MosNews
Created: 02/11/2006
An asteroid could collide with the Earth in 2029, a Sergey Smirnov, a senior researcher at the Pulkovo Space Observatory, told a press conference in Moscow on Thursday, Interfax news agency reports.
On April 13, 2029 the asteroid Apofiz-99942 will be at its closest distance to the Earth for 200 years, Smirnov said.
The asteroid will pass the Earth at a distance of 30,000 to 40,000 km. ìThis crosses the geo-stationary orbit, where all the telecommunications and a lot of military satellites are,î he said.
Whatever happens, the Earth will feel the effect of the asteroid, and in the worst case, it will collide with the Earth, and at best it will damage equipment in space in the geo-stationary orbit.
Columbia University Research Finds Correlation Between Meteorite and Comet Impacts and an Increase in Volcanic Activity Development
Earth Institute News
Created: 01/17/03
Supporting the theory that catastrophic events significantly influence major Earth processes, researchers have determined that comet and meteorite impacts on Earth occurring over the last 4 billion years have directly correlated with the activity of strong and normal mantle plumes - heated mantle rock causing volcanic eruptions (e.g. Hawaii, Iceland).
Dr. Dallas Abbott, of the Lamont-Doherty Earth Institute, and Ann Isley, of SUNY Oswego, assembled an expanded database of terrestrial impacts over the last 4 billion years. They used clues from known craters such as impact spherules created from impact melt, and from impact breccias that are created from shattered debris fused under high temperatures and pressures. They also examined the activity of normal and strong mantle plumes over geological time. Time series derived from this data showed that 10 major peaks in terrestrial impact activity were seen on Earth over this time period. Nine out of 10 of these impact peaks are directly matched by peaks in normal to strong mantle plume volcanism. In addition, there are two prominent lulls in impact activity, also corresponding to periods of lower activity of mantle plume volcanism.
The biggest mystery remaining is the mechanism by which large impacts might intensify volcanism. Abbott and Isley propose three possibilities: impacts may cause cracking and de-stressing of the crust, allowing melts that had been trapped due to tectonic stress and/or impermeable boundaries to rise more easily to the surface; impacts may produce large cracks in the surface of the Earth allowing new plate boundaries to form with consequent thinner lithosphere and longer melt columns; or impacts may produce microdikes at the core mantle boundary, which, if very thin, would allow molten core and mantle material to mix, increasing the amount of heat available for melting the mantle and producing a rapid intensification of existing mantle plumes.
Another question raised by the correlation between impacts and volcanism concerns widely adopted theories that meteorite and comet impacts were the cause of mass extinctions of life on Earth. Was it the impact alone or could major episodes of mantle plume volcanism have contributed to these extinctions?
Dallas Abbott is an adjunct research scientist at The Lamont-Doherty Earth Observatory. Her primary research focus is the thermal history of the earth, and the manner in which heat transport through the crust and upper mantle influences geological processes, both ancient and present-day.
Abbott and Isley's research paper, "Extraterrestrial Influences on Mantle Plume Activity," is appearing in Earth and Planetary Science Letters this month.
The Lamont-Doherty Earth Observatory, a research unit of the Earth Institute, is one of the world's leading research centers examining the planet from its core to its atmosphere, across every continent and every ocean. From global climate change to earthquakes, volcanoes, environmental hazards and beyond, Observatory scientists continue to provide the basic knowledge of Earth systems that must inform the future health and habitability of our planet.
The Earth Institute at Columbia University is among the worldís leading academic centers for the integrated study of Earth, its environment, and society. The Earth Institute builds upon excellence in the core disciplines ó earth sciences, biological sciences, engineering sciences, social sciences and health sciences ó and stresses cross-disciplinary approaches to complex problems. Through its research, training and global partnerships, it mobilizes science and technology to advance sustainable development, while placing special emphasis on the needs of the worldís poor.
'Band of misfits' theory: Meteors are not that rare
By Sandra Blakeslee / The New York Times
Created: November 14, 2006
At the southern end of Madagascar lie four enormous wedge-shaped sediment deposits, called chevrons, that are composed of material from the ocean floor. Each covers more than 100 square kilometers with sediment hundreds of meters deep.
On close inspection, the chevron deposits contain deep-ocean microfossils that are fused with a medley of metals typically formed by cosmic impacts. And all of them point in the same direction - toward the middle of the Indian Ocean where a newly discovered crater, 29 kilometers, or 18 miles, in diameter, lies 3,800 meters, or 12,500 feet, below the surface.
The explanation is obvious to some scientists. A large asteroid or comet, the kind that could kill a quarter of the world's population, smashed into the Indian Ocean 4,800 years ago, producing a tsunami at least 183 meters high, about 13 times as big as the one that inundated Indonesia nearly two years ago. The wave carried the huge deposits of sediment to land.
Most astronomers doubt that any large comets or asteroids have crashed into the Earth in the past 10,000 years. But the self-described "band of misfits" that make up the two-year-old Holocene Impact Working Group say astronomers simply have not known how or where to look for evidence.
Scientists in the working group say the evidence for such impacts during the past 10,000 years, known as the Holocene epoch, is strong enough to overturn current estimates of how often the Earth suffers a violent impact on the order of a 10-megaton explosion. Instead of once in 500,000 to 1 million years, as astronomers now calculate, catastrophic impacts could happen every few thousand years.
The researchers, who formed the working group after finding one another through an international conference, are based in the United States, Australia, Russia, France and Ireland. They are established experts in geology, geophysics, geomorphology, tsunamis, tree rings, soil science and archaeology, including the structural analysis of myth. Their efforts are just getting under way, but they will present some of their work at the American Geophysical Union meeting in December in San Francisco.
This year the group started using Google Earth, a free source of satellite images, to search the globe for chevrons, which they interpret as evidence of past giant tsunamis. Scores of such sites have turned up in Australia, Africa, Europe and the United States.
When the chevrons all point in the same direction to open water, Dallas Abbott, an adjunct research scientist at Lamont-Doherty Earth Observatory in Palisades, New York, uses a different satellite technology to look for oceanic craters. With increasing frequency, she finds them, including an especially large one dating back 4,800 years.
So far, astronomers are skeptical but willing to look at the evidence, said David Morrison, a leading authority on asteroids and comets at the NASA Ames Research Center in California.
Surveys show that as many as 185 large asteroids or comets hit the Earth in the far-distant past, although most of the craters are on land. No one has spent much time looking for craters in the deep ocean, Morrison said, assuming that young ones do not exist and that old ones would be filled with sediment.
Astronomers monitor every small space object with an orbit close to the Earth. "We know what's out there, when they return, how close they come," Morrison said. Given their observations, "there is no reason to think we have had major hits in the last 10,000 years," he continued, adding, "But if Dallas is right and they find 10 such events, we'll have a real contradiction on our hands."
Peter Bobrowski, a researcher of natural hazards at the Geological Survey of Canada, said that "chevrons are fantastic features" but do not prove that megatsunamis are real.
Catch a meteor show this weekend
By Joe Rao Skywatching columnist
Created: Nov. 17, 2006
Mid-November brings us the return of the famous Leonid meteor shower, which has a storied history of producing some of the most sensational meteor displays ever recorded.
These meteors travel along the orbit of periodic Comet 55P/Tempel-Tuttle, and whenever that comet is passing through the inner solar system, the Leonids have a chance to provide us with a dramatic show. But the most recent passage of the comet around the sun came back in 1998, and we are now well past the favored time frame when, for several years running, observers in various parts of the world were witnessing very strong, even storm-level Leonid activity.
The most recent Leonid storms occurred in 2001 and 2002.
That's why this weekend, when the Leonids traditionally should be at their most numerous, we normally would expect to see no more than 10 meteors per hour, even with the promise of excellent viewing conditions thanks to a new moon on the 20th.
Still, for parts of Europe, Africa and eastern North America, a far more prolific Leonid show could be in the offing this year.
Judging the future by the past
On the morning of Nov. 17, 1969, an unexpected burst of Leonid activity was observed from parts of the eastern United States.
Meteor rates had been rather lackluster that morning ó until quite suddenly, at around 8:50 GMT, Leonids began falling fast and furiously. Some observers reported an average of two to four meteor sightings per minute. Peak activity apparently occurred within a few minutes of 9:00 GMT. Then, just as abruptly as the surprising display began, it rapidly diminished until by around 9:20 GMT, things had pretty much returned to normal.
Most of the meteors that were observed were relatively faint ó although as is typical of the ultrafast Leonids, there were several brilliant meteors, leaving persistent trains in their wake that lasted for many seconds.
What caught observers off guard on that morning 37 Novembers ago was Earth's passage through a very narrow trail of dust that had been ejected from Comet Tempel-Tuttle back in 1932. The densest part of that trail was probably about 30,000 miles (48,000 kilometers) wide, yet Earth, traveling in its orbit around the sun at 18.5 miles per second (29.8 kilometers per second), swept through it in only about a half an hour.
What to expect
In 1999, astronomers Robert McNaught and David Asher published a report concerning Leonid dust trails and cited the case of the 1969 outburst. They also forecast that in 2006 the Earth would encounter an adjoining section of that very same dust trail from 1932.
The time of this year's encounter is predicted for Sunday at 4:45 GMT (11:45 p.m. ET Saturday). Other reputable meteor forecasters such as Thomas Van Flandern of the United States, Esko Lyytinen of Finland and Jeremie Vaubaillon of France confirmed in their own Leonid studies (to within minutes of McNaught and Asher's) that Earth would indeed encounter the 1932 dust trail again in 2006.
But while another short-lived outburst seems probable this year, it likely will not be of the same intensity as what was seen in 1969. In that year, it had been about 4.5 years since Comet Tempel-Tuttle swept past the sun. But this November will be almost nine years since the comet last passed this way. So when Earth interacts with that same 1932 trail this year, the particles probably won't be as thickly clustered together as they were in 1969, and the resultant display might be only about half as strong.
Most forecasters are indicating that a sharp peak of perhaps 100 to 150 (mostly faint) Leonids per hour might be seen this year.
Radical Rethink in Meteorite Impact Timing
Henry See / Signs of the Times
Created: 15 November 2006
For years the mainstream scientific community has fed us the line that there is nothing to worry about down on on Earth from meteor impacts because the really big ones only happen once every 500,000 to 1,000,000 years. Now, a small group of scientists are challenging that view:
Scientists in the working group say the evidence for such impacts during the past 10,000 years, known as the Holocene epoch, is strong enough to overturn current estimates of how often the Earth suffers a violent impact on the order of a 10-megaton explosion. Instead of once in 500,000 to 1 million years, as astronomers now calculate, catastrophic impacts could happen every few thousand years.
Using Google Earth, they are identifying numerous impact craters that have gone undiscovered. The scientists, who call themselves the Holocene Impact Working Group, have found numerous impact craters they say were created within the last 10,000 years. You can read the full article on today's page.
Signs of the Times has been tracking new accounts of fireballs. We have noticed an increase in reports in recent years, including a recent report of a cottage in Germany that burned down due to a small meteorite impact, and another from New Orleans several years ago that put a hole in the roof of a house.
We have been warning our readers of the possibility of a cosmic bombardment for many, many years. We can't give you a date because we aren't prophets. However, our research indicates that there are cycles of bombardment. One of these is approximately 3600 years. There are also other cycles that would include the 2800 B.C. impact cited in the article above, the 540 A.D. impact that wasted a large portion of Europe and brought on the Dark Ages. See Mike Baillie's book Exodus to Arthur for more on that impact.
The mechanisms of these cycles are outlined in Laura Knight-Jadczyk's article Independence Day. In brief, our sun is part of a double star system. The sun's companion star is a brown dwarf with an orbit of 27 million years. When the dark star is moving towards its closest point to the sun, it passes through the Oort Cloud, a band of debris circling the solar system far beyond the orbit of Pluto. The effect of this close passage is a dampening of solar activity on the one hand, and the kicking off of a new cycle of cometary impacts in the solar system as it kicks out a large cloud of rock and debris towards the inner solar system.
Twenty five years ago, Jupiter had 13 identified moons, Saturn had 10. Today, Jupiter has 63 and Saturn 56! Many of these are pieces of rock that are no more than two or three kilometres across.
One explanation is that telescopes have so improved that we are capable of seeing ever more tiny satellites around the planets. The second possibility is that these new "moons" are pieces of the cosmic cloud that have been caught in the gravity of these two large planets as the cloud makes its way into the inner solar system.
From 1645 until 1715, the Earth underwent a strong cold spell. The solar activity of the sun spent the period in an extended minimum, known as the Maunder Minimum. This extended minimum has flummoxed researchers, who have been unable to explain how and why it occurred. The close passage of the dark companion would explain such a dampening.
Admittedly, this evidence does not constitute proof that there is a devastating collection of space rock headed on a collision course for Earth. Nor does it confirm in any way the 3600 cycle hypothesis. However, it is strong enough evidence to support the current working hypothesis. Given that this hypothesis suggests that the last event in the 3600 year cycle occurred in around 1628 with the eruption of Mt Thera on the island of Santorini, the event that has been tied to the fall of the Bronze Age, there is good reason to think that a new cataclysm is in the offing. If the hypothesis of the dark star and its close approach in the last three hundred years is correct, the Thera event would have been the last of the old cycle while the catastrophe that awaits us is the first of a new cycle, that is, the devastation will be much greater.
Seen in this context, the current political scene takes on a different colour. The shocking lack of care for the planet and the environment on the part of our leaders, both elected and non-elected, might well be tied to a special knowledge they have of things to come. If society as we know it, not to mention the physical landscape itself, is to be subject to radical upheaval, then why worry about global warming, the ozone layer, or the depletion of resources? What would be important to the pathocrats is to set themselves up as the survivors of such a great tragedy, so that it is their children who would inherit the Earth.
The massive underground complexes built by the military to protect governments and business, financial, and other "leaders" take on a new, and even more sinister air under such a scenario. The war on terror is a sideshow meant to keep us occupied, our attention diverted from the ultimate enemy, while justifying the repressive measures that will be necessary when the people of the planet awaken to the real threat and demand why their leaders have done nothing to protect them. Unlike the recent disaster movies that showed a worried government sending Hollywood heroes into orbit to nuke the incoming comets and meteors, our real-life leaders couldn't care less what happens to the rest of us. Their future, they believe, is secure. We are to be left to suffer the consequences of massive mega-tsunamis, volcanoes, earthquakes, and the subsequent "nuclear winter" that will block sunlight and put the planet into a long-term deep-freeze.
Such is our future if the myths handed down to us by our ancestors are understood as warnings, if the hypothesis that we have formed based upon data collected and collated from researchers is confirmed, and if the horrifying events justified by the so-called "war on terror" are seen in context.
The possibility exists, therefore, that the majority of the inhabitants of this planet will be dead, perhaps in only a few years. The survivors would be reduced to dwelling in caves, while the pathocrats would continue to rule from their 'underground cities', living in the luxury to which they are accustomed, and setting out for another round of "civilisation".
What would be the consequences if this knowledge were to become generally known? How would the planet's people react if they knew they were facing their own mortality? Their children's mortality? The end of everything they know?
Clearly, such knowledge can never be allowed to become widespread. It is a threat to the existence of the established powers, to the pathological figures who lead us. They would be forced to put into place repressive measures to keep "the people" in their place. They would strive to foment conflicts and wars between as many different groups as possible in order to keep the people from unifying against their common enemy, the pathocracy. In short, they would be doing exactly what is being done today.
As to what any of us can do in the face of such a hypothesised scenario, we can only suggest that our readers watch for new data, for an increase in fireballs and unexplained 'sonic booms', for increased volcanic and seismic activity, possibly due to the increased gravitational stress on the planet from the approaching cloud. It is possible that one or two impacts of minor importance could occur. These events would be followed by assurances that the danger is past, that we should forget about it for the moment, that 'lightning doesn't strike the same place twice'.
But if our hypothesis is correct, this will only be the lull before the storm.
See our Signs Supplement on Meteors, Asteroids, Comets, and NEOs.
Wanted: man to land on killer asteroid and gently nudge it from path to Earth
David Adam / The Guardian
Created: Friday November 17, 2006
It is the stuff of nightmares and, until now, Hollywood thrillers. A huge asteroid is on a catastrophic collision course with Earth and mankind is poised to go the way of the dinosaurs.
To save the day, Nasa now plans to go where only Bruce Willis has gone before. The US space agency is drawing up plans to land an astronaut on an asteroid hurtling through space at more than 30,000 mph. It wants to know whether humans could master techniques needed to deflect such a doomsday object when it is eventually identified. The proposals are at an early stage, and a spacecraft needed just to send an astronaut that far into space exists only on the drawing board, but they are deadly serious. A smallish asteroid called Apophis has already been identified as a possible threat to Earth in 2036.
Chris McKay of the Nasa Johnson Space Centre in Houston told the website Space.com: "There's a lot of public resonance with the notion that Nasa ought to be doing something about killer asteroids ... to be able to send serious equipment to an asteroid.
"The public wants us to have mastered the problem of dealing with asteroids. So being able to have astronauts go out there and sort of poke one with a stick would be scientifically valuable as well as demonstrate human capabilities."
A 1bn tonne asteroid just 1km across striking the Earth at a 45 degree angle could generate the equivalent of a 50,000 megatonne thermonuclear explosion. Attempting to break it up with an atomic warhead might only generate thousands of smaller objects on a similar course, which could have time to reform. Scientists agree the best approach, given enough warning, would be to gently nudge the object into a safer orbit.
"A human mission to a near Earth asteroid would be scientifically worthwhile," Dr McKay said. "There could be testing of various approaches. We don't know enough about asteroids right now to know the best strategy for mitigation."
Matt Genge, a space researcher at Imperial College, London, has calculated that something with the mass, acceleration and thrust of a small car could push an asteroid weighing a billion tonnes out of the path of Earth in just 75 days.
Gianmarco Radice, an asteroid expert at Glasgow University, said the best approach would be to land a device to dig into the object. "You could place something on the surface to eject material that would push the asteroid in the other direction."
Mirrors, lights and even paint could change the way the object absorbed light and heat enough to shift its direction over 20 years or so. With less notice, mankind could be forced to take more drastic measures, such as setting off a massive explosion on or near the object to change its course. In 2005, Nasa's Deep Impact mission tested a different technique when it placed an object into the path of a comet.
Dr Radice said robots could do the job just as well, doing away with the need for a risky and expensive manned mission. Last year Japan showed with its Hayabusa probe that a remote spacecraft can land on an asteroid.
But with manned missions to the moon and possibly Mars on its to-do list again, Nasa is keen to extend the reach of its astronauts.
Dan Durda, a senior research scientist in the Department of Space Studies at the Southwest Research Institute in Boulder, Colorado said an asteroid landing mission would be a good way test the new Constellation programme spacecraft, the Apollo-style planned replacements for the space shuttle with which Nasa hopes to return to the moon.
He told Space.com: "A very natural, early extension of the exploration capabilities of this new vehicle's architecture would be a "quick-dash" near-Earth asteroid rendezvous mission."
Tom Jones, a former shuttle astronaut, said: "After a lunar visit, we face a long interval in Earth-Moon space while we build up experience and technology for a Mars mission. An asteroid mission could take us immediately into deep space, sustaining programme momentum, adding public excitement and reducing the risk of a later Mars mission."
Europe has its own efforts to tackle asteroids. Its planned Don Quijote mission will launch two robot spacecraft, one to tilt at a harmless passing space rock, and a second to film the collision and watch for any deviation in the asteroid's path.
'Not if, but when...' Hits and near misses
At Nasa's Jet Propulsion Laboratory, in California, scientists monitor all "potentially hazardous asteroids" that might one day end up on a collision course with Earth. So far they number 831. The next close-ish shave - at a mere 17 times the distance from the Sun to the Earth - will be asteroid 2004QD14 on November 29.
The Earth has a long history of asteroid strikes. Thirty five million years ago, a 5km-wide asteroid ploughed into what is now Chesapeake Bay, in the US, leaving an 80km crater. In 1908, an asteroid devastated swaths of Siberia when it exploded mid-air with the force of 1,000 Hiroshimas. The theory that the dinosaurs were wiped out by a huge asteroid striking Mexico 65m years ago is controversial since scientists uncovered rocks from the crater predating the extinction of the dinosaurs by 300,000 years.
A near miss, when asteroid QW7 came within 4m km of Earth in September 2000, led Liberal Democrat MP Lembit Opik to declare: "It's not a case of if we will be hit, it is a question of when. Each of us is 750 times more likely to be killed by an asteroid than to win this weekend's lottery."
In January 2002, the former science minister, David Sainsbury, announced the government's response to the threat from hurtling asteroids: a new information centre based in Leicester.
Fireball in sky excites locals
Daily Telegraph
Created: November 28, 2006
In what sounds like a scene from the 70s movie Close Encounters of the Third Kind, people in South Australia and western Victoria deluged police and media with reports of a spectacular meteor sighting.
The Bureau of Meteorology confirmed the object was a meteor.
Police in SA said they took calls from just after 8pm (CST) yesterday from Renmark and Loxton in the Riverland, most Adelaide suburbs and then from people living south of the city, with reports of a fireball in the sky.
In Victoria, callers to local radio from Bendigo to Horsham in the state's northwest down to Colac in the southwest, reported seeing a bright green object shooting westward in the sky.
One caller, Jeff, said he saw what he thought was a comet about 8.30pm (AEDT) as he was driving into Horsham.
"It was green like a meteorite or shooting star," he told ABC radio.
"It was really pretty bright and you could see something else coming down as well, but what it was I don't know."
Monty from Kaniva, near the SA border, said the object was bright and appeared to have debris trailing behind it.
"It was before sunset and normally you only see those things in the dark," Monty said.
"The trail hung in the sky for at least 15 minutes afterward like a jet stream."
Allen at Colac said: "I was sitting at the Shell servo at Colac and I was looking to the north and you could see the green light with the tail thing behind it."
Brian, who owns a farm at Laanecoorie, west of Bendigo, said he and his wife were outside when they saw the comet-like object streak across the sky.
"We looked up and there was a green comet-like thing dropping out of the western sky," Brian said.
"It dropped over the trees at the back of our property and it was making a tail as it went down."
Meteor sighting in SA, Vic skies
Created: Tuesday Nov 28 09:55 AEDT
In what sounds like a scene from the 70s movie Close Encounters of the Third Kind, people in South Australia and western Victoria have deluged police and media with reports of a spectacular meteor sighting.
Police in SA said they took calls from just after 8pm (CST) on Monday from Renmark and Loxton in the Riverland, most Adelaide suburbs and then from people living south of the city, with reports of something looking like a fireball in the sky.
In Victoria, callers to ABC Radio, from Bendigo to Horsham in the state's north-west down to Colac in the south-west, reported seeing a bright green coloured object shooting westward in the sky.
"It was green like a meteorite or shooting star," he told ABC Radio.
"It was really pretty bright and you could see something else coming down as well, but what it was I don't know."
Monty from Kaniva, near the SA border, said the object was bright and appeared to have debris trailing behind it.
"It was before sunset and normally you only see those things in the dark," Monty said.
"The trail hung in the sky for at least 15 minutes afterward like a jet stream."
Allen at Colac said: "I was sitting at the Shell servo at Colac and I was looking to the north and you could see the green light with the tail thing behind it."
Brian, who owns a farm at Laanecoorie, west of Bendigo, said he and his wife were outside when they saw the comet-like object streak across the sky.
"We looked up and there was a green comet-like thing dropping out of the western sky," Brian said.
"It dropped over the trees at the back of our property and it was making a tail as it went down."
An SA Police spokesman said later that the Bureau of Meteorology confirmed the object was a meteor.
Study: Single Meteorite Impact Killed Dinosaurs
By Ker Than
Created: 28 November 2006
Analysis of ancient sediment taken from the bottom of the Atlantic Ocean supports the view that the dinosaurs' extinction was caused by a single rogue meteor striking Earth, and not by multiple space rock impacts, a new study finds.
"The sample we found strongly support the single-impact hypothesis," said lead researcher Ken MacLeod of the University of Missouri-Columbia.
Geological evidence shows that a giant meteorite about six miles wide smashed into the Yucatan Peninsula close to the current Mexican town of Chicxulub 65 million years ago.
According to the standard theory, the impact set off volcanic eruptions, massive earthquakes and tsunamis that sent dust flying high into the atmosphere, where it lingered and blocked the sun's light for decades or centuries.
Deprived of the sun's life-giving rays, plants and animals began to die. The dark skies also caused temperatures to plummet and white-hot debris falling back to Earth ignited wildfires all over the globe, the smoke of which mixed with rain clouds to create a scalding acid downpour.
Many scientists believe the combined calamities killed off most of the life on Earth, including dinosaurs, in the so-called K-T extinction event .
A small team of scientists, however, have argued that a single meteorite was not enough to end the dinosaurs' reign, and that the Yucatan impact occurred 300,000 years too early. The biggest proponent of this alternative scenario is Gerta Keller of Princeton University.
Keller thinks that the Chicxulub impact, combined with volcanoes in India and global warming, only upset the ecological balance, causing many species to shrink in size. But these things weren't enough to trigger a mass extinction, she believes. Instead, Keller speculates that a second, currently unidentified meteor crashed sometime after Chicxulub.
But a new examination of sediments taken from the Demerara Rise in the Atlantic Ocean casts fresh doubt on Keller's minority view.
Located some 3,000 miles from the Yucatan Peninsula, the Demerara Rise is considered an intermediate distance from the impact site. Interpretation of samples collected from locations close to the crater are complicated by factors such as waves, earthquakes and landslides that were triggered by the impact and which shuffle the sediment layers. Samples from farther away, meanwhile, received little impact debris and are much less helpful in recreating events.
The Demerara Rise sample thus provides an unusually clear picture of the events at the time of the mass extinction that claimed the dinosaurs, MacLeod argues. Analysis revealed a unique layer composed of impact-related material, but none above or below that layer.
The Demerara Rise sediment, therefore, shows "no support for multiple impacts or other stresses leading up to or following the deposition of material from the impact," MacLeod said.
Light in sky probably space junk or meteor
By Eric Fleischauer and Seth Burkett
Created: November 29, 2006
LACON ó At 5:28 p.m. Tuesday, Morgan County 911 lines began ringing. A brilliant lime-green light had appeared, callers said, possibly a downed aircraft.
Callers to The Daily described the same thing, some saying they saw an object falling from the sky and breaking into pieces before the light appeared.
No airplanes crashed, and astronomers said the event was probably a "bolide," a random meteor that could have been natural or man-made.
Morgan County Sheriff Chief Deputy Mike Corley said the reports came from southern Morgan County and Cullman County. Firefighters and various police agencies searched the area but found no crash site.
"(We found) no fires, no explosions or anything to explain it," said Corley. "It was like a falling star."
Decatur astronomer Loren Ball said the bolide likely came from "space junk." He said the North American Aerospace Defense Command is tracking 9,000 pieces of man-made junk including nuts, bolts, gloves and pieces of expired satellites that, because of friction with the upper atmosphere, are gradually approaching Earth.
The lime-green color, Ball said, is consistent with the color that would come from burning aluminum as it entered Earth's atmosphere.
The fact that the object broke into pieces is no surprise, whether the object was natural or man-made. Moving at 10 to 40 miles per second, it would generate tremendous energy, much of it in the form of light. He said a bolide the size of a golf ball generates enough light to trigger calls to the media.
"Something like this happens every day, but there are not always people around to see it," Ball said.
Space junk
According to some studies, there are 4 million pounds of space junk ó as many as 110,000 objects larger than 1 centimeter ó in low-Earth orbit. They provide a brilliant display on Earth, but can be hazardous to astronauts.
A small speck of paint from a satellite shooting around the Earth once dug a quarter-inch pit in a space shuttle window.
Earth's atmosphere extends 250 miles above its surface, Ball said, a fact that forces the International Space Station and the Hubble Space Telescope to periodically correct their orbit so they won't be pulled into a downward spiral.
Gene Byrd, professor of astronomy at The University of Alabama, said the sightings were too late to be explained by a meteor shower that took place last week.
Bolide explanation
He said the composition of the bolide could explain its greenish color, but the human eye might also explain it. The eye has greater sensitivity to blue and green colors, he said.
Byrd's guess was that it was "a large, sporadic meteor." He said such meteors occasionally emit a sonic boom, and usually are rock fragments from the asteroid belt.
In the 1950s, he said, a small meteor actually struck a woman in Sylacauga, sending her to the hospital with a severe bruise. Astronomers believe a 10-mile-wide meteor that hit Mexico caused the extinction of the dinosaurs, Byrd said.
Corley said he saw the event from his home.
"It did have an unusual color. It had a bright, glowing, lime-green color to it," Corley said.
The Alabama sightings came a day after a similar green fireball was seen in the skies above Australia.
Meteorologists there identified the object as a meteor, likely produced as the Earth passed through the tail of the comet Tempel-Tuttle according to news reports.
Last week, a Russian cosmonaut hit a golf ball into orbit from the International Space Station as part of a publicity campaign to raise money for the Russian space program.
The golf ball joined the other pieces of space junk that will eventually burn up in the upper atmosphere.
Comment: Sure, it was only space junk. Nothing to worry about here, folks. Move along now. Don't fret about the increase in reports oif bright fireballs. It's only space junk. Really. Have we ever lied to you before?
Mystery lights reported for second night
The Age.com
Created: November 29, 2006
For the second night in a row residents in western Victoria have reported seeing a bright light in the sky.
Residents at Ballarat, west of Melbourne, said they saw something that looked like a UFO after spotting an orange-coloured light in the sky about 10pm yesterday.
The object hovered for more than one minute. But one resident said it could have been a model helicopter.
"A lot of guys fly night choppers here and they have the LCD lights around the blades and they have lights all down the boom and tail rotor," the man, identified only as Ian, told Southern Cross Broadcasting.
"These models can hover and they can go from zero to about 100 kph in a few seconds."
On Monday night, people in South Australia and western Victoria deluged police and media with reports of a spectacular meteor sighting.
Police in SA said they took calls from just after 8pm (CST) on Monday from Renmark and Loxton in the Riverland, most Adelaide suburbs and then from people living south of the city, with reports of something looking like a fireball in the sky.
In Victoria, callers to ABC Radio from Bendigo to Horsham in the state's north-west down to Colac in the south-west, reported seeing a bright green coloured object shooting westward in the sky.
A South Australia Police spokesman said later that the Bureau of Meteorology confirmed the object seen on Monday night was a meteor.
We need a statue of Ms Hodges and her meteor
David Williamson, Western Mail
Created: Nov 30 2006
Let's pause for a moment and ponder Elizabeth Hodges of Sylacauga, Alabama.
On this day in 1954 she was napping in her living room when a meteorite the size of grapefruit crashed through the ceiling, bounced off her radio, and gave her a nasty bruise.
This is the only time in human history that we can say with certainty someone was hit by a space rock.
What's fascinating about this story is the collision between the ordinary and the extraordinary.
American universities are crammed with scientists who nightly abandon their families to search the skies for heavenly bodies. Like pond-dwelling creatures looking up through murky waters at the strange shapes of fishermen standing on dry land, these astronomers yearn to see with certainty the universe beyond the foggy stratosphere.
Kindly gods might have made their day and directed a meteorite to their front door, but instead one plummeted into the abode of snoozing Ms Hodges.
How did this change her life? Did she feel incredibly lucky that out of all our species she was the one "chosen" to so dramatically encounter a celestial rock? Or did she spend her subsequent years with sensations of victimhood, disturbed that the movement of planets had conspired to direct a meteorite on a centuries- long journey to wreck her living room?
Magazines which detail the lives of celebrities sell more than those chronicling the movements of monarchs because they throb with the tantalising myth of stardom: that individuals are periodically plucked from obscurity.
We love to read of the moment when the dog of Hollywood super-agent Joyce Selznick sunk its teeth into the leg of David Hasselhoff and inadvertently dragged the ambitious waiter onto fame's runway.
Such seemingly random incidents are laced with destiny: If you or I had been bitten by the dog, would we one day be filmed saving Californians from choppy waters with Pamela Anderson - or was there something intangibly special about the man who would one day thrill Germans with his passionate range of self-expression?
Of course, as Ms Hodges herself might feel inclined to tell us with a wag of a figure, our entire species could be heading for a decidedly disastrous date with destiny.
According to some calculations, on St Patrick's Day 2880 there is a one in 300 chance that the cheerfully named asteroid 1950 DA will strike our planet. An ocean hit would send waves of up to 400 ft soaring towards cities in an Armageddon-style day of destruction.
The notion is horrendous, but such a prospect triggers an equal and opposite pulse of excitement. If humanity was threatened with annihilation, we like to think, we would all respond with the alacrity of Hasselhoff in his prime and do whatever might be conceivably necessary to avert such a calamity.
We dearly need such dreams at a time when the world is riven with division. Wales has far fewer statues than Rome - maybe there's space to erect one of Ms Hodges and her meteor?
Comment: Poor guy. He still thinks that our political leaders would clue us in in such an eventuality!
News from Nearby Space
By Gregg Easterbrook
TMQ
Meanwhile the more researchers learn about asteroid and comet strikes on Earth, these events seem much more common than previously assumed -- which is definitely not good news. Last summer, TMQ laid out the disturbing evidence that space-rock strikes powerful enough to cause mass extinctions were not confined to the primordial mists: Something gigantic smashed into the Earth about 10,000 years ago, and there might have been a severe comet or meteorite strike as recently as the year 535. Recently researcher Dallas Abbott of the Lamont-Doherty Earth Observatory at Columbia University has found indications that a huge comet or asteroid fell into the Indian Ocean about 4,800 years ago, causing global tsunamis.
Abbott's work is especially important because she is studying the oceans, not land. Most of what's known about past space-object strikes comes from the study of land craters. But three-quarters of Earth's surface is water; Abbott reasoned that three-quarters of space objects must crash into the seas. Her work suggests a lot of comets and large rocks have hit the seas, many recently in geologic terms. As recently as a decade ago, most scientists assumed that space-rock strikes powerful enough to cause general devastation happen only every million years or so. Now it looks like they are far more frequent. If a rock comparable to the one that struck the Indian Ocean 4,800 years ago struck today in Kansas, half the population of the United States might die. And as TMQ endlessly points out, what is NASA doing about this? Absolutely nothing.
NASA will fund this if the agency is assured it will be incredibly expensive and serve no purpose.
NASA continues to waste about 10 billion of your tax dollars annually on a space station project that had no scientific value, existing solely to justify money for aerospace contractors and staff budgets at NASA manned-flight centers. NASA plans to waste 200-500 billion of your tax dollars on return-to-the-Moon missions that don't even have a theoretical justification -- the sole purpose of return-to-the-Moon is money for NASA insiders. Yet if a comet or large meteor was spotted heading toward our world, NASA could do nothing. And NASA isn't even researching possible anti-space-rock technology. No agency of your government wastes taxpayers' money more cynically or systematically than the National Aeronautics and Space Agency. If a big space object strikes the Earth, sending humanity's survivors back into the Dark Ages, our descendents will consider the present Washington government history's worst collections of fools for doing nothing while there was time.
'UFO' sightings most likely meteors
The World Today - Wednesday, 29 November , 2006 12:46:00
Reporter: Nance Haxton
ELEANOR HALL: Over the last two days, police and news organisations in South Australia and western Victoria have been inundated with reports of mysterious lights in the night sky.
Some have described a fireball shooting across the horizon just before sunset, while callers in north-west Victoria have reported seeing a bright object flying across the sky.
The Astronomical Society of South Australia's Dr Tony Beresford has told Nance Haxton that while the sightings have sparked some UFO speculation, the cosmic mystery is most likely a meteor.
ELEANOR HALL: Over the last two days, police and news organisations in South Australia and western Victoria have been inundated with reports of mysterious lights in the night sky.
Some have described a fireball shooting across the horizon just before sunset, while callers in north-west Victoria have reported seeing a bright object flying across the sky.
The Astronomical Society of South Australia's Dr Tony Beresford has told Nance Haxton that while the sightings have sparked some UFO speculation, the cosmic mystery is most likely a meteor.
TONY BERESFORD: It was just one particular meteor which was widely observed. It was observed from around the metropolitan area to, I suspect, over in the border regions of Victoria and New South Wales.
NANCE HAXTON: And how do we know that it was a meteor?
TONY BERESFORD: Well, it was a short time, it was moving quite fast, faster than a satellite would've and there were no satellites due to come in.
NANCE HAXTON: And are there any reports of what happened to that meteor? I mean, does it burn up before landing or...
TONY BERESFORD: This one almost certainly did. It's... in fact, I have several reports which indicated at the end it more or less exploded.
NANCE HAXTON: How common is it for meteors such as this to be seen so brightly and be reported by people?
TONY BERESFORD: Well, about once a year or so, maybe twice.
NANCE HAXTON: So meteors are really falling from the sky all the time, it's just sometimes we see them?
TONY BERESFORD: Some, yes. We're in a cosmic shooting gallery. There are several moderately recent craters in the Australian continent, but the most recent appreciable-sized one is of course the very famous meteor crater in Arizona, only about 50,000 years ago.
NANCE HAXTON: 50,000 years ago? So hopefully our number's not coming up for a while yet?
TONY BERESFORD: Well, you don't... you never know. I'm one of these people who think we should do proper surveys for an asteroid that could possibly impact the earth, because we... if we did find one then we could probably divert it enough. You don't have to change its orbit very much.
The Australian Government doesn't believe in it, but the Americans are spending money employing two people up at Siding Spring looking for it.
NANCE HAXTON: You think that the risk of an asteroid hitting earth is enough that Australia should really look at taking more note of the risk?
TONY BERESFORD: Yes, yes they should. The risk is very small, but the number... the possible global consequences are enormous.
ELEANOR HALL: That's the Astronomical Society of South Australia's Dr Tony Beresford speaking to Nance Haxton.
UFO crashes in Krasnoyarsk
08:02 GMT, Dec 01, 2006
Interfax Information Service
KRASNOYARSK. Dec 1 (Interfax) - An unidentified flying object has
reportedly crashed between the towns of Yeniseisk and Lesosibirsk in the
Yenisei district of the Krasnoyarsk territory.
Local residents say they observed the crash at about 10 a.m. local
time, adding that they also saw traces of fire in the taiga, the main
department of interior affairs of the territory told Interfax.
"An investigative group of the department of interior affairs of
the Krasnoyarsk territory and representatives of the transport
prosecutor's office and Rosavianadzor were sent to the scene of the
crash," the department said.
The Siberian regional center of the Russian Emergency Situations
Ministry told Interfax it cannot confirm the crash. A Mil Mi-8
helicopter flew over the scene and no traces of any crash were detected,
it said.
Older than the sun, the meteorite scientists call 'the real time machine'
Ian Sample, science correspondent
Friday December 1, 2006
The Guardian
- Rock which hit lake is oldest object ever found
- Tests reveal fragment created before solar system
As lumps of rock go it looks much like any other, unexceptional despite the deep red of its cool, smooth surface. The pieces range in size from pea-sized lumps to larger fist-sized chunks. But today, scientists will announce this is no ordinary stone. Prised from a frozen lake in northern Canada, it has become a prime candidate for the oldest known object on Earth.
The chunk came from a meteorite that scored an arc of fire across the skies before slamming into Lake Tagish in British Columbia in 2000. It has been pored over by scientists ever since, and is today revealed to contain particles that predate the birth of our nearest star, the sun.
The Tagish Lake meteorite was already regarded as exceptional because its mineral composition linked it to the earliest days of the formation of the solar system, more than 4.5bn years ago. The fragments of meteorite that still exist are among the most pristine in the world, as they were protected from contamination when they became wedged in blocks of lake ice.
The latest research shows that peppered throughout the meteorite are grains that formed even earlier, in a frigid cloud of molecules, possibly at the edge of the swirling disc of dust that ultimately collapsed to form the sun and all the planets of the solar system.
The discovery suggests that while the first light from the sun fell on the fledgling Earth, as the dinosaurs rose and died out and humans gained dominance, the meteorite was hurtling around the heavens on a billions-of-years-long journey destined to terminate with a thud in Yukon territory.
Researchers at Nasa's Johnson Space Centre in Houston examined a two gram fragment of the meteorite and focused on tiny, hollow, carbon spheres embedded within it. Each "globule" measured just a few thousandths of a millimetre across.
Using electron microscopy and isotope tests, the scientists looked at the chemical make-up of the grains and discovered they had unusual ratios of different forms of nitrogen and hydrogen. Ratios of the isotope nitrogen-15 to nitrogen-14 were nearly twice those on Earth, while the ratio of deuterium, a heavy form of hydrogen, to normal hydrogen, was between 2.5 and nine times higher than usual.
Reporting in the journal Science today, a team lead by Keiko Nakamura-Messenger and Michael Zolensky show the levels of the isotopes in the meteorite could only arise from chemical reactions taking place in an extremely cold climate, where temperatures were as low as -260C. Those conditions would only be found in remote molecular clouds before the formation of the solar system, or at the very edge of what is known as the protosolar disc that was later to coalesce into the celestial bodies of the solar system. "These little particles within the meteorite seem to predate everything else. We don't know exactly how old they are, but they could be billions of years older than the rest of the meteorite," said Dr Zolensky.
Between 40,000 and 60,000 tonnes of meteorite matter is believed to land on Earth every year, and around 90% of this rains down steadily as fine particles that are rarely even identified.
Much of the material immediately disappears beneath the waves, and significant amounts are lost in the world's deserts and forests. Only a few tens of kilograms, in larger chunks, are usually recovered from any year's fallout.
Fragments of the Tagish Lake meteorite were recovered after locals spotted the fireball it created as it tore through the atmosphere at 20 miles per second. Large clumps of the meteorite were collected from the surface of the frozen lake, but other chunks were removed later embedded in blocks of ice, and transported to research labs. Around one tonne of fragments from the meteorite is now held in the Natural History Museum in London and at other sites in the US, Canada and Germany.
"These are the real time machines, the material that goes back to the earliest formation of the solar system," said Caroline Smith, meteorite curator at the Natural History Museum.
The meteorite is known as a carbonaceous chondrite and contains what many scientists regard as the building blocks for life: carbon, myriad clay minerals and even amino acids. Scientists say the clay layers, principally silicates, can form protective pockets around the organic chemicals and act as reaction chambers where more complex molecules can form. The possible role of these pockets in the ultimate emergence of life has lead some scientists to refer to them as "wombs".
"These things tell us what kind of chemicals are out there in interstellar space. They could have been the original seeds for life to get started," said Dr Zolensky.
Meteor shower could be sign of comet that could come dangerously close to earth
HELSINGIN SANOMAT
Jarmo Moilanen, a municipal computer expert and amateur astronomer in the Finnish community of Vaala, has detected a new shower of meteors in the tale of a hitherto unknown comet.
Moilanen's two monitoring cameras that he keeps pointed at the sky and linked to his computer, registered an unexpected meteor shower already in October last year.
The discovery was published in the Finnish astronomy magazine T?hdet ja avaruus ("Stars and Space") on Wednesday. Moilanen's article was written with the help of NASA meteor expert Peter Jenniskens, who is considered one of the world's leading authorities in the field.
The comet itself has not yet been pinpointed, but it is believed to have an orbit around the sun that is about 4,000 years long. It comes closest to Earth just inside this planet's orbit, and is considered one of the five most potentially dangerous comets for Earth in the long term.
Nevertheless, experts say that the likelihood of a collision with Earth in the coming millennia is vary small.
"It could be coming, or then the meteor shower could be material that it has left behind, such as dust or grains of sand. There is no sense in being too frightened by it", Moilanen says.
It was confirmed this autumn that the shower can be seen each year in October. The name that was proposed for the the event is the October Camelopardalis, because the meteor showers linked with the comet appear in the sky near the constellation Camelopardalis, or giraffe.
Bubbly meteor hints at seeds of life
By Lucy Sherriff ? More by this author
Published Monday 4th December 2006 10:22 GMT
Scientists have found evidence that the seeds of life may indeed have fallen from the sky.
Analysis of a meteorite that fell onto the frozen Tagish Lake in Canada in 2000 has shown the space rock to be riddled with organic material that is at least as old as the solar system itself. Researchers speculate that this kind of matter could have played a vital role in the development of early life on Earth.
The Tagish Lake meteorite is unusual because it is so well preserved. Most meteorites, although usefully frozen in space, thaw or become contaminated when they arrive on Earth. This has frustrated researchers' attempts to test the hypothesis that organic material could have arrived on the primordial Earth on comets, asteroids, and meteors.
A team of NASA scientists, led by Keiko Nakamura-Messenger, scanned the Tagish meteorite in slices with a transmission electron microscope. This revealed sub-microscopic "globules", which consisted largely of carbon, hydrogen, nitrogen, and oxygen, the researchers report.
The ratio of isotopes of each of the chemicals shows that the globules formed at near absolute zero. To have captured such exotic isotope mixes, the meteorite must have formed much further from the sun than the Earth, Nakamura-Messenger says, which confirms that the chemicals are not contaminants, but are native to the space rock. They were most likely part of the cloud of material from which the planets themselves formed.
The team suggests two possible ways that the globules formed: in both cases they began life as icy grains that formed on the rock in the outer reaches of a very young solar system. It is possible that the grains then formed a hardened shell when bombarded by radiation. The centre would later have evaporated, leaving a hollow shell of organic matter. Alternatively, the grains were exposed to alkali compounds in the meteor itself, which could have hollowed out the centres.
The research, which is published in the journal Science, cites 26 such globules. But Nakamura-Messenger says the meteorite could contain billions of them. The team restricted its analysis to such a small sample because of the complexity of processing the rock.
"We're sure that these [globules] are not alive," Messenger told Scientific American. "But they may have been important ingredients for the first life-forms."
Frequent Fireballs
By: Spaceweather.com
Published: Dec 4, 2006 at 07:03
Have you ever stepped outside after dinner to walk the dog--just in time to see a bright fireball streak across the sky? It makes you wonder, how often does that happen?
Pretty often, according to astronomer Bill Cooke of the Marshall Space Flight Center. Using a computer model of Earth's meteoroid environment, he made this plot showing the global number of fireballs per day vs. the brightness of the fireball:
According to his calculations, fireballs as bright as Venus appear somewhere on Earth more than 100 times daily. Fireballs as bright as a quarter Moon occur once every ten days, and fireballs as bright as a full Moon once every five months.
The vast majority are never noticed. About 70% of all fireballs streak over uninhabited ocean. Half appear during the day, invisible in sunny skies. Many are missed, however, simply because no one bothers to look up. So grab a leash and a dog (optional), and head outside. The chance of a fireball is better than you think.
Comment: So all of the reports in the newspapers? Furgettaboutit. Nothing important here, folks. Move along.
The world's biggest meteor crater
Mary Alexander
Two billion years ago a meteorite 10km in diameter hit the earth about 100km southwest of Johannesburg, creating an enormous impact crater. This area, near Vredefort in the Free State, is now known as the Vredefort Dome.
It was voted South Africa's seventh World Heritage site at Unesco's 29th World Heritage Committee meeting in Durban in July 2005.
The meteorite, larger than Table Mountain, caused a thousand-megaton blast of energy. The impact would have vaporised about 70 cubic kilometres of rock - and may have increased the earth's oxygen levels to a degree that made the development of multicellular life possible.
The world has about 130 crater structures of possible impact origin. The Vredefort Dome is among the top three, and is the oldest and largest clearly visible meteorite impact site in the world.
The original crater, now eroded away, was probably 250 to 300 kilometres in diameter. It was larger than the Sudbury impact structure in Canada, about 200km in diameter.
At 2-billion years old, Vredefort is far older than the Chixculub structure in Mexico which, with an age of 65-million years, is the site of the impact that led to the extinction of the dinosaurs.
Vredefort's original impact scar measures 380km across and consists of three concentric circles of uplifted rock. They were created by the rebound of rock below the impact site when the asteroid hit. Most of these structures have eroded away and are no longer clearly visible.
The inner circle, measuring 180km, is still visible and can be seen in the beautiful range of hills near Parys and Vredefort. It is this area that was named a World Heritage site.
Internationally, there are 812 World Heritage sites, in 137 countries. Africa has 65 sites and South Africa now a total of seven - three cultural, three natural and one of mixed cultural and natural heritage. The Vredefort Dome is a natural heritage site.
South Africa's other six World heritage sites are Robben Island, the Greater St Lucia Wetlands Park, the Mapungubwe Cultural Landscape, the Cradle of Humankind, the uKhahlamba Drakensberg Park and the Cape Floral Region.
"The Vredefort site is rich in the symbolic representation of our culture; it demonstrates the meeting between scientific and cultural philosophy and practice," Arts and Culture Minister Pallo Jordan said after the inscription of the site on the World Heritage list.
"At Vredefort, opportunities exist to engage in geological research and explore and understand more sensitively the rich culture of the Basotho, Batswana and Khoi-San and the early evidence of human cognitive and artistic endeavour their cultures boast.
"This demonstrates that heritage can be a tool for nation-building."
The Vredefort Conservancy
Further evidence of the meteorite impact site can be seen in the columns of granite that were injected into existing rock by the force and heat of impact.
In 1937, earth scientists John Boon and Claude Albritton Boon were the first to suggest that the Vredefort structure was the scar of an ancient meteorite impact. Since then the site has been studied extensively by earth scientists from around the world.
The Vredefort Dome Conservancy, as it is now known, is not just of scientific value. It also has great scenic beauty, making it an ideal tourist destination.
The Dome Conservancy contains a finely balanced ecosystem made up of open plains, bushveld, mountains and ravines with abundant flora and fauna. At least 99 plant species have already been identified, of which the world's largest olive wood tree forest is probably the best known.
The area is considered an important birding area, with over 450 species already identified. It also has as many identified butterflies as the whole of Great Britain, and is home to rare animals such as the rooikat, aardwolf, leopard and the endangered rock dassie.
The Department of Environmental Affairs and Tourism plans to spend R18-million on tourism and infrastructural development at the site - including the eradication of alien invasive vegetation, creation of hiking trails and construction of a tourism centre.
The Vredefort Dome site fulfils all the criteria set by Unesco for a World Heritage site. It is of outstanding universal value from a scientific point of view, and is remarkable evidence of an important moment in the earth's geologic history.
Dire Predictions 2007!
John Townley
AstroCocktail
Last December, our "Dire Predictions 2006" pinned the meters, as an unexpected flood came to find out what was expected. This year's harvest of frightening futures is even more outlandish than the last, as reality has made future-casters stretch the envelope just to surpass the current news. Since chaos, madness, and a world spinning into reckless destruction have become dinnertime TV, the urge to descry something even more compelling has propelled predictions to new levels of intensity. Almost every linked end-of-the-world forecast below has a harvest of other links, ad infinitum, so even if you live in a parallel universe, it's likely that one's about to end, too. The cornucopia of coming catastrophes falls into four rough categories:
Old Themes For The New Age. Armageddon is still definitely scheduled for 2007, in the Middle East of course, though that just seems so yesterday - or, in real terms, today, because it appears to be already happening. But despite some traditional end-of-the-worlders getting a thumpin' at the ballot box, there are still plenty of Biblically-proportioned endings on the table...
New Themes From The Old Age. But maybe that's also why someone so traditional as Mel Gibson has brought us not an Easter update but Apocalypto instead. The Mayans predicted the end of the world for 2012, but they managed it for themselves centuries earlier. For them, it's come and gone, so maybe they know something we don't. But then, it's so hip to be already history there's a gamesite about it...
Deadly Databases. Since the end of the world is more popular than ever, it gets more analysis than ever. From ticking doomsday clocks to laying endgame bets, a good dose of discussion may throw light (or darkness, as may be) on the matter. You needn't consult fringe fortunetellers, either, when hard science is chock full of doom, from killer asteroids to the Sixth Great Extinction... (that's us!)...
Unique Perspectives. There are still individual entrepreneurs who, like Nostradamus, seek to trump them all. Why reduce yourself to simple surveys, traditional terrors, or fallible fads when you can tune into personal disaster dreams, perhaps vote for your favorite, or even take charge and publish your own revelation...
Ultimately, when you know the end is near, it's time to have fun with it. Last year we picked the K-rave party in Toronto, but for this New Year's Eve we say with terminal conviction: radio fans especially, get yourself to Chicago...
Flashback: Wanted: man to land on killer asteroid and gently nudge it from path to Earth David Adam
Friday November 17, 2006
The Guardian It is the stuff of nightmares and, until now, Hollywood thrillers. A huge asteroid is on a catastrophic collision course with Earth and mankind is poised to go the way of the dinosaurs.
To save the day, Nasa now plans to go where only Bruce Willis has gone before. The US space agency is drawing up plans to land an astronaut on an asteroid hurtling through space at more than 30,000 mph. It wants to know whether humans could master techniques needed to deflect such a doomsday object when it is eventually identified. The proposals are at an early stage, and a spacecraft needed just to send an astronaut that far into space exists only on the drawing board, but they are deadly serious. A smallish asteroid called Apophis has already been identified as a possible threat to Earth in 2036.
Fireball Streaks Over Colorado At Dawn
The Denver Channel
08/12/2006
DENVER -- A bright fireball streaked across Colorado early Friday, prompting a number of e-mails to 7News, and calls to authorities and researchers, but no debris was immediately reported.
"It came in from the east, over the plains, and was seen to disappear over the mountains to the west," said Chris Peterson, a meteor researcher with the Denver Museum of Nature and Science.
The bright light was spotted at abut 6:45 a.m. and was bright enough to be categorized as a fireball, he said.
Click here to find out more!
"Meteors are called fireballs when they are brighter than Venus," said Peterson.
Meteors are common over Colorado but this one was unusual because it was so bright it could be seen as the sky was getting light, Peterson said.
"This one may have been much brighter (than most), more like the brightness of the moon," he said. "Events like that happen every year or so."
Peterson, who operates a Web site on meteors, said he received several witness reports but did not see the meteor himself.
"It was still burning as passed out of view at the lower horizon," wrote one 7News viewer from Dillon. "Normally they come down and flame out long before they get to the horizon."
Peterson said any debris from the meteor would be hard to find.
"You'd just be looking at a handful of rocks," he said. "The rocks would have probably fallen somewhere where there's a lot of other rocks."
Peterson said if any part of the fireball did make it to the ground it might be in northwest Colorado, in the vicinity of Meeker.
Prize offered to tag an asteroid
By Jonathan Amos
Science reporter, BBC News, San Francisco
Thursday, 14 December 2006
The Planetary Society will give a prize to the designers of a mission that would allow the huge asteroid's orbit to be tracked with the most precision.
A $50,000 (?25,000) competition has been launched to find the best way to tag a 400m-wide asteroid.
The Apophis space rock is set to make a close pass of Earth in 2029 and scientists would like to confirm that it poses no danger to our world.
The competition has support from the US and European space agencies.
"The threat of a strike from asteroids is always a very low probability at any given time, and yet bad things will happen," said the Planetary Society's director of projects, Bruce Betts. "We need to know whether Earth's name is on it," he told BBC News.
Apophis will come closer to Earth in 2029 than the orbits of many communications satellites - but it will not hit the planet, that is clear.
The concern centres on the small chance that its orbit could be perturbed enough in the flyby to put the rock on a collision path for its return in 2036.
Concept mission
Further investigations with ground telescopes are expected to show beyond doubt that this will not happen and that Apophis represents zero risk.
And Planetary Society thinks an innovative tracking mission could make doubly sure. Hence, the prize for an individual or team that can put together the best concept for tagging a huge lump of rock.
"You could use a beacon; you could put a reflector on it that you ping; you could put a spacecraft in orbit and track that. There are any number of possibilities and ones we haven't thought of, I'm sure," said Betts.
The Society is organising the competition in cooperation with the European Space Agency (Esa), the US space agency (Nasa), the Association of Space Explorers (ASE), the American Institute of Aeronautics and Astronautics (AIAA), and the Universities Space Research Association (USRA).
The winning entry or entries will be submitted to space agencies to see if they want to carry the ideas through.
Already they are considering a number of concept missions that would assess the best way to deflect or destroy dangerous space rocks.
The Planetary Society competition was launched here at the American Geophysical Union Fall Meeting.
Jonathan.Amos-INTERNET@bbc.co.uk
Comment: Perhaps this article should take into consideration the likelihood that this might indeed pose a lot of danger to our world.
Furthermore, it should be noted that many other studies confirm the likelihood of comets hitting the planet much sooner, and even at the present time. See here
Fireball Friday 15th December Over Albuquerque
Written by John Fleck
Friday, 15 December 2006
Albuquerque Journal
I've gotten several reports of a pretty spectacular fireball last night over the Albuquerque area, at around 6:40 p.m. One reader described it as having "a very long yellow tail and the most brilliant electric blue head you could imagine". Dick Spalding out at Sandia Labs, who tracks these things with a rooftop all-sky camera, said it was visible for 13 seconds - an unusually long time. His camera also picked up a second, similar one at about 8:30 p.m.
Meteor Shoots Across Scottish Skies?
Scotsman
21/12/2006
AT first he froze with fear as what appeared to be a burning aeroplane dropped from the sky towards a Midlothian field.
But when he realised he wasn't witnessing an aviation disaster unfold as he took his daughter to school, David Carson reached for his camera.
For the next ten minutes, the 40-year-old took dozens of pictures of a strange streak of light across the Lothians sky that eventually broke into an orange glow and then appeared to hit the ground.
A frantic call to police confirmed to Mr Carson that it wasn't a downed aircraft, but astronomers today were at odds about what the phenomenon actually could have been.
Professor John Peacock, of the Institute for Astronomy at the University of Edinburgh, said it had probably been a meteor fireball.
But acclaimed astronomer Alan Pickup was adamant the strange streak of glowing cloud was simply a condensation trial from a passing aircraft.
Mr Carson was just getting into his van to take his 14-year-old daughter Jane to school when a peculiar flash of light in the sky to the east caught his eye.
"I saw a vapour trail that looked like it belonged to a plane then below it was this really strange streak of light," explained the furniture restorer and amateur photographer, who had taken his camera out with him to capture the frosty sunrise on Monday morning.
"I honestly thought a plane had been blown out the sky at first and just panicked.
"I was shouting at Jane, 'What do I do? What do I do?'.
"I grabbed the camera and started taking pictures of the streak as it got nearer to the ground.
"A bit at the front appeared to break off and turned bright orange before looking like it crashed into the ground.
"I was really all over the place because I didn't know if it was the end of the world or what, it was such a strange sight."
The incident, which took place about one mile south of Penicuik near to Ravensneuk Farm, lasted about ten minutes from 8.30am on Monday morning.
The fireball - if that is indeed what it was - would have crashed to Earth about a couple of miles east of the A701 Peebles Road.
If the rock hit the earth it would be classed as a meteorite rather than a meteor.
Professor John Peacock, of the Institute for Astronomy at the University of Edinburgh, said: "It is probably a meteor fireball - quite a rare and spectacular example, and well worth publishing."
However, a spokesman for the British Geological Survey said that there had been no seismic activity that could have been caused by a meteorite strike in the Penicuik area during the time of the incident.
Astronomy writer Alan Pickup said he thought the streak was simply a vapour condensation trail from an overhead aircraft. He said: "Condensation streaks in the direction of the rising sun can look very odd but there is no way this was a meteor.
"There are a lot of false sightings because of conditions like this but if it had been a meteor then it would occurred a lot quicker than this and would have been much brighter."
A police spokeswoman confirmed officers attended Mr Carson's home and made inquiries with the British Geological Survey and British Airport Authority.
Catastrophe Calculator: Estimate Asteroid Impact Effects Online
By Robert Roy Britt
Senior Science Writer
12 April 2004
The history of Earth's encounters with asteroids remains largely mysterious to scientists. They can't even agree whether a huge space rock that hit Mexico's Yucatan Penninsula 65 million years ago killed off the dinosaurs or not.
Nor can astronomers say when the next catastrophic impact will occur. They only know that it will happen, sooner or later.
However, now anyone with a passing interest in the fate of the planet can remove some of the mystery regarding the effects of the next collision. A new University of Arizona web page allows visitors to plug in a hypothetical space rock's size, the visitor's distance from the impact site, and other parameters to generate an outline of devastation.
But be warned: Removing the mystery invites a bit of terror over the hypothetical slams, bangs, fireballs, falling skies and rushing winds generated by a giant impact.
Prepare to be scared
Being somewhat of a voyeur when it comes to natural catastrophe, I couldn't resist running some scenarios through the new catastrophe calculator.
If you read on, please keep in mind that the odds of a serious impact occurring in any year are extremely low. A civilization-ending impact, while possible, almost surely won't happen within our lifetimes (90 percent of all asteroids big enough and close enough to do the job will be found by 2008) and is extremely unlikely even over the next millennium.
But hurling big virtual rocks at the planet is admittedly kind of fun. And in this case it's at least more scientifically meaningful than the average video game. I started by dropping a 9.3-mile-wide (15-kilometer) asteroid -- the estimated size of the suspected dinosaur killer -- on San Francisco.
The Bay Area doesn't do so well.
The resulting crater, at 113 miles (181 kilometers) wide, pretty much tells the story. The entire metropolis vanishes faster than you can say where you left your heart. What isn't consumed is knocked over in an earthquake of magnitude 10.2, bigger than any in recorded history. Heat from a scorching fireball would turn much of the state, and parts of others, into toast.
The quick end to the Bay Area turns out to be a blessing compared to what Los Angeles residents face.
About 10 seconds after impact, radiation from the fireball sears Southern California, igniting clothing and even plywood. Within two minutes the ground under Hollywood begins to shake. Weak brick structures crumble. Concrete irrigation ditches are damaged. Frame houses not properly bolted to their foundations are knocked off. Even tree branches fall.
And then it gets nasty.
'Bad things happen'
Six minutes after impact, much of earth that used to be under San Francisco has soared high into the atmosphere and begins to fall on the City of Angels (and just about everywhere else). Ultimately, a blanket of ejected material nearly 18 feet (5.5 meters) deep is deposited in and around LA.
Within a half-hour of the initial cosmic impact, on comes a 66-mph (30 meters per second) wind to rake what's left of Los Angeles.
"If you're close to the site of a major impact, some pretty bad things happen," said Jay Melosh, an expert in impact cratering at the University of Arizona.
Melosh oversaw the computer program's development. It's intended to help scientists further their research and journalists to report on the risks of asteroid impacts. "We could have put in some worse stuff, but it started getting grisly," he told SPACE.com .
I continued with my West Coast disaster scenario by heading across the country. Denver, about a third of the way over, is coated with nearly a foot of ejected material, called ejecta. Winds reach 22 mph.
New York City residents are spared enough that they can at first sit comfortably and watch all this on TV (to the extent there are any video feeds). Still, about 13 minutes after impact, windows and doors rattle in the East. After about 21 minutes, stuff shot out from the world's largest new crater starts to rain down on the East, depositing a half-inch blanket across the city. About 3-1/2 hours later an 8-mph wind arrives.
Object as big as the one that presumably wiped out the dinosaurs -- some investigators aren't convinced it was the sole cause -- are extremely rare, slamming into the planet perhaps just once every 300 million years.
Presently there are no asteroids known to be on a collision course with Earth. And experts agree that one this big would almost surely come with decades or centuries of warning time, being fairly easy to spot well before it becomes an imminent threat. By then, experts hope, methods will be developed to divert or destroy such a rock.
More likely scenarios
But what about something the size of the asteroid that dug out Meteor Crater in Arizona? That 600-foot-deep (180-meter) hole in the ground, popular now with tourists, is less than 50,000 years old and was created by a space rock so small that another one like it might not be noticed until it hits.
The Arizona culprit was only about 66 feet (20 meters) wide. But instead of fragile stone, it was composed mostly of iron. Examples linked with the online impact-effect program show how to specify this harder, more destructive material. A rock this size (though not of this density) is thought to hit Earth every 158 years, on average.
I duplicated the Meteor Crater script in Newark, New Jersey, 10 miles (16 kilometers) from Manhattan as the crow flies.
Location, of course, is everything. A nearly mile-wide crater is dug in New Jersey. A moderate earthquake of magnitude 4.7 rattles the region. New York City has handled such temblors in the past and largely endures. No significant ejecta hits Manhattan, and winds reach an insignificant 3.7 mph.
So I cranked it up a bit.
An asteroid the size of two football fields, even if stony in nature, is another story. It carves a crater in New Jersey that's 2 miles wide (3.4 kilometers). The resulting earthquake is magnitude 6.4, enough to frighten the pants off New York City emergency planners. A rock this size hits the planet about every 14,000 years.
Just estimates
Melosh developed the program along with fellow researcher Gareth Collins and undergraduate Robert Marcus. Melosh said the program should prove valuable to scientists who otherwise would have to wade through complicated calculations to generate impact scenarios for their research.
It's important to point out that what actually happens when an asteroid crashes into the surface is not well known, because scientists have never actually witnessed an impact event of any scale. But they have used computer models to explore the probable effects of impacts, and they have some craters to study on Earth.
Researchers assume the blast of heat generated by a cosmic collision would be similar to nuclear bomb detonations. So for these thermal radiation effects, Melosh's team relied on a 1977 publication, "The Effect of Nuclear Weapons," by the U.S. Defense Department and the Department of Energy.
"We determine at a given distance what type of damage the radiation causes," said Marcus, who did most of the grunt work developing the computer program. "We have descriptions like when grass will ignite, when plywood or newspaper will ignite, when humans will suffer 2nd or 3rd degree burns."
For earthquake predictions, the researchers culled data from actual California events and knowledge of how earthquakes propagate like sound waves through the planet.
The global effects of an asteroid impact are harder to predict. Many scientists think the larger impacts throw so much dust into the atmosphere that a global winter would ensue, lasting for months or years. Melosh is skeptical about the dust.
"Nuclear explosions are good at raising dust that's already there, but they're not good at creating it," Melosh said. He figures most of the ejected material is melted and then hardens into tiny, hardened and almost microscopic spheres. "Most of the ejecta comes down within an hour." He calls the massive dust creation "a media myth."
More to come
There is much left out of the new online impact program. Melosh wanted it to be practical to use, and he's open to suggestions for improvement.
Important details of an impact -- exactly how it penetrates the atmosphere and the surface, are simplified. And one major effect is not considered: the tsunami that would result from an ocean impact (Earth's surface is two-thirds water). In addition, the results of a user's input do not mention that a rush of wind can't blow down a tree that's buried under ejecta, nor does either matter if the tree were already burned to a crisp.
Minor and major revisions to the program may be made based on input from other scientists, Melosh said. And in coming weeks, his group will post background information explaining the complex calculations behind the program.
The Impact Effects program.
Catch the Wave: Asteroid-driven Tsunami in U.S. Eastern Seaboard's Future
By Tariq Malik
02 June 2003
A giant, 40 stories tall wave could one day drench the eastern United States, the result of an asteroid-driven tsunami. However seaside dwellers need not move just yet, the asteroid isn't due for another eight centuries.
Researchers in California have developed a computer simulation depicting the ocean impact of the asteroid 1950 DA, a half-mile wide (1.1-kilometer) space rock that swings uncomfortably close to Earth in 2880. Although the probability of such an impact is remote to say the least -- astronomers estimate it to be somewhere around 0.3 percent -- the computer model does give researchers insight into the destructive power of tsunamis caused by near-earth objects.
"You'd want to first decide how far away [from impact] the effects are going to be felt," Steven Ward, a research geophysicist at the University of California Santa Cruz (UCSC), said in a telephone interview. "And once you know that, maybe you could set up a zone of evacuation." According to Ward's research, about 120 million people live in coastal areas at elevations within 65 feet (20 meters) of sea level and just over a mile (two kilometers) of the ocean.
Ward is the lead author of the simulation study, which will appear in the June issue of the Geophysical Journal International.
Ward and co-author Erik Asphaug, an associate professor of earth sciences at UCSC, used 1950 DA as the asteroid in their simulation because of its history. Astronomers first discovered the asteroid in 1950 and tracked it for 17 days. The object was seen again in 2000, when researchers determined its radius and other characteristics. Its most recent Earth flyby last year led researchers to determine its future paths up through 2880, when it crosses the planet's orbit.
Asteroids are fascinating objects because they're the only disasters that you can prepare for, not like volcano eruptions, earthquakes or major storms," Asphaug told SPACE.com.
On March 16, 2880 the Earth's Atlantic Ocean is turned toward 1950 DA, and with 70-percent of the Earth covered in water an ocean impact would be the most likely to model.
In the simulation, 1950 DA slams into the Atlantic Ocean about 360 miles (579 kilometer) off the eastern coast of the United States. The asteroid, traveling at 38,000 miles an hour (61,155 kilometers per hour), is vaporized in the impact's 60,000-megaton blast and blows a hole in the ocean straight to the seafloor.
Seawater rushes into the cavity, which spans 11 miles in diameter and three miles deep (about 17 kilometers wide and five deep), and a halo of waves begin their journey outward from the impact site like overgrown ripples from a pond. Two hours after impact, waves 400 feet (121 meters) high hit the coastline from Cape Cod in Massachusetts to Cape Hatteras in North Carolina, and could ultimately penetrate more than two miles (about four kilometers) inland.
1950 DA is one of the larger asteroids that astronomers worry might hit the Earth. On the average, space rocks its size strike the earth every 100,000 years or so. Smaller asteroids up to 300 meters wide do so more frequently, about every 5,000 years, and so pose a larger tsunami danger for coastal residents, Ward said.
Asphaug, who led a NASA-sponsored workshop on asteroid hazards in September 2002, said that while not a lot can be done about larger, kilometer-sized objects that can cause global devastation, some action could be taken for smaller rocks. Observations, for example, could be fed into the already existing Pacific Tsunami Warning Center to track potential impacts.
"It takes time for these tsunamis to reach coastlines from the point of impact," Asphaug said, adding that once a satellite spots the flash of an impact, there will be a period of hours before the first big waves hit the shore. "It's possible to think that in 800 years, we might have enough technology to pinpoint which areas to evacuate and then do it."
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