Larry O'Hanlon
Discovery News
Mon, 31 Mar 2008 04:51 EDT
A new report of tiny beads of meteor impact glass strewn high in Antarctica's Transantarctic Mountains may expand a debris field to a tenth of Earth's surface -- despite no sign of the crater which spewed out the molten rock 800,000 years ago.
The accidental discovery of the glass "microtektites" in the high mountains of Antarctica extends what's called the Australasian tektite strewn field south by nearly 2,000 miles (3,000 kilometers).
The microtektites were found while a team of researchers were searching the exposed rocks atop the Transantarctic Frontier Mountain for more pieces of an unrelated meteorite that disintegrated in the skies there long ago.
"The gradiometer kept on beeping at every fracture of the granitic bedrock surface," recalled Italian researcher Luigi Folco of the Museo Nazionale dell'Antartide, Università di Siena and the Italian Programma Nazionale delle Ricerche in Antartide.
A magnetic gradiometer detects minute changes in magnetic fields caused by rocks containing magnetic minerals. The most likely cause for the beeping was magnetic minerals in volcanic ash from one of the relatively recent volcanoes in the region.
"When we get back to the lab, to our great surprise, we found thousands of micrometeorite and cosmic spherules thus explaining the magnetic signal," Folco told Discovery News.
But they also found glass spheres 0.5 millimeter in diameter with a pale-yellow color, which is unusual for glassy cosmic spherules, which are the debris of meteors melting in Earth's atmosphere.
The chemical composition of the yellow spheres revealed them to be Earth rocks. That meant there was only one likely way they could have been created -- in the heat of an impact, which flung melted rock into space and then rained back down, cooling and solidifying into spheres while in free fall.
The discovery was written up and reported in the April issue of the journal Geology.
The analysis of the microtektites revealed they are similar enough in appearance, composition and age to represent the edges of the Australasian strewnfield, said Folco. That strewnfield already had been found to extend from the Indian Ocean to the Pacific.
"It's a pretty big strewn field," said tektite pioneer and professor emeritus Bill Glass of the University of Delaware.
Larger tektites from the impact have been found all over Australia and smaller microtektites have been extracted from the bottom of the Indian Ocean, he told Discovery News. But this is the first good evidence that the debris might have been flung even further, he explained.
"You'd think that something that big would be easy to find," said Glass. "It's a real puzzle."
The most likely location of the hidden crater is somewhere in Indochina, said Glass. One possibility is that the meteor struck down on what is the sea floor today. But 800,000 years ago, an ice age would have lowered the sea level and exposed the seafloor. Since then it could have been buried by marine sediments.
Shooting Star Shower Spotted on Mars
Dave Mosher
Space.com
Tue, 01 Apr 2008 20:42 EDT
A shower of shooting stars has been recorded by instruments on Mars for the first time, astronomers say.
Meteors have been spotted before by the Mars rovers, but no device has ever detected a full shower until now.
United Kingdom astronomers predicted the event by tracking a comet's path near Mars, then comparing their forecast with Mars Global Surveyor (MGS) satellite data of the red planet's ionosphere - the upper reaches of atmosphere teeming with charged particles.
"Just as we can predict meteor outbursts at Earth, such as the Leonids [shower that occurs every November], we can also predict when meteor showers are going to occur at Mars and Venus," said Apostolos Christou, an astronomer at the U.K.'s Armagh Observatory who helped predict the martian meteoric event.
Christou is set to present findings about the meteor-showering pass of comet 79P/du Toit-Hartley at the Royal Astronomical Society's National Astronomy Meeting in Belfast on April 2.
Meteor central
Just as on Earth, meteor showers on Mars can occur when a planet passes through the dusty trail of a comet.
There are no conventional photos of the meteors in the new findings, but studying the brightness and length of meteor streaks in optical and radio data, Christou said, can help determine the age, size and composition of a comet's core.
Scientists think four times as many comets dust Mars with their tails compared to our home planet, as a high proportion of comets hang out near Jupiter - the red planet's next-closest neighbor. So there could be many more meteor showers visible from Mars than from Earth.
Some even blame such frequent comet dusting of Mars for the puzzling course change of Mariner 4, the first spacecraft to visit Mars, in the 1960s.
Fuzzy details
Christou said detecting the distant meteor shower wasn't easy.
"We believe that shooting stars should appear at Venus and Mars with a similar brightness to those we see at Earth," he said. "However, as we are not in a position to watch them in the martian sky directly, we have to sift through satellite data to look for evidence of particles burning up in the upper atmosphere."
Christou and his colleagues predicted six meteor showers caused by the intersection of Mars with dust trails from comet 79P/du Toit-Hartley since 1997, which was when the MGS satellite entered orbit.
The team pinpointed meteor streaks indirectly by measuring disturbances in electrical density of Mars' atmosphere with the spacecraft's radio communication system.
Out of the two showers MGS could have recorded - in 2003 or 2005 - Christou and his colleagues found hints of a shower only in data of the 2003 event.
"We don't see anything in the 2005 data because the meteors burned up deeper in the atmosphere," he said, adding that the depth would cover up an electrical signature. "If we are going to get a clear picture of what is going on, we need more optical and ionospheric observations of meteor showers at both the Earth and Mars so we can establish a definitive link between cause and effect."
Bruno Matarazzo Jr.
Salem News
Tue, 01 Apr 2008 09:56 EDT
IPSWICH - A bit of a mystery is lingering over Crane Beach: A
Beverly man wants to know what he saw falling from the sky yesterday
afternoon.
"It definitely was not a UFO," stressed Richard Wilson, an engineer originally from Wales. "It was bloody bizarre."
Wilson was spending the afternoon enjoying the beautiful weather
with his wife and son at Crane Beach. His walk was just ending when
something caught the attention of him and other beachgoers.
Wilson saw two objects fall within 15 minutes of each other. The
first, a rather large piece, fell between Crane Beach and Little Neck
near the Ipswich River.
The second object fell as he and his family were headed for the parking lot.
"We were walking back to our car, crossing over the boardwalk, and
someone ran towards us," Wilson said. "I looked up at the sky and there
were 20 to 30 pieces really high up and they fell on the dunes."
One man managed to pick up the smaller piece but Wilson couldn't get
to him without walking a long way on the dunes. The rest of the pieces
blew away to a swampy area behind the dunes.
The first piece fell at 1:30 p.m. and was much bigger, about 200 to 300 feet long, Wilson estimated.
"There was a plane in the sky doing aerobatics near the sea - this
stuff was higher than that," Wilson said. "It rolled over and (was)
moving like a piece of material, getting blown away."
The first piece to fall caught the attention of many beachgoers, and they stared up at the sky.
While Wilson said many people were captivated by the falling object,
park rangers from The Trustees of the Reservation, which owns the
beach, said no one informed them of any falling objects.
Ipswich police were not notified until about 2 p.m. when a Boston
television station called them about the report, which they heard about
from a viewer.
Police Sgt. Justin Daly said officers from the day shift responded
to the beach to investigate, but no one reported seeing anything.
"After a brief investigation it was determined nothing fell out of the sky," Daly said.
Police in Rowley and Newbury also reported no calls about objects falling from the sky.
Wilson said he may return to Crane Beach to do more of his own investigation and try to locate the smaller fallen pieces.
"It's a mystery," he said.
Staff writer Bruno Matarazzo Jr. can be reached at 978-338-2525 or by e-mailing bmatarazzo@salemnews.com.
Paul Gorman
press.co.nz
Thu, 03 Apr 2008 16:00 EDT
Teenager Andrew Wilkinson captured an apparently fiery object in the Canterbury sky on his digital camera last night.
 |
| ©Andrew Wilkinson |
| Teenager Andrew Wilkinson captured this mysterious picture of a fiery trail in the sky above Christchurch. |
Wilkinson, 17, photographed the object, from his Halswell home at 7.27pm.
He said it was too slow to be a meteor or a plane, and wondered if it might be satellite debris in the western sky.
A handful of other observant Cantabrians also spotted the orange ribbon standing out brightly in the dusk.
"I got the camera and took a photo. It was moving extremely slowly,
so I thought it might have been a plane for a minute. The front looked
like a fireball.
"I didn't hear any noise. It looks like it might have been extremely high up, given the speed it was moving," he said.
Police southern communications shift supervisor Trevor Cross said he
received one phone call about the phenomenon. A policeman at Oxford
also saw it and thought it might be a vapour trail.
The superintendent of the University of Canterbury's Mount John
Observatory at Tekapo, Alan Gilmore , said his "immediate reaction" was
it was a plane.
"The slowness would be due to the plane's movement. I assume from
the contrail's angle that it is a plane heading for Australia," Gilmore
said. "The trail doesn't look at all like a meteor or space-debris
trail."
P. Jenniskens, Carl Sagan Center, SETI Institute
Space.com
Thu, 03 Apr 2008 13:04 EDT
Each generation seems to get a chance, or two, to see a
mind-boggling display of shooting stars one night. The most spectacular
displays in my memory are the 1999 and 2001 Leonid storms. Before my
time, observers swore by the 1966 Leonids, and could not stop talking
about the spectacular 1933 and 1946 Draconid storms. Those were not
quite as intense as the Leonids, but the Draconids moved so slowly that
several were seen gliding across the sky at the same time.
In the 19th century, the most spectacular storms were the 1872 and
1885 Andromedids, which were almost as strong as the Draconids and also
very slow moving. At the time, Chinese astronomers wrote: "shooting
stars fell like rain." From the counts of meteors in the west, we now
estimate that rates peaked around two per second.
Some years earlier, in 1846, a comet
called 3D/Biela had been observed to break into at least two pieces.
The pieces had drifted further apart in 1852. Based on the rate of that
drift, the moment of breakup is thought to have been in either 1842 or
early 1843, when the comet was far from the sun, near Jupiter's orbit.
Because of their phenomenal intensity, the Andromedid storms were
believed to be caused by Earth traveling through the debris created
during that breakup.
So, did we pass through the breakup debris of comet 3D/Biela?
Astronomer Jeremie Vaubaillon, now at Caltech, and I decided to
investigate. We calculated where the debris from 1842/43 would have
ended up in the comet orbit
and discovered that a breakup far from the sun does not disperse dust
easily. The dust tends to keep the same orbital period, returning back
at the same time. The cloud of dust tends to hang around the position
of the comet, only gradually lagging the comet as a whole due to the
push of solar radiation.
We concluded that Earth has never encountered the debris created
during the 1842/1843 breakup! So what caused the Andromedid meteor
storms? Upon further reflection, we calculated that Earth had passed
through the dust trails that were generated when the two fragments came
back towards the sun in 1846 and 1852. Ejection close to the sun
results in higher ejection speeds and thus a relatively large variation
of orbital periods. After one orbit, some dust returns early, other
dust late, and thus all dust spreads out along the comet orbit much
more quickly. We found that the planets happened to steer those new
dust trails into Earth's path every time when observers on the ground
noticed unusual Andromedid rates in later years.
What if Earth would have crossed the dense cloud of debris of the
broken comet shortly after 1843? The resulting meteor storm would have
been a hundred times more intense, if not more. The impressive storms
of 1872 and 1885 were caused by a tiny bit of dust, we estimate 30
times less than what came off during the initial breakup. Moreover,
that dust had spread out quite a bit. Just imagine what could have
been. We appear to have missed out on a truly spectacular sight.
Then again, the next generation may be in for a surprise. The
Andromedids have moved on and now pass far from Earth's orbit, but
other comets continue to break and create new meteoroid
streams. One date to keep in mind is May 31, 2022, when Earth will pass
very close to (but perhaps will just miss) debris created during the
1995 breakup of comet 73P/Schwassmann-Wachmann 3. And there may be
others; we don't know yet what dormant comet nuclei may be out there
that could break any time now.
Read more about these calculations in the paper "3D/Biela and the
Andromedids: Fragmenting versus sublimating comets," by P. Jenniskens
and J. Vaubaillon (Astronomical Journal, 134, 1037-1045).
7Days
Fri, 04 Apr 2008 12:14 EDT
An eagle-eyed 7DAYS reader believes this picture (below) could hold
the answer to the mysterious fate of thousands of dead fish that were
washed up on a beach in Jumeirah. Chenine Groenewald pictured what she
thought was a meteorite falling from the sky on Monday.
 |
| ©Chenine Groenewald |
It coincides with the unusual sight of thousands of small silver
fish found dead on the beach on the same day. Authorities still do not
know what killed the fish, which locals were seen gathering up for
food. But Groenewald believes the meteorite could have fallen into the
sea, killing the marine life. "I'm not sure if it is related to the
fish being washed up dead, but I saw something falling from the sky on
Monday evening, in that direction, which I would assume is a
meteorite," she said.
The MET Office, however, rubbished the idea that the picture is of a
meteorite. "We are not astronomers, but it looks like a contrail from
an airplane," a spokesman said. But a defiant Groenewald responded: "It
was coming down quite quickly and I didn't see any plane nearby - I've
never seen anything like it."
TV3 New Zealand
Fri, 04 Apr 2008 13:00 EDT
 |
| ©Andrew Corner |
| Jet vapour trail or something else? |
A bright shining light that streaked across the Canterbury sky at
sunset earlier this week has now been identified by the experts.
A deer hunter on a mountain top near Arthur's Pass caught the object
on his video camera, allowing astronomers to take a look at it as well.
Andrew Corner did not expect to see an unidentified flying object
flying through the sky as he hunted deer in the back of beyond.
Corner and his friends discussed the fireball burning across the
sky, wondering whether it was a plane or space debris burning up. They
say they did not discuss the possibility of aliens.
Craig Garner of Stardome Observatory says: "Looking at this particular picture I would say it's definitely a jet vapour trail."
The hunters failed to get any deer on the hunt but say the fireball sighting made up for it.
Chaz Firestone
The Brown Daily Herald
Fri, 04 Apr 2008 06:36 EDT
Last September, something strange landed near the rural Peruvian village of Carancas. Two months later, so did Peter Schultz.
One was an extraterrestrial fireball that struck the Earth at 10,000
miles per hour, formed a bubbling crater nearly 50 feet wide and
afflicted local villagers and livestock with a mysterious illness. The
other is the Brown geologist who may have figured out why.
 |
| ©Brown Daily Herald |
| Professor of Geological Sciences Peter Schultz |
The fiery mass shot across the morning sky bursting and crackling
like fireworks, villagers said after the Sept. 15 impact. An explosive
crash tossed nearby locals to the ground, shattered windows one
kilometer away and kicked up a massive dust cloud, covering one man
from head to toe in a fine white powder. Many thought the streaking
fireball - brighter than the sun, by some accounts - was an aerial
attack from neighboring Chile.
Curious shepherds and farmers approached the crash site to find a
smoking crater reminiscent of a Hollywood film, laden with rocks and
stirring with bubbling water that emitted a foul vapor. But curiosity
turned to fear when unexplained symptoms began to crop up in Carancas:
headaches, vomiting and skin lesions struck more than 150 villagers,
Peru's Ministry of Health stated days later. Locals reported that their
animals lost their appetites and bled from their noses. Children were
restless and cried through the night.
But according to Schultz, the professor of geological sciences who
visited the site last December, the true mystery in Carancas is how any
of this happened in the first place.
Sophisticated theory and conventional wisdom have long agreed that
most meteors break into fragments and fizzle out before they can reach
the Earth's surface. Even those large and durable enough to make it
through the atmosphere hit the ground as ghosts of their former selves,
"plopping out of the sky and forming a bullet hole in the Earth,"
Schultz said. "This meteor crashed into the Earth at three kilometers
per second, exploded and buried itself into the ground."
Last month, Schultz delivered a highly anticipated lecture at the
39th Lunar and Planetary Science Conference in League City, Texas. And
if he's right, the bold theory he proposed there may shake loose a "gut
response" entrenched within the geological, physical and astronomical
sciences: "Carancas simply should not have happened."
A Web of speculation
The handful of shepherds who happened to lead their Alpaca herds
near the arroyo that day may have been the first humans ever to witness
an explosive meteor impact. But the rest of the world quickly got its
chance, if vicariously, through a flurry of activity in the blogosphere.
Hundreds of scientists, journalists and captivated amateurs weighed
in on the bizarre events as they unfolded, offering scores of pet
theories and radically revising them as more information streamed in
from Peru.
Pravda, a Russian online newspaper born out of a print version run
by the country's former Communist Party, ran the headline "American spy
satellite downed in Peru as U.S. nuclear attack on Iran thwarted" five
days after the impact. The story attributes the villagers' illness to
radiation poisoning from the satellite's plutonium power generator.
Other proposed explanations were less sensational. Nevadan wildlife
biologist and amateur geologist David Syzdek wrote a Sept. 18 blog post
titled "Meteorite strike in Peru gassing villagers? Maybe not." In it,
he proposed that a mud volcano producing toxic gases was responsible
for both the illness and the crater.
"The Andes are very active geologically so I think there is a good
possibility that this crater was caused by an outburst of geothermal
activity," he wrote.
As for the blinding light shooting across the sky, Syzdek chalked it up to coincidence.
"Fireballs are quite common," he wrote. "One possible scenario is
that the people who saw the fireball just happened on a recently formed
mud volcano while they were out looking for the fireball impact site."
Though Pravda and Syzdek drew radically different conclusions from
the reports, what they shared with each other, many bloggers and even
some scientists was a healthy skepticism about reports coming out of
Peru. Pravda and Syzdek both pointed out in their posts that an
explosion powerful enough to create such a large crater would be
equivalent to 1,000 tons of TNT, or a tactical nuclear strike.
"When I first saw the news reports, they just didn't seem right,"
Syzdek later said in an interview. "Explosive impacts like this just
don't happen."
'A hyperspeed curveball'
Gonzalo Tancredi, a Uruguayan astronomer who collaborated with
Schultz in Carancas, said initial reports of the impact confounded
amateurs and Ph.D.s alike. Bewildered scientists even entertained the
possibility of a hoax as rumors floated around the scientific community.
"At the beginning, there were some doubts about what really happened
there," Tancredi said. "We thought maybe it was a meteor fall or maybe
it was something else, even something fake."
But when Tancredi visited Carancas a few weeks later, what he
observed silenced the conspiracies and pointed unequivocally to one
conclusion.
Tancredi interviewed locals, who reported a large mushroom cloud
that formed over the crater and compression waves that knocked
villagers to the ground. He also found pieces of soil and rock that had
been launched over three football fields from the crater - one piece
even pierced the roof of a barn 100 meters away. Combined with analyses
of infrasound detectors and the patterns of crater "ejecta," the
evidence pointed to a genuine and very powerful meteorite impact.
But the question that remained on everyone's mind was how the meteor
got there at all - a scientific riddle that was made even more
challenging by Michael Farmer.
Farmer is a controversial figure in the geological community. He is
a meteorite hunter, a poacher of alien rocks who travels to impact
sites around the world - usually the "bullet hole in the Earth" type
mentioned by Schultz - and collects whatever he can find, often
brushing up against authorities and other hunters. Meteorite hunting is
Farmer's full-time job; he profits from selling what he finds.
Farmer, who said he is "totally self-taught" when it comes to
meteors, said he was as skeptical as the rest when he first heard the
reports coming out of Peru while on hunt in Spain. But 16 days later,
he and his partners found themselves staring into the Carancas impact
crater, the first Americans on the scene - and they stumbled on an
extraterrestrial gold mine.
"We got there and just started picking up pieces off the ground,"
Farmer said. "The entire ground was white, just white powder which was
all meteor."
Farmer and his team eventually accumulated 10 kilograms of small
meteorite fragments and sold them to private collectors and
universities for an astronomical $100 per gram.
But despite his rocky past with the geological community, Farmer and
his expensive fragments made a priceless contribution to scientists.
Within minutes of arriving on the scene, Farmer discovered that the
Carancas meteorite was a chondrite, or stony meteorite, as opposed to
an iron meteorite.
Though far more common than iron meteorites, chondrites are highly
vulnerable to ablation - the cracking, eroding and even exploding that
occurs when a meteor enters the atmosphere and undergoes extreme
changes in temperature and pressure. As a result, chondrites are far
less likely than the more durable iron meteorites to make it to the
Earth's surface in large pieces - which makes the Carancas meteorite
all the more baffling.
"For a while, the only information we were getting was from Farmer's
Web site," Schultz said. "This was not the type of object you'd expect
to get through the atmosphere in a tight clump."
With most pieces of the geological puzzle on the table, the stage
was set for Schultz to visit the site for himself. But when he arrived
there in December with a Brown graduate student, Tancredi and Peruvian
astrophysicist Jose Ishitsuka, a budding geologist actually made the
crucial discovery. Scott Harris GS said he collected some soil samples
"initially out of curiosity" to look for evidence of shock deformation,
which occurs when an object rapidly decelerates in cases like impacts
or explosions. When Harris looked at the material under a microscope,
he found tiny mineral grains that had turned into glass because of heat
and massive shock forces, indicating a very high-speed impact. Here was
yet another mystifying piece of evidence.
"At the minimum," Harris said, "this would support a velocity of
three kilometers per second - a real high-velocity explosion instead of
just a plop in the ground."
By this time, more reputable scientific theories of the impact had
supplanted the initial speculation, the most popular of which came from
a group in Germany and Russia. They proposed that the meteor entered
the Earth's atmosphere at a very shallow angle, allowing it to reach
the surface gradually and avoid a sudden increase in pressure - "the
difference between diving in and doing a belly flop," Schultz said.
But their theory's relatively low impact velocity of 180 meters per
second, or about 400 miles per hour, was consistent with every piece of
evidence but Harris', which pointed to a velocity of about 10,000 miles
per hour at impact.
"This was nature's way of throwing us a curveball," Schultz said. "A hyperspeed curveball."
Changing shape, changing theory
Back home in Providence, Schultz was now faced with the task of
fitting the puzzle pieces together into a cohesive theory. And to do
it, he looked to Earth's closest planetary neighbor, Venus.
"Our models make predictions about what kind of objects can make it
to the surface at what velocity, and the Carancas meteor isn't usually
one of them," Schultz said. "But Venus has a much denser atmosphere and
we still find craters on its surface. How did they get there? I think
it might be the same thing here."
To explain the alternative theory he developed, Schultz compared a typical meteor's descent to a waterskier behind a boat.
"Normally when you're on the outside of the wake, you're pushed out
further," Schultz said. "From my experience looking at Venus, I
realized that there was a certain condition where the waterskier will
stay inside the wake, and actually get pushed inward."
At last month's Lunar and Planetary Science Conference, Schultz
proposed that the meteor did break up into pieces, but shock waves
created by the speeding mass may have kept them close together. And
since the meteor descended as a clump of fragments instead of one large
piece, it reshaped itself along the way to become more aerodynamic,
like a football or a javelin cutting through the air instead of a
poorly shaped hunk of rock.
"It's like having a Volkswagen turn into a Ford Taurus," Schultz
said, adding that this sort of reshaping is well known to geologists
who study islands and land-water interaction. "If you put a big pile of
dirt in a stream, that mound will eventually turn into a teardrop
shape. It's trying to minimize the friction."
Tancredi, who co-authored the paper with Schultz, Harris and
Ishitsuka, said Schultz's theory is gaining popularity but is still
being debated, even among the group that proposed it.
"This is the hot question right now," he said. "We still have to demonstrate that this phenomenon is possible."
In the meantime, another hot question had remained without a
definitive answer - the etiology of the strange illness that afflicted
the people of Carancas. But the group may solve that mystery, too.
Schultz, Harris and Tancredi all dismissed the possibility of the
meteorite emitting harmful gases that would sicken villagers. Instead,
they proposed a simpler cause: the power of the mind.
The meteorite impact sent out a powerful compression wave that
knocked nearby villagers and animals to the ground and injected the
soil with air, which later bubbled up through the crater. Shepherds and
cattle may also have breathed in the thick dust thrown up by the crash
and smelled the sulfurous gases produced as water reacted with iron
sulfide in the meteor.
But what the group thinks later spread through the town was not disease, but panic.
"We think it was probably more of a psychological response," Harris
said, adding that commonplace symptoms like headaches and nausea could
easily have been caused by the disorienting impact and then mirrored by
frightened villagers.
Harris also admitted the possibility of the meteorite releasing
arsenic deposits, which are known to exist in Peru, but said it would
be very unlikely for those gases to have caused the illness.
"In order to really get arsenic poisoning, you'd need high
concentrations," he said. "You'd have to be there inhaling the vapor
filled with the stuff right after the meteorite hit."
Poisonous or not, the Carancas meteorite could have important
implications for public safety. Tancredi said there's no reason an
impact like this couldn't happen in a major city, wiping out a few city
blocks. He also pointed out that today's most advanced meteor detectors
aren't nearly powerful enough to detect an object as small as the
Carancas meteorite.
"Near-Earth detectors detect objects that could create a global
catastrophe, something maybe a kilometer across," he said. "We don't
have any kind of technology that could detect this object before
reaching the atmosphere, so it will not be possible to know when and
where one of these objects could strike again."
But Schultz said the most important lesson to learn from Carancas is
that the foundation of good science is hard empirical evidence, even -
and especially - when it contradicts established principle.
"We tried to understand what the rocks told us rather than looking at the theory," he said. "Nature trumps theory, every time."
Kunio M. Sayanagi
ars technica
Fri, 04 Apr 2008 14:12 EDT
By now, we have all heard about a handful of asteroids that are
big enough to level a city or two and have a small but non-negligible
chance of hitting Earth. Should we find one heading straight at Earth,
what can we do about it, if anything at all?
That is the question addressed by Carusi and colleagues in a study published in the April issue of Icarus,
a leading international journal in the planetary sciences. They
conducted case studies of two near-Earth asteroids (NEAs) known as
99942 Apophis and 2004 VD17, whose initial orbit estimates indicated
measurable probabilities of hitting Earth in 2036 and 2102,
respectively. Although refinements to their orbital calculations
through intensive follow-up observations have substantially lowered
their chances of collisions with Earth, the authors treated the
asteroids' initial orbital estimates as full-blown drills to study how
such asteroids can be deflected, and to build realistic strategies to
prepare ourselves for such events.
The report presents computer simulations that calculate the minimum
orbital velocity change we must impart on the asteroids to deflect them
away from Earth. A larger velocity change requires a stronger force,
and thus imposes a greater technological and financial challenge. To
make the exercise realistic, the authors considered performing their
deflection maneuvers only when the asteroids cross the orbit of Earth -
as the asteroids under consideration are NEAs, they have repeated Earth
orbit crossings leading up to the predicted impact dates.
As expected, in general, the authors' calculations show that greater
speed changes are needed as the hypothesized impact date comes closer.
However, a careful examination also reveals that there are windows of
opportunity in which deflection becomes considerably easier largely due
to the relative orbital geometry of the asteroids and Earth. For
example, in the case of 99942 Apophis, estimated to be a 400 meter
chunk of rock, an impactor with 300 kg mass can deflect the asteroid to
safety with a carefully angled interception on January 27th, 2020,
about 16 years before impact. The authors note that such a deflection
maneuver is already achievable with currently existing technologies.
However, their study illustrates that things are not always that easy.
The other asteroid they considered, 2004 VD17, has an orbit closely
overlapping that of Earth's over a longer span than 99942 Apophis does,
and such orbital characteristics makes its deflection much more tricky.
Still, the scientists found windows of opportunity such as one in 2021,
81 years before its hypothesized collision with Earth, in which an
impactor weighing about a ton could deflect the asteroid away from
Earth.
The authors' findings also come with a bit of bad news.
While it may be technologically feasible to exert a force large enough
to deflect 2004 VD17, their calculations also reveal that the impactor
could shatter the asteroid, which is equivalent to converting an
approaching rifle bullet into a shotgun round, with consequences that
are unpredictable at best. 99942 Apophis, in contrast, should survive the relatively modest forces required to deflect it.
This study by Carusi et al. shows that deflecting real asteroids is
within reach of currently existing technologies, given enough time and
planning. By definition, NEAs orbit near Earth, so any that threaten us
are expected to have a few close encounters with Earth, during which
they are easy to find, before the final collision. Therefore, the long
planning period considered in this study is realistic.
The current study's strategy will not, however, work well
for deflecting objects with highly elliptical orbits such as long
period comets; nevertheless, most objects that impose
significant threats to Earth are NEAs since their orbits bring them so
close to here. The study highlights the importance of efforts such as
the SpaceWatch project hosted by the University of Arizona - its goal is to find and track all objects with chances of impacting Earth. It
may well turn out that spotting an asteroid heading our way before it
is too late is far more difficult than developing technologies to
deflect them.
American Chemical Society
Sun, 06 Apr 2008 11:19 EDT
Flash back three or four billion years - Earth is a hot, dry and
lifeless place. All is still. Without warning, a meteor slams into the
desert plains at over ten thousand miles per hour. With it, this
violent collision may have planted the chemical seeds of life on Earth.
Scientists presented evidence today that desert heat, a little
water, and meteorite impacts may have been enough to cook up one of the
first prerequisites for life: The dominance of "left-handed" amino
acids, the building blocks of life on this planet.
In a report at the 235th national meeting of the American Chemical
Society, Ronald Breslow, Ph.D., University Professor, Columbia
University, and former ACS President, described how our amino acid
signature came from outer space.
 |
| ©Los Alamos National Laboratory |
| A simulated ribosome (white and purple subunits) processing an amino acid (green). |
Chains of amino acids make up the protein found in people, plants,
and all other forms of life on Earth. There are two orientations of
amino acids, left and right, which mirror each other in the same way
your hands do. This is known as "chirality." In order for life to
arise, proteins must contain only one chiral form of amino acids, left
or right, Breslow noted.
"If you mix up chirality, a protein's properties change enormously.
Life couldn't operate with just random mixtures of stuff," he said.
With the exception of a few right-handed amino acid-based bacteria,
left-handed "L-amino acids" dominate on earth. The Columbia University
chemistry professor said that amino acids delivered to Earth by
meteorite bombardments left us with those left-handed protein units.
"These meteorites were bringing in what I call the 'seeds of
chirality,'" stated Breslow. "If you have a universe that was just the
mirror image of the one we know about, then in fact, presumably it
would have right-handed amino acids. That's why I'm only half kidding
when I say there is a guy on the other side of the universe with his
heart on the right hand side."
These amino acids "seeds" formed in interstellar space, possibly on
asteroids as they careened through space. At the outset, they have
equal amounts of left and right-handed amino acids. But as these rocks
soar past neutron stars, their light rays trigger the selective
destruction of one form of amino acid. The stars emit circularly
polarized light - in one direction, its rays are polarized to the
right. 180 degrees in the other direction, the star emits
left-polarized light.
All earthbound meteors catch an excess of one of the two polarized
rays. Breslow said that previous experiments confirmed that circularly
polarized light selectively destroys one chiral form of amino acids
over the other. The end result is a five to ten percent excess of one
form, in this case, L-amino acids. Evidence of this left-handed excess
was found on the surfaces of these meteorites, which have crashed into
Earth even within the last hundred years, landing in Australia and
Tennessee.
Breslow simulated what occurred after the dust settled following a
meteor bombardment, when the amino acids on the meteor mixed with the
primordial soup. Under "credible prebiotic conditions" - desert-like
temperatures and a little bit of water - he exposed amino acid chemical
precursors to those amino acids found on meteorites.
Breslow and Columbia chemistry grad student Mindy Levine found that
these cosmic amino acids could directly transfer their chirality to
simple amino acids found in living things. Thus far, Breslow's team is
the first to demonstrate that this kind of handedness transfer is
possible under these conditions.
On the prebiotic Earth, this transfer left a slight excess of
left-handed amino acids, Breslow said. His next experiment replicated
the chemistry that led to the amplification and eventual dominance of
left-handed amino acids. He started with a five percent excess of one
form of amino acid in water and dissolved it.
Breslow found that the left and right-handed amino acids would bind
together as they crystallized from water. The left-right bound amino
acids left the solution as water evaporated, leaving behind increasing
amounts of the left-amino acid in solution. Eventually, the amino acid
in excess became ubiquitous as it was used selectively by living
organisms.
Other theories have been put forth to explain the dominance of
L-amino acids. One, for instance, suggests polarized light from neutron
stars traveled all the way to earth to "zap" right-handed amino acids
directly. "But the evidence that these materials are being formed out
there and brought to us on meteorites is overwhelming," said Breslow.
The steps afterward that led towards the genesis of life are
shrouded in mystery. Breslow hopes to shine more light on prebiotic
Earth as he turns his attention to nucleic acids, the chemical units of
DNA and its more primitive cousin RNA.
"This work is related to the probability that there is life
somewhere else," said Breslow. "Everything that is going on on Earth
occurred because the meteorites happened to land here. But they are
obviously landing in other places. If there is another planet that has
the water and all of the things that are needed for life, you should be
able to get the same process rolling."
Leonard David
Live Science
Fri, 04 Apr 2008 11:25 EDT
Keep an eye on a bill introduced in the House of Representatives by Congressman Dana Rohrabacher on Near Earth Objects (NEOs).
The NEO Preparedness Act calls upon the NASA Administrator to
establish an Office of Potentially Hazardous Near-Earth Object
Preparedness. That office would "prepare the United States for
readiness to avoid and to mitigate collisions with potentially
hazardous near-Earth objects in collaboration with other Agencies
through the identification of situation- and decision-analysis factors
and selection of procedures and systems."
NASA has also been tasked to request the National Academy of Science
to look into issues with detection of potentially hazardous NEOs and
approaches to mitigate these hazards. The exact statement of task is
still being hashed out, but that study should be underway in a couple
of months or so, I've been advised.
According to Jim Green, Director of NASA's Planetary Science
Division, speaking at a recent meeting on outer planet exploration,
part of the NEO assessment will focus on use of ground-based or
space-based observations for NEOs and approaches to developing
deflection capability.
It's not within NASA's charter to protect the planet from
threatening NEOs, Green noted. Such a mission could go to the
Department of Defense, he said, "but we'll see how it goes."
In NEO-related news, Green also reported on the huge Arecibo radio
telescope in Puerto Rico. "We have confirmed with the NSF [National
Science Foundation] that they will fully-fund Arecibo operations in
fiscal year 2008," he explained.
Conversation between NSF and NASA about funding Arecibo operations in upcoming years has begun, Green said.
Ananova
Mon, 07 Apr 2008 09:41 EDT
A Bosnian man whose home has been hit an incredible five times by meteorites believes he is being targeted by aliens.
Experts at Belgrade University have confirmed that all the rocks Radivoje Lajic has handed over were meteorites.
They are now investigating local magnetic fields to try and work out
what makes the property so attractive to the heavenly bodies.
But Mr Lajic, who has had a steel girder reinforced roof put on the
house he owns in the northern village of Gornja Lamovite, has an
alternative explanation.
He said: "I am obviously being targeted by extraterrestrials. I
don't know what I have done to annoy them but there is no other
explanation that makes sense. The chance of being hit by a meteorite is
so small that getting hit five times has to be deliberate."
The first meteorite fell on his house in November last year and
since then a further four have smashed into his home. The strikes
always happen when it is raining heavily, never when there are clear
skies.
He said: "I did not know what the strange-looking stones were at
first but I have since had them all confirmed as meteorites by experts
at Belgrade University.
"I am being targeted by aliens. They are playing games with me. I
don't know why they are doing this. When it rains I can't sleep for
worrying about another strike."
Patrick J. McDonnell and Andres D'Alessandro
Los Angeles Times/ LA Plaza
Mon, 07 Apr 2008 15:27 EDT
The space rock reportedly crashed late Sunday somewhere in Entre Rios Province, some 260 miles northwest of Buenos Aires, reports the daily Clarin,
which quoted a witness, Milton Blumhagen, a student and astronomy buff:
"For three or four seconds I saw an object in flames, changing color
until it turned blue when it approached the ground.'' A fire department
source said the impact was felt for miles around. No damage was
reported.
The curious are headed out to the isolated rural zone where the meteorite, or whatever it was, is believed to have struck.
Last year, as this L.A. Times news story recounts,
a meteorite strike near Lake Titicaca caused a regional sensation: Area
residents said they became sick, and meteor hunters rushed to the site
to purchase chunks of space debris, which can fetch high prices on the
international market. Scientists dismissed any links between the
meteorite and the reported illnesses.
Faye Flam
The Philadelphia Inquirer
Mon, 07 Apr 2008 09:09 EDT
Magnified 25,000 times under Drexel University's scanning electron
microscope, a couple of flecks of dirt offer up a landscape full of
crags, valleys, ridges - and, to Dee Breger's eyes, a window back in
time.
 |
| ©Dee Breger |
| Colorized scanning electron micrograph shows a tiny spherule that is believed to have formed from a vaporized or melted fragment when a piece of a comet slammed into the Indian Ocean an estimated 4,800 years ago. Marine geophysicist Dallas Abbott hypothesizes that such an impact was the source of deluge legends like Noah's ark and Gilgamesh. |
The tiny grains came from the sea floor below the Gulf of
Carpenteria in northern Australia, part of an underground layer dating
to the first millennium. Breger and her colleagues believe the material
holds signs that a fragment of a comet crashed to Earth during that
period. Such an event might explain the months of cold summers and dark
days that began in A.D. 536 and led to a well-documented period of
famine and unrest.
And, they say, while such an event would have been catastrophic, it
was not unique. By comparing the historical and archaeological records
with hard-to-prove physical evidence, they are trying to make a case
that rocks from space were responsible for altering human affairs in
ways so huge that some have entered mythology.
It is an uphill battle.
"We're mavericks," says Breger, a microscopist who is not formally
trained in science. Scanning her dirt sample on a nearby screen, she
zooms in on what looks like a splotch of paint. "We call that a splat."
 |
| ©SHARON GEKOSKI-KIMMEL / Inquirer Staff Photographer |
| Dee Breger, senior microscopist at Drexel University , works with one of the scanning electron microscopes that she usesin her studies. She is part of the Holocene Impact Working Group, which is advancing the idea that impacts from comets and asteroids not only doomed the dinosaurs but have influenced human history, even in the past millennium. |
Breger instructs the machine to analyze the composition. Traces of
some metals in the form of a splat can be a sign of a powerful
explosion, she says - one you might get if a piece of a comet or
asteroid slammed into the Earth.
Scanning further, she stops at a sphere, less than a hundredth of a
millimeter across (much smaller than the width of a human hair). Under
the electron microscope it resembles a planet or some exotic moon, the
surface scarred with rifts and cracks, all suggestive of molten rock or
metal that was blasted into the air and quickly cooled.
It was Dallas Abbott, a marine geophysicist at Lamont-Doherty Earth
Observatory in New York, who brought these samples to Drexel. Breger
teamed up with Abbott while working at Lamont-Doherty, first as a
scientific illustrator and then as a microscopist. The former art
student moved to Drexel four years ago for the chance to work with more
powerful instruments.
"The lab here is state-of-the-art," she says.
They and a few colleagues in the Holocene Impact Working Group -
named for the period covering the last 20,000 years - have been
proposing for years that several large objects from space hit the Earth
with enough force to influence global climate within human history.
Abbott estimates this happened perhaps five times in the last 6,000
years.
Most sudden climate changes over the eons remain unexplained, and
most scientists argue that a lack of convincing evidence for any theory
is not much of a reason to support this one.
"Impacts are the solution of choice when you don't have any data,"
says astronomer Donald Yeomans of NASA's Jet Propulsion Laboratory.
Still, astronomers generally agree that the Earth has been smacked
around by comets and asteroids, and that some altered the history of
life. The most famous of them fell around 65 million years ago -
kicking up enough debris, it now appears, to cool the planet and kill
off the dinosaurs.
Much more recently, for 18 months around A.D. 536, a thick haze and
freakish cold gripped Europe. As Byzantine historian Procopius of
Caesarea put it: ". . . the sun gave forth its light without brightness
. . . and it seemed exceedingly like the sun in eclipse, for the beams
it shed were not clear."
Tree growth rings dated to that time appear narrow and sickly as far
away as North America and Central Asia, an indication that the cold and
darkness spanned the globe. The period coincided with devastating crop
failures that some have linked to the fall of the Roman Empire.
 |
| ©DEE BREGER |
| This is a magnification of tree rings from a Siberian pine in A.D. 534-539. The deformed ring at center indicates severe cooling. Europe, around 536, experienced 18 months of darkness and cold. Volcanos are the usual explanation; a new theory suggests a meteor hit. |
There definitely was a climate anomaly at that time, says Richard
Alley, a climate expert and glaciologist at Penn State University. But
he, like most in the field, favors an alternative explanation: that a
large volcanic eruption dimmed the skies. Not only are eruptions
relatively common compared with large impacts, he says, there now
appears to be a record stored in ice caps near Greenland and Antarctica.
Scientists drilling out deep cores can date ice laid down in that
era to within a year or two, Alley says, and evidence of telltale
volcanic sulfates in layers from A.D. 536 was published just last month.
Looking more broadly, Abbott and Breger are also seeking clues to a
possible impact 4,800 years ago. Around that time, many different
cultures advanced myths of catastrophic floods, Abbott says, including
the biblical account of Noah's ark.
To find out what happened, she's gathering clues on scales small and
large. With satellite images now widely available through Google Earth,
Abbott is examining massive, V-shaped formations in northern Australia
and, at the other end of the Pacific, in Madagascar, the island off
East Africa. She argues that these were created by a giant impact in
the Indian Ocean that sent a mega tsunami in different directions.
"The one in Australia rises more than 100 feet above sea level,"
Abbott says. Her critics contend these are just big sand dunes created
by prevailing winds, an explanation that she says doesn't go nearly far
enough.
And the actual point of impact?
With remote sensing technology, Abbott says she's found signs that
might indicate the presence of an 18-mile-wide crater. But it's more
than 1,000 feet below the surface and hard to confirm. She's seeking
funding for a more thorough exploration.
If they put together enough lines of evidence for enough separate
events, Abbott says, the work may back up an idea promoted by a
minority of British astronomers that a few thousand years ago a massive
comet swung inward from the fringes of the solar system, broke up near
the Earth - and has been periodically dropping pieces on the planet
ever since.
What's left, these astronomers proposed, is now called Comet Encke -
a tiny chunk of ice and dirt that orbits the sun every three years.
Others say that while the idea that pieces of what is now Encke fall
to earth is plausible, the evidence is unconvincing. "It's a little
dinky comet right now," says David Morrison, a planetary scientist at
NASA's Ames Research Center in California. "If Encke was responsible
for something, it's aged quickly."
By tracking asteroids that cross Earth's orbit and observing craters
on the moon's surface, astronomers are able to estimate how frequently
they hit in the past. Potentially climate-changing impacts with
asteroids average less than once in a million years, they say, and
comet collisions even less often.
That doesn't mean there weren't recent major comet impacts, Morrison says. It's just very unlikely.
Proving that a given geological formation was caused by an impact is
not a simple matter even when it's on land, says Jay Melosh, a
planetary scientist at the University of Arizona's Lunar and Planetary
Lab.
It's even harder under water. In that case, one of the best
indicators is the concentration of rare elements, especially iridium,
that would have come with the comet or asteroid and then blasted
through the atmosphere on impact.
And it's one thing to find evidence of an impact, Melosh says, and
another to demonstrate that it was big enough to lead to global climate
change.
The only clear-cut case is the impact that marked the end of the
dinosaur era 65 million years ago. Underwater remote sensing has found
a massive crater under the Gulf of Mexico, and geologists have
discovered more than 200 places around the globe where rock samples
have yielded unusually high levels of iridium in the same layer of
geological strata after which dinosaurs suddenly vanish.
Mainstream astronomers say asteroids and comets do hit often enough
that we should worry about them. Those optimistic enough to think we'll
survive more than a few thousand years say a rock or comet will
eventually get us. Unless we can figure out how to deflect it, we will
go the way of the dinosaurs.
Science Daily
Tue, 08 Apr 2008 11:58 EDT
The Indiana Asteroid Program began with a borrowed lens and a
bet over a chocolate ice cream cone. Almost 60 years later, its final
chapter was written with the naming of a heavenly body after one of the
most dedicated staff members Indiana University Bloomington's
Department of Astronomy has ever seen.
The program -- launched in 1949 by Hoosier astronomy legend Frank
Edmondson -- aimed to locate and calculate the orbits of asteroids
"lost" during World War II. During the next 28 years, the program also
identified 119 new asteroids by studying more than 3,500 image plates
showing 12,000 asteroid images.
But because asteroids are not named until their orbits are
calculated and confirmed, the final IU asteroid wasn't named until
earlier this year, more than 40 years after the program ceased
searching the skies.
Frank Edmondson, now professor emeritus of the Department of
Astronomy, headed the program when this last asteroid was discovered,
thus was responsible for its naming -- he named it in honor of Brenda
Records, who recently retired as office manager of the astronomy
department after 20 years of exemplary service.
"I did not expect it at all," said Records, who now spends her time
at home and visiting her grandchildren in Louisville. "I was very
surprised and honored that Frank named the asteroid after me."
Edmondson named the final IU asteroid, "Records," partly due to her
efforts as office manager and administrative assistant, and partly in
recognition of her hard work transcribing his book, AURA and its U.S. National Observatories.
Records -- one of the few people who could read Edmondson's handwriting
-- spent years typing his manuscript, which was written in longhand.
"Brenda was a very important part of the astronomy department for a
very long time and instrumental in getting my book published," said
Edmondson. "We were very lucky to have her."
During the Indiana Asteroid Program's tenure, Edmondson and company
discovered many asteroids and named them after Indiana astronomers and
faculty, both recent and retired. Some familiar names include IU
Presidents Bryan and Wells, IU astronomers K.P. Williams and Wilbur
Cogshall, current IU faculty members James Glazier and Stuart Mufson,
and famous Indiana astronaut Gus Grissom.
"There are some pretty major chunks of rocks -- some the size of
Bloomington -- floating around out there bearing the names of some very
famous IU faculty, staff and alumni," said IU Astronomy Professor
Emeritus R. Kent Honeycutt, who has served as chair of the astronomy
department twice and is currently director of the university's Goethe
Link Observatory.
Edmondson, now 95, began building the astronomy department with a
chocolate ice cream cone. In 1937, he bet Astronomy Department Chair
William Cogshall a chocolate ice cream cone that recently appointed IU
President Herman Wells would fund a graduate student fellowship
position at the newly constructed Goethe Link Observatory in Brooklyn,
Ind. At that time, the observatory belonged to Dr. Goethe Link, an
Indianapolis surgeon and amateur astronomer.
Cogshall doubted they would get the funding, but must have wanted
that chocolate ice cream cone, because he ultimately agreed. What he
didn't know was that Edmondson had already convinced Wells to fund the
position.
"You may question my morals," said Edmondson, grinning broadly. "But
I was betting on a sure thing, and the bet got the money to start the
program."
The position proved instrumental to both the Indiana Asteroid
Program and the astronomy department because a decade later, the
astronomer Edmondson hired -- James Cuffey -- located and borrowed a
10-inch lens from the University of Cincinnati to search for asteroids.
Without that lens, the Indiana Asteroid Program would have never
existed.
Edmondson and Cuffey decided to acquire the lens because the
International Astronomy Union had issued a plea for help to search for
asteroids with orbits that had been lost during the war due to
observatories shutting down.
"We felt it was our duty to help if we could," said Edmondson. "And
none of it would have happened without that 10-inch lens, Dr. Cuffey,
or that chocolate ice cream cone."
Ker Than
National Geographic
Thu, 10 Apr 2008 16:41 EDT
The meteorite that wiped out the dinosaurs might have been less than half the size of what previous models predicted.
That's the finding of a new technique being developed to estimate
the size of ancient impactors that left little or no remaining physical
evidence of themselves after they collided with Earth.
Scientists working on the technique used chemical signatures in
seawater and ocean sediments to study the dino-killing impact that
occurred at the end of the Cretaceous period, about 65 million years
ago.
They also looked at two impact events at the end of the Eocene epoch, roughly 33.9 million years ago.
In what could be a major scientific puzzle, the team's new size
estimate for the dino-killing meteorite is a mere 2.5 to 3.7 miles (4
to 6 kilometers) across.
The most recent computer models predicted a size of 9 to 12 miles (15 to 19 kilometers) across.
The team notes that their findings could also mean that the makeup
of the impactor is different from what scientists commonly assume.
"We are hoping this will lead to further work," said study leader Gregory Ravizza of the University of Hawaii in Honolulu.
Impact Fingerprints
The fiery passage of asteroids and comets through Earth's atmosphere leaves chemical traces in the land, sea, and air.
The most common types of meteorites to hit Earth are chondrites, stony objects that originate in the asteroid belt.
Chondrites contain two different versions, or isotopes, of the naturally occurring element osmium: osmium 187 and osmium 188.
Seawater and sediments also contain the two osmium isotopes, but the
ratio of osmium 187 to osmium 188 is usually much larger in the ocean
than it is in chondrites.
When a small- to medium-size meteorite enters Earth's atmosphere,
much of the object is vaporized and the osmium ratio in seawater around
the world is temporarily decreased.
Over time, this osmium imprint is transferred to sediments at the ocean bottom, creating a more enduring record of the impact.
The new technique therefore looks for osmium spikes in ocean
sediments and analyzes the isotope ratio. Scientists can then predict
when an impact event occurred and the size of the projectile.
The research is detailed in tomorrow's issue of the journal Science.
Dramatic Upheaval
In addition to the smaller Cretaceous impact, the team estimates
that two known meteorites from the late Eocene were smaller than
previously believed.
Boris Ivanov, an impact modeler at the Russian Academy of Sciences,
said that if the new size estimates prove correct, they would create a
"dramatic controversy" within the impact physics community.
"Most numerical modeling specialists believe the current modeling
gives us fidelity of a factor of a few times the mass of a projectile
with assumed average impact velocity," Ivanov said.
Study co-author Francois Paquay, also at the University of Hawaii,
said that more work needs to be done to confirm the latest estimates.
"We think the discrepancy is important and it will need to be addressed in future [scientific] meetings," Paquay said.
Jay Melosh, a planetary scientist at Arizona State University who
was not involved in the study, called the new method a "potentially
powerful" technique for filling gaps in the geologic impact record.
"It's a very valuable contribution to the tool kit of ways we have
of estimating the presence of impacts in the geologic record," Melosh
said.
Astrobiology Magazine
Thu, 10 Mar 2005 18:26 EST
Scientists have discovered why there isn't much impact-melted rock
at Meteor Crater in northern Arizona.The iron meteorite that blasted
out Meteor Crater almost 50,000 years ago was traveling much slower
than has been assumed, University of Arizona Regents' Professor H. Jay
Melosh and Gareth Collins of the Imperial College London report in the
cover article of Nature.
"Meteor Crater was the first terrestrial crater identified as a
meteorite impact scar, and it's probably the most studied impact crater
on Earth," Melosh said. "We were astonished to discover something
entirely unexpected about how it formed."
 |
| ©Jim Hurley |
| Meteor Crater, Arizona |
Previous
research supposed that the meteorite hit the surface at a velocity
between about 34,000 mph and 44,000 mph (15 km/sec and 20 km/sec).
The meteorite smashed into the Colorado Plateau 40 miles east of
where Flagstaff and 20 miles west of where Winslow have since been
built, excavating a pit 570 feet deep and 4,100 feet across enough room
for 20 football fields.
Melosh and Collins used their sophisticated mathematical models in
analyzing how the meteorite would have broken up and decelerated as it
plummeted down through the atmosphere.
About half of the original 300,000 ton, 130-foot-diameter
(40-meter-diameter) space rock would have fractured into pieces before
it hit the ground, Melosh said. The other half would have remained
intact and hit at about 26,800 mph (12 km/sec), he said.
That velocity is almost four times faster than NASA's experimental
X-43A scramjet -- the fastest aircraft flown -- and ten times faster
than a bullet fired from the highest-velocity rifle, a 0.220 Swift
cartridge rifle.
But it's too slow to have melted much of the white Coconino
formation in northern Arizona, solving a mystery that's stumped
researchers for years.
Scientists have tried to explain why there's not more melted rock at
the crater by theorizing that water in the target rocks vaporized on
impact, dispersing the melted rock into tiny droplets in the process.
Or they've theorized that carbonates in the target rock exploded,
vaporizing into carbon dioxide.
"If the consequences of atmospheric entry are properly taken into
account, there is no melt discrepancy at all," the authors wrote in Nature.
"Earth's atmosphere is an effective but selective screen that
prevents smaller meteoroids from hitting Earth's surface," Melosh said.
When a meteorite hits the atmosphere, the pressure is like hitting a
wall. Even strong iron meteorites, not just weaker stony meteorites,
are affected.
"Even though iron is very strong, the meteorite had probably been
cracked from collisions in space," Melosh said. "The weakened pieces
began to come apart and shower down from about eight-and-a-half miles
(14 km) high. And as they came apart, atmospheric drag slowed them
down, increasing the forces that crushed them so that they crumbled and
slowed more."
Melosh noted that mining engineer Daniel M. Barringer (1860-1929),
for whom Meteor Crater is named, mapped chunks of the iron space rock
weighing between a pound and a thousand pounds in a 6-mile-diameter
circle around the crater. Those treasures have long since been hauled
off and stashed in museums or private collections. But Melosh has a
copy of the obscure paper and map that Barringer presented to the
National Academy of Sciences in 1909.
At about 3 miles (5 km) altitude, most of the mass of the meteorite
was spread in a pancake shaped debris cloud roughly 650 feet (200
meters) across.
The fragments released a total 6.5 megatons of energy between 9
miles (15 km) altitude and the surface, Melosh said, most of it in an
airblast near the surface, much like the tree-flattening airblast
created by a meteorite at Tunguska, Siberia, in 1908.
The intact half of the Meteor Crater meteorite exploded with at
least 2.5 megatons of energy on impact, or the equivalent of 2.5 tons
of TNT.
Elisabetta Pierazzo and Natasha Artemieva of the Planetary Science
Institute in Tucson, Ariz., have independently modeled the Meteor
Crater impact using Artemieva's Separated Fragment model. They find
impact velocities similar to that which Melosh and Collins propose.
Melosh and Collins began analyzing the Meteor Crater impact after
running the numbers in their Web-based "impact effects" calculator, an
online program they developed for the general public. The program tells
users how an asteroid or comet collision will affect a particular
location on Earth by calculating several environmental consequences of
the impact. The program is online.
David Shiga
NewScientist
Thu, 10 Apr 2008 19:11 EDT
 |
| ©CDW/NSF |
| Most asteroid impacts on Earth have left few persistent signs, but they may still be detectable in ocean sediment records. |
Mud at the bottom of the ocean holds precious clues about asteroids that struck Earth in the past, a new study reveals.
Scientists would love to have a better record of asteroid and comet
impacts to understand how these catastrophic events have affected life
and Earth's climate. But most impactors that made it through the
atmosphere either gouged out a crater that was subsequently erased or
splashed into the ocean.
Now, scientists have developed a new tool to uncover these events,
based on concentrations of the metal osmium found in mud at the bottom
of the ocean. The technique was developed by François Paquay of the
University of Hawaii in Honolulu, US, and his colleagues.
Osmium atoms come in several varieties, or isotopes. Paquay's team
looked at two particular isotopes, one of which is slightly heavier
than the other. Crucially, the osmium in meteorites is much richer in
the lighter form than the stuff native to Earth. As a result,
scientists can determine how much of the otherworldly stuff is present
in any given deposit of the metal they find.
Paquay's team has been looking for the metal in samples of ocean
sediment obtained by drilling into the ocean floor. The sediment was
laid down in layers over time, allowing scientists to date when they
were deposited.
Multiple strikes
In 1995, members of Paquay's team pointed out high levels of the
lighter osmium isotope - associated with extraterrestrial material - in
ocean sediment laid down around the time of the impact that killed off the dinosaurs 65 million years ago.
Since then, they have found another big spike in extraterrestrial
osmium laid down at the time of another known impact event that
happened 35 million years ago. At that time, multiple impacts shook the
Earth in what is known as the Late Eocene impacts.
The team estimates that 80,000 tonnes of osmium from the object that
wiped out the dinosaurs was vaporised by the heat of the impact. It
then dissolved into seawater and eventually accumulated on the ocean
floor. The Late Eocene impacts 35 million years ago laid down an
estimated 20,000 tonnes.
Smaller impacts
Based on these amounts, the team estimates that the dinosaur-killing
object was 4.1 to 4.4 kilometres across, while the largest of the Late
Eocene impactors would have been 2.8 to 3 km across.
These are much lower than previous estimates based on the size of
the craters associated with these events. These have given impactor
size estimates of 15 to 19 km for the one that killed off the
dinosaurs, and 8 km for the larger of two impactors involved in the
Late Eocene impacts.
What accounts for the difference? For one thing, the calculations by
Paquay's team assume that 100% of the osmium from the impactors was
vaporised and dissolved into seawater. If a smaller percentage actually
ended up on the ocean floor, then the impactors could have been bigger.
Comet impacts?
But even after taking this into account, Paquay thinks the impactors
were smaller than the crater-based calculations suggest. If the
impactors were as large as these calculations imply, then 90% of the
osmium from the impactors is hiding somewhere other than in ocean
sediment. "We think that this is unlikely, but we can't rule this
possibility out without additional work," he says.
Another possibility is that the impacting objects were comets rather
than asteroids, and contained much less osmium to begin with. But
chemical traces of the impactors left behind in rocks and reported in
previous studies suggest otherwise.
Kenneth Farley of Caltech in Pasadena, US, who has studied other traces of impacts in sediment, but is not a member of Paquay's team, is impressed with the new method.
"I am hoping that this technique will allow the detection of
previously unknown impacts so we can get a better handle on impact
frequency and assess whether - and how - impacts affect life and
climate," he told New Scientist.
Unique signature
Although impacts are also known to contribute unusually large
amounts of an element called iridium to sediment, the iridium
concentrations are much harder to translate into impactor sizes, Farley
says.
Unlike osmium, extraterrestrial iridium does not have a unique
isotope signature, so is harder to distinguish from iridium native to
Earth.
And while samples show osmium is laid down evenly across the planet,
the distribution of iridium is very patchy, making it hard to draw
conclusions without a large number of samples from different parts of
the planet.
Journal reference: Science (DOI: 10.1126/science.1152860)
Comets and Asteroids - Learn more about the threat to human civilisation in our special report.
Comment: Read our Special Report series: Comets and Catastrophe
NSF
Fri, 11 Apr 2008 17:14 EDT
Scientists have developed a new way of determining the size and frequency of meteorites that have collided with Earth.
Their work shows that the size of the meteorite that likely
plummeted to Earth at the time of the Cretaceous-Tertiary (K-T)
boundary 65 million years ago was four to six kilometers in diameter.
The meteorite was the trigger, scientists believe, for the mass
extinction of dinosaurs and other life forms.
François Paquay, a geologist at the University of Hawaii at Manoa
(UHM), used variations (isotopes) of the rare element osmium in
sediments at the ocean bottom to estimate the size of these meteorites.
The results are published in this week's issue of the journal Science.
When meteorites collide with Earth, they carry a different osmium
isotope ratio than the levels normally seen throughout the oceans.
"The vaporization of meteorites carries a pulse of this rare element
into the area where they landed," says Rodey Batiza of the National
Science Foundation (NSF)'s Division of Ocean Sciences, which funded the
research along with NSF's Division of Earth Sciences. "The osmium mixes
throughout the ocean quickly. Records of these impact-induced changes
in ocean chemistry are then preserved in deep-sea sediments."
Paquay analyzed samples from two sites, Ocean Drilling Program (ODP)
site 1219 (located in the Equatorial Pacific), and ODP site 1090
(located off of the tip of South Africa) and measured osmium isotope
levels during the late Eocene period, a time during which large
meteorite impacts are known to have occurred.
"The record in marine sediments allowed us to discover how osmium changes in the ocean during and after an impact," says Paquay.
The scientists expect that this new approach to estimating impact
size will become an important complement to a more well-known method
based on iridium.
Paquay, along with co-author Gregory Ravizza of UHM and
collaborators Tarun Dalai from the Indian Institute of Technology and
Bernhard Peucker-Ehrenbrink from the Woods Hole Oceanographic
Institution, also used this method to make estimates of impact size at
the K-T boundary.
Even though these method works well for the K-T impact, it would
break down for an event larger than that: the meteorite contribution of
osmium to the oceans would overwhelm existing levels of the element,
researchers believe, making it impossible to sort out the osmium's
origin.
Under the assumption that all the osmium carried by meteorites is
dissolved in seawater, the geologists were able to use their method to
estimate the size of the K-T meteorite as four to six kilometers in
diameter.
The potential for recognizing previously unknown impacts is an important outcome of this research, the scientists say.
"We know there were two big impacts, and can now give an
interpretation of how the oceans behaved during these impacts," says
Paquay. "Now we can look at other impact events, both large and small."
The London Telegraph
Sat, 12 Apr 2008 07:54 EDT
A Bosnian man claims his home has been hit five times by meteorites.
Radivoje Lajic claims he is being targeted by aliens and has reinforced his roof in Gornja Lamovite with a steel girder.
He said: "I am obviously being targeted by aliens. I don't know
what I have done to annoy them but there is no other explanation that
makes sense.
"The chance of being hit by a meteorite is so small that getting hit five times has to be deliberate."
The chances of just one meteor hitting your house is many billions to one.
Belgrade University has confirmed that all the rocks Mr Lajic has
handed over were meteorites, but not that they all hit his house.
An investigation is under way into local magnetic fields to see if they have any influence.
The first meteorite fell on Mr Lajic's house in November and since then a further four have smashed into his home, he claims.
The strikes happen when it rains, he said.
"I don't know why they are doing this. When it rains I can't sleep for worrying about another strike."
Lisa Duchene
PsyOrg
Wed, 09 Apr 2008 14:57 EDT
In the early morning darkness on April 15, 1912, as the R.M.S.
Titanic was sinking in the freezing Atlantic, survivors witnessed a
large number of streaking lights in the sky, which many believed to be
the souls of their drowning loved ones passing to heaven.
 |
| ©Yan On-Sheung |
Says Kevin Luhman, what they most likely were seeing was the peak
of the Lyriad meteor shower, an annual event occuring in mid-to-late
April.
Though folklore of many cultures describes shooting or falling
stars as rare events, "they're hardly rare or even stars," says Luhman,
Penn State assistant professor of astronomy and astrophysics.
"From the dawn of civilization people have seen these streaks of
light that looked like stars, but were moving quickly across the sky,"
he notes. "These 'shooting stars' are actually space rocks - meteoroids
- made visible by the heat generated when they enter the Earth's
atmosphere at high speeds." These bits of ice and debris range in size
from a speck of sand to a boulder. Larger objects are called asteroids,
and smaller, planetary dust, Luhman explains.
Most meteoroids are about the size of a pebble and become visible 40
to 75 miles above the earth. The largest meteoroids, called "fireballs"
or "bolides," explode into flashes so bright they can be seen during
the day, says Luhman.
More common, though, are falling meteors too dim to see in daylight.
"Meteors are falling all the time," he adds. "There's debris all
throughout the solar system. Every minute somewhere around the Earth
there's some little piece of rock or ice that's falling from space."
A dark spot in the northern hemisphere promises the best viewing of
falling meteors, notes Luhman. The pre-dawn hours of any clear night
are the best time because, as Earth slowly spins around its axis, the
side facing into its orbit tends to encounter more space grit. "You're
better off using just the naked eye versus the telescope, which shows
just a small patch of sky," he suggests. "If you look at the entire
sky, that gives you a better chance of spotting the meteor."
The very best viewing times, when "you might see one or two meteors
per minute," says Luhman, are the eleven or so meteor showers each year
when Earth passes through a debris trail left behind by a comet - a
giant ball of ice and grit also orbiting the sun. "They are named after
the constellation in the sky out of which the meteors appear to come,"
Luhman explains, noting the Leonid and Perseid showers as the most
famous and spectacular.
The Perseids, appearing every August and named for Perseus, occur as
Earth moves through a thousand-year-old cloud of cosmic debris ejected
from the comet Swift-Tuttle, last seen in 1992, and - at six miles
across - the largest object known to make repeated passes near Earth.
Says Luhman, it would have been hard to miss the falling lights of
the 1833 Leonid meteor storm, which were so bright and fell so fast,
about 100,000 in an hour, that many feared the end of the world. The
storm, widely regarded as the birth of modern meteor astronomy, marked
the discovery of the Leonids, visible every November 17 and caused by
debris from the comet Tempel-Tuttle.
While meteors are now well-understood, meteorites - fragments of
meteoroids and asteroids that survive both the passage through our
atmosphere and the ground impact - are helping scientists to learn of
the solar system's origins, says Luhman. "These rocks are basically
leftovers or raw ingredients from when the solar system was born 4.5
billion years ago."
Some meteorites even tell us about planets. "If a comet or asteroid
hits Mars, it can throw some of the pieces of the crust into space and,
after millions of years, some of that material falls down to Earth's
surface," says Luhman.
One of 34 Martian meteorites reached fame in 1996 when NASA
scientists announced it showed signs of primitive life from more than
3.6 billion years ago. Closer study explained the formation as a
geologic effect, all but ending the scientific controversy, explains
Luhman.
Yet, shooting stars have hardly fallen out of our everyday
conversations. Our movies, songs and poetry still speak highly of the
bright lights as a magical sight, worthy of wishes. As the Disney
company's theme song has taught generations of children, "When you wish
upon a star, your dreams come true."
Helen Altonn
Star Bulletin
Sat, 12 Apr 2008 23:10 EDT
The asteroid impact believed to have wiped out dinosaurs 65 million
years ago was only about half the gigantic size previously estimated, a
University of Hawaii doctoral student has found.
Francois Paquay, in the department of geology and geophysics,
developed a method using osmium isotopes in deep-ocean sediments to
determine sizes of chondritic meteorites that have collided with Earth.
By his calculations, the asteroid believed to be behind the
Chicxulub Crater under Mexico's Yucatan Peninsula - and the dinosaurs'
extinction - was about 2.5 to 3.7 miles in diameter. It has been
estimated from 9.3 to 12 miles in size from crater simulations.
Many other species also disappeared after that impact, although
global warming and other theories have also been advanced as the cause.
Paquay's research with his adviser Gregory Ravizza was reported in
yesterday's issue of the journal Science. Collaborators were Tarun
Dalai of the Indian Institute of Technology and Bernhard
Peucker-Ehrenbrink of Woods Hole Oceanographic Institute.
Paquay explained in an interview that changes in levels of the
element osmium are well preserved in deep-sea sediments. "What makes it
interesting, osmium is very low concentration in sea water but very
high concentration in a meteorite.
"When it hits the surface, everything is vaporized and everything in
the vapor rains down on the land and in the ocean. It changes the
chemistry of the water," which is preserved in deep-sea sediments, he
said.
"Based on measurements you make in sediments, you can estimate how
much osmium was dissolved in the sea water and from the impact."
The osmium level spiked during the impact events studied, then
dipped, he said. "Based on this, you know using simple math what was
the size of the impactor."
Ravizza said the old method of estimating impact size with the
element iridium was labor intensive, requiring data from many different
sites.
Paquay's approach takes advantage of changes in the ocean's chemical
composition preserved in the ocean floor, he said. "It is a chemical
fingerprint of the impact."
Iridium data also can be affected by a lot of processes, but osmium
concentrations are nearly the same throughout the ocean, Ravizza said.
The team analyzed more than 130 samples from two Ocean Drilling
Program sites in the equatorial Pacific and off the tip of South
Africa. They studied two geologic time periods with well-dated impact
events and studied the sediments during and after the impacts, Paquay
said.
"These events are fascinating to me because of their magnitude,"
Ravizza said. "They represent huge explosions. ... Yet, in spite of
that, what surprises people is the (Chicxulub) event was associated
with mass extinction."
The impactor sizes estimated with osmium data were lower than those based on crater simulations.
But they were minimum estimates based on an assumption that all
osmium carried by a meteorite is dissolved in the ocean, Ravizza said,
suggesting "perhaps some of it stayed on land. That's why we think the
estimates are slightly lower than the iridium estimates."
"One of the cool things about this (osmium method)," he said, "is we
can go to just one or two sites in the world because osmium is very
well mixed in the ocean, where we need multiple sites to determine the
size of the impactor using iridium."
He said his technique "gives you more confidence in the data set."
It can be used now to identify unrecognized asteroid or comet impacts,
even those as small as about 1 mile in diameter, he said.
Elise Kleeman
New Scientist
Mon, 14 Apr 2008 16:27 EDT
Even though Japan's problem-plagued Hayabusa
spacecraft is now on its return trip to Earth, it might never complete
the journey. A catastrophic failure of its last remaining reaction
wheel, which helps point the craft, might prevent it from reaching the
Earth to drop a capsule into the atmosphere, mission members say.
Hayabusa was meant to collect samples from the asteroid Itokawa by
firing pellets into the surface of the 535-metre-long rock and scooping
up the resulting debris. But data from two landings in November 2005
suggest the pellets never fired because the craft's onboard computer sent conflicting signals to its collection instruments.
Still, mission officials hoped to bring the spacecraft back to Earth
in case some asteroid dust had slipped into its collection chamber by
chance. If it completes the trip, it is expected to drop a capsule in
the Australian outback in June 2010.
But Hayabusa's project manager, Jun'ichiro Kawaguchi, told New Scientist
that if any other systems break down, it could be fatal to the mission.
He is particularly concerned about the spacecraft's last remaining
reaction wheel. "We are eager to make it return with our best efforts,
but the situation is not optimistic," he says.
Weak thrusters
Mission managers are now pointing Hayabusa using jets of xenon gas
from the craft's ion propulsion system. The relatively weak thrusters,
which use electric fields to accelerate a beam of xenon ions, were
originally designed only to propel the craft forwards on its
2-billion-kilometre round trip to Itokawa.
Without the ability to aim the spacecraft, mission engineers could
not maintain communication with Hayabusa or keep it on the right
trajectory to return to Earth. The team lost contact once before, in
late 2005, and regained it only three months later. A glitch this time
would probably be permanent.
Despite these worries, mission planners could still pull off a safe
landing, according to Hayabusa team member Don Yeomans of NASA's Jet
Propulsion Laboratory in Pasadena, California, US. "I wouldn't bet
against them - they're doing pretty well," he says.
Indeed, the team from the Japanese Aerospace Exploration Agency has
managed to keep Hayabusa flying despite a long list of
near-catastrophic failures, including the leaks of critical fuel and a
temporary loss of contact with the spacecraft that caused its return to
Earth to be delayed by three years.
Plucky spacecraft
"Yeah, the spacecraft is hurting," Yeomans says. "It's a credit to
the Japanese that they've had some work-arounds. It's the little
spacecraft that could."
During the mission, engineers also suffered the disappearance of the
miniature robot Minerva, which was supposed to hop across the surface
of asteroid surface but instead was accidentally released to drift off into space.
Despite these setbacks, Hayabusa was successful in returning
"stunning images" of Itokawa, Yeomans says. The pictures and other data
collected by the craft revealed an unexpectedly crater-free surface and loosely compacted body.
"It seems to be what we call a rubble pile, an object that was
blasted apart and is held together by not much more than its own
gravity," he says.
"Mostly we're just marking time until the sample capsule gets back," Yeomans adds. "Hopefully the sample will get back."
Clara Moskowitz
Space.com
Mon, 14 Apr 2008 17:49 EDT
When a meteorite struck Earth before humans
were around to watch, did it still make a "splat?" Although it's too
late to witness the many pummelings our planet has already seen,
scientists are still finding the humongous holes left here by long ago
impacting space rocks.
At last count, there were more than 170 known impact craters
on our planet, according to the Earth Impact Database maintained by the
University of New Brunswick in Canada. These puncture wounds are
littered over every continent, as well as the seafloor.
There would be countless more if it weren't for Earth's constant
remodeling. Plates shift, mountains form, volcanoes erupt and erosion
washes over the planet's surface, continually hiding the evidence of
most craters.
"If there was no erosion or tectonic activity, we would look like the moon," said Lucy Thompson, a geologist at the University of New Brunswick. "The moon is just pockmarked with impact craters."
Puzzling differences
Scientists think the Earth was bombarded more heavily earlier in the
solar system's history, when planets were still forming and bushels of
debris were flying madly around. Luckily for us, things have quieted
down lately and meteorite impacts are few and far between.
One of Earth's most recently-formed holes is Arizona's Barringer
Meteor Crater, created around 50,000 years ago. Though this crater, one
of the most famous, awes tourists with its roughly three-quarters of a
mile (1.2 km) diameter, it is considered quite dinky on the geological
scale.
"That's a nice, simple bowl-shaped crater," Thompson said.
Geologists get really excited about complex craters, such as
Manicouagan in Quebec, Canada. Scientists estimate this crater is more
than a hundred times wider than Barringer, and was made more than 200
million years ago.
"With large impacts, you have complex craters forming, and instead
of having a nice bowl shape, you get a central uplift," Thompson told
SPACE.com. "It's like if you drop something in water, you get rings
forming, but the middle comes back up."
Scientists want to understand how the rock achieves this without actually becoming liquid or shattering into pieces.
Big and bad
A major heavyweight is South Africa's Vredefort crater, which at 186 miles (300 km) wide, is said to be Earth's largest verified impact crater. At more than 2 billion years old, it is also one of the most ancient.
Other contenders are the 155 mile-wide (250 km-wide) Sudbury Basin
in Ontario, Canada, and the roughly 110 mile-wide (180 km-wide)
Chicxulub crater, half submerged off the coast of the Yucatán Peninsula
in Mexico.
The latter can claim fame as the landing spot of the asteroid that purportedly killed the dinosaurs, along with most life on Earth.
If it weren't for erosion and other geological processes that erase
evidence of craters, there would likely be hundreds of thousands of
impact craters on the Earth, Thompson said. Scientists are still
discovering new craters, especially in remote areas and on the seafloor where evidence of them is easily missed.
* Gallery: Earth's Meteor Craters
* Video: Newsreel - The Tunguska Expedition
* Top 10 Ways to Destroy Earth
Yorke Peninsula Country Times
Tue, 15 Apr 2008 17:43 EDT
Did you get a bang out of life last Wednesday?
YPCT is investigating the source of a massive,
window-rattling boom that had residents from Moonta to Kadina to
Cunliffe scurrying outside in search of a cause last Wednesday evening
at around 5.30 pm.
The mystery deepened on Thursday with Kadina police saying not only
were there no reports of any damage but no one had called to report the
incident.
In the past, blasts from the army's El Alamein range across the gulf
on Eyre Peninsula have been audible on NYP with the right weather but
an Army spokesperson told YPCT there was no testing going on that day.
The idea of a sonic boom doesn't fly either, with a spokesperson
from Edinburgh airbase saying it would be highly unusual for their
craft to have that sort of impact and, after checking their records, he
confirmed there were no jets in the sky that evening.
YPCT is seeking information from Primary Industries to establish if the boom came from a mine explosion, possibly near Wallaroo.
Comment: Or possibly a meteorite exploding overhead?
Fox News
Tue, 15 Apr 2008 22:40 EDT
When a meteorite struck Earth before humans were around to watch, did it still make a "splat?"
Although it's too late to witness the many pummelings our planet has
already seen, scientists are still finding the humongous holes left
here long ago by impacting space rocks.
Comment: Just give it a few more years....
At last count, there were more than 170 known impact craters on our
planet, according to the Earth Impact Database maintained by the
University of New Brunswick in Canada.
These puncture wounds are littered over every continent, as well as the seafloor.
There would be countless more if it weren't for Earth's constant remodeling.
Plates shift, mountains form, volcanoes erupt and erosion washes
over the planet's surface, continually hiding the evidence of most
craters.
"If there was no erosion or tectonic activity, we would look like
the moon," said Lucy Thompson, a geologist at the University of New
Brunswick. "The moon is just pockmarked with impact craters."
Puzzling differences
Scientists think the Earth was bombarded more heavily earlier in the
solar system's history, when planets were still forming and bushels of
debris were flying madly around. Luckily for us, things have quieted down lately, and meteorite impacts are few and far between.
One of Earth's most recently-formed holes is Arizona's Barringer Meteor Crater, created around 50,000 years ago.
Though this crater, one of the most famous, awes tourists with its
roughly three-quarters of a mile (1.2 km) diameter, it is considered
quite dinky on the geological scale.
"That's a nice, simple bowl-shaped crater," Thompson said.
Geologists get really excited about complex craters, such as Manicouagan Crater in Quebec, Canada.
Scientists estimate this crater is more than a thousand times wider
than Barringer, and was made more than 200 million years ago.
"With large impacts, you have complex craters forming, and instead
of having a nice bowl shape, you get a central uplift," Thompson told
SPACE.com. "It's like if you drop something in water, you get rings
forming, but the middle comes back up."
Scientists want to understand how the rock achieves this without actually becoming liquid or shattering into pieces.
Big and bad
A major heavyweight is South Africa's Vredefort crater, which at 186
miles (300 km) wide, is said to be Earth's largest verified impact
crater. At more than 2 billion years old, it is also one of the most
ancient.
Other contenders are the 155 mile-wide (250 km-wide) Sudbury Basin
in Ontario, Canada, and the roughly 110 mile-wide (180 km-wide)
Chicxulub crater, half submerged off the coast of the Yucatán Peninsula
in Mexico.
The latter can claim fame as the landing spot of the asteroid that
purportedly killed the dinosaurs, along with most life on Earth.
If it weren't for erosion and other geological processes that erase
evidence of craters, there would likely be hundreds of thousands of
impact craters on the Earth, Thompson said.
Scientists are still discovering new craters, especially in remote
areas and on the seafloor where evidence of them is easily missed.
Comment: Well,
when Fox News starts reporting on impact craters, you just gotta
wonder. Are things getting a little too obvious, what with the regular fireballs being seen in the skies in recent months?
Paul Heumphreus
St. Charles Journal
Tue, 15 Apr 2008 13:52 EDT
Look! Up in the sky! It's a bird. It's a plane. It's ... a paper glider?
Cygnus, the swan, has flown solo in the Milky Way for eons, but soon
he'll be joined by a gaggle of companions. The Japanese team on the
International Space Station will release a constellation of high-flying
paper airplanes to research reentry without traditional spacecraft.
These celestial origami will soar at 17,000 miles per hour when they
hit the atmosphere. This is scorching along faster than a speeding
bullet - by a factor of 20 times a .22 caliber rifle round. At such a
speed air would turn a man of steel into glowing vapor, creating a
streaking flash across the sky; however, these super-gliders are
treated to withstand extreme heat, while quickly bleeding off speed
before piercing through denser atmosphere that would cook their goose
in an instant. Once fully immersed in air, they'll migrate leisurely
down to earth, silently searching for an unsuspecting teacher's
chalkboard to strike.
Chicken Little wasn't kidding when she called, "The sky is falling!"
Earlier this year, a satellite spiraling back to earth was about to
become a shooting star. Shooting satellites seemed like a good strategy
to prevent a land strike, and the Navy scored a direct hit that
disintegrated US 193 into pieces that were vaporized as a harmless
meteor shower.
Annihilation of Skylab wasn't possible when it fell in 1979, and
huge chunks of searing metal more powerful than a locomotive smashed
into the outback of Australia. One Australian municipality even fined
the United States $400 for littering.
Russia's MIR space station was equally spectacular when it augured
in near Fiji seven years ago. (HAL's quote in "2001: A Space Odyssey"
seemed ironically prophetic: "This sort of thing has cropped up before
and it has always been due to human error.")
These events drew stellar media coverage, unlike thousands of other scraps that fall from space every year.
There are 4 million pounds of clutter circling the globe, and far
more will be left up there in the future. This debris includes spent
boosters, missing gloves, slippery tools, defunct satellites,
port-a-potty packages and other miscellaneous flotsam. Some 18,000
items are tracked, with roughly a third of those particles being
residual riffraff from the Chinese demolition of a satellite last year.
The shrapnel from that test will threaten space systems within 2000
miles of earth for about 40 years.
US 193's destruction also briefly increased the number of fragments,
though nearly all of it fell from the heavens in forty days and forty
nights. At orbital velocities, tiny objects pack a massive wallop. A
marble-sized aluminum ball striking a satellite at 33,000 feet per
second would have the same impact as a 60-pound safe traveling 60 mph.
The craters on the moon are visible testament to how powerful cosmic
billiards are in our galaxy. Fortunately, Jupiter is a vacuum cleaner
with intense gravity that absorbs most extraterrestrial clutter before
it reaches the terrestrial planets. Jupiter showcased this superhuman
strength in 1994 by crushing Comet Shoemaker-Levy 9 and swallowing the
crumbs like a handful of chocolate chips.
Meteor Crater in Arizona is a 50 millennia-old monument proving that
Earth still gets clobbered now and then. (I also got clobbered in
Meteor Crater for teasing my sister, but that's another story). This
crater is a meager divot when compared to a cataclysmic event 65
million years ago that obliterated the dinosaurs and opened the door
for mammals to inherit the earth.
Meteor visits are not just ancient history. A mere century ago, the
Tunguska meteor blew up about five miles above Siberia, blasting away
80 million trees in an 800-square-mile region with the force of a
10-megaton warhead. As destructive as this event was, Mother Earth was
prepared with her shields up: the airbag surrounding our planet blunted
this meteor's force, preventing world-wide devastation.
We won't always be so fortunate. Somewhere in the Oort Cloud is a
huge chunk of rocky ice slowly tumbling toward our sun. Gravity from
the Jovian planets will twist this meteoroid, fracturing it into many
smaller pieces. The gas giants will capture some rubble, but some
fragments will continue the descent toward the center of our solar
system.
Most fragments will harmlessly glide by Earth and continue
on their journey, but history shows it is only a matter of time until
one finds Earth so attractive that it will just have to drop in. This
alien visitor won't listen to our shouts of terror. In space, no one
can hear you scream.
Fortunately, a major event like this is unlikely to happen within
our lifetime, so there's no need to borrow Chicken Little's umbrella.
If, however, you happen to see a paper airplane fluttering to the
ground and can't read the Haiku instructions, please take it to your
nearest mild-mannered reporter at the Daily Planet.
Paul Heumphreus is an electronics engineer who resides near St.
Peters. He is one of 18 Opinion Shaper columnists for the Suburban
Journals of St. Charles County. Opinion Shapers are chosen annually to
write five columns on topics of interest to them.
Comment:
Fortunately, a major event like this is unlikely to happen within
our lifetime, so there's no need to borrow Chicken Little's umbrella.
A "swarm" of evidence show that this statement could not be further from the truth.
AFP
physorg
Wed, 16 Apr 2008 09:26 EDT
A 13-year-old German schoolboy corrected NASA's estimates on the
chances of an asteroid colliding with Earth, a German newspaper
reported Tuesday, after spotting the boffins had miscalculated.
Nico Marquardt used telescopic findings from the Institute of
Astrophysics in Potsdam (AIP) to calculate that there was a 1 in 450
chance that the Apophis asteroid will collide with Earth, the Potsdamer
Neuerster Nachrichten reported.
NASA had previously estimated the chances at only 1 in 45,000 but
told its sister organisation, the European Space Agency (ESA), that the
young whizzkid had got it right.
Comment: In a couple of days the probability of a collision with Apophis was multiplied by 100.
Keeping in mind that Apophis is one of the numerous identified
asteroids and that the number of unidentified asteroids is even higher.
The schoolboy took into consideration the risk of Apophis running
into one or more of the 40,000 satellites orbiting Earth during its
path close to the planet on April 13 2029.
Those satellites travel at 3.07 kilometres a second (1.9 miles), at
up to 35,880 kilometres above earth -- and the Apophis asteroid will
pass by earth at a distance of 32,500 kilometres.
Both NASA and Marquardt agree that if the asteroid does collide with
earth, it will create a ball of iron and iridium 320 metres (1049 feet)
wide and weighing 200 billion tonnes, which will crash into the
Atlantic Ocean.
The shock waves from that would create huge tsunami waves,
destroying both coastlines and inland areas, whilst creating a thick
cloud of dust that would darken the skies indefinitely.
The 13-year old made his discovery as part of a regional science
competition for which he submitted a project entitled: "Apophis - The
Killer Asteroid."
Comment: If Nasa makes such obvious mistake as far
as an asteroid's impact is concerned we can wonder if this mistake is
deliberate or not.
Of course a major difference between NASA and a 13 years old
schoolboy is that the latter is not funded/controlled by the government.
Norine Albers
Lake Sun
Wed, 16 Apr 2008 12:36 EDT
The meteor crater deposits in the Decaturville area were once the center of attention for many Camden County residents.
The village of Decaturville, situated south of Camdenton on Route 5,
was founded in 1854 when James (John) Farmer opened his general store
and residence in a log building.
Eventually, there would be a blacksmith shop, drug store, barber, a grist mill and a doctor.
Decaturville's post office was opened in 1860. It closed in 1960. A
Methodist (now Baptist) church was built in 1895 and the Woodman Hall
was built nearby in 1899 by local Decaturville men.
The meteor crater deposits in the Decaturville area were once the center of attention for many Camden County residents.
Several years ago, tucked away in a far corner of the Camden County
Museum, the original narrative of the 1961 radio broadcast by native
Camden County citizen, H.B. Hart was discovered.
What follows here is the promotional flyer advertising the
broadcast. 'HEAR IT, HEAR IT, December 31, 1961, K.R.M.S., Sunday,
December 31st, 12:30 P.M., Dial 1150. The secret of a great discovery
to be revealed for the first time over K.R.M.S. A New Year's gift to
our Ozarks, millions may be spent, several plants to go up.
'It took seven years hard work and over $300,000 spent before this
discovery was made. A discovery which may prove the one important
factor to our nation's survival against the Communists. Businessmen,
teachers, ministers, all professions, certainly should hear this
message.
'You will be amazed. Something new to think about, read about, part
of which will not be found in any of our libraries. Camden and Laclede
counties have made new history for our North American continent.
The radio show was quite lengthy and included song recordings
throughout the narrative. The narrative in its entirety is available at
the Camden County Museum.
The following is a part of the narrative from the 1961 radio show by Mr. Hart:
'I personally entered into this search in January 1926.
'From outer space there came a great nickel-iron meteor traveling at
least 40 miles per second from the northeast to southwest at an angle
of near 45 degrees. This large meteor with its terrific speed and
tremendous impact struck what was formerly known as the Wheeler
property.
'We estimate the size of the meteor at possibly 400 feet in diameter
and its weight at more than 5 million tons. It struck with such force
that the impact was driven into the earth probably 6,000 to 7,000 feet
deep and then a terrific explosion resulted. The surface of the earth
at the time of the impact must have been 1,500 feet higher than it is
today.
'The force produced by this explosion was many times greater than
that of our atomic bombs today. The earth was first driven down several
thousand feet and then blown out.
'A crater was formed, the rim 2,000 feet in diameter, and a hole was
left inside 1,000 feet deep or more the rock layers even in the granite
were lifted up and curled back as though they were small pieces of tin.
The diameter of the outer shock wave rim is 8,520 feet. The diameter of the brecciaed powdered core inside is about 1,000 feet.
'The diameter of the disturbed broken area is 20,460 feet in an
almost perfect circle. Approximately, 3 1/2 miles across. Some of the
scientists seemed to think this mass may go to 6,000 feet depth.
'The terrific impact, the extreme heat, and explosion of the
Decaturville meteor may have formed and made other high pressure
minerals. We have found a quantity of large sheets of silica glass and
some sponge glass. We have here at Decaturville one mineral that
requires 3,500 degrees centigrade to boil and it takes 1,710 degrees
centigrade to melt. This is the highest melting point of any mineral
found to date.
'The discovery of the meteor crater at Decaturville should bring to
central Missouri a tremendous lot of business. This is my closing
statement. I want it definitely understood regardless of how much
wealth me and my family may realize from this great find at least 75
percent of this wealth will be immediately put into use for my many
hundreds of friends and my people. It will go for churches, services,
to educate children, the orphanages, hospitals, and to aid the sick and
inform.'
The mineral deposits were not plentiful enough to make the business venture worthwhile.
The crater rim is still visible. Even though the historical evidence
has almost vanished from the village of Decaturville, the importance of
its heritage lives on.
Gary Emerling
The Washington Times
Wed, 16 Apr 2008 15:12 EDT
A nuclear device detonated near the White
House would kill roughly 100,000 people and flatten downtown federal
buildings, while the radioactive plume from the explosion would likely
spread toward the Capitol and into Southeast D.C., contaminating
thousands more.
The blast from the 10-kiloton bomb - similar to the bomb dropped
over Hiroshima during World War II - would kill up to one in 10
tourists visiting the Washington Monument and send shards of glass
flying the length of the National Mall, in a scenario that has become
increasingly likely to occur in a major U.S. city in recent years,
panel members told a Senate committee yesterday.
"It's inevitable," said Cham E. Dallas, director of the
Institute for Health Management and Mass Destruction Defense at the
University of Georgia, who has charted the potential explosion's effect
in the District and testified before a hearing of the Senate Committee
on Homeland Security and Governmental Affairs. "I think it's wistful to
think that it won't happen by 20 years."
The Senate committee has convened a series of hearings to examine
the threat and effects of a terrorist nuclear attack on a U.S. city, as
well as the needed response.
 |
| ©Universty of Georgia |
Yesterday's panel stressed the importance of state and local
cooperation with federal authorities in the wake of an attack,
assistance from the private business sector to aid recovery and the
dire need to boost the capabilities of area hospitals.
They recommended expanding emergency personnel by training
physicians like pharmacists and dentists to aid in all-hazards care,
monitoring the exposure of first responders to radiation and clearly
disseminating information to the public.
"The scenarios we discuss today are very hard for us to contemplate,
and so emotionally traumatic and unsettling that it is tempting to push
them aside," said Sen. Joe Lieberman, Connecticut independent and
committee chairman. "However, now is the time to have this difficult
conversation, to ask the tough questions, and then to get answers as
best we can and take preparatory and preventive action."
Ashton B. Carter, co-director of the Preventive Defense Project at
Harvard University, said the likelihood of a nuclear attack on U.S.
soil is undetermined, but it has increased with the proliferation of
weapons by Iran and North Korea and the failure to secure Russia's
nuclear arsenal following the Cold War.
"For while the probability of a nuclear weapon one day going
off in a U.S. city cannot be calculated, it is almost surely larger
than it was five years ago," Mr. Carter said.
Mr. Carter described a more destructive blast effect. He said the
ground-based detonation of a 10-kiloton bomb would result in near-total
devastation within a circle about two miles in diameter, or the length
of the Mall.
The zone of destruction is projected to be less than that of
Hiroshima, where the bomb was dropped from an airplane and detonated
above the city.
A similar blast in a more densely populated city than the District,
such as Chicago or New York, would result in an injury toll up to eight
times higher. A plume a few miles long could also dole out lethal doses
of radiation, Mr. Carter said.
However, the experts emphasized that the explosion would not impact
most of a major city and that in many cases, residents could remain
safe by not evacuating immediately and clogging area roadways.
"It is also expected that, due to lack of information getting to the
public, many people will try to flee by car or on foot, often in the
wrong direction, again exposing themselves to high levels of radiation,
as vehicles provide virtually no protection," Mr. Carter said.
Mr. Dallas said a major problem facing most cities is a lack of
available hospital beds for victims of burns that would result from a
nuclear blast. He said up to 95 percent of such victims would not
receive potentially life-saving care.
"We're completely underprepared," he said. "Most of them will die."
Mr. Dallas said the District also faces a unique challenge because
of the way the city is configured geographically: A wind blowing west
to east would gradually spread radiation from the explosion into the
low-income neighborhoods of Southeast, where there are limited health
care options available and only one hospital.
Area officials have spent millions of dollars in recent years to
develop evacuation plans and stockpile emergency supplies after a 2006
study by the U.S. Department of Homeland Security said local
preparation for a disaster was "not sufficient."
Darrell L. Darnell, director of the District's Homeland Security and
Emergency Management Agency, said the city is continuing to develop its
"emergency preparedness capabilities" and has numerous methods of
informing residents of actions they should take, including through text
messages, voice alerts and Web sites like District of Columbia and Emergency Information Center.
"We are confident that the District is prepared to respond to a catastrophic incident affecting the District," Mr. Darnell said.
Still, Mr. Dallas said the majority of victims in a nuclear
explosion will likely have to fend for themselves in the first hours
after an attack.
"These people are going to be on their own," he said after the hearing. "There's no white horse to ride to the rescue."
Comment: Interesting. Perhaps panel members are aware that something wicked this way comes- something that can be interpretated as a nuclear detonation or disguised as a terror attack?
Consider the following information: From Comet Biela and Mrs. O'Leary's Cow.
Excerpt from a paper written by Robert L. Park of The American
Physical Society, Lori B. Garver of the National Space Society and
Terry Dawson, a staffer for the House Committee on Science, Technology,
and Space.
"The challenge of science is to identify objects that threaten Earth
and work out the timetables for their arrival. Here the challenge is
straightforward and technical. [...]
The emphasis has properly been on impacts that would be expected to have global consequences. Even
for objects too small to produce more than local effects, however, it
has been pointed out that an impact might be misidentified as a nuclear
explosion. Misidentification would be most likely among
nations that have recently joined the ranks of "nuclear powers" and
would therefore be expected to have less sophisticated means of
verification.
It is more than a hypothetical concern. We recall that the 1978
South Indian Ocean anomaly, detected by a Vela satellite, was suspected
at the time of being a South African-Israeli nuclear test.
Scientific American
Wed, 16 Apr 2008 05:38 EDT
Late yesterday, it seemed that a calculation in a report that a
German boy submitted to a science fair was about to shame the
processing power of the mighty NASA. But, alas, a new article in London's Guardian says the kid has potential, but, in this case, was, well, wrong.
At issue: the asteroid Apophis, which could be on a collision course with Earth. In 2004, NASA estimated
that the relatively close, 690 to 1080-foot (210-330 meter) diameter
object had a 2.7 percent chance of striking our planet on April 13,
2029. Subsequent data from the Arecibo planetary radar telescope shed
more light on the asteroid's trajectory and trimmed the odds of a crash
on that date to zip but to "miniscule" on April 13, 2036. How
miniscule? One in 45,000, according to NASA.
But the German newspaper Potsdamer Neuerster Nachrichten
reported yesterday that 13-year-old Nico Marquardt had used findings
from a telescope at the Institute of Astrophysics in Potsdam to
determine that NASA was way off - and that it was actually 100 times
more likely than the space agency had predicted that Apophis would slam
into Earth. (Here is a story from a different German newspaper called Der Tagesspiegel.)
His reason: NASA scientists had not taken into account the
possibility that when the asteroid approached Earth in 2029, it could
strike one of 40,000 artificial satellites currently orbiting Earth.
That collision could change the trajectory of Apophis, giving it a much
better shot of hitting Earth seven years later if it were knocked off
course enough to go through a roughly 2,000-ft (600 m) region of space
known as a keyhole, where Earth's gravity would set it on a collision
path.
The newspaper reported that Marquardt's calculations had been accepted by both NASA and the European Space Agency (ESA), but both deny they signed off.
"This student's conclusion reportedly is based on the possibility of
a collision with an artificial satellite during the asteroid's close
approach in April 2029. However, the asteroid will not pass near the
main belt of geosynchronous satellites in 2029, and the chance of a
collision with a satellite is exceedingly remote," NASA said in a
statement released today. "Therefore, consideration of this satellite
collision scenario does not affect the current impact probability
estimate for Apophis, which remains at 1 in 45,000." The ESA concurred, confirming to the London Register that the boy erred.
Nice try, kid.
Daniel Fischer
Cosmic Mirror
Wed, 16 Apr 2008 10:05 EDT
First the story appeared on April 4 in Germany's 'leading' tabloid ("I have calculated the end of the world ... and NASA says, I'm right"), later in more serious papers ("Nico and the end of the world") - and today, thanks apparently to an AFP story where the writer hadn't found it necessary to check anything, it has taken off around the world.
Alas: it's absolute nonsense! The claim is that a 13-year old German
schoolboy "discovered" - while working on an entry for a major German science competition - that the 2036 impact probability of asteroid Apophis
is not 1:45,000 as the NASA calculation says but actually 100 times
higher. Because during the 2029 approach the asteroid would hit a
geostationary satellite and be deflected into a much more dangerous
orbit. The newspapers also claimed that this boy not only was awarded
several prizes for his paper but that NASA had "conceded" that he got
it right and they were wrong. We're all doomed, right?
Well, here's what NASA's NEO guru Don Yeomans
told this blog yesterday: "We have not corresponded with this young man
and this story is absurd, a hoax or both. During its 2029 Earth close
approach, Apophis will approach the Earth to about 38,900 km, well
inside the geosynchronous distance at 42,240 km. However, the asteroid
will cross the equatorial belt at a distance of 51,000 km - well
outside the geosynchronous distance. Since the uncertainty on Apophis'
position during the Earth close approach is about 1500 km, Apophis
cannot approach an Earth satellite. Apophis will not cross the moon's
orbital plane at the Moon's orbital distance so it cannot approach the
moon either."
And here's how one of the German scientists mentioned in the first story, celestial dynamics expert Frank Spahn
from Potsdam University, explained events to this blog today: "I indeed
had contact with this engaged boy - he asked me which
perturbations/forces determine Apophis' orbit and especially during the
close flybys. You know that I deal with kinetic theory & celestial
mech. in the context of planetary rings, preplanetary disks etc. I
explained him the 3 and 4 body problem and gravitational interactions
in general. He did not tell me about his idea to consider a collision.
This was in January or February. The next time when I heard of him was
in in the boulevard journaillie "Bild" - together with my name.
I asked him to meet me (last Friday), he told me about the asteroid
- satellite collision thing (after I asked him how he calculated and
"corrected" the NASA result). Then I showed him at the black board
about the extremely small collision probability (frequency) with such
an object. Seeing the arising problems I attended the set of [German TV
news station] N24 and explained the leading responsible person that I
appreciate the engagement of that young student but simultaneously I
express that one has to mention the low probability of such a collision
plus expressing that this is not a correction to NASA. The filming
session went on and I had to leave for another meeting. The I saw
yesterday that nonsens in TV
- and I am shocked. By the way - I haven't seen that paper and the work
sofar, Nico told me that his computer disk had a virus so that only
hard copies are available which are with the referees of the contest at
the moment. So - I do not know how he could have won the competition,
obviously the referees were no experts."
Nor were the writers for the German newspapers or AFP - none of
which bothered to ask NASA directly or just consult the impact risk
page for Apophis. This is clearly the most used and abused Near Earth
Asteroid in many years: Still called 2004 MN4 it briefly reached a
record high impact probability for 2029 in late 2004 which quickly evaporated (as always in these cases - so far) when radar data nailed down its orbit
in early 2005. And in the following months the remaining impact
probability for 2036 also continued to dwindle, to the present 1 in
45,000: You can follow the real science - and the triumph of radar
astrometry - on this dedicated NASA website. Which certain Jugend Forscht judges and journalists should have consulted, too ...
Lee Billings
Seed Magazine
Wed, 16 Apr 2008 11:38 EDT
Until very recently, the devastating 1908 explosion of a space rock
over the isolated Tunguska region of Siberia was thought to be a
once-in-a-millennium event. Based on comparisons to nuclear weapon
blast effects, many experts estimated the Tunguska object to be 50 to
100 meters. But new simulations by Mark Boslough at Sandia National
Laboratories suggest the Tunguska object was much smaller than
previously believed. And since smaller near-Earth objects (NEOs) are
more common than larger ones, the implication is that the gap between
such impacts may be centuries rather than millennia.
 |
| ©LSST Corporation |
| A proposed design of the LSS Telescope, which will provide panoramic coverage of the sky and help detect near-Earth objects. |
"Chances are we're not going to discover one of these before it
hits," Boslough says, pointing out that the vast number of small NEOs
far outweighs the capabilities of the few surveys currently seeking
them. "The good news is most of the Earth is either sparsely populated
or uninhabited, so the probability a city or populated area will be hit
is small. The big ones, 1 kilometer or larger, are the ones we should
worry about."
While space agencies, governments, and individuals worldwide work to
develop new means to detect, and eventually prevent, an NEO disaster,
the US government - though it provides the global majority of NEO
research funding - is mostly paying lip-service to a risk that could
threaten the survival of civilization. In 2005, the US Congress built
off mandates from the 1990s, directing NASA to catalog 90 percent of
potentially hazardous NEOs greater than 140 meters in diameter by the
year 2020. Congress also asked NASA to study ways to deflect
threatening NEOs. But burdened with completing the International Space
Station and replacing the Space Shuttle fleet, NASA has yet to allot
funds to the project. Stagnant science budgets also threaten the
Arecibo radio telescope in Puerto Rico, the top facility for studying
NEOs. Citing budgetary limitations, NSF announced last year it will
defund Arecibo's operation after 2010.
"Most Americans have faith that the federal government is doing
what's necessary to protect us against threats that could destroy our
country or leave large numbers of Americans dead," says US
Representative Dana Rohrabacher, who introduced legislation last
December calling for NASA to devote more resources to NEO research.
"The fact that we haven't even formulated what our reaction would be to
a potential threat from space is disturbing, considering the magnitude
of the risk involved. You'd think there would be a plan ready, but
there isn't."
Increasingly, coordinated private efforts are working to fill the
gap in Earth's NEO defenses. Motivated in part by the upcoming US
presidential election, leading space scientists recently attended an
invite-only workshop at Stanford University to discuss shifting NASA's
priorities away from a return to the Moon and toward manned missions to
NEOs. And the B612 Foundation, a group co-founded by Apollo astronaut
Rusty Schweickart, is gathering funds to test deflection strategies on
an NEO by 2015. Earlier this year, Microsoft alumni Bill Gates and
Charles Simonyi donated a combined $30 million to the Large Synoptic
Survey Telescope (LSST), keeping it on track for first light in 2014.
One of LSST's chief missions is to detect and catalog NEOs. As for
Arecibo, Jim Cordes, a Cornell astronomer who frequently works at the
observatory, says that in the absence of government funding, a
consortium of universities may have to step in to fund the facility's
operations beyond 2010.
Schweickart summarized what's at stake in a prepared statement at a
November 2007 Capitol Hill hearing, where NASA and Congress clashed
over how to address the NEO threat: "If we live up to our
responsibility, if we wisely use our amazing technology, and if we are
mature enough, as a nation and as a community of nations, there may
never again be a substantially damaging asteroid impact on the Earth.
We have the ability to make ourselves safe from cosmic extinction. If
we cannot manage to meet this challenge, we will, in my opinion, have
failed to meet our evolutionary responsibility."
Tom Spalding
Indystar.com
Thu, 17 Apr 2008 12:27 EDT
A chunky visitor from beyond our planet left a sparkly impression over the skies of north-central Indiana.
"It certainly sounds like a meteor," said Adam Rengstorf, an
assistant professor of physics and astronomy at Purdue University
Calumet in Hammond. "It certainly sounds like a decent-sized chunk of
rock that hit."
Most meteors are the size of a pebble or a grain of sand. This one
could range from a baseball in scope to that of a small car, he said.
Initially, many residents feared the worst.
Callers flooded Howard County's 911 dispatch center with reports of
the noise and aerial display, prompting a massive search for a plane
that might have crashed or anything sinister. But Sheriff Marshall D.
Talbert said authorities have no other explanation.
"One witness told us there was a large glow of light that broke into
four smaller section of light that cascaded to earth," Talbert said.
"It does appear that it was some sort of meteorite because we did not
have an aircraft accident."
First responders in Howard and Tipton counties, along with Indiana
State Police, were mobilized within minutes of the incident. In Howard
County alone, 911 dispatchers took 146 phone calls within a 15-minute
timeframe between 10:25 p.m. and 10:40 p.m. Normally the 911 center
averages 15 to 20 calls between 10 p.m. and 6 a.m. Howard County
activated its emergency management agency just in case.
"Obviously, we're all in a heightened state of awareness," Talbert
said. "Certainly when people observe something like that, they do what
we want them to do and that's report it. But it does appear it was some
sort of meteorite."
So far there have been no reports of any debris or evidence found in
what is a broad reporting area. Callers reported the incident as coming
from the west but gave different descriptions as to the location.
Kokomo, home to about 46,000 people, is 60 miles north of Indianapolis.
Bill Burton, 52, an electrician from Komoko, was cruising the
Internet from his home Wednesday night when he said he heard a boom and
raced outside. What Burton said he saw was four distinct fragments of
white light that each turned red and were stacked together like four
period punctuation marks. The phenomenon lasted only a few seconds.
"I've seen every kind of meteor or ... shower ... anything you want.
I am telling you this was some very strange stuff. Very strange,"
Burton told the Star. "I hate to tag it, but I'd call it a UFO."
Cameron Huffman, 19, a student at Indiana University-Kokomo, was
also a witness. He was walking his girlfriend to his car when he heard
the noise. He looked up in the sky but it was several seconds before
any object appeared.
"It was really interesting," said Huffman, who believes he saw a
meteor. "People just started flooding the radio stations and the
police. It woke everybody up."
According to the Logansport Pharos-Tribune, Logansport
residents experienced a similar loud noise Tuesday night around the
same time. Shortly after hearing the boom, which shook the walls of
buildings throughout Logansport and the surrounding areas, a caller
reported seeing a fireball in an area just west of Ind. 25 on 350N.
Authorities at Grissom Air Reserve Base near Kokomo and Indianapolis
International Airport told police they had no aircraft missing, the
Kokomo Tribune reported.
Indianapolis Star
Thu, 17 Apr 2008 17:37 EDT
KOKOMO, Ind. - Kokomo Emergency responders from Howard and Tipton
counties were mobilized late Wednesday after receiving many calls about
a large explosion.
Dozens of residents reported hearing, feeling or seeing some kind of
explosion near Kokomo about 10:30 p.m., but about midnight, a Tipton
County Sheriff's Department dispatch official said police and fire
crews still were searching for debris or other evidence of a blast.
One resident interviewed on the air by WTHR (Channel 13), The
Indianapolis Star's news-gathering partner, said she felt her house
shake violently and saw a fireball.
Other witness accounts varied from a blast to bright lights to a house-shaking rumble, officials said.
About 11:30 p.m., the Federal Aviation Administration reported no missing aircraft, WTHR reported.
Kokomo, home to about 46,000 people, is about 50 miles north of Indianapolis in Howard County.
Rick Callahan
Chicago Tribune
Fri, 18 Apr 2008 09:29 EDT
INDIANAPOLIS - The commander of an Indiana
Air National Guard unit is investigating why F-16s involved in training
exercises created sonic booms two consecutive nights over north-central
Indiana, shocking residents who also saw dazzling flares used in the
missions.
A sonic boom and fireballs and flaming debris that Kokomo-area
residents reported seeing in the sky Wednesday night prompted Howard
County's police agencies to conduct a two-hour search for what many
residents thought was a crashed aircraft.
As it turned out, the fireballs were flares fired by F-16s that are
part of the 122nd Fighter Wing, an Indiana Air National Guard unit
based at Fort Wayne International Airport.
Staff Sgt. Jeff Lowry with Indiana National Guard's headquarters in
Indianapolis said the jets taking part in the training are not supposed
to exceed the speed of sound, which is about 760 mph, because
supersonic speeds produce sonic booms.
He said the 122nd's commander, Col. Jeff Soldner, will investigate
why at least one jet reached supersonic speeds Wednesday night over
Howard and Tipton counties, and also on Tuesday night over the
Logansport area, shaking the ground below.
"The sonic boom is not routine. That was a mistake. That's being
investigated right now and once the wing commander finds out he'll make
recommendations on how to change that so it doesn't happen again,"
Lowry said.
He said F-16 training often involves the aircraft dropping flares
from more than 10,000 feet above the ground, a technique that can allow
the jets to evade heat-seeking missiles in combat.
Lowry said such flares are routinely dropped during the daylight
hours and also at night but they likely would not have attracted much
attention without the accompanying sonic booms.
The investigation will determine how many of the F-16s broke the
sound barrier. Lowry said he did not know how many of the fighter jets
were involved in the training missions.
The jets were training in an area called Hilltop Military Operations
Area that's not designated for supersonic flights. The training area
extends from Grissom Air Reserve Base to West Lafayette and includes
Logansport, 30 miles north of Indianapolis bordering Kokomo.
Police switchboards in Howard and Tipton counties were inundated by
calls after residents saw bright lights just before a loud sound like a
sonic boom Wednesday night.
Smith's secretary, Janice Hart, said she was lying on her bed talking to her niece when a loud explosion rocked her home.
"It just shook my house to its depths. As soon as it happened, my
niece said, 'Oh my God Aunt Janice, what was that?' I looked out my
bedroom window and my husband went to the front of the house to see
what it was," she said.
Hart, who initially thought an explosion had rocked a nearby
factory, was busy Thursday morning handling calls about the noise and
lights.
"That's all they're talking about. I had numerous calls asking if it
was a sonic boom, a meteor, even some people joking that it was a UFO,"
she said.
Logansport Police Chief A.J. Rozzi said he heard a loud sonic boom
on Tuesday night, and then heard the sound of a jet high overheard. He
said residents also reported seeing fire streaks in the sky.
He said it is common for the 122nd to conduct missions in the area
and believes F-16 training almost certainly explains the sights and
sounds.
"They've been doing that training for quite a while. I don't know
what maneuvers they're actually doing, but they do shoot out streaks of
light," he said.
Comment: Jet
fighters don't break the sound barrier by mistake. Is it just a
coincidence, then, that Illinois had a 5.4 magnitude "earthquake" just
a day later during which residents heard a roaring sound?
CNN
Fri, 18 Apr 2008 06:52 EDT
Buenos Aires, Argentina -- Smoke blanketed
the Argentine capital Friday as brush fires apparently set deliberately
consumed thousands of acres in the provinces of Buenos Aires and Entre Ríos.
 |
| ©AFP/Getty Images |
| A haze surrounds the Palermo neighborhood of the Argentine capital early Thursday. |
The smoke, from about 300 fires, is blamed for at least two fatal traffic accidents this week that left eight people dead.
Sections of major highways and the Buenos Aires port, among the
busiest in the world, have been closed. Incoming flights to the city's
domestic airport, Jorge Newbery Airpark, have been diverted.
The Argentine government has blamed farmers looking to clear their
land for crops and grazing for the fires, which are estimated to cover
173,000 acres (70,000 hectares).
"This is the largest fire of this kind that we've ever seen," Argentine Interior Minister Florencio Randazzo said Thursday.
Randazzo called the situation a "disaster."
As of Friday morning, little progress had been made extinguishing the blazes.
No rain is predicted for the next few days, but the National
Meteorological Service predicts that the winds will change direction
soon, dispersing the smoke.
On Friday morning, the National Roads Administration closed sections
of the heavily traveled Panamericana Highway, which leads in and out of
Buenos Aires. Spokesman Ernesto Arriaga said "visibility is 5 meters"
(about 16 feet) in some sections of the highway.
"Covering highways with smoke just to clear a field of weeds is
unforgivable," Cabinet Chief Alberto Fernandez told Radio Diez. "It's
incredibly irresponsible."
Hospitals have reported an increase in visitors complaining of
breathing problems, sore throats and burning eyes in the past three
days.
Citing a high level of carbon monoxide in the air, officials have encouraged people not to exercise outside.
Schools in Pilar, a city in the province of Buenos Aires, were closed Friday because of the gray, thick air.
The smoke has obscured views of some of the capital's landmarks,
such the Obelisco monument and the government house, Casa Rosada, and
people were seen walking on the city streets covering their faces with
clothes.
This month, Argentina's farmers suspended a three-week strike over a new government export tax on commodities.
The bitter lockout left grocery shelves empty and caused major
friction between President Cristina Fernandez de Kirchner's government
and Argentina's large agricultural sector.
Comment: Interesting article considering that on Thursday, April 17, a fireball fell somewhere
in or nearby Entre Rios, 260 miles northwest of Buenos Aires. Mariano
Peter from the Entrerriana Astronomy Association said there were
reports from 4 witnesses. One of them described, "a strong light that
passed at a high speed through the sky and at a low altitude, going
towards the south and then it fell in the distance." Another witness
said, "it was very bright and it changed color between green and red."
The first fireball was reported
in Entre Rios on April 6th, 2008. A witness said: "For three or four
seconds I saw an object in flames, changing color until it turned blue
when it approached the ground.'' A fire department source said the
impact was felt for miles around. The next day a fragment of the space
rock was recovered.
See: Meteorites, Asteroids, and Comets: Damages, Disasters, Injuries, Deaths, and Very Close Calls where this item has been added to The List as a strong possible event.
Laura Knight-Jadczyk
SOTT.NET
Fri, 18 Apr 2008 11:34 EDT
Somehow, I think it is highly probable that we have a new event to add to our list of Meteorites, Asteroids, and Comets: Damages, Disasters, Injuries, Deaths, and Very Close Calls
Have a look at the excerpts from the following two news items from this
past week and see if something doesn't seem off about the glib and
facile "explanations" for a series of extremely bizarre events. Every
element of the stories is explainable in the terms presented by Clube
and Napier, Mike Baillie and John S. Lewis and which have been the
topic of the present series of articles on Comet hazards. At the same
time, the explanations given by the "official sources" simply do not
sound plausible.
Read and judge for yourself.
2008 - 15, 16, 18 April - Illinois -
Maybe we had a comet fragment impact or two or three over a period of
several nights? Perhaps a couple of overhead explosions and then,
later, a ground impact. Read the following stories and judge for
yourself:
That would explain booms and earthquake and lights in the sky spread out over three days. Damage Control: Mysterious booms, lights over Indiana were just F-16s
A sonic boom and fireballs and flaming debris that Kokomo-area
residents reported seeing in the sky Wednesday night prompted Howard
County's police agencies to conduct a two-hour search for what many
residents thought was a crashed aircraft.As it turned out, the fireballs were flares fired by F-16s that are
part of the 122nd Fighter Wing, an Indiana Air National Guard unit
based at Fort Wayne International Airport. ...Staff Sgt. Jeff Lowry with Indiana National Guard's headquarters in
Indianapolis said the jets taking part in the training are not supposed
to exceed the speed of sound, which is about 760 mph, because
supersonic speeds produce sonic booms.He said the 122nd's commander, Col. Jeff Soldner, will investigate
why at least one jet reached supersonic speeds Wednesday night over
Howard and Tipton counties, and also on Tuesday night over the
Logansport area, shaking the ground below. ...He said F-16 training often involves the aircraft dropping flares
from more than 10,000 feet above the ground, a technique that can allow
the jets to evade heat-seeking missiles in combat. ...Logansport Police Chief A.J. Rozzi said he heard a loud sonic boom
on Tuesday night, and then heard the sound of a jet high overheard. He
said residents also reported seeing fire streaks in the sky.He said it is common for the 122nd to conduct missions in the area
and believes F-16 training almost certainly explains the sights and
sounds."They've been doing that training for quite a while. I don't know
what maneuvers they're actually doing, but they do shoot out streaks of
light," he said.
5.4 earthquake rocks Illinois; felt 350 miles away
A 5.4 earthquake that appeared to rival the strongest recorded in
the region rocked people awake up to 350 miles away early Friday,
surprising residents unaccustomed to such a powerful Midwest temblor.The quake just before 4:37 a.m. was centered 6 miles from West
Salem, Ill., and 66 miles from Evansville, Ind. It was felt in such
distant cities as Chicago, Cincinnati and Milwaukee, 350 miles north of
the epicenter, but there were no early reports of injuries or
significant damage. ...."You could hear a roaring sound and the whole motel shook, waking up
the guests,'' Vibha Ambelal, manager of the Super 8 Motel in Mount
Carmel, Illinois, near the epicenter, said in a telephone interview."
Now, add the above to what happened just a little over a week earlier:
2008 - 6 April - Argentina - The space
rock reportedly crashed late Sunday somewhere in Entre Rios Province,
some 260 miles northwest of Buenos Aires, reports the daily Clarin,
which quoted a witness, Milton Blumhagen, a student and astronomy buff:
"For three or four seconds I saw an object in flames, changing color
until it turned blue when it approached the ground.'' A fire department
source said the impact was felt for miles around. No damage was
reported.
Keep your eyes and ears open!
Brian O'Neill
Pittsburgh Post-Gazette
Tue, 15 Apr 2008 14:37 EDT
A natural gas explosion? That's disappointing to all of us who had been pulling for the meteor.
We still don't know with certainty what set off the explosion at a
North Side home last week. At a news conference yesterday, Detective
Michael Burns of the city's arson unit said an illegal drug lab has
been ruled out, which leaves investigators to believe natural gas was
the cause.
 |
| ©Bob Donaldson/Post-Gazette |
| Pitt professor emeritus and meteor expert William Cassidy, right, looks with Matt Grebner toward Mr. Grebner''s Spring Hill home. The site of two destroyed North Side homes is behind Mr. Grebner, who thinks a meteorite may have caused the damage. Dr. Cassidy thinks: unlikely. |
The blast came from the kitchen of 845 Lovitt Way, Detective Burns
said. Police are checking gas appliances pulled from its wreckage. An
Equitable Gas spokesman said no leak was detected, but an
"extraordinary amount of gas passed through the meter" days before the
explosion, which brought down an adjacent house, too.
Matt Grebner, a Spring Hill resident, wasn't buying that.
"Stove creates sonic shock wave?" he asked sarcastically. "That'd be a first."
He says his house shook as he heard a boom Friday morning, more than
a half-mile away from the site of what are now the ruins of two
rowhouses. He went outside to see if something had hit his house, and
when he found nothing, he realized it was a sonic boom and began
thinking of the possibility of a meteorite.
Unlikely, sure, but not impossible. William Cassidy, 80, professor
emeritus in geology and planetary science at University of Pittsburgh,
was intrigued enough by Mr. Grebner's account to come down and take a
look. I met Dr. Cassidy at his Oakland office and he followed me via
Polish Hill to the battered North Side street.
"I don't think I'll see anything looking at that," he said when we got to Lovitt Way.
A couple of cops were on wreckage sentry duty and wouldn't let us
get close. Still, if this damage had been done by a meteorite, it had
broken all 20th-century U.S. records. Meteorites hit 13 houses or cars
between 1911 and 1994, according to Dr. Cassidy. Ten of those
meteorites weighed less than 5 pounds and did little more than
penetrate a roof or rip off a rain gutter. The largest, more than 27
pounds, crushed the back of a car in Peekskill, N.Y., in 1992.
"None of them blew the place up," he said.
The possibility of an American dwelling being hit by a meteorite in
the 1990s was about 1 in 48,560,500, according to his most recent
calculations. Odds may have gone up since then. Still, if when pulling
these houses apart, workers find a rock where it has no reason to be,
he'd like to see that. He thinks he could tell if it were a meteorite.
"I don't think it's very likely," Dr. Cassidy said. "Too bad."
Generally, his finds aren't within a few miles of his office.
Antarctica is your go-to continent for meteorites, and he has led a
number of expeditions to recover specimens, capturing the work in his
book, "Meteorites, Ice and Antarctica." Most of what he found there
dropped from the sky millions of years ago, not last week.
The homes at 845 and 847 Lovitt Way were unoccupied, but the former
belongs to Ray Glatz, 80. He moved about seven months ago to a
McCandless nursing home while in poor health, and is now getting
chemotherapy for lung cancer, but Mr. Glatz had plans to return. He
took news of his home's destruction stoically, saying he'll find a
place to live on the North Side among nieces and nephews.
Seven Decembers ago, Mr. Glatz was among neighborhood residents who
Christmas caroled outside homes of suspected drug dealers and
prostitutes. On streets where cocaine is dealt, "Frosty the Snowman"
takes on a different meaning. Mr. Glatz was unafraid to get in dealers'
faces.
He didn't fear them, but he feared fires started by squatters in
abandoned buildings around him. "I'm old enough to die," he told me in
2002, "but not in a fire. I don't want to be taken that way."
So he's glad he was elsewhere and that his cat, who had stayed in
the house alone for months while relatives checked in on it, had been
taken in by his friend, Allegheny Common Pleas Judge Cathleen Bubash,
less than two weeks before.
With all that Mr. Glatz has been through, the cosmic irony would be
just too great for his house to be taken down by a rock from outer
space. Mr. Glatz said last night he doesn't know what destroyed his
home, but the city's news conference didn't satisfy him either. No
explanation has made sense to him yet.
Asociación Entrerriana de Astronomía
Thu, 17 Apr 2008 13:46 EDT
The Asociación Entrerriana de Astronomía (AEA) [Entre Ríos Astronomy
Society, Argentina] has announced that on Wednesday 16th April 2008, at
approximately 19:30 hours, was observed a highly luminous object that
had all the characteristics of a bolide. This object was sighted from
Paraná, Oro Verde and San Benito. According to witnesses, the bolide
was intensely bright, with colours fluctuating between green, yellow
and red.
It followed a roughly north-east trajectory towards the south-west,
with an angle of 75 degrees. One observer has stated that the bolide
exploded before disappearing.
It is not possible to discount the idea that this meteor relates to
a similar fall which occurred last week over central Entre Ríos
province, and which was observed across a wide part of Argentina. The
AEA has also received over the past few days many reports of sightings
of very luminous objects in different parts from the country, e.g. from
Mar del Plata, Tucumán, Zárate, Concordia, Ituzaingó (Prov. de
Corrientes), etc.
If anyone has any further data to contribute, please email Mariano
Andrés Peter, director of the Oro Verde Astronomical Observatory (AEA),
at: observatorioaea@hotmail.com
Translation by SOTT
MIKE FLETCHER
Kokomo Tribune
Thu, 17 Apr 2008 14:15 EDT
Jets put boom speculation to rest
The loud boom heard throughout Howard and Tipton counties late
Wednesday was caused by F-16 fighter jets conducting training in the
area, the Indiana National Guard reported Thursday.
Howard and Tipton county police and fire units scrambled to the area
of U.S. 31 and 300 North in Tipton County about 10:30 p.m. Wednesday,
upon hearing numerous reports of a loud boom and strange lights in the
sky.
In Howard County, 911 dispatchers took 146 phone calls within a 15-minute timeframe between 10:25 and 10:40 p.m. Normally the 911 center averages 15-20 calls per night.
Initially, police thought it was an aircraft crash. But without any evidence of a crash or any debris, police were left puzzled.
Speculations ran rampant that the boom and bright lights were either
a plane crash, a meteor shower and even UFOs were mentioned as the
culprits.
A representative of the Indiana National Guard in
Indianapolis said Thursday that the guard takes responsibility for the
recent nighttime disturbance in Kokomo and Logansport the past two days.
Comment: SOTT reported the original article
a few days ago. Since that time the National Guard come forward with a
soothing explanation that 'F-16's' were the culprits... Nothing to see
here folks?
"Loud noises reported by citizens in northern Indiana accompanied by
flashes of light and what appeared to be falling debris early this week
were a result of training conducted by Indiana National Guard F-16
Aircraft, headquartered at Fort Wayne's 122nd Fighter Wing," a press
release from Col. Jeffery Soldner, commander of the 122nd Fighter Wing,
stated.
The Indiana Air National Guard conducts training missions on a daily basis.
"All of our military members, including our pilots and crewmembers,
require the most realistic training possible for their own safety and
those they work to protect," Soldner said.
The release explained that F-16 aircraft routinely train with the
countermeasure Chaffe-flare system which draws heat-seeking missiles
away from the aircraft exhaust.
It was the night-time engagement of this system that resulted in the
"strings of lights" reported by citizens, according to the release.
Comment: But what this doesn't explain is the earthquake-like shaking and the 'explosions' heard and seen
in the sky, not to mention the similar phenomenon observed in
Logansport the day before it occurred over Kokomo....... Was it
Military error... twice??
The flares were released above 10,000 feet in accordance with the
long-standing guidance for the Hilltop Military Operations Area that
extends from Grissom Air Reserve Base to West Lafayette and includes
Logansport, 30 miles north of Indianapolis bordering Kokomo.
Soldner also said the area is not designated for "super-sonic"
flight and an investigation will be conducted to determine if any
aircraft exceeded that speed.
"I have ordered a thorough investigation to be conducted into why
the incident took place," he said in the release. "I have also ordered
that our Flying Squadron conduct a complete review of the tactics that
were in practice at the time. We will ensure that our pilots review
airspeed restrictions in all of our practice flight training areas, and
that these restrictions are briefed prior to each flight."
Larry Smith, director of the Howard County Emergency Management
Agency, said his officers were ready in case any wreckage was found.
"We started activating our guys when the sheriff department called,"
Smith said of the incident. "We set up at U.S. 31 and Ind. 26 since we
heard it may have come from 300 North area in Tipton County. Then we
heard it may be in the area of Clinton and Howard county line so we set
up a grid search of the area and found nothing."
Smith's secretary, Janice Hart, said she was lying on her bed talking to her niece when a loud explosion rocked her home.
"It just shook my house to its depths. As soon as it happened, my
niece said, 'Oh my God, Aunt Janice, what was that?' I looked out my
bedroom window and my husband went to the front of the house to see
what it was," she said.
Hart, who initially thought an explosion had rocked a nearby
factory, was busy Thursday morning handling calls about the noise and
lights.
"That's all they're talking about. I had numerous calls asking if it
was a sonic boom, a meteor, even some people joking that it was a UFO,"
she said.
Logansport Police Chief A.J. Rozzi said he heard a loud sonic boom
Tuesday night and then heard the sound of a jet high overheard. He said
residents also reported seeing fire streaks in the sky.
He said it is common for the 122nd to conduct missions in
the area and believes F-16 training almost certainly explains the
sights and sounds.
Comment: Would the residents of these areas not know the difference between military-manoeuvres, and something out of the ordinary?
"They've been doing that training for quite a while. I don't know
what maneuvers they're actually doing, but they do shoot out streaks of
light," he said.
Leo Leonidou
Cyprus Mail
Fri, 25 Apr 2008 12:00 EDT
The British Bases yesterday maintained that none of their aircraft had caused buildings to shake in Paphos on Wednesday.
According to the Cyprus Broadcasting Corporation, "aircraft taking
part in a British military exercise went supersonic, upsetting local
residents, who feared for their safety."
The report claimed the phenomenon was felt at 11.15am, mainly in
Yeroskipou, Peyia and Kato Paphos, adding that an RAF spokeswoman
confirmed that a military exercise took place 30 nautical miles south
of the Akrotiri Base.
Bases spokesman Captain Nick Ulvert told the Mail on Wednesday that he had heard local press reports claiming that the Red Arrows were responsible.
"These rumours are unfounded, as according to our records, the Red Arrows were not in the air at that time," he said.
He confirmed that various operational training flights took place
throughout the day but stated that, "in order for buildings to start
shaking, aircraft would need to be extremely close to Paphos. The RAF
operates under strict aviation guidelines, which are always adhered to.
I cannot imagine a scenario in which our aircraft are responsible for
this."
Yesterday Captain Ulvert added: "We don't have anything to hide and
I can guarantee you that our operational training sorties on Wednesday
were conducted nowhere near Paphos."
He also said that their traces "suggest no supersonic movement".
One Paphos resident spoke about what he felt at the time. "The doors and windows of my home were shaking like mad and I heard a really loud noise," he said.
Another described similar circumstances, saying: "I thought it was an earthquake but the ground wasn't shaking."
A small earthquake measuring 4.0 on the Richter Scale was recorded
at 5.03am on Wednesday, 100km from Cape Arnaoutis and 10km below sea
level.
Kyriacos Solomi of the Geological Survey Department, however, was
adamant that the effects felt in Paphos around six hours later were not
caused by an aftershock or another quake.
"Eyewitness observations could correspond to an earthquake
of a 3.5 to 4.0 magnitude. However, we did not record any incidents,"
said Solomi. "Even if all our instruments suddenly went offline,
earthquake detecting networks in Israel, Lebanon, Syria and Turkey
would have picked something up. Nobody has reported any activity at
that particular time, meaning it was definitely not an earthquake."
Director of Civil Aviation Leonidas Leonidou said he was informed
that, "a big bang was spreading in a ten-kilometre radius from Paphos
airport to Kissonegra."
He added that the British had done everything by the book and
informed Leonidou that they would have aircraft involved in exercises.
"There was an event of some kind and it is a high possibility that
it was caused by a sonic boom. However, we cannot say this with 100 per
cent certainty."
Commenting, the Green Party issued a statement saying: "We believe
the time has come for the government to ask the British authorities to
stop conducting military exercises in and around Cyprus. The use of the
island in this manner undermines the national sovereignty of the
Republic of Cyprus and casts doubt over our national independence."
Bob Johnson
blackholesandastrostuff
Tue, 29 Apr 2008 15:07 EDT
So I was out trying to image another Sunset when out of the blue a
fireball appeared. To give you some idea of how rare these fireballs
are, a trained observer, such as moi, can expect to be treated to one,
once every 200 observing hours, factor in that it was a daytime
fireball, more rare, also factor in the fact it was close to the Sun,
more rare again and....catch breath... the fact that I had a focused
camera ready to go, and that I would actually capture an image just
after the break up with an image of the fragments, the chances of this
happening, well, it boggles the mind just thinking of it, well it
boggles my mind, mind you I'm easily boggled.
Comment: The increased appearance of these Fireballs and Meteors observed across the earth may not be as rare as the photographer concludes.
Click on the Images to expand.
 |
| ©Bob Johnson |
| Fireball Over Canada |
I get home to process the images to see what I've got, cropped and
enlarged the images, turned out quite good actually, something like
NASA might have on CNN, well maybe not NASA.. or CNN, but you get the
idea.
Fireballs come from a group of particles bigger then the usual
specks of dust grains that cause your average meteor shower. They are
caused by objects the size of pebbles people, unbelievable, but because
of the high rate of speed they hit our atmosphere, up to 160,000 mph
they create quite a show. Daytime fireballs usually have smoke trails
which start at about 50 miles altitude, they usually burn out around
9-12 miles high. It is very rare that any of the meteoroid reaches the
ground to become a meteorite because of something called Ablation,
which is when the outer layers of the meteoroid continually vaporize
due to the high speed collision with air molecules.
Just a reminder May 1st. Mercury and the Pleiades meet low in the NW. sky 45 mins after Sunset.
 |
| ©Bob Johnson |
| Photograph Closeup |
1 comment:
Sorry but that first picture is just of a vapour trail from a plane. The time and sky suggest that its at dusk. We have seen planes with pink or orange vapour trails fly over our house that look the same. Movement at the back of the trail is from the winds that move it around. Its no moteorite or rock. Its a Plane!
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