempt to deal with the illusion through counter-propaganda and it is by no means clear that any preparations are yet in place.
History is more informative in respect of this problem than many might suppose. Even the word 'revolution' for example, in its more general usage today, seems to have acquired its meaning in the past through the recognized effects of the orbiting debris of a comet! Thus it is generally accepted that its connotation signifying social upheaval was a sixteenth and seventeenth century development arising out of its earlier (Copernican) connotation signifying physical circulation. However it is perhaps not so widely appreciated that the witchhunts and political upheavals of the seventeenth century in England - which modern authorities sometimes look upon as archetypal in respect of the circumstances which generally give rise to revolution - were directly attributed by contemporaries to the unsettling effects of an (observed) celestial circulation: these contemporaries speak of celestial signs which were deliveries of "God's providence" and which were evidently mediated by "God's revolution".
Indeed these types of attribution, once the signs had passed, were very soon to mean that the blazing stars were scorned by the learned: Bishop Sprat (ed. Cope and Jones, 1959) in his History of the Royal Society speaks of a peculiar weakness on the part of his countrymen, to supposed prodigies and providences, which was now no longer to be encouraged. Thus the demise of the London Society of Astrologers broadly coincided with the transition from Interregnum to Restoration and the emergence of the Royal Society of London; and, it is apparent, also to a period of intense scientific censorship (Hill, 1975).
It is well known for example that very few of Newton's historical researches into catastrophism and the role of comets and fireballs were published in his time with the result that astronomical science, and hence natural philosophy, tended thereafter to assume uniformitarian (i.e. non-catastrophic) characteristics.
Nevertheless, we can now tell from past astronomical records when civilization was apparently unhinged by threatening signs in the sky (see Section 4.1) and it is clear that the cometary threat, on the point of being realised, is far from being a trivial occasion - our ancestors were not joking, it seems, when they saw disintegrating comets as "a warning to kings".
Even the President's men therefore may need a degree of authority and understanding in the face of incoming cometary material such as the age of 'enlightenment' has so far failed to provide.
The point here, of course, is that modern society, like its founding fathers, chooses still to ridicule the cometary threat. Ridicule was necessary perhaps as the means to a particular end - the restoration of civil order - in the wake of a previous cometary fracture and its chaotic aftermath. But this end was essentially realized and it may well be now that western civilization requires an attitude to these events in future which is a good deal more subtle than the official American approach currently allows.
There are new understandings of our environment, then, to be taken on board. Thus the last millennium or so tells clearly enough of a Western European civilization which eventually took over the New World but which was also oppressed by cosmic inputs considerably more than most of us have been given to believe.
It also tells of a civilization driven to such extremes by these external pressures that the subordinate and more reliable elements of society could only seek their freedom by aimless uprising while others with the means and some sense of purpose sought their freedom by escaping their environment.
Viewed negatively on the one hand, the cosmic inputs are an unbearable overpressure which society characteristically fails to resist and which has a roughly one in four human lifetime chance of recurring; viewed positively on the other hand, the same inputs are the cause of 'punctuational crises' which are also the principal opportunity for civilization to step out of its mold.
Each new search for civil order in the wake of oppression and chaos has proved to be an added spur to civilization's advance and a likely paradigm shift.
Something of the right note here may be struck by Trevor-Roper (1987) when he tells us, albeit without any reference to an increased fireball flux, how:
... in Germany, the ideas of Paracelsus were combined with [ ] metaphysical speculations: how there too a new era of enlightenment was expected to follow the return of a chemical prophet, 'Elias Artista', who would make all things new; and how the beginnings of the Thirty Years War were seen as the 'shakings' which would precede the fall of Antichrist and, as it were, light the fuse for the great eschatological explosion. That did not work out according to plan; but in 1640, when a new series of 'shakings' began in England, hope was rekindled. The English Puritan Revolution, which we see as a purely national struggle, appeared to many European Protestants as an event of international significance, the second stage of the Bohemian Revolution of 1618. So messianic expectations were renewed and central European enthusiasts looked, and sometimes came, to an England which, they hoped, having reclaimed its historic role, would realise the Bohemian promise of enlightenment as the prelude to the millennium.
Trevor-Roper goes on to point out that many of the time were indeed responding to the same intellectual challenge. For at one extreme of the Reformation-Counter Reformation debate we find an anticipated messianic return: that of the likes of 'Elias Artista', essentially the late medieval rendering of neo-Platonism's cosmic demi-urge, for which such as Bruno would go to the stake; whereas at the other extreme of the debate, we find a desire for permanence and stability: an establishment set against any Pyrrhonist (catastrophist) perception and determined at all costs to preserve for Christendom its basic (Aristotelian) cosmic theme. It seems though that "none of them produced a final answer. But in the convulsion of their time the old compromise was destroyed, or at least emptied of its real content, and all of them, out of its relics, incidentally contributed something to the succeeding age..."
In other words, there is a perspective on the historical process which now tells us that the Renaissance needed its Inquisition to preserve the perceived cosmic order and suppress the omens which the astrological view of nature nevertheless allowed.
Likewise the English Enlightenment needed its official ridicule to counter the cometary threat which the scientific view of nature essentially allowed.
But now, with space tentatively explored, the public has learned that neither the Inquisition nor official ridicule will impede future cosmic inputs.
The US Congress no doubt will decide how these inputs will be challenged - but if realism is to prevail, and ridicule no longer works, the new understandings of our cosmic environment will impose their new discipline on society as well!
In short, society still has to come to terms with the seriousness and comparative urgency of the cosmic threat and to recognise the need for an enabling contract between mankind and its leaders which guarantees both the discipline and the challenge.
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| ©S.V.M. Clube |
| Fig. 2. A broadsheet issued from Augsburg on the occasion of the 1521 comet, as illustrated in the upper right hand frame of the montage. Note the anticipated seismic effects due to cometary debris, as illustrated in the upper left hand frame, typical of the perceived nature of 'last times' and low-level multimegaton explosions. The lower frame is of particular interest in that it gives expression to the common general response on the part of ecclesiastical authorities and secular administrations to the activities of those who dispensed prognostication and the mitigation of fear in the presence of celestial signs (astrologers, soothsayers, witches etc.). The encitement of unrest in society through over-zealous attention to 'last times' was clearly a serious problem so far as our ancestors were concerned, one that remains to be tested in modern times! |
If history is a guide, the necessity of preventative action will of course be ignored! Thus the situation is by no means new and has occurred many times before (Cohn, 1957; 1993). Recent studies have probably given us a pretty good idea how societies respond in extreme circumstances and, to encapsulate these, we can do worse than go back to the beginnings of western civilization itself. For it is here that we find how the Roman Empire became aware of and confronted the cosmic threat during its fourth and fifth century decline, essentially realising that neither Stoics nor Epicureans had any answer to the intense public anxiety which then emerged.
Thus, it came about, so it now appears, that a whole subjugated people extending from the Eastern Mediterranean to Western Europe rather suddenly succumbed to the blandishments of a Christian community (Brown, 1971) which promulgated the notion that one could escape the torment of "demons" by electing to "belong" to an everlasting (cosmic) community of "saints". By associating these demons and saints with members of the human population as well as with clashing celestial armies and hence with an observed circulation in the sky (Section 3.5), it seems that this Christian notion had its basis in verifiable cosmic facts which had been endorsed by neo-Platonists such as Proclus and Augustine.
The point here is that a basic classical view of the Universe, originating with the pre-Socratics and given its most perfect expression in Plato's Timaeus, reached its zenith with the neo-Platonists. Plato and the neo-Platonists described how a divine agency, the demi-urge, had constructed the main features of the visible heavens: a planetary system in the plane of the ecliptic which probably included the Earth in orbit around the Sun and another divine circulation inclined to the ecliptic which not only intersected the path of the Earth but supposedly reached out beyond the sphere of stars. It was this circulation apparently, with the characteristics of elliptical motion and precessing nodes, which returned to the Earth at long intervals with catastrophic consequences. However the more cultivated and sophisticated elements of Roman society were not at first prepared to go along with this expectation. Rather both secular and ecclesiastical opinion discounted the demi-urge and held to an (Aristotelian) perception of the environment which presupposed some degree of permanence and stability in the cosmos at hand.
Before enduring the Dark Age however, the Roman Empire was to be horrified by the imprint of "deserted areas" which contemporary opinion closely associated with the imminent arrival of world-end (Esmonde Cleary, 1989). Such devastation now seems to have the character of super-Tunguska events; and, indeed, one such putative event in England, as the particular country in question was to become, was subsequently attributed to "the fire of righteous vengeance".
While enlightened scholarship has for long been in the habit of ridiculing the implications of such phraseology, several historians have recently gone out of their way to emphasise the essentially dramatic nature of this event and its consequences. These, realistically interpreted, appear greatly to exceed those expected with a mere exploratory invasion by a boatload of (Anglo)Saxon brigands as enlightened scholarship would normally have it (e.g. Myres, 1986 cf. Clube, 1992).
In other words, the possibility of severe cosmic events is no longer in principle denied and it may therefore be hardly surprising that ideas put about by neo-Platonists during the fourth and fifth centuries should have been in the ascendancy.
During the sixth century Justinian period, indeed, the social upheaval and environmental calamities appeared to be scaling new heights and it is not without significance that a firm administration then closed down the Platonist Academy in Athens and thereby effectively created a subversive undercurrent of astronomical knowledge which was to remain at the heart of Christendom's intellectual discord for at least another fifteen hundred years (e.g. Lindberg, 1992)!
Thus it was in the aftermath of catastrophe, during the latter half of the Justinian administration, that (Byzantine) Christendom securely embraced Aristotelian doctrine for the first time, to be followed a century later along this track by (Muslim, non-Arab) Islam (e.g. Brown, 1971). Subsequently, another five centuries were to pass before Aristotelian doctrine was also embraced by Western European Christendom by which time the latter came to be seen as having experienced an intellectual dark age of some seven or eight centuries.
Now, as we acquire an improved understanding of the relevant cosmic facts (Section 3), it seems that the crucial scientific advances later engineered by Kepler, Bruno, Galileo and Newton provided us with the basic framework which eventually led to the Space Age revelations culminating with the split comet by Jove and which will in due course mark the astronomical notions of the neo-Platonists as ones which should never have been set aside!
3. EVOLUTION, PUNCTUATIONAL CRISES AND THE THREAT TO CIVILIZATION
3.1. Punctuated Equilibrium
The idea that evolution on Earth proceeds at a uniform pace towards some undefined state of perfection in the remote future has given way in recent years to one involving successive states of "punctuated equilibrium" (Gould and Eldredge, 1977). Thus, in keeping with evolution's supposedly progressive nature, it is assumed that both the environment and the distribution of living species remain in successive uniformitarian states for characteristically long periods of time and that these also begin and end with much briefer periods when both the environment and the distribution of species undergo very rapid upheaval.
There is an implicit assumption here, of course, that the upheavals are then necessarily progressive whereas in practice the condition of the environment along with the distribution and character of species, treated broadly as a geophysical/biophysical cum geochemical/biochemical state, is probably most simply perceived as experiencing a catastrophic recession followed by a catastrophic advance. An 'advance' as such does not then have any absolute significance but is merely said to be so on account of its retrospective accord with the direction taken to reach the following equilibrium state.
Under these circumstances, it is to be expected that we are dealing with uniformitarian states which are broadly regressive rather than progressive - that is, tending towards some statistically average state rather than deviating from it - and punctuational states which broadly comprise a recession forced by cometary input and an arguably deterministic advance forced by the random disequilibrium so inflicted.
The significance of cometary inputs is that they allow both biophysical and biochemical effects i.e. cosmic insertions reaching different levels in the atmosphere which are capable of generating either catastrophic explosions or catastrophic loading of the atmosphere with particulate material (dust) bearing biologically active chemicals. If this understanding is generally correct then it is clear that the Darwinian perspective on evolution, suggestive of an intrinsic directional quality in natural selection, is no longer supported and that we should look to the random yet (in principle) predictable cosmic inputs and their induced chaos as the fundamental controlling factor determining the course of evolution. Natural selection, on this account, is but a counterbalancing process tending to preserve equilibrium after a disturbance and is essentially mundane!
With the advances during recent years in our knowledge of the astronomical environment, there has been a tendency to suppose these 'punctuations' might reasonably be associated with isolated 'impact crises' due to encounters with single bodies in Earth-crossing orbits. While, as a matter of definition, it might be considered arguable exactly what level of crisis qualifies as a punctuation in the terrestrial record, one can perhaps assume, as a matter of principle, that only those impinging bodies capable of significantly influencing the whole globe for a brief period should be considered.
It is on just such a basis apparently that single near-Earth objects (NEOs) greater than a kilometre or so in size have come to be the new focus of attention so far as terrestrial evolution is concerned. Indeed, through this rather simplistic perception, recognizing also that the human species is a global phenomenon, the notion that km-plus NEOs are the most serious threat to civilization has recently gained some impetus (e.g. Chapman and Morrison, 1994).
Civilization however, is not something that we necessarily associate with mankind as a whole; rather we envisage several different 'civilizations' which occupy different parts of the globe at any one time; and many 'civilizations' during the course of history which have flowered and foundered (e.g. Spengler, 1932; Toynbee 1945).
Civilization, in fact, treated as a modest evolutionary aspect of the human species, not only appears to be associated with distinct ethnographic and demographic qualities of mankind but tends to be regarded as a local rather than a global phenomenon; in which case, the theory of punctuated equilibrium would seem to require that single or multiple sub-km NEOs capable of depositing massive dust veils or inducing super-Tunguska events represent the commonest and hence most likely serious threat to an individual civilization.
At the same time, it may have to be admitted that the modern trend towards the rapid 'globalization' of civilization and its other qualities is perhaps rendering these characteristics more synonymous with mankind as a whole than was formerly accepted. But however globalized and/or superficial the evolutionary characteristics of civilization may be, it is clear that this more qualified understanding of punctuated equilibrium allows the possibility of localized evolution of a dominant strain in association with a localized cosmic input such as a super-Tunguska event and of the global extension of this dominant strain in due course. Such a turn of events is not excluded apparently by the present condition of the human species and its evolution from a single African location during the past million years or so.
It follows from considerations such as these that the evolution of civilization may be no more than a simple extension of the evolution of biological species. Thus we are accustomed to the idea of punctuated equilibrium in biological evolution reflecting isolated encounters with the single km-plus (meteoritic) asteroids which have undergone a prior series of orbital deflections since leaving the asteroid belt. But we are less familiar perhaps with the idea of 'punctuational crises' affecting biological evolution and the advance of civilization, these being due to the more sustained bombardments by fragmentation debris when active, dormant or dead comets which have deviated from the most likely source of comets (the Oort cloud, say) undergo significant splitting in Earth-crossing orbits. Such orbital debris encountering the Earth's atmosphere is evidently capable of introducing both high-level dust and low-level explosions, depending on its mass and cohesive strength, and it follows that punctuational crises are comprised of global coolings and super-Tunguska events together with a generally enhanced fireball flux.
Taken as a whole and in conjunction with a given planetary target (e.g. Jupiter, Earth etc.), the response function to the bombardments is inevitably complex. Nevertheless, we can broadly expect that the strength of a punctuational crisis will vary as the progenitor comet mass, the inverse (velocity) dispersion of its debris and the inverse (time) delay since fragmentation. In which case the encounter between Comet Shoemaker-Levy 9 (P/SL-9) and Jupiter may be taken as representing an extreme punctuational crisis where the dispersion and delay were small.
An extreme punctuational crisis affecting our planet and involving multiple comet fragments may also be envisaged for such evolutionary events as the mass extinction of species, for example the KT event 65 Myr ago. Such rare events however are at one end of the evolutionary scale: at the other end of the scale, we deal with the lesser but more frequent crises affecting the Earth which have disturbed civilization several times during recent millennia - these may have had smaller inverse dispersions and smaller inverse delays but are no less important for that!
Indeed, such crises can now be regarded as the smallest units of our overall catastrophic experience; and to place them in perspective, we need to consider the catastrophic record as a whole. This leads us to recognise the relatively sudden flowering and foundering of civilizations during interglacials as the principal signatures of punctuational crises that arise as the corresponding debris of a giant comet in a short-period, Earth-crossing orbit passes through the final stages (splittings) of its evolution and decline.
Thus we envisage a situation where the particular mass distribution of comets settling in Earth-crossing orbits includes occasional very massive candidates up to a few hundred kilometres in size for it is the evolution of these very massive comets which seems to be dominant in the terrestrial record. For example, the contemporary millennia can now be seen in the context of successive myriads of years (104 - 105 yr) in which the global coolings either persist (a glacial period under the control of a disintegrating giant comet) or remain largely in abeyance (an interglacial period under the control of a largely dispersed giant comet).
The interwoven glacial-interglacial structure which is then imprinted from time to time on the terrestrial record and corresponds to ice ages some - 106 - 108 yr in duration is then readily enough understood in terms of Oort cloud perturbations which characteristically last for such periods of time and of a resulting overall flux of giant comets settling in short-period, Earth-crossing orbits which is apparently not so very different from that currently observed (Bailey et al., 1994).
The evidence, in other words, seems to indicate that it is the cometary flux which dominates the general course of biological evolution, the general course of the global climate and the general course of the civilization to which we belong.
Such pre-eminence in terrestrial affairs accorded to comets remains, of course, a very uncomfortable proposition for much of twentieth century civilization and science.
3.2. Cumulative record of catastrophes
Our knowledge of the impactor flux reflecting the general state of the inner Solar System environment is largely based on the cumulative counts of impact craters formed on lunar mares since the end of the heavy bombardment phase. As a result, the diameter-flux relationship for the largest impactors arriving at the Earth is commonly represented by a simple uniformitarian power law:
Φ(D) = k D -α, 1 <= D <= 102.5 km
Continuity considerations require that this relationship is
applicable to the potential impactors in Earth-crossing orbits which
are currently observed. Amongst these we must include the
Earth-crossers having intermediate and long period orbits which reach
out beyond Jupiter towards the Oort cloud. However, their particular
direct influence, in comparison with that of the Earth-crossers in
sub-Jovian space, which principally derive from short-period
asteroidal (mainbelt) and short-period cometary (Jupiter family)
reservoirs, is so small that they can reasonably be neglected for the
purposes of the present discussion.
It follows that the asteroidal and cometary bodies of interest in Earth-crossing orbits, comprising mostly their sub-asteroidal and sub-cometary fragmentation products which encounter the Earth (meteorites and meteoroids, respectively), are essentially those surviving in two sub-Jovian orbital regimes. These have 'dynamical lifetimes' of ~ 108 yr and ~ 106 yr, respectively, depending on the eccentricity of their progenitor injection orbits - below and above 0.5, say. Thus, so far as these short-period reservoirs dominating the terrestrial influx are concerned, it is basically orbital eccentricity which determines the likelihood of a grazing encounter with a major celestial body such as would tend to remove these smaller bodies from inner Solar System space, and it is now recognized that the terrestrial planets are most likely to play this role when e < 0.5 (Wetherill, 1988; 1991) while the Sun and Jupiter are most likely to play this role when e > 0.5 (Froeschle et al., 1995).
Transitions between these orbital regimes are not of course excluded, so their unique categorization in terms of asteroids and comets, respectively, cannot be absolutely relied upon. Nevertheless it is broadly the case that meteorites and meteoroids have differing (top-heavy) mass distributions and fragmentation spectra as well as differing physical and dynamical lifetimes with the result that cometary-meteoroidal impactors, unlike their asteroidal-meteoritic counterparts, cannot be expected to achieve a fully relaxed spatial distribution with respect to solar ecliptic longitude and latitude. In other words, the minor body flux of cometary origin normally takes a period of time to become fully sporadic which is significantly in excess of its physical survival time. The result, as a consequence of hierarchical disintegration, is that the sporadic distribution is only present at higher (D > 1 km) and lower (D < 10-3km) mass levels while the uniformitarian law undergoes an observed steepening in the intermediate range, such that
Φ(D) = k D -β, 10 -3 <= D <= 1 km
where β > α (Shoemaker, 1983). The relationships (1) and (2) are
based on the lunar cratering record but we can also determine the
diameter-flux relationship for smaller impactors currently arriving at
the Earth, as derived from the bodies in space which are observed
either in situ or penetrating the atmosphere (Rabinowitz et at, 1993;
Ceplecha, 1992; Tagliaferri et al., 1994), whence it turns out that
Φ(D) = 10 - 100 X Φ(D), D<= 10-2 km
This may evidently be understood as a temporary condition, also in accordance with the observational steepening, and has for some while been attributed, as we have seen, to a still disintegrating, very large comet (Kresak, 1981) of the kind now believed to be present in the inner Solar System from time to time (Δ t ~ 105 yr; Bailey et al., 1994).
The steepening thus straightforwardly implies that the commonest 'evolutionary events' on Earth relating to the low mass end of the Solar System minor body population (i.e. 10-1 < D < 1 km) are due to correlated encounters with the hierarchically disintegrated products of the debris from successive giant comets.
The appeal to a contemporary giant comet does of course represent a general departure from uniformitarianism on timescales 10E4 - 10E6 yr, the typical interval between giant comets settling in sub-Jovian space. The cumulative record of catastrophes thus leaves open the question whether there are additional modulations of the terrestrial record on timescales < and > 10E4 - 10E6 yr which would also be indicative of a predominantly cometary influence on terrestrial evolution.
3.3. Punctuational crises
To many investigators, the idea that isolated impact crises rising above some global threshold are the only astronomical influence we need consider when dealing with evolutionary processes in geology and biology is simply not compatible with the evident complexity of the terrestrial record (Hallam, 1989). Thus it is widely recognized that long-term climatic and other factors must also be involved and it has been known for seventy years that the terrestrial record is marked by periodic and stochastic modulations on timescales between 106 and 109 yr indicative of a Galactic driving force (e.g. Holmes, 1927). Indeed it is for these reasons that many investigators in recent years have given greater credence to a cometary (Oort cloud) rather than a (Mainbelt) asteroidal source of 'punctuational crises' (see Section 3.4).
The role model for punctuations then is not the ostensibly narrow epoch associated with a random (km-plus) asteroid; rather it is the considerably broader epoch associated with the relatively short-lived, orbitally correlated, disintegration products of a not-so-random (km-plus) comet.
There are several points to be made here. First, these considerably broader epochs may be characterized by one or more global coolings and/or super-Tunguska events occurring as a prelude to or in association with an enhanced fireball flux: events of this kind are to be expected as a consequence of high-level dust insertions and low-level multimegaton explosions such as may be produced, depending on their cohesive strength, by sub-cometary masses of about 0.1-1 km in size. Secondly, both the cometary mass function (which is top-heavy) and the tendency of comets to undergo rapid disintegration determine that a high degree of coherence may be present in the incidence of sub-km and km-plus comets on Earth at any one time.
Cometary material in general is capable of being active, dormant or dead and for inner Solar System material of this kind whose distribution does not evolve and which has broadly unchanging orbital and constitutional characteristics, it would certainly be expected that the frequency of punctuational crises (as now defined) at any epoch would also be broadly unchanging and reflective of the integrated "minor body" mass "in residence".
With a variable mass content however, such as arises with the top-heavy mass distribution of comets settling randomly in inner Solar System space, the pattern of punctuational crises may be expected to take on the general character of a glacial-interglacial with both periodic and random groups of events on timescales < 105 - 106 yr reflecting the orbital and fragmentation history of a particular giant comet (e.g. Asher and Clube, 1993).
In other words, as a consequence of the cometary mass distribution, we envisage punctuational crises which are themselves hierarchically nested in the overall manner of glacial-interglacials, each lasting in effect for the duration of ~ 104-10 orbits in accordance with the size of the parent comet within the nested hierarchy i.e. from a few hundred to a few kilometres in size. It is thus in the general nature of the intermittently top-heavy population of comets deposited in inner Solar System space that our planet is bound to experience glacials and interglacials, the latter being themselves interspersed with global coolings of shorter duration which are in association with super-Tunguska events and sustained enhancements of the fireball flux. Several facts then come together to inform us as to the likely nature of the current environment:
a)the disintegration products of comets (meteoroids) currently incident upon the Earth outweigh the disintegration products of asteroids (meteorites) by one or two orders of magnitude (e.g. Tagliaferri et al., loc cit)
b)the sporadic flux of meteoroids in inner Solar System space is dominated by a single, very broad, elliptical torus (e.g. Stohl, 1983) suggestive of a recently disintegrated, very large, Taurid comet (e.g. Clube, 1987; Steel et al., 1994).
c) the current interglacial follows on a recent glacial at ~ 20,000 ± 10,000 BP broadly suggestive of a recently disintegrated, very large comet and is itself interspersed with sustained enhancements of the fireball flux known on several occasions to be correlated with severe global coolings (Asher and Clube, 1993; Clube, 1994; Baillie, 1994).
d) dynamical studies (e.g. Asher et al., 1993) are consistent (within a factor ~2) with a ~ 20,000 yr hierarchically disintegrated Taurid comet characterised by relative speeds of separation ~ 1 kms-1 such as are plausibly associated with differential energetic outflows (jets) from cometary fragments, the fragmentation apparently arising through tidal splitting during close encounters with terrestrial planets, through solar irradiative effects and through intrusive high velocity impacts.
The evidence indeed points to the contemporary environment having been dominated by an evolved giant comet and it is clear from the dynamical behaviour of other such bodies like Chiron further out in the Solar System (Bailey et al., 1994) that these extended inputs are currently recurring at random intervals ~ 10E5 yr. We may conclude that it is the cometary punctuational crises which are dominant on timescales < 10E6 yr.
3.4. The Holmes cycle
Unfortunately the cratering record is not yet well enough resolved to describe with certainty any of its possible modulations on timescales ~ 10E6 ~ 10E9 yr (Grieve, 1989). Nevertheless to the extent that geological and biological signatures may be understood as proxy-signatures for punctuational crises, there is good evidence for a late Phanerozoic cycle of 26.3 Myr (Rampino and Caldeira, 1992) broadly confirming previous determinations based on the extinction cycle alone (Raup and Sepkoski, 1984 cf. Holmes, 1927). It also appears that the most recent maximum phase of this cycle coincides with a mid-Miocene peak ~13-14 Myr BP from which the early Pleistocene peak ~ 2 Myr BP introducing the Sun's latest Galactic plane passage is clearly distinguished.
On the assumption that geomagnetic reversal events in particular provide a reasonably undistorted record of the major glacials due to large (inner Solar System) comets, the 26.3 Myr cycle is rather clearly interleaved with another cycle of the same period but lower amplitude; the two together being then uniquely associated with variations of the continuous and stochastic components of the Galactic 'dark matter' gravitational field acting upon the Oort cometary cloud, expected as a consequence of the Sun's vertical oscillation about the Galactic plane (Clube and Napier, 1996 cf. Matese et al., 1995). Quite apart from the not- unimportant implications for dark matter and its nature, these cycles are in fact strong prima facie evidence of a very persistent influence on terrestrial affairs due to very large comets originating from the Oort cloud and we may conclude that cometary punctuational crises are dominant on timescales > as well as < 10E6 yr.
It is perhaps an interesting aside on the theory of punctuational crises that the latest two peaks of the compound Holmes cycle, correlating with two broad spasms of increased terrestrial activity, seem, respectively, to be associated with the first appearance of hominids and with the eventual emergence of homo sapiens while the particular activity that goes with the latest, very large, comet seems remarkably well correlated with mankind's bare survival under stringent circumstances at the end of the Pleistocene during a global climatic recession (i.e. the most recent glacial at ~ 20,000±-10,000 BP) and the subsequent rise of civilization during the Holocene. Civilization in other words is merely the latest random facet of a continuing galacto-terrestrial interaction expressed through the action of comets on the resident gene pool!
3.5. Spenglerian model of civilization
To recapitulate then: by studying the longer term cycles in the terrestrial record and some of the details in civilization's advance, we have now come to recognize the fundamental role of the Galaxy and comets in terrestrial affairs. This role inevitably causes us to give particular attention to very large variations in the impact catastrophe rate. Indeed we can now recognize a broad category of evolutionary events described here as punctuational crises.
Punctuational crises can have an elaborate structure in practice but are no different, in principle, from the recent P/SL-9 encounter with Jupiter. Thus the differences in general are merely those that arise due to the differences in the target, the fragmentation agency and the degree of orbital correlation.
So far as civilization is concerned, the aspect of the matter which gives punctuational crises their special distinction over isolated impact crises is their capacity for inducing social destabilization as a result of fragmentation and the perceived statistical inevitability of encounters with the Earth.
In the case of P/SL-9, since another planetary target was involved, mankind was able to take a detached view of the subsequent proceedings. In the case of an Earth encounter however, since the enhanced fireball flux is indicative of its more massive correlates, the view can never be detached. Such enhancements have in fact occurred frequently in the past - ostensibly in association with the Taurid stream (Clube, 1994: see also Fig. 1) - and the next occurrence, as we have seen, has a roughly one in four human lifetime chance.
Historically, inasmuch as these enhancements have frequently been interpreted as indicating the imminence of 'last times', predisposing even the most advanced societies to break up and lose control, the corrective response has usually depended on the disposition of society as it experienced punctuational crisis.
A study of past civilizations appears to indicate differing responses depending on whether society is subject to theocratic or secular control, the crucial factor being the ability of the administration to maintain basic freedoms whilst avoiding any descent into social chaos.
The situation is not satisfactory for it seems that theocratic states will tend to censor any perceived deviation from the perceived celestial norm (whatever form this takes) while secular states will merely seek to trivialize any threat posed by comets.
As we have already noted, neither censorship nor trivialization is likely to be effective in future and it is not clear therefore that civilization is currently well placed to handle the next punctuational crisis. Indeed, any benefit accruing to civilization through the uncritical endorsement of the Spaceguard programme (Chapman and Morrison, 1994) does little at present to alleviate the pressures due to the next punctuational crisis.
Ultimately, there is a problem here because we still belong to a period of human history in which the Darwinian or progressive view of our past is so securely entrenched that we set aside contemporary and near-contemporary proponents of any alternative view. There is no lack of concern of course as to the fate of civilization but academe still requires a supposedly uniformitarian terrestrial environment and a supposedly innate tendency on the part of the human species to evolve through natural selection towards some perfectly civilized state. It seems in fact that the currently adopted scientific paradigm requires us to take a severely anthropocentric view of the environment, virtually guaranteeing catastrophes will not occur.
Insofar as we pay any respect to the environment, we are encouraged to believe that mankind has it essentially under control. That is, we assume as a matter of principle that the environment can be preserved in a uniformitarian state. Accordingly we no longer pay much attention to any teleological or eschatological view of history (Butterfield, 1981; Bultmann, 1957) and have very little patience with historians such as Spengler (1932) or Toynbee (1945) who have seen in civilization a necessarily ephemeral characteristic of the human species. The former indeed, in his once renowned The Decline of the West, saw only a tendency for the various cultures and their corresponding civilizations to stand alone in space and time in a demonstrably self-contained way. This was not to propose that the principal paradigms of a culture are not part of a longer term evolutionary trend but to indicate that the paradigms which prevail across an interface between successive cultures in time are characterized by a process of random selection and a degree of rapid remoulding. Each such culture-civilization so pre-formed did admittedly evolve but always in a repeated and characteristic manner which depended not so much on the environment or the state of technology but on an inner combination of perceptions borne and successfully conveyed to succeeding generations by a dominant founding group. Thus there would be a frenzied 'spring' and a staid 'autumn', periods of growing dominance and settled equilibrium, respectively, but always such civilizations would begin and end with periods of trauma which marked them off in time. Spengler described these periods of trauma as "psuedomorphic" rather than "punctuational", seeming to imply nevertheless some kind of mainspring which he described as "cosmic". The nature of the cosmic mainspring has not been evaluated, as it happens, but the model was applied to world history, as it was known, with some evident success - albeit with implications which, whilst they were not accepted into the mainstream, have never been precisely refuted.
Foremost amongst these implications was the recognition of a significant pseudomorphosis during the seventh century BC (cf Starr, 1961) associated with the emergence of three major civilizations, those of China, India and the Mediterranean, culturally aligned with Taoism, Buddhism and Stoicism, respectively. Of particular significance to the long term development of these civilizations, so Spengler inferred, was the emergence and decline during the subsequent millennium, of the so-called Magian culture centred on and around Babylon. This he evidently pictured as the main intellectual conduit through which the basic knowledge of an underlying cosmic influence, as it was perceived in earlier neighbouring civilizations such as the Persian, the Mesopotamian, the Egyptian and the Aegean, came to be harmonized and perpetuated. Thus Spengler was able to describe how the domain of Christendom became the principal bearer of an original, predominantly Magian, culture which also underwent significant metamorphosis in the hands of the Greeks. But he also made it clear that this metamorphosis created inherent ambiguities since the modified culture experienced successive schisms at three determining councils (Nicea, Ephesus, Chalcedon) before spreading in its various doctrinal forms broadly along the Eurasian temperate zone.
The significance of the Magian culture, if Spengler is correct, lies then in its cosmic paradigm: the fact of alternative fundamental perceptions of the astronomical environment, both of which came to have very wide, almost global, acceptance by the major civilizations of the world.
Broadly speaking, what we are dealing with here is the (original) pre-Socratic or (later) neo-Platonic version of the Universe and the fact of an intervening unresolved schism which resulted in the Aristotelian version of the Universe eventually being accepted throughout Christendom. We deal in effect with a pre-existing, essentially physical, perception of the astronomical environment which takes the Universe to be infinite in extent, both temporally and spatially; but, inasmuch as the trauma of pseudomorphoses have been moderated by the adoption of a more pragmatic philosophy, we also deal with an imposed, essentially comfortable, perception of the astronomical environment which takes the Universe to be finite in extent, both temporally and spatially, and subject to external, benevolent control. It is the finite version apparently western civilization currently takes the lead in preserving.
It was Aristotle of course who reminded us of a mythical tradition of extreme antiquity in which the stars are gods and in which "the divine embraces the whole of nature". But it was he also who disapproved of the existence of any infinite object or any infinite plurality of objects to explain the Universe, claiming instead that the fixed stars at the same distance from the Earth essentially marked the limit of the world.
Plato, it will be recalled, likewise thought of stars and planets along with the sun and moon as relatively local features of the Universe; but with the important difference in his case that these objects were all temporary products of the recent and even on-going evolution of a former "cosmic egg". Thus Plato and his predecessors quite clearly did not accept the Aristotelian limit and considered the Universe to be infinite. Indeed, the pre-Socratics and the early atomists subscribed to the idea of innumerable worlds or "cosmic eggs" scattered throughout infinite space which passed into and out of existence.
The underlying idea was that of an infinite or 'boundless' Universe whose constituents therefore represented the unlimited 'stuff' of the Universe. Such stuff was of an ungenerated and imperishable nature; it was also in a state of eternal motion, being therefore classified as immortal and divine. In addition though, the pre-Socratics were hylozoists in that they went beyond the mere atomistic conception of dead matter in mechanical motion and the Cartesian dualism of matter and mind supposing that the primary stuff of the Universe carried in some form the essential characteristics of animate, conscious beings (e.g. Cornford, 1952). The soul-stuff of life on Earth, for example, was thus thought of as being in some kind of continuum connecting it with the soul-stuff of a corresponding life-form in the visible, evolved heavens. The living world to which we belong, according to the pre-Socratics and neoPlatonists, was therefore a limited cosmic entity both representing the evolved constituents of a particular cosmic egg and occupying a volume of finite extent in both space and time. It was necessarily part of the Universe but since the latter was of infinite extent in both space and time, it was natural that the immediately visible world was also perceived as the 'world-cavern'.
In effect, the 'world-cavern' was a cosmic setting for the living community, or species, to which we and our basic soul-stuff could be considered to belong. It was a cosmic setting which was also conceived to possess a beginning and an end, both chaotic periods when the relevant cosmic egg was considered to undergo deconstruction and reconstruction, respectively.
But whereas Plato's Universe gave us uniformity beyond the stars - a world of cosmic eggs stretching from here to infinity and from now to eternity - together with an interaction beneath the stars between heaven and Earth, essentially permitting the basic astrological principle; we find that Aristotle's Universe, based on a similar framework of facts- gave us uniform (circular) motion for the planets between the stars and the Earth and thus an absence of any local interaction between heaven and Earth within the world-cavern, essentially discarding the basic astrological principle.
It is the discarded astrological principle of course which removes the theoretical possibility of cosmic terror afflicting civilization and which gives the Aristotelian Universe its particular charm so far as any pragmatic leadership is concerned.
One cannot be surprised therefore that ecclesiastical authorities and secular administrations, anxious to maintain some kind of stability in the face of cosmic stress, should be diverted by the charms of a principle which merely 'saved appearances' and created the illusion of uniformitarian calm in the vicinity of our planet! Astronomers however do not have to be so diverted since the Universe, for them, is not a matter of wishful thinking!
Thus, broadly in line with the Timaeus, before mankind had achieved any kind of measurement which would indicate for certain the sizes and distances of the planets, our 'world-cavern', was thought of as somehow displaying the typical characteristics of an evolving world amongst the plurality of worlds. The general appearance of the celestial sphere seemed to imply a stellar firmament outermost which contained within its space two mutually inclined circulations of material derived originally from the relevant cosmic egg. Plato is known to have ultimately regretted his initial opinion that the Earth lay at the focus of these circulations. This suggests he may have favoured the 'central hearth' or the 'Sun as the centre of the cavern while it was the Earth rather than heaven, of these mutually inclined structures, which comprised the visible bodies we now associate with the ecliptic.
Plato also considered that the original fashioning of this construction was in the hands of the demi-urge, its apparent purpose being to introduce an interaction between heaven and Earth which was to a large extent reflected in the meteoric phenomena which we observe. Thus it was fundamental to the whole perception that the heavenly circulation returned to Earth with apocalyptic force at long intervals of time; indeed, it was a specific and enduring characteristic of the Magian culture, having cosmic significance, that "something was descried in the far future, indefinitely and darkly still, but with a profound certainty that it would come".
Eventually, as the perceived awesome nature of the forthcoming event became even more intense, there was increased speculation as to the character of the world-cavern and its association with a succession of demi-urges (or 'craftsmen' - 'sons of God'). The latter supposedly fashioned the successive ages of mankind, each new beginning being marked by the return of the everlasting fire and by the occurrence of a portentous cosmic birth, conceivably a cometary splitting and hence a recognizable 'messianic' sign (see Section 4.1).
In due course, the Magian culture would undergo transformation during the fourth and second centuries BC and then again during the first and third centuries AD before experiencing yet another profound pseudomorphosis during the Dark Age period 400-600 AD. By then, the belief in the apocalypse had intensified to the extent that it penetrated the doctrine of European Christendom where it was to remain for at least another millennium undergoing yet further transformation and revival during yet further pseudomorphoses around 1100 AD, 1500 AD, 1650 AD and 1790 AD, each time in association with enhancements of the fireball flux (Fig. 1).
At each of these epochs, the Platonist tradition is evidently restored, most intensely perhaps during the Dark Age and the Reformation, but each time only to be countered by revival of the Aristotelian tradition. In fact, the fear of "last times" has never entirely disappeared from western culture, notwithstanding Comet Biela and the Darwinian Enlightenment, and perhaps there is now an increased suspicion, arising through the line of historical development which Spengler perceived, that the modern influence of a Taurid progenitor and the ancient perception of a cosmic egg, both of which are believed to have fragmented and dispersed, have a great deal in common.
We might well suppose in fact that our Space Age findings in relation to the Taurid/Encke stream are in close accordance with the pre-Socratic cosmic perception. In other words, the Space Age like a typical fireball flux enhancement, by arousing an intense awareness of the probable nature of our astronomical environment, can ultimately be seen as providing us with a cosmic perception equivalent to that of the Platonist tradition; and it is natural that this should already have been countered (unsuccessfully!) by an entrenched Aristotelianism opposed to the implications of the Taurid-Encke stream!
4. CELESTIAL INFLUENCE OF THE TAURID-ENCKE STREAM
The air we breathe can be remotely or locally sensed, e.g. through
our eyes and nose, respectively. Likewise, to the extent that it may
continuously penetrate the Earth's atmosphere and produce condensation
nuclei in sufficient numbers to constitute recognizable atmospheric
features e.g. noctilucent clouds, the material content of the
interplanetary environment is also capable in principle of being
remotely or locally sensed.
In most instances however, it appears that the air we breathe and the material content of the interplanetary environment we are able to detect remain below the threshold of everyday experience. Thus the action of the interplanetary environment tends to be substantially unmonitored and we can only build up our general picture of what is going on largely through a process of irregular sampling as and when the development of new technology unexpectedly provides us with a new capacity to detect one of this environment's effects. The pace of technological progress has certainly advanced this process significantly during the Space Age but we cannot presume that this period will necessarily have coincided with the interplanetary environment's most dramatic effects.
4.1. Chinese astrological records
The basic perception now arrived at, as described in this article, is that of an extraterrestrial input which transfers to our planet from the sub-Jovian interplanetary environment and which in former times was regarded as transferring from within the perceived 'world-cavern'. Included from within this region at the few percent level is the asteroidal-meteoritic material diverted from the main asteroid belt but the dominant contribution by far from within this region, as we have seen, is evidently the ecliptic-wide distribution of cometary-meteoroidal material arriving at the Earth from the broadly elliptical (i.e. helion/antihelion) circulation in sub-Jovian space whose main concentration intersects the Earth's orbit in late June and early November (Stohl, 1986). The dominant component, being of comparatively recent origin, does indeed have a non-uniform -distribution in solar ecliptic longitude reflecting its continued concentration close to the orbit of the circulation's source; whence it follows that this main concentration is also the likely most significant target for intrusive hypervelocity impacts giving rise to intermittent disintegration events in sub-Jovian space.
The most prominent of these events resulting in significant dust signatures, i.e. the so-called cometary trails, are then naturally associated with the largest bodies in inner Solar system space capable of rapidly undergoing hierarchical disintegration. Such bodies are likely to be choked off and rendered inert by their dust-laden environments; likewise they may be naturally associated with the release of substantial daughter bodies, even as large as small comets, which separate only slowly from the parent source; and also with relatively short-lived meteoroidal swarms in neighbouring orbits, which may retain their coherence long enough to be repeatedly penetrated by our planet.
The picture arrived at is evidently one which allows us to bring together such prominent interplanetary features as the well known helion/antihelion flux, the conspicuous Encke trail, the major meteoroidal concentration which has been found near the core of the helion/antihelion flux and the huge intermittent enhancements of the meteoroid flux known to us through Chinese astrological records maintained during the two most recent millennia (cf. Fig. 1).
In fact, these records of fireballs are now rather firmly indicative of the Taurid-Encke stream harbouring the bulk of the disintegrating meteoroidal material in inner Solar System space and of successive major disintegration events every other century or so afflicting the Earth: the most recent of which probably gave rise to Comet P/Encke some short interval of time prior to its discovery in 1786 (e.g. Asher and Clube, 1993).
Thus, while the sizes in general of prominent daughter bodies cannot be readily predicted and while the absolute calibration of the Chinese records is uncertain due to unknown variations in the monitoring process and the detection threshold, these records do nevertheless reliably suggest a stochastic Taurid source function which has given rise to possible cometary apparitions and fireball flux enhancements (x 10-100) around AD 0-100, 400-600, 1040-1100, 1400-1460, 1500-1540, 1640-1680, and 1760-1800, the last of these active periods apparently bracketing the supposed formation epoch of Comet P/Encke and the current Encke trail. It is perhaps surprising to note on this account that Comet Encke could be merely the latest in a succession of demi-urges while the Encke trail harbours the principal (inert) remnant of the original giant comet which gave rise to the Taurid Complex (cf. Section 3.5)!
With regard to the observation of fireballs, it is worth noting that a distinction can be drawn between the fluctuations detected since the 18th century and those detected prior to this period. Thus the former reflect as much the increased scientific activity in which we currently participate while the latter reflect a moderately uniform, slowly extending, observational regime in China and the Orient, particularly Japan and Korea.
For the duration of this regime, the astronomical interests of the Orient, like those of Europe, lay with portentous rather than with astrophysical phenomena, the maintenance of suitable records being to a large extent professionally organised only in China (Schafer, loc cit). Given the presumed nature of this observational material, whatever the astrophysical reality giving rise to the recorded meteoroid flux and its correlates (e.g. high level dust insertions, super-Tunguska events), we can be confident that the phenomena, especially during the periods of their dominance lasting for several decades at a time, would most probably have been understood in both China and Europe as divine revelations or rather fearsome exemplars of a natural (presumed astrological) process in which the cosmos necessarily interferes with terrestrial affairs.
Indeed, these enhancements of the meteoroid flux which, as we have seen, are likely to be broadly associated with the most recent giant comet to have settled in inner Solar System space, are of particular interest in their European context since the periods of their principal activity happen also to coincide with periods of pronounced social and intellectual upheaval when it is clear that the normal ascendancy of secular over fundamentalist modes of thought, affecting the general view of the cosmos, experiences a sharp reverse. It is reasonable, in other words, to suppose these were the periods when cosmic agencies were expected to interfere in terrestrial affairs, when the inspiration due to the cosmos gave way to foreboding.
We note, for example, corresponding to these particular epochs: the time of Christ, the Dark Age foundation of the Holy Roman Empire, the initiation of the Crusades against Islam, the Great Schism, the Reformation, the English Revolution and the American War of Independence allied with the French Revolution. The activities during all these periods point to a much closer link between political, religious and cosmic affairs during the ancien regime than historians normally countenance. In fact, the political consequences of revived fundamentalism and the renewed interest in demonic agencies during these periods, especially their destructive tendencies, often perceived as a millenarian threat (Cohn, 1957), no longer appear to be without an identified material cause of external origin.
The prevailing tendency nonetheless, since the 12th century, has increasingly been to regard demonic agencies as a heresy (Thomas, 1971), not only distorting our view of the cosmos but raising unwarranted doubts as to the reality of the likely eschatological associations at these and earlier epochs.
4.2. Eschatology displaced
Eschatology is a relatively long-established if now somewhat obscure branch of learning currently stranded somewhere in the hinterland between history and theology where it remains comparatively untouched by scientists and by historians of science. Its concern is with the doctrine of so-called 'last times' or, more precisely, with the perceived occurrences which, as a matter of historical record, were thought of as bringing the known world to its final destruction.
The most recent authoritative account of eschatological theory by Bultmann (1957) in his Gifford Lectures at Edinburgh indicates that this subject, which was of decisive importance for the long history of the West, developed in association with the ancient concept of a periodicity in the course of world events. This idea originating with the earliest known astronomical traditions based on the ancient Near East, most probably involving a Zoroastrian tradition from Persia (Cohn, 1995), was later developed in Greek and Roman philosophy chiefly by the Stoic thinkers and is perhaps best known today through the reference in Plato's Timaeus to bodies from space which return at great intervals to cause a serious conflagration on Earth: the general concept is indeed that of a universal catastrophe deriving from the cosmic Zeus from whom also radiated a new world. Thus the astrological literature countenances a periodically moribund world-civilization in need of revival and restoration and the periodic emergence of a new star at the end of an aeon, or world-year, to mark the occasion.
Bultmann emphasises however that, in addition to this over-arching perception applicable to the known natural world, we must recognise in the earliest historical narrative an account of normal human welfare characterised by occasional catastrophes, mostly cosmic, which are typical acts of divine chastisement.
The point here is that the catastrophes of divine origin were once a common enough perception to imply relatively frequent occurrence and it is against this background that ancient authors considered the more serious effects of periodic universal catastrophes. Thus the Old and New Testaments were fundamentally distinguished by the latter's added anticipation of a forthcoming new aeon freed from Satan's (catastrophic) rule. The picture to be envisaged therefore was that of a new 'world catastrophe' which would bring to an end both the lesser catastrophes and the sequence of past 'world catastrophes'. In practice, the precise start of the new aeon was subject to a good deal of chronological reckoning based on the apocalyptic scheme due to Daniel and there was growing agreement during the period of the 'Pax Romana', even amongst secular historians, that the new order would be introduced around 500 AD.
Historians of course are in dispute over the precise nature of the Dark Age. The fact of major reverses in civilization in some parts of Europe during the fifth and sixth centuries has to be set against survival, often in reduced circumstances, in other parts. A decline in the level of civilization in Britain, for example, which is said not to have been restored for upward of twelve or thirteen centuries, is perhaps material enough evidence of the deprivation involved. Thus, in the face of this kind of reality, whatever physical hardships were endured, one can hardly be over-critical of survivors of a predicted world-catastrophe who then appear somewhat casual about the shortcomings of a failed astronomical theory i.e. it can certainly be assumed that survivors would have recognized that the 'last times' did not in fact arrive. It is perhaps but a short step therefore from Plato's soul-stuff continuously emanating from the world-cavern to the perception of a versatile if somewhat magical 'divine providence' through which such effects as a partial conflagration might be judiciously realized.
During a subsequent era, then when the possibility of a universal conflagration no longer appeared probable, one can perhaps understand that a continuing cosmic struggle might be envisaged between the dark powers of nature and unreasonableness on the one hand and divine providence on the other hand, the latter now losing its material attributes and becoming primarily the source of free will and enlightened reason!
Thus, as Bultmann supposes, "the idea of the eschatological consummation would later be interpreted as the victory of reason, regarded as the necessary end of the historical development". Indeed, by subsequently placing such an interpretation on the fifth century writings of Augustine, the Church can now be seen to move away from a purely naturalistic interpretation of the celestial influence. However we should not overlook the fact that the general period corresponding to the decline of the Roman Empire (400-600 AD) was in association with circumstances which were widely seen as predictably marking a world-end of cosmic provenance (Barb, 1963).
In fact, such anomalies of the period as the desertion of major tracts of land and the forced migration of whole peoples (Esmonde-Cleary, 1989) point to an underlying cause of the Dark Age which enveloped at least the whole of Europe and which could well have been be due to a succession of localized catastrophes involving super-Tunguska bodies as implied now by the formation epoch of Comet P/Encke and by the 1760-1800 and 400-600 AD enhancements of the fireball flux (Asher and Clube /oc cit). Thus a cometary progenitor for the Taurid meteoroidal concentration is also implied and it is the coincidence of the latter's orbital nodes with the Earth's orbit around 400-600 AD which would now lead us to envisage a wholly material cause for the Dark Age.
The evident fact of a new aeon which was not freed from Satan's rule can of course be eventually seen as a fairly pressing problem for the leaders of the subsequent Holy Roman Empire and there would have been a natural tendency for later scholars to defer the arrival of 'last times'. Indeed it was to be a feature of historiography, then in the future, that the apocalyptic tradition with its scheme of the four world empires of Daniel and the idea of an eschatological end to history were gradually reinstated as part of the protestant tradition.
4.3. Paradigm shifts
In fact, the protestant tendency, which was most seriously aroused on the occasions of an enhanced fireball flux, was generally intent on maintaining the apocalyptic tradition. The resulting debate was of course a critical factor determining the pattern of social upheaval and revolution throughout Europe until the end of the eighteenth century.
Indeed it is only since Hegel specifically pronounced against the role of "divine providence" in secular and philosophical affairs (e.g. Lewis, 1954) that the crises and catastrophes comprising the main national and world events have come to be seen as motivated by non-cosmic disputes between oppressors and oppressed. In view of the likelihood now of a straightforwardly natural (cosmic) explanation of the apocalyptic tradition, we have to face the possibility that Hegel and his successors were mistaken as to the true nature of providence as well as to the prime cause of revolutions!
Amongst the twentieth century historians, both Spengler (1932) and Toynbee (1945) have argued for the origin, growth and decay of civilizations, effectively in the tradition of eschatological history, each new growth emerging from a preceding period of chaos so that the movement of history is brought about by an unpredictable factor, namely, the behaviour of a nation in a critical situation. Spengler indeed perceived such situations as a quite natural extension of biological evolution as a whole. Thus he anticipated the theory of punctuated equilibrium with the following perceptive commentary:
"The picture that we possess of the history of the Earth's crust and of life is at present still dominated by the ideas which civilized English thought has developed, since the Age of Enlightenment, out of the English habit of life, [thus] Lye11's 'phlegmatic' theory of the formation of the geological strata, and Darwin's of the origin of species, are actually but derivatives of the development of England herself. In place of the incalculable catastrophes and metamorphoses such as von Buch and Cuvier admitted, they put a methodical evolution over very long periods of time and recognize as causes only scientifically calculable and indeed mechanical utility-causes".
Rather "all that we see about us impels us to the conviction that again and again profound and very sudden changes take place in the being of plants and animals, changes which are of a cosmic kind and nowise restricted to the Earth's surface, which are beyond the ken of human sense and understanding in respect of causes, if not indeed in all respects. So, too, we observe that swift and deep changes assert themselves in the history of the great Cultures, without assignable causes, inferences or purposes of any kind".
To Spengler therefore, civilization is no more than the fullest development of a culture or a paradigmatic view whose principal characteristics are essentially dictated from the cosmically induced chaos through which they emerge.
Accordingly, for example, we now see the fireball flux enhancement of 1640-1680 initiating the predictions of world end in England at this time, based on the latest analyses of the Book of Daniel by scholars such as Alsted, Brightman and Mede (Trevor-Roper, 1987). Received into popular currency alongside a breakdown in official censorship, these predictions were to precipitate social upheaval and intellectual chaos, as well as civil war and interregnum in the aftermath of which those affecting to make something of a principle out of pragmatic protestantism selected to discount providential fireballs (Sprat loc cit) and restore scientific censorship. Thus was silenced the recently aroused Pyrrhonist (neo-Platonist) wing within the broad protestant tradition, tipping the balance once again towards its more catholic (Aristotelian) wing. These were the ambiguous conditions under which Newton was able to make public his science and yet keep private his eschatological speculations.
Likewise, while we may now see such understandings of the stellar, galactic and cosmological environments which have emerged during the nineteenth and twentieth centuries as enriching our understanding of an earlier, neo-Platonist perception of the boundless Universe, it seems that some of the perhaps less well known astronomical findings of the Space Age now also provide us with an understanding of the Sun and its planetary and cometary environments which enriches our understanding of the Magian world-cavern!
To be precise, it now seems that the latter is neither altogether imperishable nor is it altogether temporary. Rather the Sun, its planetary system and life on Earth are comparatively ancient constructions from the boundless while it is the latest giant comet, also a product of the boundless, which we should now identify in particular with the most recent evolution of the human species and upheavals on Earth. As such, this giant comet is merely the latest in a continuing series, the overall picture being that of punctuational crises which extend over a wide range of intensities and which transform our understanding of biological and social history. The overall picture, furthermore, is one that necessarily provides divine revelation and cosmic myth with a natural material content, now essentially removing such entities from the realm of fantasy.
Indeed, it seems that the secular eschatological component of theological debate throughout history can also no longer be denied. In short, there is inspiration and foreboding generated by a giant comet which has masqueraded as both a cosmic egg and a cosmic serpent. There is also a watershed in the modern perception of cometary facts marked by the fragmentation of Comet P/SL-9 which society and government would be unwise to ignore.
5. ACKNOWLEDGEMENTS
A substantial section of this article is reproduced from two of the author's earlier papers, one of which was composed in collaboration with Dr D. J. Asher. The author would like to thank the organisers of the 'Inspirations' conference for their patience during the preparation of this article. The author also wishes to acknowledge and express his appreciation of the very material assistance, while this patience was being exercised, provided by Dr. W. M. Napier and, through the good offices of Dr S. P. Worden and Dr. S. Nozette, by the USAF (EOARD SPC-93-4076).
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Paul Icamina
AHN
Wed, 16 Jan 2008 13:25 EST
Racine, Wisconsin - Three sophomore high school students at Racine's Prairie School have discovered an asteroid, a feat that is probably unprecedented.
Sophomores Connor Leipold, Tim Pastika and Kyle Simpson will name the asteroid, now known as "2008 AZ28", in about four years, said the Minor Planet Center in Cambridge, Mass., the international body on solar system objects which verified the discovery.
"It's extremely rare and I don't know if an asteroid has ever been discovered by high school students before," said their science teacher, Andrew Vanden Heuvel. "Ninety-nine percent are discovered by professional researchers."
The asteroid must be observed two nights in a row in order for it to be considered an official "discovery," WISN.com quoted Heuvel.
"Asteroids are not easy to spot. They are very faint, about 10,000 times fainter than the faintest thing you can see with your naked eyes. You need to know how to look for them," said Heuvel who estimates that the 2008 AZ28 asteroid takes approximately five years to orbit the sun.
Five undergraduate astronomy students at the University of Washington discovered 1,300 asteroid in 2005 and 2006.
Angela Gallen
Sussex Express
Wed, 16 Jan 2008 09:09 EST
A UFO sighting has been reported by an Observer reader.
Mason Woodhams described seeing a "green fireball track across the sky" at about 11.05pm last night (Tuesday).
"The head of the fireball was white-yellowy-orange with a bright green fire trail. The whole thing lasted no more than five seconds or so.
"It was quite low and slow in the sky between 15,000 and 20,000 feet, quicker than an aeroplane but slower than a shooting star and it traveled from east to west.
"This was obviously a meteor of some sort burning up, but the fact that it was so low in the sky and a brilliant green colour made this so unusual.
"I spoke to a science teacher this morning about this and he said that either copper or barium gives off a green flame when burnt. As most meteors are made from iron/nickel, I guess this makes this quite a rare phenomenon."
Anyone else who spotted this mysterious fireball on Tuesday night can contact the Observer at observer@trbeckett.co.uk
BBC
Fri, 18 Jan 2008 06:57 EST
An observatory which monitors the potential threat to earth from asteroids has launched a campaign to raise money to install a new telescope.
 |
| ©BBC |
| The cost of installing the telescope is estimated at £54,000 |
The Spaceguard Centre in Knighton, Powys, has been offered the telescope free of charge by the Institute of Astronomy in Cambridge.
It would mean the centre could hunt for near earth objects as well as tracking them once they have been discovered.
The cost to install and house the device has been estimated at £54,000.
Known as a Schmidt camera, it has a wide field of view and takes photographs of the sky, said Jay Tate, who runs the centre.
Mr Tate said images were compared to "see what had moved" and potential comets or asteroids could then be identified.
He explained why the telescope had been offered to the centre.
"They can't use it in Cambridge anymore because of the light pollution," he said.
"This part of Wales has very dark skies so that wouldn't be a problem.
"Nasa searches for near earth objects and it funds six telescopes in the US and two in Italy and Australia, but no-one else is doing this sort of work in the UK.
"It would mean we could search for objects as well as tracking them once they have been identified."
 |
| ©BBC |
| The Spaceguard Centre monitors asteroids |
The Spaceguard Centre has a robotic telescope which is able to track asteroids and it also has an observatory which attracts school parties and tourists.
Mr Tate added that no funding was available from the Welsh Assembly Government, the UK government or the National Lottery to help pay towards installing the new telescope.
"I am now turning my attention to private sponsorship," he said.
Knighton's county councillor Ken Harris said the telescope would be a "unique tourist attraction".
"It would be great if someone or an organisation could help the Spaceguard Centre fund this expansion," he added.
Adam McNaughton
Pocono Record
Sat, 19 Jan 2008 11:05 EST
Something unusual in the sky made such an impression on a Mount Pocono man last month that he's still wondering about it.
Ernest Gross wants to know if anyone else saw the same strange, luminous, unidentified object that caught his attention.
 |
| ©Unknown |
| Meteors from the Geminid Meteor Shower on Dec 14 could be seen all over the world, as seen here from Italy. |
"At first I thought it was a satellite," Gross said. "But it was coming too low and too fast. If it was a satellite coming down then it must have landed somewhere and someone has to know about it."
Gross said he was out of bed to use the bathroom around 3 a.m. on Dec. 14, when he happened to look out the window and catch a view of the object - which he described as being twice the size of the moon - streak across the sky.
"I was looking north, at about a 30-degree angle, and saw it fly across from west to east in an arching motion," he said. "It was so fast, just a second and it was out of sight."
Gross said the object had similar illumination to the moon, with a fuzzy outline and soundless.
But it's possible, according to an East Stroudsburg University astronomer, that the object could have a scientific explanation.
"The Geminid meteor shower had peak activity over Dec. 13 and 14," said ESU professor David Buckley. "They were very visible this year and would have been best viewed after midnight."
Gross' description of a bright white, fuzzy-outlined object traveling very fast matches known descriptions of the Geminid meteors.
The annual Geminid shower has a reputation for producing bright white meteors that leave few visible streaks.
"Something moving that fast would almost certainly be a meteor," Buckley said. "And these meteors would have been visible all over the world."
But Gross remains adamant that what he saw was much too large to be a meteor, at least one that no one else noticed.
"If it was a meteor it was a huge one," he said. "I wouldn't have thought much of it if it was a tiny thing."
Gross said his description might refresh the memories of anyone else who could have seen the object and not reported it. "It was a clear night, no clouds," he said. "It's only a one-in-a-million chance that I saw it. But if anyone else did, they'd remember."
Renato Gandia
Sun Media
Sun, 20 Jan 2008 19:37 EST
Spruce Grove residents woke up yesterday to a mysterious octopus-shaped hole in a frozen golf-course pond.
A hole about 1.5 metres in diameter was visible yesterday on the pond at The Links at Spruce Grove, along with at least 20 splash marks - the longest about six metres.
 |
| ©Renato Gandia/Sun Media |
| Aaron Soos measures yesterday the depth of a mysterious hole that appeared in ice half a metre thick on a pond at The Links golf course in Spruce Grove. |
"It wasn't there (Friday)," said neighbour Tina Danyluk, whose house backs onto the pond.
She suspects it might have been a meteorite.
Whatever it was, it had to have followed a high trajectory based on "how the splash spread," Danyluk said.
Astronomer Martin Beech said he wouldn't rule out the possibility of a falling meteorite, but the marks perplexed him.
To punch through ice nearly half a metre thick, the meteor would have to be huge and would look like a bright burning ball with an associated sonic boom, said Beech, who teaches astronomy at Campion College at the University of Regina.
"Usually, it's quite a distinctive rumbling sound and people tend to notice that sound," Beech told Sun Media from Regina.
But no one reported seeing or hearing anything unusual.
"The whole pond was covered in snow (on Friday) until this morning when we saw the strange marks in the pond," said Danyluk.
Beech said he wasn't aware of any reports of fireballs in the area.
He also noted that such an object wouldn't normally melt thick ice.
"If it wasn't a meteorite, what the heck was it?" asked the baffled astronomer.
Danyluk's neighbour, Aaron Soos, said the marks were puzzling and the phenomenon had residents talking all day.
"If the pond was not frozen, we wouldn't even see those marks."
Renato Gandia
Edmonton Sun
Mon, 21 Jan 2008 09:38 EST
The mystery surrounding what Spruce Grove residents believe was a meteorite that hit an area pond last week began to unravel yesterday.
An eyewitness came forward to say he had seen a fireball shoot down from the sky.
"I first thought it was a shooting star, but it wasn't burning out," said Eric Whyte, who was driving southbound on Highway 2 between St. Albert and Morinville around 10 p.m. Thursday.
"It was a big ball of fire, bright orangey in colour, and there was a big tail behind it," he recalled.
Astronomer Martin Beech said the sighting of a fireball is crucial in determining whether it was a meteorite.
But he couldn't say for sure what dropped into the frozen pond at The Links golf course in Spruce Grove, just west of Edmonton.
Derrick Zienowicz was the first to see the strange octopus-shaped hole in the frozen pond on Saturday morning.
He immediately told his neighbours Tina Danyluk and James Shankowski, whose house is closest to the strange marks.
They initially believed the strange marks were made late Friday night or early Saturday.
But both Shankowski and Zienowicz said it is possible the marks had been there since Thursday night because none of them looked out their back windows Friday.
Also, Zienowicz said he felt his house shake at about 10 p.m. Thursday while he was standing in the kitchen.
"It's kinda weird. For about 10 seconds, the house shook. I said, 'What the heck was that?' "
He now suspects it was associated with the fireball and the strange marks.
A bright burning ball with an associated sonic boom normally indicates a falling meteor, said Beech, who teaches astronomy at Campion College at the University of Regina.
But Whyte said none of his family believed he saw a falling meteor.
"They were all saying it's a shooting star and they thought I was crazy. I read the article in the Sun (yesterday about the pond) and then it made perfect sense."
Shannon Montgomery
Canadian Press
Mon, 21 Jan 2008 16:38 EST
Maybe it's a meteorite and maybe it isn't, but it's unlikely the source of a mysterious hole at an Alberta golf course will be discovered any time soon.
The octopus-shaped opening in the slushy ice of a golf course pond just west of Edmonton has neighbouring homeowners abuzz with the possibility a small piece of space could have plummeted to earth in their very backyards.
But the mystery will likely stay submerged in the seven-metre-deep pond that provides water to irrigate the golf course, Glen Andersen, a superintendent at The Links in Spruce Grove, said Monday.
"I think it's a safety issue now," said Mr. Andersen, who added he wouldn't want to inch across the thin ice in search of what may have fallen.
"We're not going to do that. We hope people don't come out here - we'd ask them to leave."
Residents first reported the hole Saturday, and reports of a fireball in the sky two nights before have piqued the interest of many.
Mr. Andersen said while it's fun to ponder what may have fallen, those who work at the course are much more interested in golf. "It's kinda neat, interesting, but that's it."
Many objects can fall from the sky, but very few end up being meteorites, said University of Alberta professor Chris Herd, who curates the province's meteorite collection.
Space debris such as pieces of satellites sometimes rains from the sky. The mystery object that caused the hole could even be a large piece of frozen waste from an airplane, he said.
"The fact is that there could be a number of other possibilities for what punched a hole through the ice, and the fact that if there is anything, it's at the bottom of a pond, doesn't put it high on the list of priorities for investigating it, unfortunately."
While it's unusual with Canada's massive size for people to see a falling meteorite and actually be able to recover it, Herd says his lab sees about 100 rocks a year that people think may be from space. About one in 400 actually turns out to be.
A motorist who described seeing a big ball of fire in the sky Thursday night may provide a key to the puzzle. Eric Whyte, who was driving on Highway 2 between St. Albert and Morinville around 10 p.m., said he originally thought what he saw was a shooting star, but the bright-orange ball of fire with blazing tail didn't burn away.
Alan Hildebrand, a planetary scientist at the University of Calgary and co-ordinator of the Canadian Fireball Reporting Centre, said that description sounds like a falling meteorite.
He said he will review the data captured by an all-sky camera near Edmonton to see if it captured a bright trace in the sky Thursday night.
"Certainly once we have enough information, we can tell the difference between a natural object entering and man-made debris coming down," he said.
Only between 60 and 70 individual meteorites have ever been found in Canada, according to Prof. Herd.
None of these has been recovered from a pond, he said. He explained the water could act quickly to destroy much of a meteorite's interest.
"You can actually have chemical reactions take place. You can have alteration pretty quickly. It degrades the original minerals that are inside, and it's harder to study for scientific reasons."
Prof. Herd added that under Canadian law, meteorites - which tend to be heavy and can be worth a fair amount of money - belong to whomever owns the land where they touch down.
The Geological Survey of Canada, which maintains the national collection of meteorites, offers a minimum of $500 for the first specimen of any new Canadian meteorite.
Prof. Herd says he's happy to examine any potential meteorites that are recovered, but it would be far too difficult to try to recover something that could end up being of no scientific interest.
"You'd need equipment to dive down into this pond," he said. "So if somebody entrepreneuring would want to do it, I'd be happy to look at what they might find, but I can't justify the expense to go looking."
Cornell University Communications
Fri, 25 Jan 2008 14:57 EST
The Arecibo Observatory in Arecibo, Puerto Rico will observe a newly discovered asteroid on Jan. 27-28, as the object called 2007 TU24 passes within 1.4 lunar distances, or 334,000 miles, from Earth.
The asteroid, estimated at between 150 and 600 meters in diameter - about 500 feet to 1,900 feet, or the size of a football field, at 360 feet, to the size of Chicago's 110-story Sears Tower, at 1,454 feet - was discovered by the University of Arizona's Catalina Sky Survey in October 2007. It poses no threat to Earth, but its near approach gives Arecibo astronomers a golden opportunity to learn more about potentially hazardous near-Earth objects.
"We don't yet know anything about this asteroid," said Mike Nolan, head of radar astronomy at the Puerto Rico observatory. Such objects pass near Earth with relative frequency, he said - approximately one every five years or so - but it's rare that astronomers have enough advance notice to plan for rigorous observing.
"Because it's coming so close, we'll get our highest quality imaging," said Nolan.
Using Arecibo's powerful radar, which is the most sensitive in the world, researchers will gauge the object's size, observe its speed and measure its spin. Switching then to imaging mode, which will offer resolution to 7.5 meters - three times more precise than NASA's Goldstone telescope, the only other radar telescope in the world - the researchers hope to map the object's surface in detail. The Robert C. Byrd Green Bank Telescope, Green Bank, W.Va., will receive Arecibo's echo from the asteroid and transmit its data back to Arecibo.
TU2 is one of an estimated 7,000 near-Earth objects, its size or larger - most have never been closely studied.
"We have good images of a couple dozen objects like this, and for about one in 10, we see something we've never seen before," said Nolan. "We really haven't sampled the population enough to know what's out there."
Arecibo's radar is vital for continuing to classify and understand such objects, said Cornell University assistant professor of astronomy Jean-Luc Margot. "Arecibo does a fantastic job at getting images, discovering the shape, spin and reflection properties of such an object . . . all these things that are important to know."
The telescope will be trained on TU24 Jan. 27-28 and again Feb. 1-4. Goldstone's planetary radar observed it Jan. 23-24.
Lawrence Livermore National Laboratory
Fri, 25 Jan 2008 15:09 EST
Contrary to expectations for a small icy body, much of the comet dust returned by the Stardust mission formed very close to the young sun and was altered from the solar system's early materials.
When the Stardust mission returned to Earth with samples from the comet Wild 2 in 2006, scientists knew the material would provide new clues about the formation of our solar system, but they didn't know exactly how.
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| ©NASA/JPL |
| Combined long- and short-exposure images captured during the Stardust flyby of the comet Wild 2. |
New research by scientists at Lawrence Livermore National Laboratory and collaborators reveals that, in addition to containing material that formed very close to the young sun, the dust from Wild 2 also is missing ingredients that would be expected in comet dust. Surprisingly, the Wild 2 comet sample better resembles a meteorite from the asteroid belt rather than an ancient, unaltered comet.
Comets are expected to contain large amounts of the most primitive material in the solar system, a treasure trove of stardust from other stars and other ancient materials. But in the case of Wild 2, that simply is not the case.
By comparing the Stardust samples to cometary interplanetary dust particles (CP IDPs), the team found that two silicate materials normally found in cometary IDPs, together with other primitive materials including presolar stardust grains from other stars, have not been found in the abundances that might be expected in a Kuiper Belt comet like Wild 2. The high-speed capture of the Stardust particles may be partly responsible; but extra refractory components that formed in the inner solar nebula within a few astronomical units of the sun, indicate that the Stardust material resembles chondritic meteorites from the asteroid belt.
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| ©Hope Ishii, LLNL |
| Getting into the details: Stardust impact tracks and light gas gun impacts of sulfide in aerogel both display metal beads with sulfide rims indicating that GEMS-like objects in Stardust are generated by impact mixing of comet dust with silica aerogel. (left) Stardust GEMS-like material and (right) light gas gun shot GEM-like material. GEMS in cometary IDPs do not contain sulfide-rimmed metal inclusions. |
"The material is a lot less primitive and more altered than materials we have gathered through high altitude capture in our own stratosphere from a variety of comets," said LLNL's Hope Ishii, lead author of the research that appears in the Jan. 25 edition of the journal, Science. "As a whole, the samples look more asteroidal than cometary."
Because of its tail formed by vaporizing ices, Wild 2 is, by definition, a comet. "It's a reminder that we can't make black and white distinctions between asteroids and comets," Ishii said. "There is a continuum between them."
The surprising findings contradict researchers' initial expectations for a comet that spent most of its life orbiting in the Kuiper Belt, beyond Neptune. In 1974, Wild 2 had a close encounter with Jupiter that placed it into its current orbit much closer to Earth.
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| ©John Bradley, LLNL |
| One of the silicate material found in cometary IDPs are GEMS (glass embedded with metals and sulfides). Similar structures are found in Stardust impact tracks in aerogel but also in light gas gun shots of sulfide in aerogel at the Stardust impact speed. |
Comets formed beyond the so-called frost line where water and other volatiles existed as ices. Because of their setting far from the sun, they have been viewed as a virtual freezer, preserving the original preliminary ingredients of the solar system's formation 4.6 billion years ago. The Stardust spacecraft traveled a total of seven years to reach Wild 2 and returned to Earth in January 2006 with a cargo of tiny particles for scientist to analyze.
This is one of the first studies to closely compare Stardust particles to CP IDPs. This class of IDPs is believed to contain the most primitive and unaltered fraction of the primordial material from which our planets and other solar system objects formed. They are highly enriched in isotopically anomalous organic and inorganic outer solar nebula materials inherited - through the presolar molecular cloud - from dust produced around other stars. IDPs are gathered in the stratosphere by high altitude airplanes (ER-2s and WB-57s) that are typically more than 50 years old.
The Livermore team specifically searched for two silicate materials in Stardust that are believed to be unique to cometary IDPs: amorphous silicates known as GEMS (glass with embedded metal and sulfides); and sliver-like whiskers of the crystalline silicate enstatite (a rock-forming mineral). Surprisingly, the team found only a single enstatite whisker in the Stardust samples, and it had the wrong crystallographic orientation - a form typical of terrestrial and asteroidal enstatite.
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| ©NASA/JPL |
| Stardust impact tracks created by comet dust entering silica aerogel at 6 km/s. |
Objects similar to GEMS were found, but Ishii and the team showed they were actually created during the high speed 6-kilometer per second impact of Wild 2 comet dust with the Stardust spacecraft's collector by making similar material in the laboratory.
In analyzing the Stardust material, Ishii's team used Livermore's SuperSTEM (scanning transmission electron microscope). Ishii said future analyses should focus on larger-grained materials, so-called micro-rocks, which suffered less alteration.
"The material found in primitive objects just wasn't there in the samples," said John Bradley, another LLNL author. "I think this is science in action. It's really exciting because it's just not what we expected."
"Wild 2 doesn't look like what we thought all comets should look like," Ishii said. "The Stardust mission was a real success because without it, we would never have learned these things about our solar system. The sample return was vital for us to continue to unravel how our solar system formed and evolved."
In addition to Ishii and Bradley, other LLNL researchers include Zu Rong Dai, Miaofang Chi and Nigel Browning. Other institutions involved include UC Davis, the Natural History Museum of London, the University of Kent and the Netherlands Organization for Scientific Research (NWO).
Stardust is a part of NASA's series of Discovery missions and is managed by the Jet Propulsion Laboratory. Stardust launched in February 1999 and set off on three giant loops around the sun. It began collecting interstellar dust in 2000 and met Wild 2 in January 2004, when the spacecraft was slammed by thousands of comet particles including some the size of BBs that could have compromised the mission. It is the first spacecraft to safely make it back to Earth with cometary dust particles in tow.
Founded in 1952, Lawrence Livermore National Laboratory is a national security laboratory, with a mission to ensure national security and apply science and technology to the important issues of our time. Lawrence Livermore National Laboratory is managed by Lawrence Livermore National Security, LLC for the U.S. Department of Energy's National Nuclear Security Administration.
WSFA-TV
Fri, 25 Jan 2008 08:05 EST
Law enforcement agencies in our area are still trying to figure out what folks saw streaking low across the evening sky in East Montgomery.
Around 6:00 Thursday night , the phone started ringing at the Police and Sheriff's Department. Callers thought it might have been an airplane falling from the sky. A swarm of rescue workers were dispatched to the area, but found nothing.
As of now, no one knows what it was. some in law enforcement speculate it may have been a meteor. If we find anything out for sure we'll let you know.
Lucy Guzman
Inexplicata
Sun, 20 Jan 2008 22:52 EST
A cellphone report received on Saturday 01.12.08. Domingo Morales phoned Andrew Alvarez to make a report on sightings in the City of Ponce. Mr. Alvarez told him to phone me. Mr. Morales reported the following:
1. His brother, a resident of Valle Alta, Ponce, told him that on Friday, January 4 2008 at 9:30 p.m,., his wife called him over to look at a fireball over their house. Upon going outside , he saw an immense ball of red fire. The wife didn't see it approach, rather she saw it suddenly appear and light up on the spot. It remained static for some 20 minutes at an approximate altitude of 300 feet. It spent 20 minutes lighting on and off. The fireball finally diminished the intensity of its color and began moving SW in a zig-zag pattern, going up and down. It had the apparent size of a baseball stadium floodlight.
2. On Saturday January 5, 2008 at 9:40 p.m., Domingo's brother phoned again, this time to have Domingo climb onto the rooftop of his house to see if it was possible for him to see the fireball, as he (the brother) was seeing it. Domingo lives in Los Caobos, but was unable to see the object from his home. According to Domingo's brother, the fireball was over the same site, above his house and exhibiting the same behavior.
At 10:40 p.m., the fireball reappeared. This time, Domingo's brother saw it with nearly all of his neighbors. One of the neighbors was able to photograph it with a cellphone. On this occasion, a twin-engine plane flew over the area 15 minutes after the fireball vanished. This [fireball] did not appear suddenly, it came in from [the town of] Adjuntas.
3. On Sunday, January 6, 2008, Domingo and his wife decided to visit Domingo's brother to see if the were lucky enough to see the fireball. Just as they got out of the car, at 9:30 p.m., they saw two white balls of light to the SW which appeared to be joined. They looked like two orbs to the naked eye, but binoculars revealed them to be two plate like objects joined together. These were higher up, at some 5000 feet. (Domingo is a pilot, and is therefore able to calculate altitude better than the average witness). In plain sight they looked like two joined golf balls. They separated a minute later -- one heading south and another to the north.
Five minutes later, Domingo phone FURA [P.R. police aerial reconnaissance] and was told that they were going to send their helicopter for a look. Domingo never saw the helicopter engage in a fly-over. Domingo recalls that while he observed the two orbs, a woman and her daughters stopped to ask him if they were seeing the fireballs. She added that the fireballs had been visible since November in that location, becoming apparent between 9-10 p.m. and as early as 5 p.m.
4. No sightings were reported on Monday, January 7.
5. Today, Saturday, January 12, Domingo will return with a camera in an effort to take pictures of the objects.
(Translation (c) 2007, S. Corrales, IHU. Special thanks to Lucy Guzman, Ovni.Net)
Inexplicata
Mon, 14 Jan 2008 23:36 EST
On December 22, 2007, Wilmar and Frank were heading back toward Bayamon from the city of Ponce. Upon reaching Av. Los Filtros around 6:10 p.m., they watched the sunset and the arrival of twilight. Suddenly Wilma looked at the sky and saw what she at first thought was a jet. She quickly realized this was not the case, and that it could be a shooting star, but dismissed the possibility as the object remained in view and grew larger in size. She then thought it was a meteorite or something that had broken away and was falling toward the ground. That's when she asked Frank to look up, thinking that it was a meteorite or something similar. Frank told her it was a jet airplane. Wanda replied that those airplane left smoke in their wake, and this one had light. She added that it wasn't a normal aircraft, as it was flying forward and not the customary route followed by commercial planes.
Frank agreed with this assessment, and continued driving as they kept their eyes on the object. When they passed the Military Academy, the object stopped. Judging by the way the light came down, [the object] appeared cone-shaped. Suddenly, Wanda realized that another light of the same size pulled up beside it and then over the object. Unlike the first one, Wanda did not see a descending shaft of light from this craft. It only hung above the first one for some seconds. Then the cone-shaped object made a right turn (as if heading toward San Juan) making an "L" turn. It did not turn like a commercial airliner would, rather in a perfect turn that startled the onlookers. Both objects moved in unison and the lights suddenly disappeared.
Translation (c) S. Corrales, IHU. Special thanks to Lucy Guzman, Ovni.net.
Diario de Cuyo
Fri, 25 Jan 2008 08:12 EST
Yesterday the people of Santa Luc?a were surprised when a black porous rock fell from the sky. Today the CASLEO (Astronomic Complex El Leoncito) is analyzing the rock to determine if it is a meteorite or not.
"It was like a fire ball that traversed the sky", several witnesses said yesterday.
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| ©Diario de Cuyo |
Profesor Eloy Actis, director of the Observatory F?lix Aguilar, is between those who do not believe it is a meteorite because he claims "that it should weight more than 20 kg, when in reality it is only a rock of only 2 Kg. It could be a volcanic rock, but due to the area where it fell, this will be highly unlikely."
Translation by Signs of the Times
USA Today/Associated Press
Mon, 28 Jan 2008 14:33 EST
Space scientists and government officials are tracking two massive objects that are hurtling toward Earth, but only one, a dead satellite the size of a bus, is expected to hit somewhere on the globe.
Government officials said Saturday that a large U.S. spy satellite has lost power and could hit Earth in late February or early March. And an asteroid at least 500 feet long will make a rare close pass by Earth early Tuesday, but scientists say there is no chance of an impact.
The satellite, which no longer can be controlled, could contain hazardous materials, and it is unknown where it might come down, said the government officials, who spoke on condition of anonymity because the information is classified as secret.
"Appropriate government agencies are monitoring the situation," says Gordon Johndroe, a spokesman for the National Security Council.
John Pike, director of the defense research group GlobalSecurity.org, estimates that the spacecraft weighs about 20,000 pounds and is the size of a small bus. Satellites have natural decay periods, and it's possible this one died as long as a year ago and is just now getting ready to re-enter the atmosphere.
Jeffrey Richelson, a senior fellow at the National Security Archive, says the spacecraft probably is a photo-reconnaissance satellite. Those are used to gather information from space about adversarial governments and terror groups and to survey damage from hurricanes, fires and other disasters.
The closest approach of the asteroid, known as 2007 TU24, is expected to be at 334,000 miles, or about 1½ times the distance of Earth to the moon.
The nighttime encounter should be bright enough for medium-size telescopes to get a glimpse, says Don Yeomans, manager of the Near-Earth Object Program Office at NASA's Jet Propulsion Laboratory, which tracks potentially dangerous space rocks. The closest approach is expected to be at 3:33 a.m. ET.
The asteroid TU24 is one of an estimated 7,000 so-called near-Earth objects.
An actual collision of a similar-size object with Earth occurs on average every 37,000 years.
Spotted in October by the NASA-funded Catalina Sky Survey in Arizona, TU24 is estimated to be 500 to 2,000 feet long.
The next time an asteroid this size will fly this close to Earth will be in 2027.
Contributing: Reuters
Comment: Look
at that! An asteroid is having a close encounter with the Earth and a
spy satellite might hit the Earth, which no one is sure what kind of
materials it contains, yet harmful as reported. Interesting that SOTT
has carried a few editorials, very recently, on the subject of threats to Earth from space debris:
Wars, Pestilence and Witches
Cosmic Turkey Shoot
The Hazard to Civilization from Fireballs and Comets
New Light on the Black Death: The Cosmic Connection
Laura Knight-Jadczyk
sott.net
Mon, 28 Jan 2008 09:02 EST
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| ©Unknown |
| Comet of 1532 |
This morning I was thumbing through a newly arrived book: Comet/Asteroid Impacts and Human Society, published by the eminent scientific publishing house, Springer, edited by Peter T. Bobrowsky and Hans Rickman. This book is a collection of scientific papers presented at a workshop under the aegis of the International Council for Science. In the introduction, we read:
The International Council for Science recently recognized that the societal implications (social, cultural, political and economic) of a comet/asteroid impact on Earth warrants an immediate consideration by all countries in the world.
Wow! You think? You mean it's not just us here at SOTT (and a few others on the net) who are keeping track of the increasing number of Fireballs and Meteorites that suggest we are passing through rather dangerous areas of space, or that maybe Something Wicked This Way Comes?
Yes, it seems so. In the chapter entitled "Social Perspectives on Comet/Asteroid Imact (CAI) Hazards: Technocratic Authority and the Geography of Social Vulnerability" we read:
Until quite recently, research into comet and asteroid hazards was focused on establishing the scale and scope of past impacts, credible estimates of their recurrence, and models for physical impact scenarios. ... CAI hazards have moved well beyond the realm of ungrounded speculation and apocalyptic visions. The results represent more than just new findings. They revolutionize, or are about to revolutionize, some basic understandings about the Earth, its history, biological evolution and future. Although human life has had a tiny place in the story so far, our longer term fate seems to be challenged by these forces and may be decided by them.
No kidding.
In a chapter entitled "Social Science and Near-Earth Objects: an Inventory of Issues", we read:
It would have been ridiculous, not too long ago, to admit openly that you were thinking about asteroids and comets slamming into the Earth. Such events could mean the end of the world as we know it - TEOTWAWKI as millenialists call it - and that kind of talk is often ridiculed. ...
Respectable people are pondering the issues. For example, S. Pete Worden, who is a Brigadier General in the US Air Force and Deputy Director for Command and Control Headquarters at the Pentagon, has said that he believes "we should pay more attention to the 'Tunguska-class' objects - 100 meter or so objects which can strike up to several times per century with the destructiveness of a nuclear weapon."
I located the General's comments and they are now in the SOTT database. It seems that the above is not all the general said. In fact, he states quite unequivocally:
I can show people evidence of real strikes inflicting local and regional damage less than a century ago. Even more compelling are the frequent kiloton-level detonations our early warning satellites see in the earth's atmosphere. ... Within the United States space community there is a growing concern over "space situational awareness."
The general was writing back in 2000. "Less than a century ago." That would be after 1900. He said that there were "real strikes inflicting local and regional damage" since 1900?!
Did I miss something? Did all of us miss something?
Well, we'll come back to that soon enough. That's not what I wanted to talk about today. Today, I wanted to pick up where we left off last time, the end of the Hundred Years' War.
In the previous installments of this series of articles we have looked at how the Black Death was probably a period of cometary fragment bombardment leading to mass death on an unimaginable scale. In today's world, the equivalent would be the deaths of two, possibly three billion people planet-wide and many animals as well. Just contemplating what humanity would do with that many bodies to be disposed of is daunting, not to mention considering how society would continue. The Black Death was no respecter of rank, either: the elites died in proportionate numbers to the masses of ordinary people. This has some interesting implications in terms of how the elites are looking at the matter now, but again, that is something we will come back to once we have a look at the evidence.
In our discussion of the Hundred Years' War, we learned that a great cover-up was effected at the end of it all and this was mainly to reestablish the religious control of the masses because, of course, religious control has always been the right arm of princes and governments.
Inasmuch as it was popularly believed that the continued sterility of many years was caused by witches through the malice of the Devil, the whole country rose to exterminate the witches. This movement was promoted by many in office, who hoped wealth from the persecution. And so, from court to court throughout the towns and villages of all the diocese, scurried special accusers, inquisitors, notaries, jurors, judges, constables, dragging to trial and torture human beings of both sexes and burning them in great numbers. Scarcely any of those who were accused escaped punishment. Nor were there spared even the leading men in the city of Trier. For the Judge, with two Burgomasters, several Councilors and Associate Judges, canons of sundry collegiate churches, parish priests, rural deans, were swept away in this ruin. So far, at length, did the madness of the furious populace and of the courts go in this thirst for blood and booty that there was scarcely anybody who was not smirched by some suspicion of this crime.
Meanwhile notaries, copyists, and innkeepers grew rich. The executioner rode a blooded horse, like a noble of the court, and went clad in gold and silver; his wife vied with noble dames in the richness of her array. The children of those convicted and punished were sent into exile; their goods were confiscated; plowman and vintner failed hence came sterility. A direr pestilence or a more ruthless invader could hardly have ravaged the territory of Trier than this inquisition and persecution without bounds: many were the reasons for doubting that all were really guilty. This persecution lasted for several years; and some of those who presided over the administration of justice gloried in the multitude of the stakes, at each of which a human being had been given to the flames. At last, though the flames were still unsated, the people grew impoverished, rules were made and enforced restricting the fees and costs of examinations and examiners, and suddenly, as when in war funds fail, the zeal of the persecutors died out. (Burr: Linden, Gesta Trevirorum (from his manuscript in the City Library of Trier.) Latin. Printed in Hontheim's Historia Trevirensis diplomatica (iii, p. 170, note) and in Wyttenbach and Muller's ed. of the Gesta Trevirorum See this LINK for many first hand accounts and details of the witch persecutions.)
Indeed, the question that led to the persecution of witches was a religious one: How could a world created by a watchful, benevolent, and engaged God be such a mess? Answering this question led to a growth industry in persons and institutions dealing death and destruction. We see a lot of that going on in our world today: the "security industry" is booming in the mythical "War on Terror."
The Reformation divided Europe between Protestant regions and those loyal to the Pope, but Protestants took the crime of witchcraft no less seriously--and arguably even more so--than Catholics. Germany, rife with sectarian strife, saw Europe's greatest execution rates of witches--higher than those in the rest of the Continent combined. Witch hysteria swept France in 1571 after Trois-Echelles, a defendant accused of witchcraft from the court of Charles IX, announced to the court that he had over 100,000 fellow witches roaming the country. Judges responding to the ensuing panic by eliminating for those accused of witchcraft most of the protections that other defendants enjoyed. Jean Bodin in his 1580 book, On the Demon-Mania of Sorcerers, opened the door to use of testimony by children against parents, entrapment, and instruments of torture. (A Brief History of Witchcraft Persecutions before Salem)
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| ©Unknown |
| Pope Innocent VIII |
The problem is, of course, that the primary targets in any such persecutions are those who talk about the calamities themselves and point out that the religious faiths are obvious failures and perhaps it might be better to look at the world rationally and scientifically. Such individuals must be accused of being witches or "cults" and silenced because they threaten the very foundation of Western Civilization, Uniformitarianism and the Fascist control of humanity by such elements.
We know of what we speak first hand! Have a look at The Disappeared: SOTT.net and Google's conspicuous omissions and then have a look at this ongoing defamation undertaken by modern-day Witch Hunters: Laura Knight Jadczyk's Cassiopaea Cult. We wondered how long it would take the psy-ops folks to set up a 9-11 framed attack on us. As I commented yesterday, we must scare the be-jeezus out of the PTB or so much effort wouldn't be spent on trying to shut us down, suppress us, and, failing that, defame us.
But, getting back to the subject at hand (if one is going to be defamed, one might as well be defamed for telling the WHOLE truth!), in Victor Clube's narrative report funded by the USAF and Oxford, the next important period of cometary calamity was the Thirty Years' War. Let's look at a short timeline just to orient ourselves.
1337 to 1453 - Hundred Years War
1347/48 - 1351 - Black Death (included in the time period of the Hundred Years' War)
1400 - Renaissance (begins as the Hundred Years War is ending)
1431- Joan of Arc burned at the stake for being a witch (included in the time period of the Hundred Years' War)
1484 - Pope Innocent VIII announced that satanists
in Germany were meeting with demons, casting spells that destroyed
crops, and aborting infants
1486 - Malleus Maleficarum published
1500 - Witch persecutions begin
1515 - Outbreaks of witchcraft hysteria, with subsequent mass executions begin
1591 - King James authorizes the torture of suspected witches in Scotland
1600 - Renaissance ends "officially"
1606 - Shakespeare's "Macbeth" performed
1616 - Thirty Years War begins
1642 - Beginning of the English Civil War
1643 - The largest witch-hunt in French history
occurred. For two years there were at least 650 arrests in Languedoc
alone. The same time was one of intense witch-hunting in England, as
the English civil war created an atmosphere of unrest that fueled the
hunting, especially under Matthew Hopkins.
1648 - Thirty Years War ends
1651 - End of the English Civil War
1660 - Witch persecutions end - Europe saw between
50,000 and 80,000 suspected witches executed. About 80% of those killed
were women. Execution rates varied greatly by country, from a high of
about 26,000 in Germany to about 10,000 in France, 1,000 in England,
and only four in Ireland. The lower death tolls in England and Ireland
owe in part to better procedural safeguards in those countries for
defendants. (LINK)
1682 - England executes its last witch, Temperance
Lloyd, a senile woman from Bideford. Lord Chief Justice Sir Francis
North, a passionate critic of witchcraft trials, investigated the Lloyd
case and denounced it as a farce. Witch-hunting shifted from one side
of the Atlantic to the other, with the outbreak of hysteria in Salem in
1692.
I'm not too sure why the Renaissance is said to end in 1600, looks to me more like it was probably the Thirty Years' War that ended it. But, never mind, that's the date range agreed on by most scholars.
The Thirty Years' War was fought between 1618 and 1648, principally on the territory of today's Germany, and involved most of the major European powers. It began as an ostensible religious conflict between Protestants and Catholics and gradually developed into a general war involving much of Europe, related to the France-Habsburg rivalry for pre-eminence in Europe, which led later to direct war between France and Spain.
Notes to ponder: The Thirty Years' War also pretty much spanned the reign of Louis XIII of France (1610-1643). Galileo lived from 1564 to 1642. Many adherents of Catharism, fleeing a papal inquisition launched against their alleged heresies in France, had migrated into Germany and the Savoy. This may have been at the root of the initial religious conflict. In fact, Catharism may have fed the Protestant Reformation.
The Thirty Years' War was one which utilized mercenary armies to a great extent, and these hired killers were said to have devastated entire regions leaving the inhabitants to suffer widespread famine and disease which decimated the population. This affected primarily the German states and, to a lesser extent, the Low Countries and Italy. At the same time, it bankrupted many of the governmental powers involved. Sounds a lot like what is happening today, doesn't it?
The English Civil War, which began after the Thirty Years War had been going on for about 25 years (and was running out of steam and people), consisted of a series of armed conflicts and political machinations that took place between Parliamentarians (known as Roundheads) and Royalists (known as Cavaliers).
The question is, do we find any mentions of comets or other strange astronomical phenomena during this period of time? As it happens, we do.
David Herlicius published in 1619 a discourse on a comet that had appeared shortly before, in 1618, and enumerated the calamities that this comet, and comets in general, bring with them or presage:
Desiccation of the crops and barrenness, pestilence, great stormy winds, great inundations, shipwrecks, defeat of armies or destruction of kingdoms . . . decease of great potentates and scholars, schisms and rifts in religion, etc. The portents of comets are threefold - in part natural, in part political, and in part theological. [William Whiston and the Deluge]
The seventeenth-century was witness to numerous comet sightings, including those of 1618, 1664, 1665, and 1677. Inquiries into these comets produced a noteworthy number of scientific texts including Samuel Danforth's An Astronomical Description of the Late Comet (1665), John Gadbury's treatise De Cometis (1665), and Robert Hooke's 1678 report to the Royal Society, Cometa. These accounts complemented the earlier work of Brahe and Kepler and helped to expand the emerging technical understanding of this particular cosmic phenomenon.
Another reference: "This year (1618) brought on three bright comets."
Regarding Kepler: His observations on the three comets of 1618 were published in De Cometis, contemporaneously with the Harmonice Mundi (Augsburg, 1619).
My search for direct source material giving evidence of unusual events from this time has been rather frustrating. I have found that the only people reading the original documents are scholars who generally refer to the descriptions of the time as being hyperbole, or more or less "religious" metaphor, so it is frustrating to find that these actual passages are quoted in the original language - generally German. Not to be thwarted, I sent the material off to a German friend of SOTT and he quickly returned a translation.
In the journal, German Life and Letters 54:2, Geoffrey Mortimer published an article entitled "Style and Fictionalisation in Eyewitness Personal Accounts of the Thirty Years War". He writes:
Eyewitness personal accounts of the Thirty Years War are of interest not only for their overt content, but as examples of how the process of writing itself can shape both the resultant text and the meaning derivable from it by the reader. Techniques adopted, probably unconsciously, by writers seeking to give force and point to their narratives, here collectively termed 'fictionalisation', add to well-known problems of eyewitness testimony to affect the historical evaluation of such sources.
We are going to see that, apparently, Mr. Mortimer hasn't been reading the work of Victor Clube! He goes on for some pages explaining to us that the people who wrote these accounts were mostly simple individuals who had no literary pretensions, and the works themselves were things like diaries and records intended to be passed down in families. One item that he says was written to "create the desired impression, possibly at the expense of strict representational accuracy" is the following:
Due to war, pestilence, price rise and famine, our people are reduced to such an extent, that it will be difficult for our descendants to believe it.
Now, one has to keep in mind the meaning of the word "pestilence" as we discussed already in a previous section. Jon Arrizabalaga, in his article included in Practical Medicine from Salerno to the Black Death, discusses the etiology of this word and how it was understood by the peoples of the time. He writes:
The emphasis placed on celestial causes of the 'pestilence' by the different physicians studied here varied quite widely. ... In 1340 Augustine of Trent, a friar eremite of St. Augustine, justified having written a medical and astrological work on a 'pestilence of diseases' happening everywhere in Italy, because of physicians' ignorance about the roots of diseases; this fact was considered by him 'a pestiferous mistake involving many physicians', and he blamed it on their 'ignorance of astronomy'. ...
Works from other geographical areas assigned a more relevant role to celestial causes in the genesis of the 'pestilence.' ...
Jacme d'Agramaont ...said nothing concerning the term epidemia, but he extensively developed what he meant by pestilencia. He gave this latter term a very peculiar etymology, in accordance with a from of knowledge established by Isidore of Seville (570-636) in his Etymologiae, which came to be widely accepted throughout Europe during the Middle Ages. He split the term pestilencia up into three syllables, each having a particular meaning: pes = tempesta: 'storm, tempest'; te = 'temps, time', lencia = clardat: 'brightness, light'; hence, he concluded, the pestilencia was 'the time of tempest caused by light from the stars.'
And so, we have a better idea of what our German diarist meant when he said:
Due to war, pestilence, price rise and famine, our people are reduced to such an extent, that it will be difficult for our descendants to believe it.
On page 5 (101) of Mortimer's paper, we read that a young officer at the time of the sack of Magdeburg in 1631 wrote in his memoirs:
[A] grand storm-wind picked up, the town was inflamed at all possible places, so that even little aid (rescue) was of help (appreciated). ... then I saw the whole town of Magdeburg, except dome, monastery and New Market, lying in embers and ashes, which raged only about 3 or 3 1/2 hours, from which I deduced God's strange omnipotence and punishment.
A "grand storm wind" and a town that was "inflamed" all over at once, and burned to cinders in 3.5 hours? Perhaps the reader will like to go back and re-read the description of how an overhead cometary explosion would manifest, quoted at the beginning of the previous section, Wars, Pestilence and Witches.
Note the date of the above event: 1631. As it happens, there were other mysterious things happening on the planet at that time. In her book Comets and Popular Culture and the Birth of Modern Cosmology Sara J. Schechner writes:
Comets, like other marvels, were exploited by polemicists in prodigy books. In 1661-1662, for example, radical English dissenters published sensationalist reports of prodigies, including comets, which gloomily greeted the restoration of Charles II. ... There were no fewer than twenty-five apparitions visible in seventeenth century Europe, and these comets made frequent appearances in the polemical broadsheets and chapbooks hawked in the marketplaces...
Comets were apparently flinging all over the place during this time. One of these tracts shows comets in 1680, 1682, 1683. Another shows five comets between 1664 and 1682. Another talks about comets of 1618. A tract entitled "The Signs of The Times" shows a bunch of prodigies that accompanied comets. Schechner writes:
All these outbursts were concerned with specific political quarrels. Some pamphleteers, however, raised themselves above the local rough water to examine a larger vista. They thought they saw a fast-approaching end to the world and their works adopted an apocalyptic tone. The comet of 1580 confirmed Francis Shakelton in his opinion that the Day of Judgment was near at hand...
Although Regiomontanus and others agreed that 1588 would be a year of great revolutions and world mutations, Jesus had yet to reappear when William Lilly viewed the comets of 1664 and 1665 and 1673 as tokens of the beginning of the end. In comets like that of 1680, E. Tonge, Christopher Ness, and others saw the great "northern star" the messianic herald of the last days predicted by the sybyl Tiburtina and Tycho Brahe.
Panic and joy were heightened by the great conjunction of Jupiter and Saturn in the fiery trigon in 1682 which came on the heels of a comet's apparition. While great conjunctions take place every twenty years, this one was part of an astrologically profound series of conjunctions that commenced with the climacteric conjunction at the close of the sixteenth century. By definition, climacteric conjunctions occurred only every eight hundred years when the great conjunction of Jupiter and Saturn returned to the sign of Aries and to the fiery trigon. It was widely reported by the popular press that Tycho Brahe, Johannes Kepler and Johann Heinrich Alsted correlated historical periods with climacteric conjunctions and believed that they portended great mutations and reformations...
Tycho Brahe reckoned that all odd-numbered maximum conjunctions were auspicious and urged people to look forward to the period of the sabbatical or seventh climacteric conjunction since the world's Creation which he believed would follow the conjunction in Aries in 1583. During the conjunctions in Leo in October 1682, the planets allegedly would be in the same configuration as they had been at the beginning of the world. Alsted believed this might be the last conjunction of the present world and publicly announced that the Millennium would commence in 1694.
By itself, the great conjunction in the fiery trigon was a serious matter but its power was corroborated by several other signs. Mars joined Jupiter and Saturn in 1682. There was a solar eclipse. But most critically, the great conjunction was ushered in by the comets of 1680 and 1682 and the former was said to have been unrivaled in eight hundred years. Many thought the comets augured the Apocalypse... the end of the world...
In sensationalist street literature, radical pamphleteers took advantage of these comets... At the restoration, the Crown cracked down on the almanacs of Lilly and others, blaming them for fomenting insurrection and irreligion during the Civil War and Interregnum...
The author next discusses the major controls put in place at this point to stamp out the popular discussion of predictions, interpretations... of "signs in the skies." So we can understand how so much of this period of "panic" when "governments fell" was covered up. Based on the number of pamphlets and broadsides, it must have been a really crazy time and everybody was thinking the world was going to end. BUT, as we go through this description, we find a most interesting item that relates to what our young officer witnessed at the fall of Magdeburg:
The sunny disposition of the weather during the coronation (of Charles II) was seen as the fulfillment of a prophecy. In 1630, at the time of Charles' birth, a noonday star or rival sun allegedly had appeared in the sky. ... Aurelian Cook in Titus Britannicus explained its import: 'As soon as Born, Heaven took notice of him, and eyed him with a star, appearing in defiance of the Sun at Noonday....'
For Cook, the extra sun announced that Charles ruled by divine right. Moreover, the timing of Charles' entry into London on his birthday was politically calculated to fulfill what had been portended at his birth. Abraham Cowley, poet, diplomat and spy for the court wrote:
No Star amongst ye all did, I beleeve,
Such Vigorous assistance give,
As that which thirty years ago,
At Charls his Birth, did in despight of the proud
Suns' Meridian Light,
His future Glories, this Year foreshow.Edward Matthew devoted an entire book to the fulfillment of the prophecy declaring Charles "ordained to be the most Mighty Monarch in the Universe..."
Charles' return was seen as a rebirth of England and duly recorded by a special act in the statute book, which proclaimed that 29 May was the most memorable Birth day not only of his Majesty both as a man and Prince, but likewise as an actual King...
So, a "second sun" was seen on and around May 29, 1630, and on May 20, 1631, one year later, Magdeburg fell as described by our young officer.
The standard historical description of the Fall of Magdeburg goes pretty much as follows:
The fall of Magdeburg horrified Europe. The city had been starved and then was bombarded unmercifully. The artillery shelling grew so bad, the town caught on fire. Over 20,000 of the citizens perished in the siege and the cataclysm that ended it. The city itself was burned to the ground. The cruel and pointless devastation marked a new low, an act abhorred by a generation well accustomed to horrors. [Link]
The war was to continue for 17 more years. 20 or 30 years later a lot of new comets showed up, and I used to think that this "second sun" seen at the time of the birth of Charles II may have been an appearance of our sun's twin in the far reaches of the solar system. However, with the scientific information provided by Clube and Napier et al, I have changed my view.
In any event, we begin to see why Clube wrote:
[W]hen the prospect of these global catastrophes recurs, such is the nerve-racking tension aroused in mankind that the principal leaders of civilization have long been in the habit of dissembling as to their cause (and likelihood) simply in order to preserve public calm and avoid the total breakdown of civil affairs. ...
The Christian, Islamic and Judaic cultures have all moved since the European Renaissance to adopt an unreasoning anti-apocalyptic stance, apparently unaware of the burgeoning science of catastrophes. History, it now seems, is repeating itself: it has taken the Space Age to revive the Platonist voice of reason but it emerges this time within a modern anti-fundamentalist, anti-apocalyptic tradition over which governments may, as before, be unable to exercise control. The logical response is perhaps a commitment on the part of government to the voice of reason and a decision to eliminate all signs as well as perpetrators of cosmic catastrophes in order to appease a public not too far given to rabid uniformitarianism. Cynics ... would say that we do not need the celestial threat to disguise Cold War intentions; rather we need the Cold War to disguise celestial intentions!
We see that the events of those times have been covered up and/or forgotten, for the most part in their historical context.
Long after the event, John Dryden suggested that the comets of 1664 and 1665 were related to the Sun that was seen at the birth of Charles II. He described this apparition as "That bright companion of the sun..."
After the Thirty Years War was over, comets were associated with witches and both were written off as superstition by the protestants who pride themselves on having ushered in the scientific age. Andrew C. Fix, professor of History at LaFayette College, PA, writes:
Blathasar Bekker was a minister in the Dutch Reformed church first in Friesland and then in Holland. He was educated in philosophy and theology at the northern Dutch universities of Groningen and Franeker, becoming a Doctor of Theology at Franeker. Influenced by Cartesian philosophy, he was an important critic of belief in witchcraft in his book De Betoverde Weerld (the World Bewitched) in which he argued against the possibility that disembodied spirits could contact, influence, or do evil to human beings, and thus against the possibility of witchcraft. ...
After writing a work critical of the terrestrial influence of comets Bekker became interested in other popular superstitions including witchcraft and sorcery. He approached these topics from the point of view of a Reformed minister upholding the power and earthly influence of God against the supposed power of witches and spirits. ...
In the discussions around the Sabbath, the earthly effects of comets, and witchcraft Bekker was motivated in part by Cartesian rationalism, in part by his Calvinist idea of God's omnipotence, and in part by his view of Scriptural exegesis, which included the doctrine of accommodation, the idea that God had in some places accommodated his holy language to the limited understandings of men.
In volume one of The World Bewitched Bekker maintained that belief in the Devil and evil spirits as well as in such things as fortune telling, sorcery, and witchcraft were originally pagan beliefs founded upon ignorance, prejudice, and fear that had over time crept into the Catholic church and even into Bekker's own Reformed tradition.
In volume two of the work Bekker applied Cartesian dualism to argue that the material and spiritual worlds could not interact with each other outside man and therefore spirits without bodies such as the Devil could have no influence or effect on people. (Andrew C. Fix: Angels, Devils, and Evil Spirits in Seventeenth-Century Thought: Balthasar Bekker and the Collegiants)
And so it was that records of the phenomena of that time as having any impact on Earthly matters have been explained away, covered up, dismissed, consigned to superstition and "cults."
Note: If anybody can find any clues on the
event the general was referring to at the beginning of this article,
please forward it to sott!
Dirk Beauregard
Fabfrog Blog
Sat, 26 Jan 2008 13:20 EST
Visitors from space ?
A plane on fire ?
Just after 6pm Friday 25th January, residents in the southern French city of Avignon rang the local police to report seeing "strange blue and green lights in the sky." Almost immediately Gendarmes and firefighters took to the roads to follow the lights, fearing that their source may be an aircraft on fire and about to crash. However it was quickly established that the blue and green trail of light was in fact coming from a meteorite.
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| ©Dirk Beauregard |
The celestial body in question eventually fell to earth just after 6.30pm, seven kilometres from Bourges in the centre of France. (Between Bourges and the village of Trouy). Gendarmes were quickly on the scene, when local residents reported hearing a loud explosion.
Experts say, what fell to earth was only "a small chunk of meteorite". The small souvenir from space, landed in a field several hundred metres from the nearest house. No one was injured and there was no damage to buildings. The only trace that the chunk of meteorite ever came down was the small hole left on impact.
At the scene of the impact one local resident said that if the whole meteorite had hit Bourges, the town might have been wiped off the face of the Earth. Who said life in Bourges wasn't exciting!
Sue Major Holmes
Associated Press
Tue, 29 Jan 2008 17:42 EST
Albuquerque, N.M. - An asteroid that exploded over Siberia a century ago, leaving 800 square miles of scorched or blown down trees, wasn't nearly as large as previously thought, a researcher concludes, suggesting a greater danger for Earth.
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| ©AP Photo |
According to supercomputer simulations by Sandia National Laboratories physicist Mark Boslough, the asteroid that destroyed the forest at Tunguska in Siberia in June 1908 had a blast force equivalent to one-quarter to one-third of the 10- to 20-megaton range scientists previously estimated.
Better understanding of what happened at Tunguska will allow for better estimates of risk that would allow policymakers to decide whether to try to deflect an asteroid or evacuate people in its path, he said.
"It's not clear whether a 10-megaton asteroid is more damaging than a Hurricane Katrina," Boslough said. "We can more accurately predict the location of an impact and its time better than we can a hurricane, so you really could get people out of there if it's below a certain threshold."
On Tuesday, an asteroid at least 800 feet long was making a rare close pass by Earth, but scientists said there was no chance of an impact. The closest approach of 2007 TU24 will be 334,000 miles - about 1.4 times the distance of Earth to the moon. An actual collision of a similar-sized object with Earth occurs on average every 37,000 years.
Although the computer simulation shows the Tunguska asteroid was smaller, its physical size isn't known. That would depend on such factors as speed, shape, how dense or porous it was and what it was made of, Boslough said.
Smaller asteroids approach Earth about three times more frequently than large ones. So if large asteroids approach about every 1,000 years, a smaller one would be about every 300 years, Boslough said.
"Of course there's huge uncertainties," he said.
The three-dimensional computer simulations were done last summer. Boslough presented the findings at scientific meetings in September and December. A paper on the phenomenon, co-authored by Sandia researcher Dave Crawford, has been accepted for publication in the International Journal of Impact Engineering.
The simulation, which better matches what's known of Tunguska than earlier models did, shows that the center of the asteroid's mass exploded above the ground, taking the form of a fireball blasting downward faster than the speed of sound.
But the fireball did not reach the ground, so while miles of trees outside the epicenter were flattened, those at the epicenter remained standing - scorched, with their branches stripped off.
Boslough said they were likened to telegraph poles by the first Russian expedition to Tunguska - an expedition that didn't arrive until 1927 because of the distance, primitive travel conditions and turbulent times in Russia.
If the asteroid had been as large as previously thought, "it would have had really different effects on the ground," Boslough said.
"It wouldn't have just blown over trees. There would have been a zone of completely scorched earth for several miles," he said. "That fireball would have come all the way down to the surface and everything it came in contact with would have basically just vaporized."
Alan Harris, a planetary scientist at Space Science Institute in Boulder, Colo., said he's been following Boslough's work on Tunguska for several years "and I think the idea that he has there seemed very sound."
"A meteorite or asteroid coming into Earth's atmosphere has a lot of momentum," he said. "The idea that it would push down into the atmosphere seems very plausible."
"The bottom line is it takes a lot less energy, a small explosion, to create ground damage" such as that at Tunguska, said Harris, who studies the frequency of such impacts to assess hazards.
In the future, he said, he'll take Boslough's work into account and revise estimates of damage from impacts by smaller objects.
Scientists at NASA's Jet Propulsion Laboratory in Pasadena, Calif., have obtained the first images of asteroid 2007 TU24 using high-resolution radar data. The data indicate the asteroid is somewhat asymmetrical in shape, with a diameter roughly 250 meters (800 feet) in size. Asteroid 2007 TU24 will pass within 1.4 lunar distances, or 538,000 kilometers (334,000 miles), of Earth on Jan. 29 at 12:33 a.m. Pacific time (3:33 a.m. Eastern time).
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| ©NASA/JPL-Caltech |
| These low-resolution radar images of asteroid 2007 TU24 were taken over a few hours by the Goldstone Solar System Radar Telescope in California's Mojave Desert. Image resolution is approximately 20-meters per pixel. Next week, the plan is to have a combination of several telescopes provide higher resolution images. |
"With these first radar observations finished, we can guarantee that next week's 1.4-lunar-distance approach is the closest until at least the end of the next century," said Steve Ostro, JPL astronomer and principal investigator for the project. "It is also the asteroid's closest Earth approach for more than 2,000 years."
Scientists at NASA's Near-Earth Object Program Office at JPL have determined that there is no possibility of an impact with Earth in the foreseeable future.
Asteroid 2007 TU24 was discovered by the NASA-sponsored Catalina Sky Survey on Oct. 11, 2007. The first radar detection of the asteroid was acquired on Jan. 23 using the Goldstone 70-meter (230-foot) antenna. The Goldstone antenna is part of NASA's Deep Space Network Goldstone station in Southern California's Mojave Desert. Goldstone's 70-meter diameter (230-foot) antenna is capable of tracking a spacecraft traveling more than 16 billion kilometers (10 billion miles) from Earth. The surface of the 70-meter reflector must remain accurate within a fraction of the signal wavelength, meaning that the precision across the 3,850-square-meter (41,400-square-foot) surface is maintained within one centimeter (0.4 inch).
Ostro and his team plan further radar observations of asteroid 2007 TU24 using the National Science Foundation's Arecibo Observatory in Puerto Rico on Jan. 27-28 and Feb. 1-4.
The asteroid will reach an approximate apparent magnitude 10.3 on Jan. 29-30 before quickly becoming fainter as it moves farther from Earth. On that night, the asteroid will be observable in dark and clear skies through amateur telescopes with apertures of at least 7.6 centimeters (three inches). An object with a magnitude of 10.3 is about 50 times fainter than an object just visible to the naked eye in a clear, dark sky.
Scientists working with Ostro on the project include Lance Benner and Jon Giorgini of JPL, Mike Nolan of the Arecibo Observatory, and Greg Black of the University of Virginia.
NASA detects and tracks asteroids and comets passing close to Earth. The Near Earth Object Observation Program, commonly called "Spaceguard," discovers, characterizes and computes trajectories for these objects to determine if any could be potentially hazardous to our planet. The Arecibo Observatory is part of the National Astronomy and Ionosphere Center, a national research center operated by Cornell University, Ithaca, N.Y., for the National Science Foundation.
Martine Lecaudey
La Dépêche du Midi
Thu, 31 Jan 2008 08:56 EST
The meteorite that stunned several French people on January 25th , in the late afternoon, may not have fallen in the surroundings of Bourges (Cher), as was first believed.
According to the research done by Dominique Caudron, an amateur astronomer in the North of France, the falling point would be located "a little bit toward the East of Albi, in the surroundings of Paulinet".
In an article published by le Figaro, Pierre Lagrange, a sociologist of sciences and member of the College of Experts working in a team of study and information on Unidentified Space Phenomena (Geipan) at the Centre National d'Etudes Spatiales (National Center of Space Studies) in Toulouse, gives a precise description of the calculations of the young astronomer.
This new localization helps to understand the many reports from witnesses gathered in the Tarn department , even if the celestial object was also seen in other departments of the 'Midi toulousain' (the region surrounding Toulouse).
"Between 5:30 p.m. and 8 p.m. we saw very clearly a sort of 'sky rocket' falling in a diagonal direction in a forest at the end of the route going from Vabre to Cunac".
"A fireball with a silvery tail. It was very low, I had the feeling that it was going to hit my car...," remembers very clearly Michele Boyer in Blaye-les-Mines.
"It was like a rocket with sparkles all around. It was only three meters from the ground. In my opinion, it fell either on the hedge or on the neighbouring field," says Guy Morandin, a citizen of Albi.
Jacques Patenet, head of the Geipan at the CNES (National Center of Space Studies) in Toulouse confirmed yesterday evening the accuracy of Dominique Cuadron's calculation and the new hypothesis of an almost vertical path above the Tarn department.
"An atmospheric entrance between 35 and 50 miles high is seen from a very, very long distance, specially if it is a big and dense meteorite of metallic consistency. But most of the time, nothing reaches the ground."
Calling for witnesses
According to the scientist from Toulouse, "it would be an exceptional thing if we could find anything".
Jacques Patenet invites the witnesses of this event to report their observations in order to confront and add accuracy to Dominique Caudron's calculations.
Contact: geipan@cnes.fr
Some reports from eyewitnesses:
In the region of Toulouse, a luminous phenomenon was pointed out in several departments, among which we find the Haute-Garonne and especially the Tarn.
Marc Fabre saw "a big white trail" above Puech Auriol (Castres's commune), while he was playing football with his son.
Mrs Enery, living in Gaillac, saw the meteorite "passing at a very, very high speed from West to East." Still in the Tarn department, Mr. Roquelaure from Lombers claims having seen "at exactly 6:15 p.m., while he was going back home from the hairdresser in Montdragon, a red fireball with a sparkling tail like the candles on a birthday cake..."
"I saw the meteorite here, in Auch, on Friday evening. It was a big fireball that flew very rapidly across the sky at the Northeast while I was at a traffic light coming back from work. It was not dark yet, but the phenomenon was very intense," explains Dominique Amouroux, one of our readers from the Gers department. She is not the only one to have seen the fireball in the sky above Gers. Laurent Azanowsky, an inhabitant of Arblade-le-Haut said: "I saw a fireball coming from the Northwest and going Southeast, totally in the opposite direction to what the people in Bourges report."
A woman from Auscitaine also saw the celestial body when driving on Friday, between 6 p.m. and 6:30 p.m., in Ordan-Larroque: "We were at the exit of Ordan, on the road that goes to the forest of Auch. There, there are a few houses, and a lady who was in her garden also saw it," she explains.
"It was something very shiny with a white trail. We have the feeling that it fell vertically, on a field... But if that had been the case, there would have been a fire, woudn't it?" she asks. "We would like to know the why, the how," she says, hoping that the beautiful show did not end somewhere in a catastrophe.
Translated by SOTT.net
Comment: Sounds like maybe there were two of these fireballs in France that day, not just one, given the differences in the reports.
1 comments:
at around 12 20 i saw a meterite very close to olympia washington did anyone else out there see it?
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