Youtube
Wed, 04 Jul 2007 08:07
EDT
Investigations of a buried layer at sites from California to Belgium
reveal materials that include metallic microspherules, carbon
spherules, nanodiamonds, fullerenes, charcoal, and soot. The layer's
composition may indicate that a massive body, possibly a comet,
exploded in the atmosphere over the Laurentide Ice Sheet 12,900 years
ago. The timing coincides with a great die-off of mammoths and other
North American megafauna and the onset of a period of cooling in
Northern Europe and elswhere known as the Younger Dryas Event. The
American Clovis culture appears to have been dramatically affected,
even terminated, at this same time. Speakers discuss numerous lines of
evidence contributing to the impact hypothesis. The nature and
frequency of this new kind of impact event could have major
implications for our understanding of extinctions and climate change.
Part 1
This news conference is a watershed event for climate research. It's
been a long journey from the derision heaped upon Immanuel Velikovsky
in the 1950's through the 1980's when Carl Sagan famously ridiculed his
cometary thesis in the PBS series Cosmos.
New research since even when the abstracts were published prior to
the AGU meeting include the discovery of nanodiamonds in the layer just
below the Black Mat in the deposits analyzed around North America and
Belgium which can only come from a extraterrestrial impact. Here,
scientists question "Just what roll impacts play with climate." And
discuss the ice core evidence from Greenland and Antarctica: "There's
strong evidence of massive biosphere burning." They conclude that the
Younger Dryas "cooling would not have occurred without the impact."
For more information read the SOTT Focus article, The Younger Dryas Impact Event and the Cycles of Cosmic
Catastrophes - Climate Scientists Awakening.
Parts 2
Part 3
Part 4
Part 5
Part 6
Part 7
Science Daily
Fri, 06 Jul 2007 17:38
EDT
Researchers at the University of Southampton have developed a
software package for modelling asteroid impacts that enables them to
assess the potential human and economic consequences across the globe.
The software, called NEOimpactor, has been specifically developed
for measuring the impact of 'small' asteroids under one kilometre in
diameter, and early results indicate that the ten countries most at
risk are China, Indonesia, India, Japan, the United States, the
Philippines, Italy, the United Kingdom, Brazil and Nigeria.
'The threat of the Earth being hit by an asteroid is increasingly
being accepted as the single greatest natural disaster hazard faced by
humanity,' comments Nick Bailey of the University of Southampton's
School of Engineering Sciences, who developed the software with
University colleague Dr Graham Swinerd, and Dr Richard Crowther of the
Rutherford Appleton Laboratory .
'Since 1998 the international Spaceguard survey has been cataloguing
all near earth asteroids (NEA) larger than one kilometre in diameter.
However, small asteroids, under one kilometre in diameter, remain
predominantly undetected. While the direct consequences might not be
quite as extreme, these small objects exist in far greater numbers and
therefore will impact more frequently. It is on these sub-kilometre
asteroid impacts that we have been focusing to assess the consequences
for both humans and for infrastructure across the globe.'
Initial investigations have examined how the consequences of an
impact change with increasing impact energy. Taking a spherical stony
asteroid travelling at 12,000 miles per second and varying the diameter
to increase kinetic energy, the results indicate that a 100 metre
diameter asteroid will predominantly cause localised casualties and
damage across a few countries when impacting on either land or ocean.
However, the consequences of a 200 metre diameter asteroid hitting the
ocean increase significantly, with the generated tsunamis reaching a
global scale. At 500 metres in diameter, almost any ocean impact will
generate significant casualties and economic cost across the world.
The team used the raw data from the multiple impact simulations to
rank each country based on the number of times and how severely they
would be affected by each impact. Early results show that in terms of
population lost, China, Indonesia, India, Japan and the United States
face the greatest overall threat; while the United States, China,
Sweden, Canada and Japan face the most severe economic effects due to
the infrastructure destroyed.
In both rankings, the United Kingdom appears eighth in the list of
countries most affected. Of the top twenty for each ranking, over half
the countries appear in both lists.
'The consequences for human populations and infrastructure as a
result of an impact are enormous,' continues Nick Bailey. 'Nearly one
hundred years ago a remote region near the Tunguska River witnessed the
largest asteroid impact event in living memory when a relatively small
object (approximately 50 metres in diameter) exploded in mid-air. While
it only flattened unpopulated forest, had it exploded over London it
could have devastated everything within the M25.
'Our results highlight those countries that face the greatest risk
from this most global of natural hazards and thus indicate which
nations need to be involved in mitigating the threat.'
Note: This story has been adapted from a news release issued by University of
Southampton.
Univ. of South Carolina
Thu, 05 Jul 2007 22:43 EDT
A
comet theory put forth by a group of 25 geo-scientists suggests
that a massive comet exploded over Canada, possibly wiping out both
beast and man around 12,900 years ago, and pushing the earth into
another ice age.
 |
| ©USC |
| Site where most pre-Clovis work is being done. |
University of South Carolina archaeologist Dr. Albert Goodyear said
the theory may not be such "out-of-this-world" thinking based on his
study of ancient stone-tool artifacts he and his team have excavated
from the Topper dig site in Allendale, as well as ones found in
Georgia, North Carolina and Virginia.
The tools, or fluted spear points, made by flaking and chipping
flint, were used for hunting and made by the Clovis people, who lived
13,100 to 12,900 years ago, and from the Redstone people who emerged
afterwards. The two points are distinctly different in appearance, with
Redstone points more impressively long and steeple-shaped.
"I saw a tremendous drop off of Redstone points after Clovis," said
Goodyear. "When you see such a widespread decline or pattern like that,
you really have to wonder whether there is a population decline to go
with it."
For every Redstone point, Goodyear says, there are four or five
Clovis points. His findings are leading archaeologists from across
North America to reexamine their fluted points, and their inventories
are yielding similar results: a widespread decline of post-Clovis
points that suggests a possible widespread decline of humans.
"What is interesting is that Redstone people came after Clovis
people and may have lasted as many centuries as Clovis did, probably
even longer, but there are fewer of these Redstone points than Clovis
ones," Goodyear said. "That is really odd, because if the Redstone
culture simply came right after the Clovis culture you'd expect at
least as many Redstone points as Clovis ones. We just don't see that,
and the question is why, and what happened to the people who made these
tools?"
Archaeologists have long known that the great beasts of the age -
the wooly mammoth and mastodon - suddenly disappeared around the same
time period (12,900 - 12, 800 years ), but little was known about their
demise. It was thought to be the result of over-hunting by Clovis man
or climate change associated with a new ice age.
The notion that a comet collided with Earth and caused these events
was farfetched until recently, when the group of scientists began
looking for evidence of a comet impact, which they call the Younger -
Dryas Event. They turned to Goodyear and the pristine Clovis site of
Topper.
In 2005, Arizona geophysicist Dr. Allen West and his team traveled
to Topper in hopes of finding concentrations of iridium, an
extra-terrestrial element found in comets, in the layer of Clovis-era
sediment.
"They found iridium and plenty of it," said Goodyear. "The high
concentrations were much higher than you would normally see in the
background of the earth's crust. That tends to be an indicator of a
terrestrial impact from outer space."
The researchers also found high iridium concentrations at six other
Clovis sites throughout North America, as well as in and along the rims
of the Carolina Bays, the elliptically shaped depressions that are home
to an array of flora and fauna along South Carolina's coast.
The Younger- Dryas Event suggests that a large comet exploded above
Canada, creating a storm of fiery fragments that rained over North
America. The fragments could have easily killed the giant mammals of
the day, as well as Clovis man.
"No one has ever had a really good explanation for the disappearance
of mammoth and mastodon," Goodyear said. "The archaeological community
is waking up to the Younger-Dryas Event. It doesn't prove that these
Clovis people were affected by this comet, but it is consistent with
the idea that something catastrophic happened to the Clovis people at
the same time period."
The comet theory dominated the recent annual meetings of the
American Geophysical Union held in Mexico. Goodyear's Clovis-Redstone
point study and West's research on the comet were featured at the AGU
meetings and by the journal, Nature. The comet will be the subject of
documentaries featured on the National Geographic Channel and NOVA
television late this fall and in early 2008.
The Topper story
Dr. Al Goodyear, who conducts research through the University of
South Carolina's S.C. Institute of Anthropology and Archaeology, began
excavating Clovis artifacts along the Savannah River in Allendale
County in 1984. In 1998, with the hope of finding evidence of a
pre-Clovis culture earlier than the accepted 13,100 years, Goodyear
began a concerted digging effort on a site called Topper, located on
the property of the Clariant Co.
His efforts paid off. Goodyear unearthed blades made of flint and
chert that he believed to be the tools of an ice age culture back some
16,000 years or more. His findings, as well as similar ones yielded at
other pre-Clovis sites in North America, sparked great change and
debate in the scientific community.
Believing that if Clovis and Redstone people thrived near the banks
of the Savannah River, Goodyear thought the area could haven been an
ideal location for a more ancient culture. Acting on a hunch in 2004,
Goodyear dug even deeper down into the Pleistocene Terrace and found
more artifacts of a pre-Clovis type buried in a layer of sediment
stained with charcoal deposits. Radio carbon dates of the burnt plant
remains yielded dates of 50,000 years, which suggested man was in South
Carolina long before the last ice age. Goodyear's finding not only
captured international media attention, but it has put the archaeology
field in flux, opening scientific minds to the possibility of an even
earlier pre-Clovis occupation of the Americas.
Since 2004, Goodyear has continued his Clovis and pre-Clovis
excavations at Topper. With support of Clariant Corp. and SCANA, plus
numerous individual donors, a massive shelter and viewing deck now sit
above the dig site to allow Goodyear and his team of graduate students
and community volunteers to dig free from the heat and rain and to
protect what may be the most significant early-man dig in America.
WHDH-TV
Sat, 07 Jul 2007 22:33
EDT
WOBURN, Mass. -- Experts say the rock-like object that fell from the sky in Woburn is not
a meteorite.
However, they say the item probably is something from space and is radioactive.
The object came crashing through the roof of a warehouse in Woburn last week.
 |
| ©WHDH-TV |
Experts said they should definitely know what it is by the end of the month.
Comment: Not a meteorite - probably is something from
space? What explanation are they going to come up with this time?
Herts and Essex News
Sun, 08 Jul 2007 07:33
EDT
AN orange ball and lights in the sky has left a Cheshunt man wondering if aliens really do
exist.
 |
| ©Paul Adams |
| UFO Over Cheshunt |
Paul Adams, 52, snapped these strange shots and is now appealing
for anyone else who saw or can identify the potentially paranormal
activity to come forward.
His friends have suggested extraterrestrials could be behind the
drama although Paul, of Pengelly Close, is slightly more sceptical.
Paul had been watching films at about 3am on Wednesday last week when he decided to go outside for a
cigarette.
"I saw this orange ball that got bigger," he recounted.
"Within five seconds, it's right over the top of the house. Three
lines went straight up but there was no noise. It lit the sky up.
"I've gone to take another photo on my phone and it's gone."
Paul added: "I did think this is gorgeous. It was beautiful, really nice.
"But it was very strange. I've never seen anything like that. It wasn't lightning and it wasn't fireworks."
So do these photos show an alien spacecraft looking to land in the Lee Valley?
"My mates had a good laugh and said it could be a UFO," said Paul.
"However I believe in my daughter and I believe in my wife and that's about it."
UFO seen above
Hungerford...again
Miles Amoore
Newbury Weekly News
Wed, 11 Jul 2007 11:29
EDT
Taxi driver spots orange shapes in sky over Hungerford and man sees UFO the size
of four football pitches above Thatcham
 |
| ©Newbury News |
MORE reports of UFO sightings in the summer skies above West Berkshire have left people baffled.
A Swindon taxi driver recently added to the growing list of supernatural occurrences spotted by locals in the
district.
Having just dropped off a fare in Hungerford, Neil Whitby spotted four bright orange shapes in the sky.
Drifting silently across the sky at what he believed was a fairly
low altitude, the lights began to flicker before suddenly disappearing.
A few weeks earlier, a man from Newbury rang the Newbury Weekly News
claiming to have spotted circles in the sky the size of four football
pitches hovering above Henwick Fields in Thatcham for five minutes. He
said his son had also seen the lights.
The inexplicable phenomena are the latest in a whole string of local
UFO sightings dating as far back as 1909, when an organist from St
Michael's Church in Lambourn spotted a shape coming from the East that
he said intermittently let off loud explosions.
UFO expert Steve Harris of the Newbury Amateur Astronomical Society
said: "I have actually seen spacecraft returning to earth before. When
you see things that are glowing as they go through the atmosphere it is
generally spacecraft or space junk."
LITTLE green men, cigar-shaped metal objects travelling at
supersonic speeds, or balls of fire rising from the earth. West
Berkshire has had its fair share of UFO sightings.
Three years ago locals in Hungerford were left baffled by a giant
fireball attached to a solid cigar-shaped structure (pictured above),
which some saw plummet to earth before rising into the night sky again.
People said pets were behaving strangely twenty minutes before the
fireball appeared and police even dispatched helicopters to look for
debris while firefighters scoured the area in search of a point of
impact.
UFO experts from America, who were holidaying in Marlborough at the
time, became so excited by the sighting that they set up camp near
Hungerford to await the fireball's return.
The mystery was never explained and a man even saw a similar ball of flame above Thatcham a year
later.
In September 2006, a triangular-shaped formation of glowing lights
was seen drifting across the sky above Greenham Common (see additional
pictures).
Some witnesses said the lights formed a V shaped formation, hovering
over the common for three minutes before disappearing into the night
sky at lightning speed.
The MOD and Met office were left scratching their heads, unable to
explain the Greenham sightings or the power cuts and bright flashes
that accompanied them.
At the time, UFO expert Steve Harris dismissed satellites, meteors and space junk as possible explanations,
It seemed to come straight through the window and into my head...it
was very painful as these would only light up the sky for a couple of
seconds. He said: "We would have to put it down as an unidentified
flying object."
WEST Berkshire's catalogue of UFO sightings coincides with an age when rumours of alien autopsies
abounded.
In the summer of 1968, a Newbury man was drawing his curtains when a
huge circular object flashed across the horizon at break-neck speed. On
the same evening, two policemen in Kent spotted an object of a similar
description also travelling abnormally fast.
Fifteen years earlier the same man spotted a large cigar-shaped
object moving through the sky while he was walking his dog in Love Lane.
In 1971, after two sightings, the man was so impressed that he
founded the Newbury-based South-West Aerial Phenomena Society (SWAPS),
members of which made it their mission to record and investigate UFO
sightings in West Berkshire.
One of the club's first investigations into the bizarre night time
phenomena was to set up a "skywatch" to chart the movement of orange
lights seen by people in May 1972.
SWAPS sent investigators to the home of Wickham actress Coral
Atkins, who had told the Newbury Weekly News: "I saw a ball of orangey
white light coming towards me. It seemed to come straight through the
window and into my head.
"It was very painful but for a few seconds it seemed as if I was
standing back from the world and I could see everything as it should
be."
The next recorded sightings occurred in February 1972 when two UFOs
were spotted above Kintbury and Brightwalton on the same night.
Witnesses who chased the mysterious oval-shaped objects on scooters
until they vanished into the night sky said the UFOs had beams of light
radiating from them and red diodes flashing sporadically.
ONE of the few sightings that has actually been explained occurred
on Christmas Day in 1980 when a UFO scare had dozens of people all over
the district claiming they had seen alien activity.
In fact, it later became clear that the bright lights in the sky
were simply a Russian rocket breaking up as it re-entered the
atmosphere.
Mr Harris said that, while unidentified flying objects are common,
he did not believe they were part of an extra-terrestrial mission to
take over the earth.
He said: ""Interstella travel - just travelling from one star system
to another - is a million times more difficult than travelling to the
moon.
"When you consider that the nearest star is four and a half light
years away, it seems a long way to come just to hover over Greenham
Common and not make contact with us.
"Most if not all sightings are explainable, whether they are military helicopters or telecommunications
satellites."
Matthew C. Durkee
Victorville Daily Press
Wed, 11 Jul 2007 08:46
EDT
EDWARDS AFB - If your house shakes and you hear a mysterious boom during the next
nine days, look up.
NASA's Dryden Flight Research Center will be experimenting with
sonic booms today through July 20 to assess the impact on modern
housing construction.
Called the Housing Structural Response to Sonic Booms Test, the
experiment consists of an F-18 research aircraft flying at supersonic
speeds to subject an Edwards base house to sonic booms.
Engineers from NASA's Langley Research Center in Hampton, Va., will
operate more than 100 sensors inside and outside the house to measure
both pressure and vibration.
Dryden officials say the sonic booms will be focused away from
surrounding communities, but they are notifying the public that there
will be up to six sonic booms on each mission, six minutes apart. No
more than two missions will be flown on one day, officials said.
The purpose of the experiment is to find ways to make overland supersonic travel possible.
booms the planet has been experiencing recently.
Since the 1950s engineers have tried but failed to achieve
supersonic flight with low-impact sonic booms. As a result, the
usefulness of supersonic flight outside of military purposes has been
severely restricted.
The Concorde was one of only two supersonic passenger jet designs
ever operated, and it flew only transoceanic flights so that the sonic
booms would not disturb anyone. Concorde flights ended in 2003.
NASA officials have been studying ways to mitigate sonic booms throughout the past decade.
Noise-related questions should be forwarded to Air Force Flight Test Center public affairs at (661) 277
-3517.
Matthew C. Durkee may be reached at 951-6226 or mdurkee@vvdailypress.com.
Blake Jones
The Garden Island
Mon, 09 Jul 2007 22:04 EDT
Kauai -
An explosion that has yet to be explained was heard and felt
in Lihu'e Sunday night between 8:30 and 9:30, according to witnesses.
County Public Information Officer Mary Daubert said a police officer
did check out the area in response to calls but was not able to
determine the cause.
Police Commissioner Tom Iannucci, who was waiting with his kids at
the Lihu'e Taco Bell drive-through, said there was no mistaking the
noise and "slight concussion" to the car, which he likened to a
dynamite explosion.
"Being a former Marine who served in a war zone, Beirut, I know exactly what it was," Iannucci said.
Iannucci called 911 to report the blast and was told by the dispatch
operator that there had been other calls about an explosion in the area.
"It was too large to be something simple," he noted, adding that he
did not see anything, smoke or otherwise. "To ... hear it as loud as I
heard it and feel the slight jolt in the vehicle, something happened."
Don Uohara was relaying cables with a Wasa Electrical Services crew
at the stop light at Kaumuali'i Highway and Nawiliwili Road when he,
too, heard a "pretty loud" boom.
"We turned around and said, 'What was that?'" Uohara said of his and coworkers' reactions.
Kauai Film Commissioner Art Umezu said he did not know of any
pyrotechnics that took place in the area for the film "Tropic Thunder,"
which is being produced on-island. The movie follows actors shooting a
war flick who become their characters after a strange series of events.
"They don't believe they've done anything, especially on a Sunday," Umezu said after talking to the film's
production office.
According to Capt. David Bukoski of the Fire Prevention Bureau,
there have been explosions and testing in the past for the film, but
nothing was scheduled or permitted for Sunday.
Bukowski said the Fire Department has a good relationship with the certified and licensed
pyrotechnicians.
"They are very cognizant of the public," Bukoski said of the crew.
Space.com / AP
Mon, 16 Jul 2007 13:03 EDT
A forest fire has led to a
chance discovery of debris from the
impact of a meteorite 1.85 billion years ago, more than 450 miles away
at Sudbury, Ontario.
Geologists had scheduled a field trip in May along the Gunflint
Trail in northeastern Minnesota, but most areas they wanted to explore
were closed because of a wildfire that charred more than 118 square
miles.
Geologist Mark Jirsa of the Minnesota Geological Survey went up the
trail to scout new locations and, in a spot he had never visited
before, stumbled across debris now linked to the Sudbury impact.
That impact created a crater more than 150 miles across, scattering rock and dust over nearly a million
square miles.
"It's fairly dark rock,'' Jirsa said. "They look like concrete, but
in this concrete you would throw pieces of rock of all sizes and shapes
and in all possible orientations.''
Previously, material thrown out by the impact had been found as far
from Sudbury as Hibbing, about 125 miles farther to the southwest from
Grand Marais. However, the tiny fragments at Hibbing were found in core
samples from 800 to 1,000 feet below the surface, while the rock layer
containing larger chunks at the Gunflint site lies exposed.
"I think the excitement for the people of Minnesota is that we are
one place in the world where you can see evidence of an ancient
meteorite impact,'' said University of Minnesota geology professor
emeritus Paul Weiblen, who is studying the debris. "This is the
second-oldest and second-largest impact crater in the world.''
Denis St. Pierre
The Sudbury Star
Tue, 17 Jul 2007 12:36 EDT
A
Laurentian University geologist says he is intrigued, but
skeptical of a report that rock from the meteorite that created the
Sudbury basin has been found 700 kilometres away in the United States.
Andrew McDonald, a geologist and professor in Laurentian's
department of earth sciences, said he was surprised by Monday's report
of the findings of a Minnesota geologist.
Geologist Mark Jirsa of the Minnesota Geological Survey reported he
discovered the Sudbury-related rock along the Gunflint Trail in
northeastern Minnesota.
Jirsa said he found an exposed rock layer containing large chunks of
what he determined is debris from the meteorite impact that created the
Sudbury basin 1.85 billion years ago.
"It's fairly dark rock," Jirsa told the Associated Press. "They look
like concrete, but in this concrete you would (see) pieces of rock of
all sizes and shapes and in all possible orientations."
The finding was made in May and was followed by weeks of analysis.
"I think the excitement for the people of Minnesota is that we are
one place in the world where you can see evidence of an ancient
meteorite impact," said University of Minnesota geology professor
emeritus Paul Weiblen, who is studying the debris.
"This is the second-oldest and second-largest impact crater in the world," Weiblen told the AP.
McDonald said he was anxious to investigate the report, adding he
would be shocked if rock from the Sudbury meteorite landed 700
kilometres away.
"With the distance to that particular site, a surface exposure of
something like this might be a little dicey," McDonald said. "That's a
good distance."
The so-called Sudbury breccia, the mineralized rock deposited by the
meteorite, "has been found up to 60 kilometres outside Sudbury, but I'm
not familiar with it being found that far away," he said.
Still McDonald said he could not absolutely discount the report from Minnesota.
"Not knowing what they've got, or how they're making the link to
Sudbury, it's very difficult to say if what they have is truly related
to Sudbury," he said.
"There are a lot of things that basically rely on interpretation and
what one person sees is not necessarily what another person sees. So
I'm not saying these fellows are wrong or they've done something
incorrectly, I'm just saying the interpretation they make might not be
the one other people would make, in which case it may be more debatable
as to what they've actually got."
The rock found in Minnesota could be "something like a Sudbury breccia," he added.
If the Minnesota report is authenticated, "it would be a reflection
of how explosive or energetic the impact was" from the Sudbury
meteorite, McDonald said.
"But 700 kilometres is pretty darn far. If you think about it, you
have material that is being thrown that kind of a distance. That would
be quite remarkable in terms of the energy that would have been
released from the impact of the meteorite.
"But I suppose if this is in fact something related to the Sudbury
impact, it would clearly illustrate the enormity of the energy that was
released by this impact."
The Sudbury basin is about 60 kilometres long and 30 kilometres
wide. The basin is believed to be a small portion of a crater 240
kilometres in diameter created by the meteorite. As such, the crater
would be second in size only to the Vredefort crater in South Africa,
which has a diameter of about 300 kilometres.
The Sudbury area also features a second impact site from a meteor, McDonald noted.
"There are two impact sites side-by-side here in Sudbury," he said.
"Lake Wanapitei is an impact structure. That was definitely formed by a
meteorite impact, about 38 million years ago, whereas the Sudbury event
was about 1.85 billion years ago.
"So they were considerably different in time, but the proximity of one to the other is quite remarkable."
NASA
Sat, 21 Jul 2007 03:10 EDT
Scientists have recently
discovered that the planet Saturn is turning 60 - not years, but moons.
"We detected the 60th moon orbiting Saturn using the Cassini
spacecraft's powerful wide-angle camera," said Carl Murray, a Cassini
imaging team scientist from Queen Mary, University of London. "I was
looking at images of the region near the Saturnian moons Methone and
Pallene and something caught my eye."
The newly discovered moon first appeared as a very faint dot
in a series of images Cassini took of the Saturnian ring system on May
30 of this year. After the initial detection, Murray and
fellow Cassini imaging scientists played interplanetary detective,
searching for clues of the new moon in the voluminous library of
Cassini images to date.
The Cassini imaging team's legwork paid off. They were able to
locate numerous additional detections, spanning from June 2004 to June
2007. "With these new data sets we were able to establish a good orbit
for the new moon," said Murray. "Knowing where the moons are at all
times is important to the Cassini mission for several reasons."
 |
| ©NASA/JPL/Space Science Institute |
| Sixtieth moon to be discovered at Saturn, indicated in red. |
One of the most important reasons for Cassini to chronicle these
previously unknown space rocks is so the spacecraft itself does not run
into them. Another reason is each discovery helps provide a better
understanding about how Saturn's ring system and all its billions upon
billions of parts work and interact together. Finally, a discovery of a
moon is important because with this new knowledge, the Cassini mission
planners and science team can plan to perform science experiments
during future observations if and when the opportunity presents itself.
What of this new, 60th discovered moon of Saturn? Cassini scientists
believe "Frank" (the working name for the moon until another, perhaps,
more appropriate one is found) is about 1.2 miles (2 kilometers) wide
and, like so many of its neighbors, is made mostly of ice and rock. The
moon's location in the Saturnian sky is between the orbits of Methone
and Pallene. It is the fifth moon discovered by the Cassini imaging
team.
"When the Cassini mission launched back in 1997, we knew of
only 18 moons orbiting Saturn," said Murray. "Now, between Earth-based
telescopes and Cassini we have more than tripled that number - and each
and every new discovery adds another piece to the puzzle and becomes
another new world to explore."
Murray and his colleagues may get the chance to explore Saturn's
60th moon. The Cassini spacecraft's trajectory will put it within 7,300
miles (11,700 kilometers) in December of 2009.
The Cassini-Huygens mission is a cooperative project of NASA, the
European Space Agency and the Italian Space Agency. NASA's Jet
Propulsion Laboratory, a division of the California Institute of
Technology in Pasadena, Calif., manages the Cassini-Huygens mission for
NASA's Science Mission Directorate, Washington, D.C. The Cassini
orbiter and its two onboard cameras were designed, developed and
assembled at JPL. The imaging team is based at the Space Science
Institute, Boulder, Colo.
Comment: Congratulations, Saturn. You've just got your
new comet...eh, moon.
From: Forget About Global Warming: We're One
Step From Extinction!
Now let's time travel back to the future, and see what the latest information tells
us about Jupiter's moons:
Jupiter is now given 63 satellites. Forty-seven of those satellites
have been discovered since 1999. What if they weren't there before?
What about Saturn. Our 1975 text tells us that Saturn has 10 satellites. In 2007? Well, there are so many that
one source declines to give
a precise number!
However, counting the named satellites on the Timeline of discovery of
solar system planets and their natural satellites gives us a count of 62, with 41 being discovered since 2000
and another ten in the 80's and 90's.
Moving outward, we come to Uranus, given five satellites in 1975, it
now has 28, with ten being discovered in the 1980's, six in the 90's,
and 7 since 2000.
Neptune had two satellites in 1975, now it has 13.
| Planet | 1975 | 2005 |
|---|---|---|
Jupiter | 9 | 63 |
Saturn | 10 | 62 |
Uranus | 5 | 28 |
Neptune | 2 | 13 |
The explanation given most often to explain this surge in the
numbers of satellites for these planets is that telescopes have gotten
better. That is, we can see further, with greater detail, and can
therefore find things that we couldn't see before. It is an explanation
that makes sense. One small problem with this theory is that the "new"
moons of Neptune and Uranus showed up before the new moons of Jupiter
and Saturn. One would think that powerful telescopes capable of finding
moons as far away as the seventh and eighth planets would have found
the hard to see moons of the fifth and sixth first.
Another possible explanation, and one which fits with new moons
appearing around Neptune and Uranus prior to appearing around Jupiter
and Saturn, is that these new moons, or some of them, are objects that
have been trapped into orbits around these planets only recently, that
they were captured by the gravity of these planets and removed from the
incoming comet cloud. Passing the orbits of the outer planets first,
they would arrive at the inner planets afterward.
We also note that the much derided Immanuel Velikovsky, in his book Worlds in Collision,
gives a time frame of nine years as the time it would take for a comet
to cover the distance between Jupiter and Earth. The new Jovian moons
were discovered beginning in the late nineties.
Do the math.
Saskatchewan News Network
Sat, 21 Jul 2007 05:35 EDT
Geology
detectives in Saskatchewan might have made two important discoveries this summer.
And, as it usually happens for members of the multi-university
partnership Prairie Meteorite Search, the finds have come from
unexpected places.
When farmer Ken Wiggins heard that field researcher Nathan Seon was
coming to talk about meteorites with locals near Wiggins' home base of
Manor, he figured there wasn't any harm in having Seon examine an
odd-shaped depression that had been on the farm as long as anyone could
remember.
"I wondered about it when I first took a look at it, whether it
could possibly be an impact site," Wiggins said. "But there was really
no big hype about meteorites at that time so, basically, it was there,
it was a curiosity, but it was also a handy place to put some rocks."
Wiggins bought the land 35 years ago, and had used the strange hole
-- about six metres across and 1.8 metres to 2.1 metres deep -- for
dumping rocks he picked off the field. When Seon saw it, he knew it
might be something special.
Both Seon and Martin Beech of the University of Regina, who helps
co-ordinate the Prairie Meteorite Search, note the chances of the site
actually being that of a meteor impact are low.
"It's one of those things," Beech said. "As to whether it is really
a true small-impact crater, it's not that it can't be, but it's
certainly a low probability until you really sort of look into it in
much more detail than has presently been done."
But if the hole does turn out to be the final resting place of rock
from space -- and there is a possibility -- the find would be
significant.
"What would be intriguing would be to actually have such a structure
and then if one can also find meteorites associated with it," Beech
said. "That would be pretty much unique within Canada, I think it's
fair to say."
The investigation is now at a standstill. Wiggins backhoed out the
rocks dumped in the hole. Now, the researchers must find time to go
through the rocks and see if any of them actually are meteorites. So
far, Wiggins has found three rocks with some properties associated with
meteorites, but Beech, who has seen photos, says it's safe to say those
aren't meteorites.
But another stone turned into the Prairie Meteorite Search is
actually very likely a meteorite. Four or five fist-shaped meteorites
land in Saskatchewan every year. One hasn't been identified in three
years, and only 14 have been identified in total over the last century,
Beech said.
This potential meteorite -- brought in by someone who found it
almost a decade ago west of Davidson -- is currently awaiting chemical
analysis. A presence of nickel alloy needs to be identified before it
can be confirmed.
The Prairie Meteorite Search, led by Beech along with professors at
the University of Calgary and the University of Western Ontario, has
been scoping the Prairies for meteorites for the last seven years,
during which time more than 10 new meteorites have been found.
The hope is that by providing information to rural communities,
those who regularly spend time in fields will be able to identify and
report potential meteorites they come across.
Tony Long
Wired
Sat, 21 Jul 2007 05:46 EDT
1862: American
astronomer Lewis Swift discovers the presence of a
large comet that will soon bear his name. Three days later, another
American astronomer, Horace Tuttle, makes the same sighting. So this
heavenly body comes down to us as the Comet Swift-Tuttle.
Based on their observations, and those of other astronomers who
began tracking the comet's highly elongated orbit, it was calculated
that Swift-Tuttle would make its next appearance during the 1980s. They
were close. Japanese astronomer Tsuruhiko Kiuchi rediscovered the comet
in 1992.
 |
| ©H. Mikuz |
| Comet 109P/Swift- Tuttle |
Aside from its unusual orbit, Swift-Tuttle is also significant as
the host body of the Perseids meteor shower, one of the most prominent
in the northern sky.
Oh, and there's one more thing.
Comets come and go, literally, but Swift-Tuttle's orbit is of
particular interest to us earthlings since astronomers calculate that
it is very likely to strike either
the Earth or the moon on its next pass. They've even zeroed in on a date: Aug. 14, 2126.
We'll just have to wait and see.
Manit Sanubboon
Bangkok Post
Sat, 21 Jul 2007 09:02
EDT
Thailand will have a close encounter with an asteroid expected to
move closer to the Earth than the moon in the next 29 years, according
to a prominent astronomer Worawit Tanwutthibundit. The asteroid,
named 99942 Apophis, will come into close orbit with the Earth 22 years
from now and it will come by again, even closer, seven years after that.
This has sparked fears over the possibility that it could collide with the Earth.
Mr Worawit, an executive member of the Thai Astronomical Society,
said the asteroid will come within about 34,400 kilometres of the Earth
on April 13, 2029.
He cited a report released by the US National Aeronautics and Space Administration (Nasa).
On that day, the asteroid will make its closest approach to the
Earth, about eleven times closer than the moon will pass by _ for the
first time in 1,000 years, according to Mr Worawit.
The astronomer said the asteroid's visit on that day will provide a
basis for calculations about whether it could hit the Earth in the
future.
The same asteroid is predicted to pass by the Earth again on April
13, 2036 and it will be even closer then, Mr Worawit said, citing the
Nasa report.
He said the calculations will determine whether the asteroid would
be on a collision course with the Earth in 2036 or not. ''If it struck
the Earth on that day (April 13, 2036), the possible target would be
the northern part of Mexico.
''The impact of the collision would be like the power of 870 megatonnes of TNT going off,'' Mr
Worawit said.
Mr Worawit said 99942 Apophis is 320 metres in diameter, and orbits the sun every 323 days.
On April 13, 2029, the asteroid will come into view at dusk at a
42-degree angle in the western sky in the constellation Cancer, Mr
Worawit said.
It will be able to be observed in the Middle East, Europe, Africa and Thailand.
The 99942 Apophis asteroid was discovered in June 2004. It was then called 2004 MN4.
TV3
Sat, 21 Jul 2007 08:48 EDT
Early risers in Auckland were treated to
a
natural fireworks display this morning - spotting a meteorite flashing
across the West Coast sky.
Experts explain the phenomenon as a piece of either a comet or an
asteroid, which vaporises in a great cloud of light when it hits our
atmosphere.
The Hawke's Bay Astronomy Society says it is a common occurrence
with at least one hitting every day, but only about ten a year are
reported to them.
Vice President Graham Palmer says people often mistake the shower
of light as plane explosions or UFOs, but he says there is no cause for
concern.
Comment: With the amount of reported fireballs and meteorites
falling on earth in recent years, and the amount of UFO sightings
multiplying as time goes by, there is of course "no cause for concern".
Back to sleep folks!
SanLuisObispo.com
Wed, 18 Jul 2007 22:23 EDT
Sheriff's
Department officials reported
receiving dozens of calls from residents around the county who reported
feeling shaking and loud booms at three different times before about
1:30 p.m. Residents from California Valley to Arroyo Grande reported
feeling the shaking and hearing the booms.
Military aircraft appear to be responsible for sonic booms and
shaking that residents around the county are feeling this afternoon,
officials said.
Edwards Air Force Base officials said they sent an F-22 airplane out
to a testing area about 50 miles off the coast this morning that could
have explained the rattling residents reported, base public affairs
spokesman John Haire said. But the area is also used by other branches
of the U.S. military that could have had aircraft in the area, Haire
said.
In addition, NASA was conducting sonic boom testing this morning at
the base that may have been heard by residents along the coast. The
base is located in the Mojave Desert, near the Kern and Los Angeles
county line.
Comment: From the comments section of the article:
I've lived in California all of my 48 years, and
I've heard sonic booms many times before, including the big double boom
of the shuttle coming in. This was much different. It was 3 or 4
seconds of what sounded like a jackhammer on my walls, followed by a
window rattling boom.
If the Air Force is playing with a new secret toy, fine, say "no comment", but this story isn't working for me at
all.
David Shiga
NewScientist.com
Mon, 23 Jul 2007 23:04 EDT
A new
space rock has been found that devotedly travels around with
Mars as it orbits the Sun, bringing the total number of such 'groupies'
to four. But astronomers say it was Mars - not its tiny companions -
that originally insinuated itself into the rock group billions of years
ago.
The asteroid, called 2007 NS2, was discovered by astronomers at the
La Sagra Observatory in southern Spain on 16 July. Based on its
brightness, it is estimated to be about 1 kilometre across.
It follows Mars in its orbit, occupying a spot called L5, which lags
the Red Planet by 60° as it moves around the Sun. It shares L5 with two
other objects, while a fourth object orbits 60° ahead of Mars at a
point called L4.
Objects that wander into the L4 and L5 points of a planet tend to be
confined there by the combined gravity of the planet and the Sun.
Mars is one of just three planets known to have such "Trojan"
objects in its orbit. About 2200 are known to accompany Jupiter in its
orbit, and a handful have been discovered in Neptune's orbit as well.
Jupiter and Neptune may have collected their Trojans about 3.8
billion years ago, at a time when the orbits of these planets were
shifting and their gravity was flinging vast numbers of comet-like
objects around the solar system.
How Mars got its Trojans is uncertain, but the Red
Planet may have collected them at a much earlier period, just after the
dawn of the solar system a little more than 4.5 billion years ago, says
Trojan researcher Alessandro Morbidelli of the Observatoire de la C?te
d'Azur in Nice, France.
Temporary companions
At that time, an embryonic Mars may have been kicked around the
solar system through gravitational interactions with other planetary
embryos. Any asteroids that happened to be at the L4 and L5 points of
its new orbit would have been trapped there by the Red Planet's gravity.
"They did not move, but the planet did," Morbidelli told New Scientist.
After the discovery of 2007 NS2, astronomers found the asteroid in
old images from the Arizona-based LONEOS and LINEAR near-Earth object
surveys dating back to 1998. This has allowed researchers to calculate
a more precise orbit for the object.
Calculations by Aldo Vitagliano of the Universita di Napoli Federico
II in Naples, Italy, show the asteroid is stable at Mars's L5 point.
The newly found space rock has now been added to the list of Mars
Trojans on the website of the Minor Planet Center in Cambridge,
Massachusetts, US.
Earth has no known Trojans, perhaps because our home planet is too
heavy to have been knocked around the same way that Mars was,
Morbidelli says. "Mars jumped around because of its small mass, but not
the Earth," he says. Mars is just 11% as massive as the Earth.
Although no asteroids are known to occupy Earth's L4 and L5 points,
there are a handful of so-called Earth co-orbital asteroids. These
objects have corkscrew orbits, slowly looping around Earth, while
following its orbital motion around the Sun. This configuration is
unstable, so these objects are only temporary companions to Earth.
One such object, a 200-metre-wide asteroid called 2005 GU9, has been
looping around Earth this way for 500 years, but is expected to
eventually drift away.
If some wayward objects from the asteroid belt did become trapped as
Trojans around Earth, the objects would not be easy to spot, Vitagliano
says.
Their position relative to Earth means they would not reflect much
light towards us, making them relatively dim. And because of their
position, they would appear fairly close to the Sun, which means they
would only be visible above the horizon for a short period of time at
night.
Economist.com
Tue, 24 Jul 2007 05:36 EDT
ONE of the main
weaknesses of the
environmental movement has been its unfortunate predilection for using
doom-laden language and catastrophic superlatives to describe problems
that are serious but not immediately disastrous. But one calamity that
truly deserves such a description is almost never talked about. There
are tens of millions of asteroids in the solar system, and several
thousand move in orbits that take them close to Earth. Sooner or later,
one of them is going to hit it.
 |
| ©NASA |
Several have done so in the past. Earth's active surface and
enthusiastic weather conspire to scrub the tell-tale impact craters
from the planet's surface relatively quickly, but the pockmarked
surface of the moon - where such scars endure for much longer -
testifies to the amount of rubble floating in the solar system. Earth's
thick atmosphere makes it better protected than the moon: asteroids
smaller than about 35 metres (115 feet) across will burn up before
hitting its surface. Nevertheless, plenty of craters exist. The Earth
Impact Database in Canada lists more than 170.
Fortunately, such impacts are relatively rare, at least on human
timescales. Statisticians calculate that the risk to lives and property
posed by meteorite strikes are roughly comparable with those posed by
earthquakes.
Although the chance of an impact may be small in any given year, the
consequences could be enormous. The effect of an impact depends on an
object's size and speed. A meteorite a few metres wide could level a
city. The largest (a kilometre or more in diameter) could wreak
ecological havoc across the entire globe. David Morrison, a NASA
scientist, argued at a recent conference that a large meteorite strike
is the only known disaster (except perhaps global nuclear war) that
could put civilisation at risk.
Examples give a more visceral illustration than statistics. The
Chicxulub crater, buried beneath modern Mexico, is 65m years old and
180km (112 miles) across. Some think that the ten-kilometre meteorite
that created it threw so much dust into the atmosphere that it blotted
out the sun and led to the extinction of the dinosaurs. In 1908 a
comparatively tiny piece of space-borne rock, 30-50 metres across,
exploded above Tunguska, a remote part of Siberia. The blast - hundreds
of times more powerful than the atom bomb dropped on Hiroshima 37 years
later - felled 80m trees over 2,150 square kilometres. Only blind luck
ensured that it took place in a relatively unpopulated part of the
world. Astronomers are currently trying to work out whether a 270-metre
asteroid named 99942 Apophis will hit Earth in 2036 (probably not, but
it would be nice to be sure).
Happily for humanity, technology has advanced to the point where it
is possible, in principle, to avoid such a collision. In 1998 NASA
agreed to try to find and catalogue, by 2008, 90% of those asteroids
bigger than 1km in diameter that might pose a threat to Earth. Any
deemed dangerous would have to be pushed into a safer orbit. One
obvious way to do this is with nuclear weapons, a method that has the
pleasing symmetry of using one potential catastrophe to avert another.
But scientists counsel caution. A nuclear blast could simply split one
large asteroid into several smaller ones, some of which could still be
on a collision course.
Other plans have been suggested. One is to use a high-speed
spaceship simply to ram the asteroid out of the way; another is to land
a craft on the rock's surface and use its engines to manoeuvre the
asteroid to safety. A subtler method is to park a spaceship nearby and
use its tiny gravity to pull the asteroid gradually off course. For
now, all such suggestions are theoretical, although the European Space
Agency is planning a mission, named Don Quijote, to test the ramming
tactic in 2011.
These schemes offer consolation, but any effort to deflect an
asteroid requires plenty of advance warning, and that may not always be
available. NASA has so far catalogued only the very largest,
"civilisation-killing" asteroids. Plenty of smaller ones remain
undiscovered, and they could inflict considerable damage. In 2002 a
mid-sized asteroid (50-120 metres across) missed Earth by 121,000km -
one-third of the distance to the moon. Astronomers discovered it three
days after the event. Comets, which originate from the outer reaches of
the solar system, are faster moving and harder to track than asteroids,
but carry just as much potential for catastrophe.
But perhaps the biggest problem is humanity's indifference.
Currently only America is spending any money on detection, and even
there, politicians have other priorities. Much of the work is done by
Cornell University's Arecibo radar in Puerto Rico, which is facing
federal funding cuts. The telescope costs roughly $1m a year to
operate. As an insurance policy for civilisation, the price looks cheap.
Comment: Well, SOTT has been saying it all along, and
supported it with research and data: Forget
About Global Warming: We're One Step From Extinction!
Joyce L. Miller
Lake Sun Leader
Tue, 24 Jul 2007 23:40 EDT
The
United States Air Force has launched an investigation and hope
to provide residents who heard a series of loud booms Monday with an
answer to clear up any confusion.
Military officials at Whiteman Air Force Base at Knob Noster, Mo.,
assured the Camden County Sheriff's Department that their staff would
do everything they could to determine what caused all the commotion
Monday afternoon. Air Force personnel were not aware of any missions or
training exercises in the area at that time that would have caused the
booms that were accompanied by shaking in some areas. The staff at
Whiteman informed the sheriff's department Wednesday that they will go
through the necessary channels to determine if the mysterious sounds
were caused by aircraft.
Residents from one end of the county to the other reported hearing
loud, sonic-type boom sounds beginning around 2:15 p.m. The sounds and
shaking that accompanied the booms shook windows, rattled dishes and
may have caused some damage to walls where the sheet rock cracked.
The sheriff's department had contacted Whiteman, the St. Louis
Earthquake Center and other agencies to find out what caused the noise.
AP
Fri, 27 Jul 2007 10:25 EDT
DUBUQUE, Iowa - Large chunks of ice,
one of them reportedly about 50
pounds, fell from the sky in this northeast Iowa city, smashing through
a woman's roof and tearing through nearby trees.
 |
| ©Telegraph Herald/AP |
| Jan Kenkel holds a piece of ice that fell through the roof of her Dubuque, Iowa, home on Thursday. |
Authorities were unsure of the ice's origin but have theorized the
chunks either fell from an airplane or naturally accumulated high in
the atmosphere - both rare occurrences.
 |
| ©Herald Tribune/AP |
| The mysterious falling ice left a hole in the roof of Kenkel's home. |
"It sounded like a bomb!" 78-year-old Jan Kenkel said. She said she
was standing in her kitchen when an ice chunk crashed through her roof
at about 5:30 a.m. Thursday. "I jumped about a foot!"
She traced the damage to her television room, where she found a
messy pile of insulation, bits of ceiling, splintered wood and about 50
pounds of solid ice.
Karle and Mary Beth Wigginton, who live a block away, heard a loud
"whoosh" coming through the trees. They discovered several large chunks
of ice in front of their home and some smaller ones in the yard and in
the street.
"I could see where branches were shredded, which told me it was definitely coming out of the sky," Karle
Wigginton said.
He estimated the original chunk of ice was the size of a basketball.
"It was pure white," he said. "The main parts I picked up were very
smooth."
Elizabeth Cory, a spokeswoman for the Federal Aviation
Administration, said investigators would contact Kenkel to try to
determine the source of the ice.
"It is very uncommon for something like this to come from an
aircraft," Cory said. "That is really unusual if it is pure white ice,
especially at this time of year."
Occasionally, aircraft latrines discharge contents at altitude,
resulting in chunks of descending ice. Airplanes also sometimes
accumulate ice on their edges in certain atmospheric conditions,
including high altitude and extreme moisture, said Robert Grierson, the
Dubuque Regional Airport manager and a pilot.
The moisture involved in such a scenario could have come from the
tops of strong thunderstorms. However, Dubuque had clear skies at the
time the ice fell, said Andy Ervin, a meteorologist with the National
Weather Service in Davenport. "There was nothing unusual going on," he
said.
David Travis, a professor of geography and geology and an associate
dean at the University of Wisconsin-Whitewater, has studied the
phenomenon of large chunks of ice falling from a clear sky. He said
it's possible the ice could have been a megacryometeor - "similar to a
hailstone, but without the thunderstorm."
Travis is part of a research team that has documented more than 50
possible megacryometeor cases during the past five years. Some involve
ice chunks the size of microwave ovens.
"It is hard to keep something like that suspended in air without a thunderstorm," Travis said.
Most megacryometeor sightings have occurred in coastal areas, where
atmospheric turbulence helps keep ice suspended long enough to grow
into large chunks.
Travis' research team speculates the phenomenon could be linked to
global warming, suggesting that climate change might make the
tropopause portion of the atmosphere colder, moister and more turbulent.
"But those don't typically happen in the summer time," Travis said.
"It seems like they are mostly associated with the passage of passing
cold fronts."
Joyce L. Miller
lakesunleader.com
Tue, 24 Jul 2007 10:47
EDT
CAMDEN COUNTY ' The United States Air Force has launched an
investigation and hope to provide residents who heard a series of loud
booms Monday with an answer to clear up any confusion.
Military officials at Whiteman Air Force Base at Knob Noster, Mo.,
assured the Camden County Sheriff's Department that their staff would
do everything they could to determine what caused all the commotion
Monday afternoon. Air Force personnel were not aware of any missions or
training exercises in the area at that time that would have caused the
booms that were accompanied by shaking in some areas. The staff at
Whiteman informed the sheriff's department Wednesday that they will go
through the necessary channels to determine if the mysterious sounds
were caused by aircraft.
Residents from one end of the county to the other reported hearing
loud, sonic-type boom sounds beginning around 2:15 p.m. The sounds and
shaking that accompanied the booms shook windows, rattled dishes and
may have caused some damage to walls where the sheet rock cracked.
The sheriff's department had contacted Whiteman, the St. Louis
Earthquake Center and other agencies to find out what caused the noise.
Max Hirsch
Taipei Times
Sat, 28 Jul 2007 10:40 EDT
It was so faint
amid the star-freckled blackness that professional
star-gazer Lin Chi-sheng missed it as he photographed the heavens from
Lulin Observatory, Nantou County, earlier this month.
Luckily, Lin's camera, recording time-lapse images of space through
the observatory's telescope, didn't miss it -- a mighty chunk of ice
and rock "a few kilometers" in diameter and hurtling toward Earth:
"Asteroid C/2007-N3."
Since named "Lulin Comet," the galactic "dirty snowball" -- as an observatory press release calls it --
won't
mean much to the average terrestrial, except perhaps on Feb. 27, 2009,
when the comet will likely become visible to the naked eye as it
cruises within 60 million kilometers of Earth -- a "close shave" in astronomical terms.
For Taiwan, however, Lulin Comet and a smaller "near-earth asteroid"
(NEA) captured in the same photograph are the first discoveries of
their kind by local astronomers -- a rare find that puts the nation on
the map in the global astronomical community.
"It seemed like just another night," Lin told a press conference
yesterday, referring to his July 11 late shift at the remote,
mountaintop observatory.
But Lin's camera was trained on a lucky slice of sky that evening,
snapping shots of a starry patch between Jupiter and Saturn. Beating
fantastic odds, a comet and a 1km-wide NEA made it into the frame, said
Lee Lou-chuang, president of National Central University, which runs
the Observatory.
"This is Taiwan's first discovery of a comet and its first discovery of an NEA," Lee said.
The comet was also the first such object to be named after a place
or person in Taiwan, the press release said, adding that,
statistically, only one in 100 discovered asteroids qualifies as an
NEA, and only one celestial body among 1,000 discovered qualifies as a
comet.
Asked what the trick is behind snapping such revealing pictures of
space, Lulin Observatory director Lin Hung-chin said: "It's just luck
really."
But, in an interesting political twist to the celestial find,
astronomers yesterday admitted that China's cooperation was key in
identifying the objects.
While cross-strait relations on many fronts continue to fizzle,
cross-strait astronomical cooperation has flourished, they said. The
two finds announced yesterday, for example, were facilitated by the
"Lulin Sky Survey," a Lulin Observatory-based program that pools the
efforts of Taiwanese and Chinese star-gazers to catalogue the sky, Lin
Chi-sheng said.
Lacking a high-powered telescope of their own, Chinese astronomers
contribute to the program by selecting areas of the sky for the Lulin
Observatory to watch and photograph, and by analyzing the photos, he
said. Chinese participants, he said, were the ones who had first
detected the comet and NEA in the photographs.
US astronomer James Young at the Table Mountain Observatory in California later confirmed the finds, the
press release said.
As the only country in Asia scheduled to participate in
"Pan-STARRS," a US-based program focused on finding asteroids on a
collision course with Earth, Taiwan is also working closely with
astronomers in the West, Lee said.
Scheduled to begin next month, the Hawaii-based program will call on
US Air Force and University of Hawaii resources, as well as
observatories in the UK and Germany, according to the Pan-STARRS' Web
site.
Taiwan, observatory officials said, will contribute by searching the
heavens with its high-powered telescope for dangerous asteroids.
"If we could find an asteroid with the potential to hit the Earth,
that would be very interesting," Lee said, his scientific curiosity
apparently trumping any fear of annihilation. "That'd be worse than
global warming."
Science Alert
Sun, 29 Jul 2007 08:23 EDT
Most nights, as the southern
hemisphere
sleeps, Rob McNaught is awake and on guard. He's part of an
international team of astronomers scanning the skies for Near Earth
Objects (NEOs), such as asteroids and comets, that could pose a threat
to our planet. Scientists believe that large objects colliding with the
Earth in the past may have had cataclysmic effects, wreaking
destruction at the point of impact, altering global climate patterns
and causing mass extinctions. Working with colleagues at the University
of Arizona, McNaught has discovered or co-discovered more than 30
comets and thousands of asteroids from his base at Siding Spring in
outback New South Wales. So far none of the NEOs appear to be an
immediate threat. But very rarely, one of these space travellers does
pass close to our planet with spectacular results.
 |
| ©Rob McNaught |
| The peacock-like tail of the comet became clearly visible once it entered darker skies. This shot was captured by Rob McNaught on 25 January at Siding Spring. |
If anything, McNaught's expectations were lower than usual when he
began routine scans at the Uppsala Schmidt telescope on the night of 7
August 2006. This is just one of the optical telescopes housed by the
ANU Research School of Astronomy and Astrophysics at the site. The moon
was full, and he was due to observe a section of sky close to the edge
of the Milky Way where the stars are denser - two factors that add up
to poor NEO spotting. But one of the scans showed up a faint point of
light emerging out of the brightness of the Milky Way. Further analysis
showed this to be a comet headed towards the Sun, which McNaught
reported to the Central Bureau of Astronomical Telegrams, the
international clearing house for comet discoveries. Tracking the comet
over the next few days, he saw that this object was going to pass
reasonably close by the Sun, well within the orbit of Earth and even
perhaps within that of Mercury. This could translate into quite a show
for space spotters, but it could also mean that the comet would become
lost in the glare of the Sun.
On hearing of the discovery, the response from the astronomical
community was muted. This caution was a lesson learned from the
disappointment of Comet Kohoutek in 1973, which was initially hailed as
the 'comet of the century' before it fizzled out. McNaught says it's
common for a comet's rate of brightening to diminish as it nears the
Sun, so astronomers have learned not to get their hopes up.
"At the time, I wasn't sure what it would be like," McNaught says.
"My peers thought there was no reason to believe it would be unusual.
But after observing it over time, I noticed fairly early on that it had
a rapid rate of brightening, which was quite unusual."
As it journeyed closer to the Sun, the comet continued to grow in
luminescence. McNaught became more confident that this was something
out of the ordinary. By mid-January, his predictions were confirmed.
This ball of ice and dust brightened so dramatically as it approached
that it became visible to the naked eye in daylight. Astronomers and
amateur stargazers thrilled at the sight of what was soon dubbed 'the
Great Comet of 2007'. This object that shone in the sky brighter than
the Venus was designated C/2006 P1, but most people came to know it as
'Comet McNaught', after the convention that a comet is named for its
finder. And for him, it was the fulfilment of a long-held dream.
"I wanted to see and discover comets ever since I was a kid,"
McNaught says. "So to see this one turn out so big and bright was
hugely exciting. Just witnessing it with my own two eyes was much more
important than being credited with the discovery."
To ensure he would have a good chance of viewing the comet when it
was at its brightest, McNaught booked a flight to Hong Kong. He knew
from previous experience that comets near the Sun are more easily seen
from altitude, where there is less pollution, fewer clouds and the
horizon is much lower. A trip to the Northern Hemisphere would also
allow him to view the comet a day before it became visible in Australia.
On 12 January 2007, from the window of a passenger jet, McNaught
witnessed his very own comet punch a pin hole in the late-afternoon sky.
"I was really excited," he says. "It was the first time I'd seen a
comet with the naked eye in daylight. It was a special moment."
His excitement remained high after he returned to Siding Spring, as
Comet McNaught remained visible in the southern hemisphere for several
weeks. Emails and media requests flooded in from around the world as
more people spotted the light in the sky. After reaching perihelion
(the point in its orbit that's closest to the Sun) on 12 January, the
comet appeared higher relative to the horizon, placing it in darker
skies. Here, as if delivering a parting gift as it began its long
journey back to the outer edges of the solar system, C/2006 P1 revealed
an incandescent tail. This peacock-like effect is caused by ejected
dust being pushed outward from the Sun by the pressure of sunlight, but
also lagging behind the comet as it undertakes its tight turn on
passing the Sun.
Comet McNaught's showy pass by Earth allowed scientists to study it
in detail. Although the comet's composition is still largely unknown,
it's believed that this was its first passage through the inner solar
system where our planet resides. It's thought that the comet
originated in the Oort Cloud, a dense ring of icy objects orbiting the
Sun at the distance of about one light year, or slightly less than ten
million kilometres. Even though it made the trip at a fair
clip, it won't be back by Earth for many thousands of years. But there
are more comets and asteroids where it came from, and probability says
that one of them could intersect Earth's orbit. When it comes to the
prospect of an NEO impact, McNaught says we need to be alert but not
alarmed.
"There are many dangers that we treat as simple consequences of
living, but are too busy getting on with our lives to worry about,"
McNaught says. "I don't think it would be healthy to worry about the
prospect of a comet impact. But it does make sense for us to be aware of the threat, quantify it and
prepare to deal with any potential threat."
Comment: For more information, read the SOTT focus
article: Forget About Global Warming: We're One
Step From Extinction! to understand what is really coming our way. Preparations could be underway to
prepare for the future, yet, the Pathocrats
ruling the planet continue to funnel resources into widespread
genocide. Rest assured that their own contingency plans are in place,
however.
SPX
Tue, 31 Jul 2007 15:47 EDT
Since 1986, four different comets --
Halley, Borrelly, Wild 2 and
Tempel 1 -- have been examined in impressive detail by a wide variety
of American, European and Russian spacecraft, including one that has
actually returned a small dust sample to Earth and another that crashed
a large piggyback spacecraft into a comet's nucleus to try and reveal
some of its subsurface structure. And in 2014, the still more ambitious
European "Rosetta" mission will rendezvous with the nucleus of a fifth
comet (Churyumov-Gerasimenko), examine it from just 25 kilometers away
(or less) for over a year and a half, and even drop a small survivable
lander onto the nucleus' surface.
All this attention is entirely justified, given the fact that comets
are the only preserved pieces of the "planetesimals" that were made by
accretion out of the initial dust, ices and gas of the primordial
pre-Solar System nebula itself, and which in turn merged together to
form the planets.
 |
| ©NASA |
So they can give us invaluable data on the composition and structure
of that initial nebula, and thus on the earliest evolution of the Solar
System. But even after Rosetta there will still be one very important
piece missing from our first-stage exploration of the comets -- a piece
that would have been provided by the only comet mission to fail thus
far.
The reason is that we have known for a long time -- from Earth-based
spectra of the gas comas surrounding comets (and our lesser
observations of their accompanying dust) that comets vary to a really
surprising degree in their composition. They are all composed largely
of water ice, but it is mixed with a very wide variety of other frozen
gases -- most of them being simple organic compounds -- that also thaw
out and sublimate into vapor as the comet approaches the Sun and is
warmed by it: carbon monoxide and dioxide, hydrogen and methyl
cyanides, methanol (methyl alcohol), methane, acetylene and ethane,
ammonia, formaldehyde, sulfur dioxide and others -- many of which have
boiling points far lower than that of water and so naturally volatilize
into gas much more easily as a previously distant chunk of cometary
material approaches the Sun. Moreover, their quantities of these other
ices vary greatly from comet to comet.
Our more limited analyses of the "carbonaceous" mineral dust that
forms the other part of a comet's substance indicate that it can also
vary suprisingly. Earth-bound telescopes and astronomy satellites have
taken detailed spectra of the dust cloud thrown up from Tempel 1 by the
Deep Impact crash -- and also of the natural dust vented into space by
the huge 1997 comet Hale-Bopp -- that strongly suggested the presence
of phyllosilicates (clay minerals) and carbonates, such as would be
formed if the carbonaceous silicate minerals originally in the grit had
been exposed to traces of liquid water.
These have also apparently been seen in our spectra of the
protoplanetary disks circling other young stars. But the actual sample
of dust returned from Wild 2's nucleus by "Stardust" shows no trace of
these water-related minerals. There also seem to be significant
differences in the amounts of more complex, less easily vaporizable
organic compounds that have been measured in various comets.
What accounts for these major differences? Originally, astronomers
expected to see a recognizable pattern. Comets can be divided into two
general types: "Oort Cloud" and "Kuiper Belt" comets. Oort comets now
orbit -- by the hundreds of billions -- in the vast reaches of
interestellar space trillions of kilometers from the Sun (thousands of
times farther away than Pluto), but they actually originated among the
hundreds of trillions of ice and dust planetesimals in the early outer
Solar System.
Most of these crashed together to create the four giant planets, but
a smaller fraction made close flybys of the giant planets and were
flung outward by their gravity, either escaping from the Sun completely
or ending up in their hugely distant Oort orbits -- from which one is
occasionally twisted, by the gravity of passing stars and even of the
entire Galaxy, onto a path back toward the Sun, and occasionally even
back into the central reaches of the planetary Solar System. When they
do so, they approach the Sun from every conceivable angle and tilt;
half of them even now swing around the Sun backwards as compared to the
planets.
However, most visible comets with an orbital period of less than 20
years follow orbits tilted no more than 30 degrees to the ecliptic, and
virtually none of them circle the Sun backwards. It's been suspected
for a long time that they had a different source -- a more orderly belt
of a few billion comets beyond the orbit of Neptune, just a few billion
kilometers from the Sun -- and this was confirmed in the 1990s when the
growing sensitivity of our telescopes finally allowed direct detection
of the Kuiper Belt objects (of which Pluto and its moon Charon were the
only previously known members).
Occasionally the gravitational tuggings of the giant planets will
cause one of these to veer far enough back toward the Sun to fly by
Neptune, which in turn can divert it further inwards to carom around
among the four giant planets -- with a certain number of these
"Centaur" comets finally flying past Jupiter and being diverted by its
powerful gravity all the way into the warm inner Solar System.
Paradoxically, it was at first thought that such short-period Kuiper
comets would actually contain colder frozen gases than the Oort comets,
because they had actually been originally formed near or beyond
Neptune, rather than closer in to the Sun in the midst of the four
giant planets like the Oort comets. However, no such pattern has shown
up -- short-period comets and long-period Oort comets seem about
equally rich in very low-temperature frozen gases like carbon monoxide,
methane and ethane.
And new computer simulations of the long-time orbital evolution of
Solar System objects suggest that most (and maybe even all) Kuiper
comets first formed, like the Oort comets, closer in toward the Sun in
the midst of the four giant planets, but were flung less dramatically
outwards from the Sun by the gravitational tuggings of those planets.
(Some Kuiper Belt objects follow relatively neat, circular orbits
around the Sun, and may still have formed out there to begin with,
unlike the Kuiper objects with more elongated or tilted orbits -- but
simulations show that those orderly Kuiper objects are also much less
likely ever to wander back in towards the Sun so that we can detect the
cometary gases boiled off them.) So, the current orbits of comets tell
us almost nothing about how close to the Sun they first formed.
But even more puzzling, however, is the fact that our data up to now
also shows little correlation between the amounts of the different
low-temperature ices in comets -- comets that are rich in carbon
monoxide ice are often poor in methane and ethane ice, or vice versa.
So far, there seems to be little evidence that the distances from the
early Sun (and its warmth) at which comets originally formed had any
consistent effect on the relative amounts of the various different ices
out of which they are made. So what in the world did cause them to vary
in composition as dramatically as they do?
Moreover, most comets (and most Kuiper and Oort objects in general)
are thought to each consist of multiple separate planetesimals that at
some point banged into each other and stuck, like the weapons in a
giant snowball fight. In that case, one would expect the ices making up
any individual comet to vary greatly in mixture from one place on the
comet to another, just as entire separate comets thus vary greatly. But
the evidence on this point, too, is contradictory.
When Deep Impact flew by Tempel 1, it found that one of the two
major natural jets on its surface was emitting mostly water vapor,
while the other was emitting large amounts of carbon dioxide -- which
would indeed fit with the "conglomerate makeup" theory of comets. But
two comets -- the Oort comet "C/1999 S4 (LINEAR)", and the short-period
comet Schwassmann-Wachmann 3 -- have been examined in detail by
Earth-based spectrometers both before and after suddenly breaking up
into multiple pieces (as comets frequently do), and the ratios of the
different gases vaporizing out of their suddenly exposed interior parts
seem identical with the ratios of different gases that had been
vaporizing off their original outside surfaces, indicating that their
mixture of different ices was actually very uniform from place to place.
Finally, there's still another puzzle -- what looks like a
contradictory indication that Oort comets and short-period comets might
have different compositions after all. Most of the Oort comets that
we've seen have incredibly elongated orbits with periods of up to
several million years, indicating that they are still following the
initial orbital path by which they first fell out of the distant Oort
Cloud back into the main Solar System.
A smaller number of them, however, have obviously at some time in
the past made a close flyby of one of the giant planets that shortened
their orbit, such as Hale-Bopp (whose orbital period is now only about
2500 years) and Halley (whose period has been trimmed down to a mere 76
years). But our orbital simulations indicate that there should be a
much bigger number of these orbit-trimmed Oort comets than we're
actually seeing -- which suggests that Oort nuclei are made out of some
very fragile substance and usually burst apart after at most a few
dozen flights through the warm inner Solar System.
Short-period comets, however, have much more staying power -- our
mathematical backtracking of their orbits indicates that they usually
survive for hundreds or even thousands of passes through the warm inner
Solar System before bursting apart or drying out completely. They seem
to be made of tougher stuff. But how can this be, if (as all other
indications show) they were originally formed in just the same zone of
the early Solar System as the Oort comets?
One possible explanation may be that Kuiper comets, during their
initial "Centaur" days, tend to originally wander very gradually
inwards from the Kuiper Belt through the realm of the four giant
planets and into the inner System over a period of thousands of years
-- whereas Oort comets plunge directly from the supercold regions of
the outer Solar System (or near-interstellar space) into the warm inner
System.
It may be that this much slower gradual initial warming of Kuiper
comets does something to "toughen" them by allowing them to vent a
large part of their new inner gases more gradually, so that they avoid
an internal pressure buildup of the type that Oort comets undergo. But,
once again, we don't know. It may be instead that there's just
something currently wrong with our computer calculations of the number
of orbit-trimmed Oort comets that should exist.
As an additional puzzle, the clear closeup photos that we've now
gotten of three comet nuclei -- Borrelly, Wild 2 and Tempel 1 (the
"Giotto" probe's much fuzzier photos of Halley's nucleus aren't nearly
as useful) show some similarly baffling physical differences between
them.
Wild 2's surface, as seen by Stardust, was utterly bizarre. The
nucleus was pockmarked with strange-looking craters that -- unlike the
bowl-shaped meteor impact craters on other worlds -- had flat floors
but very steep wall slopes as deep as 200 meters, making the craters
look as though they had been punched out by a cookie cutter.
There is still debate over whether these might be impact craters,
but their shape suggests instead that they may be "sublimation pits" --
in which a small initial depression (a small normal impact crater or a
gas-vent hole) becomes gradually wider as the ice mixed into its walls
vaporizes away under the solar warmth on perhelion passes, with the
dark rock grit than was mixed in with it then sliding to the bottom of
the slope (or being blown some distance beyond the foot of the slope,
under the comet's extremely faint surface gravity, by the pressure of
the vapor from the sublimating ice).
On flat surfaces, on the other hand, after the surface ice vaporizes
away, the remaining "lag deposit" of rock dust would simply continue to
sit on the surface, forming a blanket that soon becomes thick enough to
choke off further vaporization of the ice underneath it. And so the
initial crater or vent hole would continue to grow steadily wider as
more and more of its walls crumbled away, but without the hole getting
much deeper -- and the initial difference between the steeper slopes of
its upper walls and the lesser slopes of its lower walls and floor
would also become greater and greater, turning any initial bowl-shaped
depression into that flat-bottomed, steep-walled cookie-cutter-type
hole.
Such sublimation of ice off slopes, as the process proceeded
steadily onwards, would also produce other effects -- such as initial
sublimation pits growing wider and wider until they actually ate away
most of the comet's initial layer of surface, leaving behind only
isolated mesas with steep walls but flat tops, and even leaving behind
isolated steep pinnacles. All of these have been seen on Wild 2 --
there is even one place along the edge of the biggest and steepest
crater seen on Wild 2 where this methodical eating away of ice by solar
warmth seems to have produced an overhanging lip!
While the photos of the surface of Comet Borelly's nucleus taken by
Deep Space 1 in 2001 are a good deal fuzzier because the probe was
farther from the comet, they also show clear signs of this same sort of
thermal erosion. There are indeed steep-walled isolated mesas up to 100
meters tall on the surface of Borrelly, and other areas where the
ground seems to have been eaten away in roughly circular depressions --
although we don't see anything as dramatic as the steep-walled craters
of Wild 2. Both comets look as though their surfaces are peeling away
in patches like the skin of a bad sunburn victim.
But the surface of Tempel 1, when Deep Impact viewed it, was
radically different. Whereas Wild 2 has large numbers of slopes of up
to 70 degrees (to say nothing of that overhang), virtually all the
slopes on Tempel are relatively gentle -- there seem to be none over 26
degrees. There is one big area with a smooth flat top which has a
steeper-sloped edge, which could be due to the same kind of methodical
nibbling away at slopes that we see on Wild and Borrelly -- but its
edge seems to be only about 30 meters high.
We see some other evidence for the kind of layer-by-layer
sunburn-like peeling that we see on Wild and Borrelly, but it is always
much shallower and its edge slopes are far gentler. And the craters on
Tempel are also far less strange-looking than those on Wild -- some of
them are gentle depressions with rounded walls, while others have sharp
steep edges but have inner walls that are very low, with the craters'
flat floors being at almost the same level as the plain beyond the
crater. (Deep Impact's Impactor crashed near two such craters.)
Some scientists think that we are actually looking at what were
originally standard meteor impact craters on Wild and Tempel, which
were then extensively modified in form by the thermal slope-ice erosion
that I've mentioned. But it is rather hard to see how impact craters
could endure very long on the nuclei of these comets, since their
surfaces are eroded so fast by ice sublimation; it makes more sense to
assume that we are looking on both nuclei at sublimation pits that grew
from what were originally far smaller impact craters or gas vents.
Wild 2 was a Centaur-type object that never came close to the Sun
than Jupiter's orbit until only 33 years ago, at which time it made a
close flyby of Jupiter that flipped its orbit into an entirely new one
taking it into the inner Solar System. Since then it's made only five
orbits into the warm inner System -- so it's been proposed that only a
few meters of its icy surface will have vaporized away, allowing the
big impact craters that had formed on Wild's surface during its ages in
the cold outer Solar System to still exist on its surface at this point.
But most such Jupiter-crossing comets have been shown by computer
calculations to switch back and forth repeatedly between periods where
they do stay in the cold outer System, and other periods where a
Jupiter flyby flips them into the inner System for a while before a
later Jupiter flyby flips their orbit back into the cold outer System
again -- so it's likely that Wild's surface has actually been eroded
away by the Sun's warmth for a total period much, much longer than just
33 years. This returns us once again to the idea that its big craters
must be sublimation pits, rather than big meteor impact craters that
were somehow preserved on its surface despite the major erosive effects
of the Sun's heat.
In any case, we're left with the question: why are the slopes on
Tempel 1 so much gentler and less tall than those on Wild 2 and
Borrelly? Is it just that its top surface material is far more crumbly
than that on those other two comets? I've mentiond earlier that the
conclusion was initially drawn from the shape, size and timing of the
ejecta cloud thrown up by Deep Impact's Impactor that the comet's
surface must be incredibly soft, fluffy and non-conhesive, something
like dry talcum powder -- but I've also noted that Kevin Housen and Ken
Holsapple think that this underestimates the effects of newly vaporized
gases erupting from underneath after the impact, so that the surface
material may actually be somewhat sticker and firmer than that.
However, this could still leave it far more crumbly than the surface
material on Borrelly and Wild, and thus incapable of sustaining their
kind of steep, tall slopes and cliff walls -- even given the extremely
faint surface gravity on all three comet nuclei.
But in that case, why is Tempel's surface softer -- and why does it
look as though Borrelly's slopes are also somewhat less steep than the
surrealistically steep cliffs on the surface of Wild 2? Were the three
comets made from the start of ice and dust mixtures of different
compositions, and thus different firmnesses -- with the three comets
varying in their ice-dust ratios, or Tempel's ices perhaps being made
out of more volatile gases that boil away into vapor more easily than
the surface ices of Wild and Borrelly? Or have their surfaces been
affected by different complex sequences and amounts of solar heating
over their histories, since their orbits have all likely changed
repeatedly in the manner that I've described?
Finally, Arizona comet expert Michael J.S. Belton has suggested that
some of the layering seen on all three comets may not be thermal
peeling, but may actually be the result of the collisions between
smaller blobs of ice/dust that created them in the first place in the
outer System or in the Kuiper Belt. He posits the "Talps" theory
(that's "Splat" spelled backwards), in which -- when one such snowball
hits a bigger one -- it is flattened out into a sheet that spreads
around part of the surface of the bigger snowball.
This could explain, in particular, what seems to be one layer of
material that actually runs through the middle of Tempel's nucleus, so
that we see a cross-section of the layer as a straight-edged
200-meter-wide band running across one part of the nucleus. Once again,
though, in that case we would expect to see different patches of any
individual comet nucleus being made out of a different mixture of
various ices and dust -- and while Deep Impact did see some sign of
such compositional patchiness on Tempel 1 (where one of the comet's
surface jets expels just water vapor while the other expels a lot of
carbon dioxide), we don't seem to see it in the separate fragments of
other comets that have ruptured into pieces.
In short, our first space probes have shown that different comet
nuclei vary as dramatically in their physical makeup and structure as
they do in chemical composition. To get any good understanding of what
causes these differences -- and what they may say about different
comet's' actual original formation conditions in the early Solar System
(as distinguished from the complex effects that comets' different
orbital histories, and thus their varying degrees of warming by the
Sun, may have had on their surface appearance) -- we are clearly going
to have to look at a much larger sampling of different comet nuclei,
just as the great variations between the Asteroids means that we must
get a closeup look at a large sampling of them to understand them
properly. Just looking at a few comet nuclei -- even when you look at
one of them in such spectacularly close detail as Europe's "Rosetta"
comet rendezvous-and-landing mission will do in 2014 -- won't be
adequate.
And the one comet probe intended so far to look at a whole
multiplicity of different comets failed disastrously in 2002. In the
last part of this series, I'll examine how comet scientists hope to
recover from that failure -- and how the new extended missions of the
Stardust and Deep Impact probes can help us do that.
The most powerful of those was Deep Impact's "High-Resolution
Imager" (HRI), which at the time had by far the most powerful optic
system ever carried on a Solar System probe: a reflective telescope
with a 30-cm wide mirror, which was intended to take pictures of the
comet nucleus' surface with a resolution of only 2 meters per pixel
from a range of 700 km. Unfortunately -- in an eerie replay of the
Hubble Telescope's initial mirror problem -- it was discovered after
launch that the mirror was slightly out of focus.
The mathematical image-processing known as "deconvolution" largely
compensated for this for photos of the relatively bright comet nucleus
surface itself, but deconvolution is less effective in deblurring
images of dim light sources because it amplifies random noise in the
photo (which is why it could do little to correct Hubble's problem
before astronauts installed a focus-correcting mirror on the telescope).
However, Drake Deming of the Goddard Space Flight Center came up
with an ingenious proposal for a Deep Impact extended mission that not
only managed to use Deep Impact's HRI for genuine astronomy studies,
but actually makes some lemonade out of the lemon of its focusing
problem.
Leonard David
MSNBC
Mon, 30 Jul 2007 06:01
EDT
Advocates believe in scientific payoff; critics say mission is too
dangerous
 |
| ©Digitalspace / DigitalSpace |
| NASA is considering sending astronauts on an asteroid mission, as illustrated here. |
GOLDEN, Colo. - NASA's Constellation Program - including the
deployment of the Orion crew vehicle replacing the space shuttle - will
first be assigned to international space station flights, then propel
humans and cargo to the Moon. Expeditionary missions to Mars and beyond
will follow.
But there's ongoing discussion of mounting a piloted mission to an
asteroid - a voyage by astronauts to a near-Earth object. These
proponents feel certain of the scientific payoff from reaching,
first-hand, an asteroid - perhaps even becoming able to exploit these
chunks of celestial flotsam to further humankind's plunge into the
cosmos.
Space technologists argue that a NEO trip could be a valuable
shakeout of people, equipment, and procedures prior to hurling
astronauts beyond the Moon to the distant dunes of Mars.
For others, NEOs are viewed as downright dangerous, in terms of a
head-on collision between Earth and a space rock. It's best to get to
know these incoming beasts ahead of time.
NASA's NEOphytes
Internal looks by a small group of NASA "NEOphytes" have projected
that a human trek to one of those mini-worlds may involve two or three
astronauts on a 90 to 120-day spaceflight, including a week or two week
stay at the appointed asteroid.
Dispatching astronauts to a NEO is a sensible idea, said Harrison
Schmitt, Apollo 17 astronaut, geologist and current chair of the NASA
Advisory Council.
In fact, the Exploration and Space Operations subcommittees of the
NAC were briefed July 18 by NEO study team members from the NASA
Johnson Space Center, although there has been no Council action on the
topic.
Schmitt told Space.com: "I think examination of a NEO mission and
the development of the stand-by monitoring systems, plans, protocols
and procedures for the diversion of a potentially Earth-impacting
asteroid would be very prudent activity for the U.S. to undertake."
Additionally, Schmitt said that a NEO mission would be a potentially
important demonstration of the versatility and capability of the
Constellation systems and a "gap-filler" before any Mars landing
mission.
"So far, the arguments for asteroid science and resources
are interesting, but not well-developed or potentially as historically
or politically persuasive as a demonstration of long-term Earth defense," Schmitt said.
Extended flight
At this point in time, NASA has not issued any formal requirements
to augment the Orion spacecraft to handle a piloted NEO mission,
explained John Stevens, Director of Business Development for the human
spaceflight line of work at Lockheed Martin Space Systems, near Denver,
Colorado.
However, the company - builder of the crew-carrying Orion spacecraft
- internally funded two years worth of studies to flesh out
technologies to support a diversity of destinations, Stevens said. For
sojourns to a near-Earth asteroid, he said, future block upgrades to
Orion are necessary.
"It's not that difficult from an architecture point of view to fly
by an asteroid and then come back," Stevens said. But pulling off a
rendezvous and docking with such an object, then rocketing back to
Earth, requires more propulsion oomph, he noted, along with the need
for larger living quarters for transiting crews, as well as recycling
hardware to handle oxygen and water needs.
Also, any roundtrip - Earth-to-NEO-to Earth - is an extended flight,
way beyond that required for Moon travel. So that brings up crew
psychological-sociological issues. "It's a concern...but we don't know
how much of a concern," Stevens advised.
Stevens said that the near-Earth object human mission can be viewed
as an intermediate step between a Moon mission and a Mars mission. "In
terms of complexity and the length of time that you have to stay
out...it does represent a good stepping stone between the kinds of
missions you do at the Moon and the kinds of missions that you next
bite off...which is the Mars mission," he said.
Visualize this space
DigitalSpace, a privately held company based in Santa Cruz,
California, has just released a design simulation of a notional crewed
mission to an as-yet identified asteroid.
"This visualization is DigitalSpace's design concept for the
mission, produced as an independent effort for the benefit of an
internal NASA feasibility study completed in 2007," said Bruce Damer,
founder of the company that provides leading edge Internet content and
tools for communication, collaboration, and visualization.
The NASA study was performed to show that such a mission is possible
with the new Constellation architecture, Damer said. DigitalSpace
received input from numerous experts inside and outside NASA to produce
the NEO mission visualization.
"It is important to note that this is not a NASA concept, nor has
NASA given it any kind of technical blessing...it is a design created
by the DigitalSpace team to stimulate discussion in the space
community," Damer emphasized.
Indeed, many in the space community see any pilgrimage to an
asteroid - by either robots or astronauts - as having multiple
benefits.
Tooling up for NEOs
Learning about NEOs offers much in both scientific and practical
terms. That's the perspective offered by Clark Chapman, a planetary
scientist at the Southwest Research Institute's Department of Space
Studies in neighboring Boulder, Colorado.
The reasons are many, Chapman said: Because there are many of them,
because they are made of materials both common and exotic compared with
materials available near the Earth's surface, and because they have
negligible gravity...they are an obvious source of raw materials for
future human exploration of outer space.
Tooling up for NEOs is already being tackled by specialists at Ball
Aerospace & Technologies Corporation, also in Boulder. They have
been looking into a small, low-cost landing probe design that could
characterize both the surface and interior of small solar system
objects, such as an asteroid.
The device is about the size of a basketball and weighs just a few
pounds, said Dennis Ebbets, Senior Business Development Manager for
Ball Aerospace's Space Science division. He and staff consultant,
Richard Reinert, along with Rich Dissly, Ball's Deputy Director for
Solar System Advanced Systems, suggest that several of the probes could
be hauled to a target object and deployed individually.
Once released, these non-propulsive surface probes would freefall
onto an asteroid's surface and begin transmitting results from their
respective locales. The probes are outfitted with deployable panels to
ensure self-righting to begin their errands.
Each self-energized probe might employ tiny imagers, accelerometers,
x-ray spectrometers, sample collection and analysis gear - perhaps even
utilize small explosive charges to create seismic waves that help gauge
an asteroid's internal structure.
While asteroid surface probes could be deployed from an automated
spacecraft, they are also a "perfect candidate" to be toted onboard a
human expedition to a near-Earth object, Ebbets told Space.com.
Ebbets said asteroids deserve attention to help figure out what they
are, where they come from, why they are different, and why there are
families of these objects that are the same.
Additionally, "there's a non-zero chance of being hit by one of these things,"
Ebbets noted. He said he was a big fan of dropping a transponder onto
an asteroid that's been branded as a potential troublemaker.
"Putting a transponder on it would be an excellent thing to do,"
Ebbets added. "You can get a very, very accurate orbit...predict years
into the future whether it's on a collision course with us or not."
Long-delayed expectations
Along with the need to come to grips with scalawag asteroids that
could harm Earth, SwRI's Chapman senses other NEO exploration outcomes.
"Though I am a space scientist strongly oriented toward the
cost-effective robotic exploration of the solar system, I also grew up
on science-fictional accounts of human expansion into the cosmos, and I
endorse that more expensive - but ultimately inevitable - direction for
human exploration," Chapman said.
Chapman said that it makes sense to him that NEOs could be used as
"way-stations" to Mars. "Human visits to NEOs can go part-way toward
understanding the challenges of going to Mars, yet not invoke the most
serious challenges," he said.
Regarding concerns in some quarters that efforts to send humans to
NEOs may be a distraction from the main, early focus of sending humans
to the Moon, Chapman said: "In the current environment where the
'Vision' dominates NASA and the budget tends to restrict what we might
do under the umbrella of the 'Vision' to the narrowest aspect of the
'Vision'...the focus must be on the Moon."
More than the Moon
But Chapman continued by noting that the dreams of people worldwide
who want to expand their long-delayed expectations of going into
interplanetary space, NASA - assisted by the budgetary processes in the
Congress - must find a way to do more than just return to the Moon.
"I happen to believe that scientific exploration of the Moon...could
be extremely significant. And the Moon is much more easily explored and
developed than Mars, which must remain a longer term challenge. But
NEOs offer a special, practical, and inspiring challenge that we should
keep on the table," Chapman explained to Space.com.
In the context of the hazard of destructive impacts by NEOs
on the Earth, Chapman said that "everything we can learn about the
physical nature of NEOs can incrementally enhance our chances of
dealing effectively with one, should one be discovered that seriously
affects us." He explained that robotic exploration of such a
NEO would be essentially as good as human exploration of that
threatening object.
"But the generic exploration of NEOs - even if solely in the goal of
getting to Mars - can have side benefits not only for understanding the
range of issues we might have in dealing with a threatening NEO, but
also in learning how we might mine the resources of NEOs for future use
in human exploration of the solar system," Chapman concluded.
The Cornishman
Fri, 03 Aug 2007 10:40
EDT
Penwith's ufo mystery deepened this week as further sightings of
"fiery" objects in the night skies emerged - including one close
encounter captured on film.
Unidentified flying objects have now been spotted over three West Cornwall towns in the past fortnight.
First to be seen by an amazed witness in Hayle were "fiery red/orange" objects flying at high altitude.
Now it has emerged that he is not alone - with perhaps dozens of
other people in St Ives and Penzance reporting similar incidents.
Laura Husband of St Ives contacted The Cornishman after reading last week's report of the Hayle
sighting.
She claims her brother, James, recently had a similar experience in
St Ives. Intriguingly, she may have seen the same thing in the same
part of town - two years ago.
Laura, a holiday park receptionist, explained: "I saw a single fiery
object exactly as described in last week's Cornishman article several
years ago in St Ives.
"The memory of what I saw has stayed with me as I was so amazed. The
week before this story was printed my brother came home and said I
wouldn't believe him but he had just seen these strange fiery balls.
"I did believe him. He described exactly what I had seen and the
stranger part was that he had seen them in exactly the same spot I had
seen them a few years earlier."
Then, in a further twist, a work colleague of Laura revealed a
friend had captured another UFO incident above Penzance's harbour area
on their mobile phone's video camera.
"You can clearly see this fiery ball moving around un-like anything else.
"It bounces around just above the street lights, then, all of a
sudden it appears to move away into the far distance at great speed.
"I think it's fascinating that there have been so many similar sightings of the same description around the
same time of night.
"I'm keeping an open mind about what it might be but it's
interesting that so many people are talking about seeing these
similar-sounding objects."
Meanwhile, the Cornwall UFO Research Group is hoping to discover the truth about the sightings.
Founder David Gillham told The Cornishman West Cornwall appeared to
be experiencing a spate of UFOs, and revealed further sightings had
been reported at Sennen Cove and Porthcurno.
"There's a hell of a lot of people seeing these things at the moment," he said.
* The Cornwall UFO Research Group can be contacted on 01872 276381, or found online at
www.cornwall- ufo.co.uk .
ELIZA STRICKLAND
ABC News
Sat, 04 Aug 2007 05:00
EDT
Former astronaut Rusty Schweickart has already earned his place in
the history books by flying in space on the Apollo 9 mission. However,
should an asteroid crash into the Earth anytime soon, killing millions
and causing catastrophic damage, he'll also be remembered as the guy
whose warnings we ignored.
 |
| ©AP |
In 2001 Schweickart, now 71, helped found the B612 Foundation (named for the asteroid home in The
Little Prince) to
raise the alarm about the potential of death from above. The foundation
has been loudly asking the world's space agencies to locate all the
near-Earth asteroids, determine if any are likely to crash into us, and
make plans to deflect them if necessary. But NASA and the other
agencies have taken little action. Wired News spoke to Schweickart about the importance and
frustrations of his latest mission.
Wired News: You've devoted the last
six years to warning people about the catastrophic possibility of a
near-Earth asteroid crashing into the Earth. Does this stuff keep you
awake at night?
Rusty Schweickart: (laughs) Does it
keep me up at night? Yes, but not in the way you're probably asking. I
don't stay up at night worrying about an impact. I do stay up and work
over in my mind various technical issues, and think about the work that
needs to be done.
WN: When did you first start thinking about the threat posed by near-Earth
asteroids?
Schweickart: My interest came from my
prior interest in astrobiology, which is the research field looking at
the origins and extent of life in the universe. When you look
at the origins and evolution of life on Earth, it's been severely
affected by asteroid impacts through history. I came to the clear
understanding that this is not a historical process, or something that
is no longer in effect. It's a continuing process, and we're
continually vulnerable to, essentially, a control-alt-delete.
Life has sustained a number of those hard boots, to continue the
metaphor, the demise of the dinosaurs 65 million years ago being only
the most recent example that people are aware of. But there
have been very damaging impacts far smaller than the one that occurred
65 million years ago, and they are far more frequent. Those are of more
concern to humanity, but they're also predictable. If we know that something
is going to happen and there's something we can do about it, we ought to start getting prepared.
WN: You were in the news a few years back talking about the
asteroid 9942 Apophis, when it appeared there was a chance that it
could hit the Earth in 2029 or 2036. That got some media attention,
until further studies reduced the likelihood of impact to nearly zero.
Were you relieved, or maybe a little disappointed that there was no
urgent cause for action?
Schweickart: When the probability of impact in 2029 dropped
to zero, I think everyone was very relieved. There is still to this day
a possibility of impact in 2036. It is quite low, and it will most
likely drop to zero. But Apophis has been a tremendous learning
opportunity for the (near-Earth asteroid) community. It exemplifies the
kind of challenge we will encounter in the future. There will be tens
of thousands of near-Earth asteroids discovered in the next 10 to 20
years.
WN: The Planetary Society is still
offering a $50,000 prize for the best plan to put a tracking device on
Apophis when it swings by in 2029. Although it appears that will be
unnecessary, do you think the design contest still serves a purpose?
Schweickart: In responding to that
challenge, there are probably teams of people learning a great deal.
The possibility of Apophis continuing to be a real threat is one in
45,000. But in terms of understanding the challenge that we're going to
be facing with other near-Earth asteroids that we find -- and we will
definitely find some that will be more threatening -- it's very useful.
The more people we have thinking seriously about this, the better.
And I'm not talking about the general public wringing their hands, I
mean technically qualified people seriously looking at the challenge of taking action.
It's important to have people studying the orbital mechanics, the
techniques we could use for deflection, and looking at the
decision-making process that would be involved in deciding which
asteroids to deflect. The legal and political implications will
probably be the most difficult challenges.
WN: Why is that?
Schweickart: Who is it that makes the
decision: Do we or do we not deflect this particular asteroid? Is it
small enough that someone will say, "We'll just take this hit, we won't
deflect this one"? If it's just going to impact a few counties, are
they the only ones who pay for it? There are a million questions of
that kind that will have to be answered, and not after we discover one
that has our name on it, but before, so we don't end up in a
decade-long debate when we're threatened.
Brent Whiting
azcentral.com
Sat, 04 Aug 2007 05:10 EDT
The
unidentified flying object, described as a small rocket about
two feet long and four inches in diameter, was reported over a Yavapai
County neighborhood then landing near the Verde River.
However, searchers have combed the area southeast of Cottonwood and
have found no evidence of any flying object, authorities said Friday.
"At this point, the search for the object has concluded," said Scott Reed, a spokesman for the Yavapai
County Sheriff's Office.
The rocket sighting was reported by two residents who live on Hogan
Lane in Bridgeport, a community between Cottonwood and Cornville, Reed
said. The color of the rocket was not reported.
"There were no reports of other suspicious activity in the air," Reed said.
He said that people with information about model rockets being fired
in the Bridgeport area are urged to phone Yavapai County sheriff's
deputies at (928) 771-3260.
Deputies searched the area Thursday evening, then returned early
Friday for another ground search along with helicopter support from the
U.S. Forest Service, all with "negative" results, Reed said.
Officials at Luke Air Force Base were advised of the rocket
sighting, but base officials have no information to shed light on the
mystery, said Mary Jo May, a Luke spokeswoman.
Operations from Luke don't include flight patterns over the Cottonwood area, May said.
The Sunday Times
Tue, 07 Aug 2007 16:26
EDT
It might have felt like an earthquake to Sydney coastal residents but it wasn't, scientists
say.
Dozens of Sydney coastal residents reported their houses shaking
this afternoon but Geoscience Australia said it was not an earthquake.
Residents reported windows shaking about 3.45pm (AEST) in the
eastern beach suburbs of Maroubra, Clovelly, Bondi and Tamarama, a
Geoscience Australia spokesman said.
"We're pretty happy to say that it wasn't an earthquake," the spokesman said.
"At this stage Geoscience Australia has not recorded any seismic
activity. It would certainly have to be very, very small for us not to
register it."
Radio talkback callers also reported several houses shaking on Sydney's north shore and northern
beaches.
Kristen Philipkoski
Wired
Tue, 07 Aug 2007 16:58 EDT
On
Friday Wired News profiled
a "lonely" former astronaut, Rusty Schweickart, who is leading a
campaign to protect the earth from the possibility of an asteroid
crashing into Earth and killing millions of people.
Turns out he wasn't so lonely. While we said in the Q&A that
NASA was doing little to protect us from an asteroid crash, it turns
out the agency's been working on an anti-asteroid nuclear missile.
 |
| ©Flight |
NASA's Marshall
Space Flight Center has designed a nuclear-warhead-carrying spacecraft, to be launched by the US
agency's proposed 's Ares V cargo launch vehicle, to deflect an asteroid that could threaten all life on Earth.The 8.9m (29ft)-long "Cradle" spacecraft would carry six 1,500kg
(3,300lb) missile-like interceptor vehicles that would carry one 1.2MT
B83 nuclear warhead each, with a total mass of 11,035kg.
NASA says that by the 2020s, the interceptor will be able to detect
a dangerous asteroid 5 years in advance, and deflect it two years in
advance.
NASA Plans Armageddon Spacecraft to Blast Asteroid
Sydney Morning Herald
Wed, 08 Aug 2007 06:37
EDT
For the first time, there is solid data to refute a popular theory
that life came to Earth aboard a comet, Rutgers researchers say.
Deteriorated DNA from microbes, frozen for millions of years in the
Antarctic ice, shows that organisms could not have survived the
bombardment of cosmic radiation during deep space travel from outside
the solar system, said Paul Falkowski, a Rutgers biologist and
oceanographer.
"It's almost an impossibility for comets to seed other planets with
life after they've been in space for millions of years," Falkowski said.
That's because genetic material is severely damaged or destroyed by exposure to so-called "cosmic
radiation flux", he said.
Falkowski is co-director of the two-year study of frozen glacial
microbes, conducted in conjunction with Boston University, and
published in the Proceedings of the National Academy of Sciences.
The researchers were mainly interested in whether genetic material
from the microbes, which they identified as different types of
bacteria, could have mixed with that of other organisms in the Earth's
ancient oceans, and influenced evolution, Falkowski said.
The Rutgers study refutes at least part of the "panspermia
hypothesis" - a theory from the Greeks, and popular among many
scientists since the 19th century - that micro-organisms and
biochemicals were carried to the planet by comets, meteors and
asteroids.
Other scientists in New Jersey said that they were intrigued by the
Rutgers study, but suggested there might be ways some organic material
could survive long-term rides on a comet.
"The only question I'd have is whether the radiation can penetrate
into the interior of a comet," said Dale Gary, an astrophysicist at the
New Jersey Institute of Technology in Newark.
Comets are called "dirty snowballs", which implies there is a
certain amount of rocky material at their centre which could provide a
shield for travelling DNA, Gary said.
"Certainly anything on the surface of comets would suffer radiation
damage," he said. Gary, chairman of physics at NJIT, had not seen the
study.
"Perhaps they (Rutgers) have done some calculation of the
penetration of these cosmic rays through ice, and concluded that, for a
certain radius, it can destroy DNA deep inside.
"However, we don't know everything there is to know about the
interior of comets," he said. A large comet might have enough rock in
its core "to keep DNA material rather pristine and safe", Gary said.
Radiation might be a problem for microbes, but not for very basic
organic material, said Kevin Conod, an astronomer and manager of the
Dreyfuss Planetarium at the Newark Museum.
"I think the theory of panspermia is not about microbes from space,
but amino acids, the building blocks of life," Conod said. "Radiation
wouldn't necessarily affect those enough to kill pieces of protein."
The Rutgers researchers thawed five microbial samples taken from ice
between 100,000 years and eight million years old, and were able to
grow several organisms in liquid media, said Kay Bidle, a Rutgers
marine microbiologist and oceanographer.
They also wanted to know how long organisms could live over extended geologic periods, Bidle said.
"This is of interest to whether there is life on Mars," he said, as
the site in Antarctica resembled icy regions on the Red Planet.
Microbes might survive a trip from Mars if encased in a meteorite,
Falkowski of Rutgers said. "So we could all be Martians," he said.
Sanjeev Chopra
Indian Express Newspapers
Fri, 03 Aug 2007 10:49
EDT
Hotipur (Sangrur): This non-descript village near Khanauri today hit
headlines when a meteorite fell in the fields on Wednesday night,
leaving many villagers baffled. The police have taken possession of the
8-cm meteorite to hand it over to a three-member team of Geological
Survey of India (GSI), led by a director-level officer, which is
arriving tomorrow.
Curious villagers queued up in the fields of Pargat Singh to see the
"heavenly object". While the farmer, who was the only witness to the
fall of the "fireball", said, "I got scared of the big fireball that
was coming my way at 8:45 pm on Wednesday night. I ran for cover as I
felt that it will fall on me." "I rushed home and decided not to tell
anyone about it. Yesterday morning, I gathered some courage and went to
see the spot and found a rock-like object lying in the mud. It was then
that I informed the villagers about it, who felt that it was a heavenly
object."
There was no crater at the spot where the fireball fell. "Since all
meteorites are the property of Geological Survey of India, we informed
them and are now waiting for them to arrive," said Sangrur SSP Arun Pal
Singh. The GSI team is likely to question the lone witness, Pargat
Singh.
Meanwhile, a much sought-after Pargat was busy guiding curious
onlookers to his field with pride and giving interviews to a host of TV
channels.
Sahara Samay
Wed, 08 Aug 2007 20:11
EDT
Jaipur, India - A family in Jaipur told the scientists of Geological
Survey of India (GSI) here that a meteorite fell in the courtyard of
their home on Monday evening, Sahara Samay sources said.
A female member of the family told that a piece of sparkling stone
fell in her home on Monday evening. I continued to look at it in awe
for sometime before I went near it, she added.
However, the scientists of Geological Survey of India have said that
the piece of sparkling stone does not appear to a meteorite. Even a
meteorite of small size can cause a big damage, said Dinkar Srivastava,
a scientist.
He said that the speed of meteorite is several thousand kilometres
per second and even a small meteorite is usually bigger in size than
the one found in a home here.
He further added that the GSI could be able to say anything only after testing the piece of stone or
meteorite.
It is worth noting here a similar sparkling stone was found in a village in Sangrur district of Punjab a
couple of days ago.
Beth Duckett
The Arizona Repulic
Thu, 09 Aug 2007 22:33
EDT
SCOTTSDALE - Stanley Fosha is looking for what woke him early
Wednesday morning with a giant flash of white light and a thunderous
boom.
The sky erupted around 2:15 a.m. near his home at 56th Street and Pinnacle Vista Road in Scottsdale, he
said.
"I seriously thought someone was in my back yard taking a picture,"
Fosha said. "It sounded like someone taking a sledgehammer and banging
a big metal drum."
Worried he imagined the light, Fosha asked his neighbor Tami Biggs about it the next day.
Biggs said she saw it, too.
"I was outside saying goodbye to some friends. It was a big, bright
light and a loud bang," said Biggs, who lives two doors away from
Fosha. "It certainly caught our attention."
So what exactly was this unidentified burning object?
A bolide, predicts Prof. Jeff Hester with the Arizona State University School of Earth and Space Exploration.
Bolides, or large meteoritic fireballs descending from the sky, are known to hit ground on occasion, Hester
said.
In fact, he has seen a few himself.
"They are just spectacular, remarkable things," Hester said. "They can literally explode."
And this bolide made its entrance just days before the annual Perseid shower is expected to peak.
Hester said it is on Sunday this year.
Though likely not as large as Fosha's sighting, the meteors should
be pretty plentiful, he said. And with a new moon on Sunday, it also
should be a pretty clear show.
The shower, best viewed after 11 p.m. and before dawn, boasts its greatest activity between August 8 and
14, he said.
The key is getting away from city lights, Hester said.
"Then you just lay back and let your eyes adapt to the dark and
relax," he said. "You might see as many, on average, as every minute or
so."
The Perseids are dubbed after the constellation Perseus, where most of them appear to originate, he
said.
They are remnants of a debris path left by the comet Swift-Tuttle.
"You get a meteor shower when the earth passes through these debris
paths," Hester said. "When comets come in close to the sun, the sun
causes the surface to sublime and a bunch of dust is blown off into
interplanetary space."
Don't expect to see the comet anytime soon. Swift-Tuttle only shows up once every 133 years, Hester
said.
All Hungary News
Fri, 10 Aug 2007 11:07
EDT
The southern Transdanubia area of Hungary at
the border of Tolna County was shaken by the sound of an explosion
Sunday afternoon when a melon-sized meteor apparently hit the ground in
Bonyh?d. Astronomers are analyzing the impact crater, which is two
meters deep and seven meters in diameter, reports fn.hu.
Istv?n Tepliczky, secretary of The Hungarian Astronomical
Association (Magyar Csillag?szati Egyes?lt), said by analyzing the
impact marks they concluded that the angle of the meteor made it
impossible for people to see, since it came from the west in the exact
angle of the setting sun.
Until the analysis is finished, it cannot be confirmed a meteor
crashed into Hungary. Tepliczky mentioned that the left side of the
crater was slightly above the right side, which proves the impact of an
object coming from the west.
"Meteor striking is a very rare phenomenon in the Earth, even though
we can find clues in the Solar system," said Szaniszl? B?rczi,
professor at ELTE University Department of Materials Physics. "Other
planets show shapes caused by cosmic impacts and the crater found at
the border of Bonyh?d shows a similar one."
The speed of the meteor was an estimated 10km/sec and the power of
the impact destroyed it; meteorites typically evaporate and dissolve
into the ground after impact. The meteorite itself won't be found, but
its substance can be detected in the sample taken from the ground.
Comment: A couple of points about this incident:
1. If you are a regular reader of these pages, you know that a meteor striking the Earth is not as uncommon
as it once was...
2. No one saw it because it came from the west during the setting of the sun. Think about that one for a
minute....
Stephen Battersby
NewScientist.com
Wed, 08 Aug 2007 19:55
EDT
A rare meteor shower predicted to hit Earth on 1 September should
give astronomers only their second chance to study an ancient comet's
crust. It could also help them develop a warning system against an
otherwise insidious threat - a comet aimed at Earth from the dark
fringes of the solar system.
September's shower, called the alpha Aurigids, has only been seen
three times before, in 1935, 1986 and 1994. The reason for this
elusiveness is the shower's unusual origin.
Most meteor showers are caused by short-period comets, dirty
iceballs that loop around the inner solar system on orbits lasting less
than 200 years, shedding debris each time they approach the Sun's heat.
This debris builds up into a broad band along the comet's orbit. Every
year, when we pass through, it burns up in the atmosphere and appears
as shooting stars.
The Aurigids come from a comet that takes 2000 years to orbit the
Sun. With such infrequent visits, Comet Kiess can't build up a broad
dust band; it only generates a narrow trail of debris each time.
The showers happen when Earth passes through one of these dust
trails in particular, which was thrown off by the comet in 83 BC. "It
is only a very narrow trail, and it is only once in a while that it
crosses Earth's path," says Peter Jenniskens of NASA's Ames Research
Center in Moffett Field, California, US.
He thinks the gravity of Jupiter and Saturn controls the path of the
dust trail, waving it around like a garden hose, occasionally aiming it
at Earth. Along with his colleague J?r?mie Vaubaillon at Caltech, US,
Jenniskens has calculated that the hose should be pointed at us again
this year.
Hard crust
Several teams of astronomers will be watching the shower, both from
the ground and from two aircraft following the Earth's shadow.
They are hoping to see fragments of the ancient crust of Comet
Kiess. For 4.5 billion years before some gravitational accident nudged
it towards the inner solar system, Kiess was drifting among a vast
swarm of icy bodies called the Oort cloud lying far beyond the planets.
All that time, high-energy particles called cosmic rays bombarded
the comet, and astronomers suspect that created a hard crust by
blasting out some of its more volatile substances.
Only once before have astronomers knowingly seen a shower from a
long-period comet, when Jenniskens predicted an appearance of the alpha
Monocerotids in 1995. They penetrated unusually far into the
atmosphere, suggesting that they were made of relatively tough
material, perhaps from such a cosmic-ray-produced crust.
This time, astronomers will be looking at the spectral signature of
evaporating meteors to test this theory. "Now we are better prepared,
we can do more in-depth studies to understand the properties of the
material," Jenniskens told New Scientist.
Contribute observations
He also wants to know whether meteor showers such as this could warn
of planetary peril. At present, astronomers can only spot a long-period
comet a few years before it arrives in the inner solar system, leaving
little time to deflect it if it were pointed right at Earth.
But if it had visited the inner solar system before, the resulting
meteor shower might be used to trace the comet's orbit and get a much
earlier warning. The size and number of Aurigid meteors will tell the
researchers how debris has spread along the orbit and how these showers
evolve.
They are keen for amateurs to contribute their observations. "We're
interested to know what is the brightest, biggest Aurigid," says
Jenniskens. "Somebody is going to capture that, and it's probably not
going to be us."
The best view of the meteors will be from the west coast of North
America, before dawn on 1 September. Based on past showers, there
should be up to 200 bright meteors visible per hour, and they may have
an unusual blue-green colour.
The shower probably won't return for at least 50 years, according to
Jenniskens' calculations. "It's a once in a lifetime event."
BJ Hansen
MyMotherLode.com
Sat, 11 Aug 2007 19:51
EDT
Sonora - Representatives with the Sonora
Police Department and both the Tuolumne and Calaveras County Sheriff's
Departments say they fielded numerous calls early this morning in
regards to a "loud boom," and "structures shaking."
According to a Sonora Police Department report, there were several
calls from residents who reported seeing "a blue light," just before
the "loud boom." The incident reportedly occurred at 12:09am. The
Police Department notes that it also received a call from a resident in
Tuolumne, in which a female reported seeing what she thought was
fireworks, and then something spiraling over her house.
Early indication from the law enforcement agencies is that the loud boom was somehow the result of a
meteor shower.
Comment: "somehow the result of a meteor shower" - this
isn't a meteor
shower:
A "meteor shower," also known as a "meteor storm," is a celestial
event where a large number of meteors are seen within a very short
period of time. These meteors are small fragments of cosmic debris
entering Earth's atmosphere at extremely high speed, leaving a streak
of light that very quickly disappears. Most of the small fragments of
cosmic debris are smaller than a grain of sand, so almost all fragments
are burnt up and never hit the earth's surface. Fragments which do
contact earth's surface are called meteorites
The description from the article is of a possible bolide entering
and then exploding either in the atmosphere or on the surface of the
earth, which causes structures to shake.
AFP
Sun, 12 Aug 2007 13:46 EDT
Russian
police were combing the northern Siberian city of
Krasnoyarsk on Friday for a three-tonne meteorite that has disappeared
from under the nose of its keepers.
The giant rock was stolen from the yard of the Tunguska Space Event
foundation, whose director said it was the part of meteor that caused a
massive explosion in Siberia in 1908, news agency Interfax reported.
"It winds up that it disappeared back in June, when the foundation
was moving out of its old building," a police spokesman told the agency.
"Our colleagues are establishing what got lost, where the rock is and why they only came to us about it now,"
he said.
Foundation director Yury Lavbin brought the three-tonne rock to
Krasnoyarsk after an 2004 expedition to the site of the so-called
"Tunguska event" -- a mysterious mid-air explosion in Siberia in 1908
that was 1,000 times more powerful than the nuclear bomb dropped on
Hiroshima in 1945.
Lavbin claimed at the time to have discovered the wreckage of an alien spacecraft during the expedition.
Scientists continue to argue over the cause of the explosion, which
flattened over 2,000 square kilometres (800 square miles) of Siberian
forest.
Kelly Beatty
SkyandTelescope.com
Mon, 13 Aug 2007 12:16
EDT
Here at Sky & Telescope we get wind of
all kinds of reports of meteorite falls. Few are legitimate. But on
July 6th the sky really was falling over South America, when an
incoming object broke apart in the lower atmosphere with a trio of
ferocious explosions that shattered windows and shook the ground
violently. Moments later, stones rained from the sky and pelted homes
in the poor barrios surrounding the notorious city of Cali, Colombia.
 |
| ©Michael Farmer |
Nothing gets the adrenaline of meteorite collectors rushing like a
fresh fall, and it wasn't long before Michael Farmer and Robert Ward
flew south from Tucson, Arizona, in search of cosmic treasure. After
reaching Colombia, they teamed up with local amateur astronomers and
headed into the barrios to try to recover some of the fragments.
After a few days of searching, they'd rounded up and purchased
several small pieces - some of which had smashed through the roofs of
homes - totaling about 270 grams (10 ounces).
But not all of their exchanges with the locals were pleasant, as
word got out that some gringos with money were in the area. Farmer
explains:
"As we tried to drive through a barrio just near where one of the
stones was found, a man ran at our taxi with a large gun screaming at
us to stop. I saw the people in the front of the taxi duck down and
then saw the gunman running at us. The driver hit the gas and we
swerved around him, but the gun was about 1 meter from my head. He did
not fire, thank God, but what a scare!"
Now safely back in Tucson, Farmer estimates that the Cali event must
have dropped fragments far more massive than what he and Ward were able
to collect. Unfortunately, it all ended up in dense cane fields and
will never be found. And although the recovered "hammer stones" turned
out to be a rather common type of chondritic (rocky) meteorite, they're
already fetching thousands of dollars per gram among meteoritic
aficionados.
Comment: For more information that was collected on
this meteorite event go to this link
KLTV7
Mon, 13 Aug 2007 13:32 EDT
"It was
big... It was huge in the sky, " Cynthia Costello says.
Cynthia Costello is no stranger to meteor showers in shingle springs
this time of year... But nothing prepared her for what she saw
overnight.
 |
| ©KLTV7 |
Cynthia says "It looked like kind of flashes for a little bit for
just a couple seconds and then it was just a big burst and it startled
me so bad... And said did you see that and he huh... He was asleep."
She's convinced the explosion in the sky was a meteor.
Cynthia says "it looked kind of like lighting but confined in a
spherical type... It was very, very, bright, brighter than lighting...
Cause it lit up the whole backyard and lit up the inside of the
house.... It was like two seconds max."
Costello soon found out she's not the only one who caught the night show.
Cynthia says "I figured i'll call in the morning to see if something happened, and they said
we are not sure what it is but we are looking into it."
We sent the e-mails to the discovery museum in sacrmento. Judy Pischalnikoff shares her opinion as a
space educator.
Judy says "I would call it a meteor but not part of the meteor shower. Because it was so huge."
While space educators say this video was likely of a meteor, they
have no way of knowing if it hit the ground like this meteorite that
fell long ago in Arizona. It's believed other pictures sent in are of
space debris. If you missed the show last night, not to worry. Meteor
showers can be seen in the sky for the next week.
Comment: To see the news report that shows the video of
the meteorite from the picture above watch Mysterious Object Seen In Sky
Also, this meteorite may be related to this story "Loud Boom" Believed To Be The Result Of Meteor Shower -
California
Cheryl Dybas
National Science Foundation
Tue, 14 Aug 2007 03:54
EDT
New scientific findings suggest that a large comet may have
exploded over North America 12,900 years ago, explaining riddles that
scientists have wrestled with for decades, including an abrupt cooling
of much of the planet and the extinction of large mammals.
 |
| ©Allen West, UCSB |
| A "black mat" of algal growth in Arizona marks a line of extinction at 12,900 years ago; Clovis points and mammoth skeletons were found at the line but not above it. |
The discovery was made by scientists from the University of
California at Santa Barbara and their colleagues. James Kennett, a
paleoceanographer at the university, said that the discovery may
explain some of the highly debated geologic controversies of recent
decades.
The period in question is called the Younger Dryas, an interval of
abrupt cooling that lasted for about 1,000 years and occurred at the
beginning of an inter-glacial warm period. Evidence for the temperature
change is recorded in marine sediments and ice cores.
According to the scientists, the comet before fragmentation must
have been about four kilometers across, and either exploded in the
atmosphere or had fragments hit the Laurentide ice sheet in the
northeastern North America.
Wildfires across the continent would have resulted from the
fiery impact, killing off vegetation that was the food supply of many
of larger mammals like the woolly mammoths, causing them to go extinct.
Since the Clovis people of North America hunted the mammoths
as a major source of their food, they too would have been affected by
the impact. Their culture eventually died out.
The scientific team visited more than a dozen archaeological sites
in North America, where they found high concentrations of iridium, an
element that is rare on Earth, and is almost exclusively associated
with extraterrestrial objects such as comets and meteorites.
They also found metallic microspherules in the comet fragments;
these microspherules contained nano-diamonds. The comet also carried
carbon molecules called fullerenes (buckyballs), with gases trapped
inside that indicated an extraterrestrial origin.
The team concluded that the impact of the comet likely destabilized
a large portion of the Laurentide ice sheet, causing a high volume of
freshwater to flow into the north Atlantic and Arctic Oceans.
"This, in turn, would have caused a major disruption of the ocean's
circulation, leading to a cooler atmosphere and the glaciation of the
Younger Dryas period," said Kennett. "We found evidence of the impact
as far west as the Santa Barbara Channel Islands."
NSF's Paleoclimate Program funded the research.
Kevin Krajick
Popular Science
Fri, 17 Aug 2007 13:23 EDT
A recent
study showed that the U.S. and China are the nations most
vulnerable to a devastating meteorite strike. With funding uncertain,
astronomers are struggling to contain the threat of a
civilization-ending galactic visitor.
What's Out There
There are between one and two million near-Earth objects (NEOs) -
chunks of space rock whose orbits may pass within 30 million miles of
Earth - that pose a significant impact threat to the planet. Of the
4,535 NEOs detected and tracked (704 of which are real whoppers), none
are on a definite collision course, but there could be millions more,
many of them potentially lethal, lurking in the cosmos.
Detection
Who's Watching? Most spotting is done
by half a dozen optical telescopes in the U.S., Italy, Japan and
Australia, coordinated by such programs as the Lincoln Near-Earth
Asteroid Research (LINEAR) project, a NASA-funded collaboration between
MIT's Lincoln Laboratory and the U.S. Air Force tasked solely with the
detection and cataloging of potential NEOs. Amateur astronomers
worldwide also aid the effort. Collectively, the programs discover a
new NEO every few days.
What's the Plan? Since 1998, NASA has
funded Spaceguard, a consortium of observatories working to find 90
percent of the half-mile-plus NEOs by 2008; the group has found three
quarters of the predicted 1,100 NEOs in this size class. Spaceguard's
next step is to find 90 percent of NEOs measuring 460 feet or larger -
potentially up to 12,000 objects - by 2020, but funding has not been
secured. Larger wide-field scopes should come online in Hawaii, Arizona
and Chile in the next decade, greatly speeding detection.
The Hot List NASA's NEO office
maintains a watch list of about 140 especially high-risk asteroids. The
baddest asteroid so far is 820-foot-wide 99942 Apophis. Discovered in
2004, it briefly presented a 1-in-38 chance of collision on April 13,
2029. As more data helped scientists to pinpoint its orbit, Apophis has
since been downgraded to 1 in 45,000 in 2036 - still the biggest
collision threat in the known universe.
Deflection
A handful of scientists, both at NASA and the privately funded B612
Foundation, have proposed various protocols for diverting or destroying
a collision-course NEO. None currently have funding, although the
asteroid fly-by mission Dawn will launch this month. And NASA has
looked into using existing rocket and spacecraft technology to land an
astronaut on an asteroid, a move that, if successful, could help hone
future deflection strategies. Here, a few plans on how to save the
planet.
Nuke It We already have the bombs, but
the risk is that an explosion could turn one killer asteroid into many
smaller killer asteroids, thrown into unpredictable trajectories - and
radioactive.
Smack It A spacecraft would ram the
object, altering its orbit or shattering it. Elegant, but could
multiply the threats as with the bomb scenario above.
Lean On It A craft would push or pull
the object. Not sideways - too energy-intensive - but backward or
forward to slow it down or speed it up. A few pounds of force applied
over several months would alter a medium-size body's rate of travel
such that it would miss hitting Earth by four or five minutes and
thousands of miles. An asteroid tugboat would attach to a NEO and
deliver a speed-altering nudge. A gravity tractor would hover close to
a NEO and use mutual gravitational attraction to divert it ever so
slightly. A solar sail would move a NEO with the subtle pressure of
light from the sun.
forgetomori
Fri, 17 Aug 2007 13:34
EDT
Following the terrible natural disaster on Peru, which caused hundreds of casualties, some local news
agencies are also speaking about reports from locals of flashes of light in the sky both before and
after the event.
According to El Comercio from Peru,
"During the night ... before and after the stron earthquake,
neighbours from the districts of Miraflores, La Molina and Cercado de
Lima assured having seen the sky light up because of an unexpected
lightning in the middle of the night. Nevertheless, the National
Hydrology and Meteorology told El Comercio that it didn't detect any
anomaly in Lima's skies, and assured that this phenomenon could have
been caused by the light of a beacon or some spinning panels that exist
in the city".
Over at MarcianitosVerdes,
Luis Ruiz Noguez is receiving and collecting more reports from multiple
witnesses who also claim to have seen the lights. Noguez prudently
warns that before speculating if the incidents were indeed earthquake
lights, the prosaic explanations must be ruled out first.
The video above, posted on Marcianitos, is allegedly of one of the
incidents. It was suggested to Noguez, and has been also featured over at this
blog, that suggests it's triboluminescence.
I think the point of light that can be seen in the video along with
the flash is from a conventional source (an emergency light), maybe
it's the same point of light that can be seen before the blackout. But
the flash of light itself must have been indeed intense, and as there's
no sound along with it, and apparently the local institutions did not
report any weather anomaly, it may possibly be the record of an earth
light.
For those who don't know about it, there's a quick summary about earthlights.
In Spanish, MarcianitosVerdes have in-depth dossiers on the subjects -
one of the reasons people looking for more info on Google ended up
finding his excellent blog: Las luces de los terremotos.
Update: Marcianitos just posted another video:
Several flashes, including a big one around 40 seconds after the
video starts, can be seen over the horizon. Noguez remarks once again
that it must be verified if they weren't explosions from the power
transmission lines and transformers.
According to the reports the flashes were not accompanied by any
sounds, and some say they originated in the sea. As we all know, light
travels a lot faster and farther than sound, so explosions on one place
could have been noticed as just lights from far away.
But at first glance, the flashes are so bright that one suspects
that if they had conventional causes, then even if the sound was not
heard, the causes would be quickly pointed to their origins, as the
explosions themselves may have been quite significant, probably
injuring or killing people.
There still seems to be much confusion, and the Peruvians need more
urgent help and solidarity for their death and injured. Which also
doesn't mean we should ignore the possibility of so many records and
reports of what may have been a poorly understood phenomenon associated
with earthquakes.
We follow all the news with great interest and hope for the best. Check Marcianitos in Spanish for the latest
updates.
UPDATE: Check the latest post on the subject, Earthquake
lights or Electrical transformers? The answer seems to be electrical transformers, though there may still
have been erthquake lights involved.
Tim Moran
Modesto Bee
Wed, 22 Aug 2007 17:24 EDT
Corrina
Vargas, 26, was cooking breakfast in her mother's neighborhood home Monday morning when she heard an
explosion.
Her son, Carlos Mendez, 10, was sitting on a bed in the living room
watching cartoons when something came through the roof. A small piece
of the debris hit him in the back of the head.
They ran outside, and Vargas' mother, Mary Montano, gathered the rest of the adults and children in the
house and got them out.
No one was hurt by what turned out to be a bowling ball-sized chunk
of ice that crashed through the roof. The hole in the roof appeared to
be two to three feet wide.
Police spokesman Sgt. Craig Gundlach said investigators were not
sure where the ice came from, but it may have dropped from a commercial
airliner.
"We are in contact with the (Federal Aviation Administration), and
they are not aware of where it could have come from," Gundlach said.
"There is no indication it was anything but an accident."
FAA spokesman Ian Gregor said investigators were en route to Modesto
to examine the ice and try to determine where it came from.
It may be "blue ice" that leaked from an aircraft, Gregor said.
Airplane bathrooms can sometimes leak, and the effluent, containing
human waste, forms a chunk of ice outside the plane, Gregor said.
It is frequently blue because of the blue liquid used to flush
toilets in planes. The air at the altitude airliners fly can be 50
degrees below zero, Gregor said.
When the airplane descends, the ice thaws and sometimes falls off the plane, he said.
Falling blue ice from airplanes is reported around the country from
time to time. An incident was reported a few months ago in Ontario,
Calif. east of Los Angeles, Gregor said.
How often blue ice falls from airplanes is difficult to track,
because if the ice doesn't hit a home or damage anything, no one would
know, Gregor said.
"It's not common, but it's not unheard of," he said.
Some commercial planes are prone to bathroom leakage, according to a
2004 FAA directive. Several models of the Boeing 737 are required to
undergo repetitive leak checks and bathroom maintenance.
Modesto is under the flight path of airliners coming into San
Francisco International Airport, Gregor said. The planes are at a
little more than 20,000 feet when they pass over, he said.
Gundlach said the ice didn't appear to have come from a low-flying
plane arriving or leaving Modesto Airport, which is across the street
from the house.
If it were from an airplane flying at 20,000 feet, a chunk of ice
that size could reach a speed of 120 to 200 mph, according to Joseph
Alward, a physics professor at University of the Pacific. Alward
estimated that the ice chunk may have been traveling at 160 mph.
The ice chunk hit the house with explosive force, according to Vargas.
"It was just a big old boom, and all that debris," she said. "I was
just stunned. I thought it was a fire from the water heater."
There were four adults and five children inside when the ice hit it, Gundlach said.
The ice punched a sizable hole in the roof, broke through a roof
truss and continued through the living room ceiling, he said. Had it
not shattered as it penetrated the home, it would have landed about a
foot from where Carlos Mendez was sitting, Gundlach said.
"With the velocity that chunk of ice had, we are very lucky no one was severely injured or killed," he said.
Firefighters said the fragments were brown and white, and looked like dirty ice. They found
two brick-shaped chunks and lots of smaller shards.
Gundlach said evidence would be turned over to the FAA.
There is a possibility that the ice chunk wasn't from a plane.
Several incidents have been reported around the world of large
chunks of ice falling to the ground that are apparently unrelated to
airliners.
Jeszs Martmnez-Frias, a Spanish geologist, thinks the ice may form
in the atmosphere, similar to the way hailstones are created.
He coined the term "megacryometeors" for the ice chunks. His
hypothesis is controversial, however. Other scientists question whether
ice chunks that large could be formed in that way.
FAA investigators may know more in the next few days, Gregor said.
Science Daily
Thu, 23 Aug 2007 04:26
EDT
The space-borne infrared observatory AKARI, observed asteroid
Itokawa last month with its Infrared Camera. The data will be used to
refine estimates of sizes of potentially hazardous asteroids in the
future.
 |
| ©JAXA |
| The asteroid Itokawa was observed by the Infrared Camera (IRC) onboard AKARI at 7 micrometres on 26 July 2007. The above image is a composite of three images from the data showing the motion of Itokawa over 12 minutes. The image covers an area of roughly 7.4 arcminutes x 7.4 arcminutes around the target. The Hayabusa spacecraft itself was too faint to be detected. |
The data collected by AKARI, a JAXA mission with ESA participation,
complements that from JAXA's asteroid explorer Hayabusa in late April
this year.
As AKARI observed Itokawa on 26 July it was in the constellation of
Scorpius, and was about 19 magnitudes bright in visible light. The
asteroid and Earth were closest to each other, at a distance of about
42 million km (for comparison, Earth is 150 million km from the Sun).
Given how close it was, Itokawa moved a significant distance on the sky
over the short observing time.
Using observational data of asteroids such as Itokawa in combination
with data from the explorer, models that estimate asteroid sizes can be
made more accurate. This is especially useful for estimating the size
of potentially hazardous asteroids which may be discovered in the
future.
Before Hayabusa arrived at Itokawa, many observations to determine
the asteroid's approximate size had already been attempted. Among the
many different methods of measurement, the most accurate estimate was
achieved by mid-infrared observations.
With AKARI, it was possible to observe Itokawa at several different
wavelengths in the mid-infrared range, obtaining a much more
comprehensive set of data. This data is very important, not only for
the study of the asteroid's infrared properties, but also for use as a
template and source of comparison with other asteroids, to improve the
estimates of their sizes.
Most sunlight falling on Itokawa is absorbed, heating the asteroid
up. It then re-emits this energy as bright infrared light, which was in
turn observed by AKARI. Only a small fraction of the incident sunlight
is reflected from Itokawa, making it a very faint object when observed
in visible light. It is very hard to observe using telescopes of sizes
similar to that of AKARI from ground.
Asteroid size is one of the most sought-after pieces of information.
For asteroids that are not explored directly, their sizes can be
estimated based on various observations from Earth. The temperature of
asteroids is determined by the balance between the energy input from
incident sunlight, and the output, emitted as infrared radiation.
Existing computer models estimate the temperature distribution in
asteroids by considering their shape, rotational motion, and surface
conditions.
Observational data in the mid-infrared gives information on the
infrared light emitted by the asteroid. Asteroid size can be derived by
comparing observational data in the mid-infrared, with that expected
from the calculations of the model. The models can further be improved
by using the infrared observational data of well-studied asteroids,
such as Itokawa.
AKARI has also made observations of possible candidates for future
asteroid exploration. It is expected that this detailed information
will help greatly further our knowledge of these interesting relics of
our Solar System.
Note: This story has been adapted from a news release issued by European Space
Agency.
Richard Edmondson
stuff.com.nz
Wed, 29 Aug 2007 13:04
EDT
A mysterious object seen in skies over the Tasman Sea near Kaitaia is baffling UFO
experts.
 |
| ©W FERGUSSON |
| Disc-like: The object's shape suggests a circular 'something' with a dome-like top says world UFO expert Dr Bruce Maccabee. |
Last month, The Northern News reported that UFO Focus New Zealand
(UFOCUS NZ) and world UFO expert Dr Bruce Maccabee were studying a
series of unusual photographs taken at Ahipara on April 28.
The digital photos, taken of the sky and sea at 5.42pm, showed a
bright object which did not look like a cloud and had the appearance of
a craft.
The story attracted intense interest and remained one of the most
viewed stories on the Northland page of the Stuff news website three
weeks after publication.
Last week, UFOCUS released its report on the sighting and we can now bring you photos.
The report says the photographer watched the object for nearly five
minutes while it moved silently across the sky in a northerly direction
reducing in size and disappearing.
Dr Maccabee, an optical physicist in the United States Navy, says in
the report that the object does not display flight characteristics that
distinguish it as a 'craft' of unknown origin.
However, its shape suggests a circular 'something' with a dome-like top.
The object could also be a jet aircraft's vapour trail viewed end on, he says.
Air Traffic Control says there were no scheduled flights in the area at the time.
It would expect to see consistency of shape from both trails and a
'flow-off' similar to a cirrus cloud blown by winds if the object was a
jet contrail.
Instead, the shapes in the photos are compact.
UFOCUS has consulted the Carter Observatory and ruled out the object
being space junk or a meteorite, says the group's coordinator Suzy
Hansen.
"Neither space junk nor a meteorite would present the images we
have. They would be a ball of fire burning up rather than a bright
object."
 |
| ©W FERGUSSON |
| Unexplained: UFO experts are classifying an object captured in photos taken at Ahipara in April as an 'unusual aerial phenomenon' or UAP. |
Dr Maccabee has not commented on whether the photographer may have manipulated the eight photos,
says Ms Hansen.
While the UFO group cannot rule out the possibility of manipulation, she thinks it is unlikely the photos are a
hoax.
"I have directly asked the witness if he hoaxed the photos, and he was most adamant that he had not.
"When you see the full series, you will see that it would take hours and hours to hoax such a thing."
UFOCUS and Dr Maccabee have agreed that no firm conclusion can be drawn about what the object is, says
Ms Hansen.
They are classifying it as an unusual aerial phenomenon - UAP - but are keen to know what the
public thinks it may be.
Peter Jenniskens, Ph.D., Meteor Astronomer, Carl Sagan Center, SETI
Institute
Space.com
Thu, 23 Aug 2007 04:13 EDT
The meteors that are about to
rain down in the early morning of
September 1 date from around 4 A.D., the latest calculations show.
It is not often that we can tell when a shooting star was first
released from a comet into space, to travel as a meteoroid in an orbit
around the Sun, and finally collide with Earth's atmosphere to shine as
a meteor for our enjoyment. Most meteors that sporadically flash across
the sky on a dark moonless night date from anonymous times. Only in
recent years have we learned to trace young meteor showers, just a few
revolutions old, to their date of origin.
The oldest such shower, but only one revolution old, is due in the
early morning of September 1, 2007. Our calculations indicate Earth is
about to cross the dust trail of comet Kiess, a comet that takes some
2000 years to complete one orbit around the Sun. The trail is very
narrow, so Earth will be hosed by meteoroids for only about an hour and
a half. The meteoroids will approach from the direction of the
constellation Auriga, the charioteer, in the north-eastern part of the
sky, causing a meteor shower called the "Aurigids."
If you spot one of those meteors, you may be only the fourth person
alive who is known to have seen this meteor shower. In recent times,
the shower was spotted in 1994 by two observers and in 1986 by one
observer.
If you are lucky enough to catch a picture of an Aurigid meteor using your digital camera, you will be the very
first to do so.
Tips on how to observe meteors and where to report the results can be found at: http://aurigid.seti.org
The shower is visible from only part of the world. If you live in
the western parts of the USA, Canada and Mexico, including Hawaii and
Alaska, you might spot an Aurigid meteor. Plan to step out around 4
A.M. PDT in the early morning, warmly dressed with a blanket wrapped
around your shoulders, away from city smog, with the Moon behind an
obstruction, and with a wide view on the sky. Gaze up at the sky,
waiting, and you may spot one of these elusive bits of matter that
Comet Kiess lost 2000 years ago.
This is your only chance to see this shower; the dust trail is not
going to hit again in our lifetime. It is also our best chance yet to
test meteor shower prediction models and look for evidence of the crust
that a comet is suspected to build up during the time it spends in the
Oort cloud. Comets in shorter orbits have long lost this pristine crust.
Jon Giorgini of JPL/Caltech has identified observations of Comet
Kiess when it returned in 1911. The orbit is now better determined than
before and calculating backwards in time puts the comet near Earth's
orbit in 4 A.D., give or take 40 years. It was at that time that the
dust was released that we now see as meteors. The dust was ejected in
wider orbits than the comet and took somewhat longer to return.
Jeremie Vaubaillon of Caltech calculated where the dust would end up
at Earth's orbit on September 1, 2007, if it was ejected in 4 A.D. and
he found that, indeed, the dust trail will be in Earth's path. The peak
is expected at 11:33 UT, or 4:33 a.m. PDT, give or take 20 minutes.
From past Aurigid showers, we anticipate a shower of mostly -2 to +3
magnitude meteors with a peak Zenith Hourly Rate about 200 per hour
during a 10-minute interval, with rates above 100 per hour for only 25
minutes. With a bright Moon in the sky, only 4 days past full, that
translates to several tens of chances to make a wish on a meteor from
around 4 A.D.
To increase our chances of catching these rare meteors, we will be
observing the shower from two Gulfstream GV aircraft (flying at 45,000
ft) on a parallel flight path from Wisconsin, over the Bay Area in
California, and on to the Pacific in the early morning of September 1.
An international team of 24 researchers will have 21 windows to aim
their cameras through. The cameras are of different types, some similar
to your own digital camera and camcorder, others using technologies
more familiar to cameras used on astronomical telescopes or those in
night vision goggles. Near the horizon, we hope to see many more
meteors than will be visible from the ground, but each of us will be
glad if the shower actually shows.
You can participate in this research by making an effort to
photograph or film the Aurigid meteors. Chances are that one of you,
not us, will catch the brightest Aurigid out there. Even simple cameras
can provide information about how the meteoroids break apart, as each
image is composed of three different images: one in blue light, another
in green, and one in red. Each color traces different aspects of the
meteor's light.
More information at our Aurigid Multi-Instrument Aircraft Campaign mission website:
http://aurigid.seti.org
international.news.bg
Tue, 28 Aug 2007 18:37
EDT
The Center for small objects in the Solar system in Harvard, USA,
acknowledged the three new asteroids found last week by Bulgarian
astronomers in the Capricorn constellation.
This announced the University center on space research and
technologies at the Physics faculty of Sofia University "St. Kliment
Ohridski", cited by Darik radio.
The objects are temporarily labeled as 2007 PN28, 2007 PQ2 ? 2007
QD2 and are situated in the main asteroid zone. They circle between the
orbits of Mars and Jupiter with periods respectively 4.7, 3.6 and 5.4
years.
In 2005 the Bulgarian astronomers found the asteroid 2005UT12, which was the first since 18 years, noticed
by Bulgarians.
Since then despite the lack of state funding the young scientists have found seven space objects.
At the moment the astronomers from the observatory "Star society -
MPC A76" and their colleagues from the national observatory "Rojen"
conduct additional observations for specifying the characteristics of
the new objects.
The team, which made the discoveries includes E. Mihaylova, Ch. Kaldiev and their supervisors F. Fratev
and Ya. Shopov.
Philip Bradfield
Belfast Today
Tue, 28 Aug 2007 21:14 EDT
The
mystery of what caused a sonic boom-like noise over Co Down has
deepened after the RAF denied reports a supersonic fighter jet was in
Ulster skies at the time.
Residents in north Down were alarmed when they heard what they thought was an earthquake on Tuesday
afternoon.
News Letter journalist Lesley Walsh was at her Bangor home just after 3pm.
"It lasted for about three seconds and I felt it right through me,"
she said. "It shook the decking outside, reverberating right through it.
I was on the phone to a friend a mile away and she heard it too.
"At one point I thought it was a bomb, then maybe an earth tremor.
"It was not like ordinary thunder, it was a palpable noise. It was
an absolutely perfect blue sky and I could see nothing overhead."
Police said it was "believed to be the sonic boom of a low-flying aircraft", adding their information came from
the Coastguard.
However, the George Best Belfast City Airport could offer no explanation for the incident.
Yesterday, a Coastguard spokesman who also lives in Bangor, said he
too heard the sound. "I was in my garden and my dog bolted when we
heard the noise," he said. "It was like thunder but there was not a
cloud in the sky. It was a strange sound."
He said the PSNI also had reports of the noise from Portavogie and
that the RAF in Scotland had said it was a supersonic Typhoon fighter
jet.
"RAF Kinloss confirmed a Typhoon had been transiting the area and had now departed on its way," said the
Coastguard spokesman.
However, an RAF spokesman at the Ministry of Defence in London said
none of their aircraft were in the area at the time and he was at a
complete loss to explain how the Coastguard had come by a report to the
contrary.
The RAF spokesman said a Nimrod had been flying off the coast but agreed it was not a likely
explanation.
Four months ago, callers to BBC Northern Ireland reported strange
orange lights in the night sky over Bangor. Air traffic control at
Belfast International Airport said it had also received reports,
including one from the Coastguard, but there were no records of
aircraft in the area.
The Mull of Kintyre is only 25 miles away from the Northern Irish
coast and in 2002 the tourist organisation Visit Scotland said Scotland
had the highest concentration of UFO sightings of any nation in the
world.
In January 1996 the Scotsman newspaper reported concerns that the
top-secret USAF aircraft Aurora, which flies at three times the speed
of sound, was flying from RAF Machrihanish on the Mull of Kintyre.
In articles spanning several years, the newspaper claimed the
stealth spyplane may have been responsible for numerous UFO reports and
that its unusual sonic boom was thought to be responsible for
earthquakes and avalanches in the Netherlands.
Terry Moseley of the Irish Astronomical Association said that there was an alternative explanation if it was not
a plane. It could have been "a fireball exploding up in the atmosphere - perhaps a meteorite or a piece of
a comet".
"If that happens above the clouds, you would not see it from the ground," he said.
"That is the most likely explanation if it wasn't a jet."
WJLA-TV
Mon, 27 Aug 2007 22:08 EDT
A
series of explosions in Northeast have some residents looking for
answers, and some law enforcement sources have an idea of what could be
to blame.
Debris from used fireworks litters the neighborhood's streets, but
residents do not think that is the source of the ear-splitting noise on
Friday and Saturday nights along Isherwood street.
"Boom! It was loud; it just sound like something was coming down," said Northeast resident Brittany
Slaughter.
Residents say it sounded like a plane crash or an earthquake.
"It could have been a plane, but no plane," said Jewel Thorne.
"Wasn't no smoke; it was just the loudest boom I ever could hear."
According to ATF sources, the sounds could be caused by flashbang grenades.
The devices produce a bright flash of light and a loud bang. They are used by law enforcement to distract
people during raids.
Some flashbangs recently have been stolen from D.C. police emergency response cruisers in
Southeast.
There is no established connection between the missing flashbangs and the
noises.
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