PLEASE NOTE:


*

CCNet 34/2001, 2 March 2001
---------------------------


THE METEOR-WRONG SONG

By Matthew Genge

Meteor-rite or meteor-wrong?
Here are some clues to go along.

If it was hot to touch, or glowed bright red;
if it smoked or spat, or sizzled or cracked;
if it made a little hole not a great big crater;
then a meteor-wrong you can expect a bit later.

It if fell from the sky, then when all is said,
its usually been thrown from the neighbour's shed.
If it was black as coal, and crumbles like cake,
then don't bet on it being the next Tagish lake.

If it scared their granny in the middle of the night,
with a bang and a flash of strange coloured light;
if they saw it fall as a great glowing ball,
then it probably wasn't a real meteor-rite fall.

Matthew Genge
Natural History Museum
M.Genge@nhm.ac.uk



"Awful weather, an horrific train crash, a rampant disease
threatening the farming industry, an earthquake in Seattle; whatever
could happen next in this litany of doom? A meteorite hitting the Earth?
Well, yes. Happily, the extraterrestrial rock that landed yesterday
morning at the edge of a field in Hopgrove, near York, was not quite as
large as the one which, 65 million years ago, crashed into what is
now the Yucatan Peninsula and wiped out the dinosaurs."
--Charles Arthur, The (truly) Independent, 2 March 2001
 
http://www.independent.co.uk/news/Uk/Science/2001-03/impact020301.shtml


 
"AMID a winter of national emergencies, perhaps the last thing that
Britain needed was a visitor from outer space. [...] Dr Phillip Manning,
keeper of Geology at the Yorkshire Museum in York, said: "I've never
seen anything like it. It was all caused by an electrical fire deep
underground. We all thought it was a meteorite - even the Army said the hole
was from an impact from above not something below ground. We are quite
happy to have got to the bottom of it and that people have shown such
an interest. At least if it happens again, we will know what we are
looking at."
--Nigel Hawkes, The Times, 2 March 2001
          http://www.thetimes.co.uk/article/0,,2-92870,00.html


"I'm quite disappointed to discover I've not survived a meteorite
falling from the skies at the speed of sound. But it will give someone
a laugh to discover we were all fooled."
--Sylvia Mercer, 1 March 2001



(1) 'METEORITE' FEVER COMES DOWN TO EARTH WITH A BANG
    Daily Telegraph, 2 March 2001

(2) GAMMA-RAY READINGS FROM EROS
    Andrew Yee <ayee@nova.astro.utoronto.ca>

(3) POOR SCIENCE REPORTING: NEO COMMUNITY RIDICULED FOR JOB WELL DONE 
    Andrew Yee <ayee@nova.astro.utoronto.ca>

(4) NEAR-EARTH 'ASTEROID' SURPRISES ASTRONOMERS
    Space.com, 1 March 2001

(5) A WORD OR TWO FOR THE FRIENDS OF PLUTO: DEBATE IS OVER
    The New York Times, 2 March 2001

(6) BUCKBALLS AND GASES *MAY* MARK MASSIVE EXTINCTION
    PSRD DISCOVERIES, 28 February 2001

(7) DOUBTS EMERGE ABOUT P/T IMPACT HYPOTHESIS
    Benny J Peiser <b.j.peiser@livjm.ac.uk>

(8) NEW TASK FORCE ON EUROPEAN STATEGY FOR SPACE
    ESA <esaweb@esa.int>

(9) THE YORK "METEORITE" AND OTHERS
    Andrei Ol'khovatov <olkhovatov@mtu-net.ru>

(10) GEOLOGY KEEPER RUSHED CONCLUSIONS
     Ron Baalke <baalke@zagami.jpl.nasa.gov>

(11) "BACKGROUND RADIATION": ANOTHER FALSE ALARM?
     Phil Plait <badastro@badastronomy.com>

(12) THE "CHRISTMAS" COMET
     Jonathan Shanklin <jdsh@bas.ac.uk>

(13) PALEOECOLOGY & MAMMOTHS
     Bas van Geel <vangeel@bio.uva.nl>

=============
(1) 'METEORITE' FEVER COMES DOWN TO EARTH WITH A BANG

From Daily Telegraph, 2 March 2001
http://www.telegraph.co.uk/et?ac=002549632124328&rtmo=weAiMMib&atmo=rrrrrrrq&pg=/et/01/3/2/nufo02.html

By Robert Uhlig, Technology Correspondent
 
WITH a supersonic boom, a whoosh and a plop, meteorite hysteria fell to
Earth in a sleepy suburb yesterday morning, leaving a smouldering, fizzing
hole a few feet from a startled woman walking her dogs.
 
Sylvia Mercer had her close encounter with an unidentified heavenly object
in a quiet country lane in Hopgrove, York. "I was walking my dogs when I
heard two bangs," she said.

"Then there was a rush of wind whistling past my head and a plopping noise.
I froze in terror and thought my last moments had come. When I looked at the
ground I saw a smouldering hole.

"There was smoke and noise coming from it and it was making strange and
frightening sounds. You don't usually expect to get attacked from outer
space while you are out for a stroll. It is absolutely amazing." She ran
home to raise the alarm and then returned to cover the 12in-wide and
5ft-deep hole with a dustbin lid.

Within minutes, police, the Army Bomb Disposal Squad from Catterick,
university geologists and museum experts from York were rushing to the
scene. As police sealed off the crater and prepared to evacuate the area,
meteorite experts at the Natural History Museum in London were commandeering
cars, ready to race to York to examine what they were promised was a
brain-sized 12lb lump of primordial space rock.

Phil Manning, keeper of geology at the Yorkshire Museum, was one of the
first specialists on the scene. He said it was the biggest meteorite to hit
Britain for 100 years. "The bangs Sylvia heard were sonic booms. The
meteorite would be travelling at the speed of sound and the hissing and
popping were caused by the heat it discharged," he said.

A policewoman who was ordering locals to keep away told reporters that the
hole had certainly been caused by a meteor impact. "We just cannot attribute
it to anything else." While bomb disposal experts peered into the hole,
scientists developed theories to explain its strange blue colouration.

Only the meteor and planetary experts at the Natural History Museum in
London urged caution at the growing meteorite hysteria. A mechanical digger
brought in to excavate and retrieve the rock found nothing. And nine hours
after Mrs Mercer's narrow escape, experts told her that it was nothing more
than a low-flying clod of earth.

A high-powered electricity cable, buried 3ft deep, had split, shorted and
blown - causing the gurgling and popping noises. A spokesman for City of
York council said: "The hole was caused by the earth being blown out, not by
an object going in at high speed and burying itself. What flew past Mrs
Mercer's head was nothing more than a big clod of earth."

Last night Mrs Mercer said: "I'm quite disappointed to discover I've not
survived a meteorite falling from the skies at the speed of sound. But it
will give someone a laugh to discover we were all fooled."

Copyright 2001, Daily Telegraph

========
(2) GAMMA-RAY READINGS FROM EROS

From Andrew Yee <ayee@nova.astro.utoronto.ca>

Applied Physics Laboratory
Johns Hopkins University
Laurel, Maryland

NEAR image of the day for 2001 Mar 01

Gamma-Ray Readings from Eros
[ http://near.jhuapl.edu/iod/20010301/ ]

This chart shows the gamma-ray spectrum from the surface of Eros. These
scientific data -- the first ever collected on the surface of an asteroid --
result from 7 days of measurements following NEAR Shoemaker's historic
landing on February 12.

The gamma-ray instrument has two detectors -- marked above by the red and
blue traces -- which picked up clear signatures of key elements in the
composition of Eros. These data, which surpass in quality all the data
accumulated by this instrument from orbit, will help NEAR scientists relate
the composition of Eros to that of meteorites that fall to Earth.

Built and managed by The Johns Hopkins University Applied Physics
Laboratory, Laurel, Maryland, NEAR-Shoemaker was the first spacecraft
launched in NASA's Discovery Program of low-cost, small-scale planetary
missions. See the NEAR web site for more details, http://near.jhuapl.edu/ .

=========
(3) POOR SCIENCE REPORTING: NEO COMMUNITY RIDICULED FOR JOB WELL DONE 

From Andrew Yee <ayee@nova.astro.utoronto.ca>

[Extracted from inScight, Academic Press,
http://www.academicpress.com/inscight/03012001/graphb.htm

This item is supplied by the AAAS Science News Service.]

Thursday, 1 March 2001, 5 pm PST

Wind Startles Scientists
By MARK SINCELL

The Spacewatch Project, which monitors the ether for possible
Earth-threatening objects, found just what they were looking for, and
dreading, on 19 February. A telescope on Arizona's Kitt Peak captured a
bright streak of light in the night sky: an unidentified automobile-sized
object motoring straight toward Earth. An analysis of the object's path
showed that it would pass within 0.0039 astronomical units -- or a scant
500,000 km -- from the home planet.

The Minor Planet Center (MPC) in Cambridge, Massachusetts, promptly named
the threatening interloper MPEC 2001-D47 and alerted the astronomical
community, sending several international teams scampering to their
telescopes.

As the data flowed in, Jon Giorgini and Lance Benner, astronomers at the Jet
Propulsion Laboratory in Pasadena, California, decided to run the orbit
analysis backward to figure out where the object had come from. Judging from
its orbit, 2001-D47 was not a recently arrived  asteroid; rather, it had to
have already made several loops around the Earth-moon system, including a
near collision with the moon on 19 August 2001.

"At that point we suspected it was manmade," says Benner. But what? "That
was an easy one," says Jonathan McDowell, an astronomer and space history
buff at the Harvard-Smithsonian Center for Astrophysics in Cambridge,
Massachusetts, who pegged it as the WIND satellite, launched in 1994 to
study the solar wind. Scientists sling WIND around the moon to place it in
different orbits. "It regularly confuses the Near Earth Object people," says
McDowell, "but this is the first time it ever got [an MPC] designation."

© 2001 The American Association for the Advancement of Science

==========
(4) NEAR-EARTH 'ASTEROID' SURPRISES ASTRONOMERS

From Space.com, 1 March 2001
http://www.space.com/scienceastronomy/solarsystem/no_asteroid_010301.html

Near-Earth 'Asteroid' Surprises Astronomers
By Robert Roy Britt

While searching for space rocks on Feb. 19, 2001, Robert McMillan made a
routine discovery of a streak of light in the sky that appeared to be a
relatively nearby object. McMillan hunts for asteroids that might collide
with Earth. So following normal procedure, he reported the object to the
International Astronomical Union's Minor Planet Center.

"I didn't know what the object was at the time of discovery, only that the
Minor Planet Center's Web site did not list any known minor planet at that
location," said McMillan, who scans the skies as part of the Spacewatch
program at the University of Arizona's Lunar and Planetary Laboratory.

It is important work. If an asteroid is heading our way, we want to know.

Scientists at the Minor Planet Center were immediately intrigued by the
object. They calculated where it was headed. The object was about 1.5 lunar
distances from Earth. Anything this close needed to be watched carefully.
But the scientists were suspicious. Something wasn't right. The orbit was a
very unlikely one. It even seemed to share characteristics with Earth's
orbit around the Sun.

"When you have small objects in orbits that resemble the Earth, there is
always a suspicion that an object is artificial," said Gareth Williams,
associate director of the Minor Planet Center.

Still, Williams gave the object an official space rock stamp of approval:
Asteroid 2001 DO47.

Williams said yesterday that in the past, scientists have complained about
how long it sometimes took to get an object listed, a critical step to
circulating information so others can turn their telescopes toward the
potentially dangerous rock and make orbital calculations. Efforts have been
made to speed up the process since a new staff member was added midway
through last year.

E-mails flew from coast to coast as researchers discussed the object's
strange orbit and scrambled to pin it down.

After 2001 DO47 was announced, Jon Giorgini of NASA's Jet Propulsion
Laboratory looked at the object's orbit. He ran some orbital solutions on
his computer and determined that it had passed within 6,064 miles (9,782
kilometers) of the Moon last August. Giorgini also noted that the orbit was
"difficult to obtain by accident." (Williams called it "weird.")

It looked like the object might be captured in a temporary Earth orbit. Sort
of a second moon.

More data arrived on Friday, Feb. 23, and researchers were anxious. The
object was not behaving as predicted. Nobody needs a near-Earth asteroid
behaving erratically. But Giorgini and others became more and more
suspicious that the object might not be a real space rock. Calculations
continued.

On Sunday at the Minor Planet Center, Williams finally got word on the true
nature of the object from the local satellite expert Jonathan McDowell. He
broke the news to his boss, Brian Marsden: "2001 DO47 has switched on its
engine!"

Williams suggested that confirmation of the presumed engine firing be
obtained from Giorgini before announcing anything. Giorgini agreed that an
engine had been activated, and the announcement was made that 2001 D047 was
a machine.

Asteroid 2001 DO47 is actually NASA's WIND spacecraft, launched in 1994.
NASA says the craft was to go into a "sun-ward, multiple double-lunar
swing-by orbit ... followed by a halo orbit at the Earth-Sun L-1
(Lagrangian) point."

No wonder it confused researchers.

"We would have liked to check out the artificial possibility before
announcing the object, but our local ... satellite expert, Jonathan McDowell
... was away observing in Arizona," Williams said in an electronic posting
after the object's true identity was revealed.

WIND has tricked scientists before, Williams said, but the last time around
it didn't undergo any official name changes.

"Part of the problem," Williams told SPACE.com on Wednesday, is that "many
artificial satellites with highly elliptical orbits [making it easy to
confuse them with asteroids at certain points in their orbits] are not
tracked and so orbital elements are not available for them."

Copyright 2001, Space.com
 
=========
(5) A WORD OR TWO FOR THE FRIENDS OF PLUTO: DEBATE IS OVER

From The New York Times, 2 March 2001
http://www.nytimes.com/2001/03/02/science/02PLUT.html

By KENNETH CHANG
 
The American Museum of Natural History plans to install a plaque today to
answer a question often asked by visitors to its Rose Center for Earth and
Space: "Where's Pluto?"

They're missing Pluto because it has been mentioned only in passing in the
museum's exhibits. The scientists don't consider it a planet - in fact, they
don't even consider the term "planet" scientifically useful.

The scientists hope to clear up any confusion among visitors by adding the
plaque, and by updating the video kiosks with a discussion of the current
scientific debate on whether Pluto is a planet or something else.

"The fact people are so interested in it means we have to answer their
questions and put out more information," said Dr. Michael Shara, curator of
the museum's astrophysics department. "If it makes people think, it's a
positive thing."

But the changes do not mean the astrophysicists have changed their opinions.
"Absolutely not," Dr. Shara said. "What can I tell you? I don't think Pluto
is a planet."

The Rose Center's "scale walk," which depicts the relative sizes of objects
in the universe, includes models of the solar system's four inner
terrestrial planets mounted on the handrail and the four gas giant planets
hanging from the ceiling.

Pluto, an icy body at the outer edge at the solar system and far smaller
than the eight planets, did not fit into either category and was left out
when the Rose Center opened a year ago. To some visitors who recall school
lessons about nine planets in the solar system, the omission has been
confusing and even distressing.

The new plaque, to be mounted next to the photographs of the planets, notes
that Pluto shares a similar orbit and composition with a ring of icy bodies
beyond Neptune known as the Kuiper Belt.

"Some astronomers regard Pluto as a Kuiper Belt object, some call it a
planet, and others think of it as both," the plaque says. "This confusion
arises because a consensus has yet to emerge on the scientific definition of
`planet.' "

A 1.75-inch-wide circle on the plaque shows the relative size of Pluto,
which is smaller than the Earth's moon.

The kiosk display offers additional information about Pluto and the Kuiper
(pronounced KY-per) Belt, and presents arguments on both sides.

Dr. Frank Summers, one of the museum's astrophysicists, begins the segment
by saying that this isn't the first time that scientists have had to change
their minds about whether an object really is a planet. He recounts the
story of how the asteroid Ceres was initially counted as a planet until more
and more asteroids were discovered, and Ceres had to be recognized for what
it was.

The International Astronomical Union, the pre-eminent professional society
of astronomers, calls Pluto a planet, as do other major planetariums and
science museums. Some opponents are quite critical of the Rose Center
exhibits and even point out that the latest additions reflect some change in
its position.

"They're doing a little papering over, but they haven't fixed their
problem," said Dr. S. Alan Stern, director of the Southwest Research
Institute's space studies department in Boulder, Colo. "You can see them
breaking into a sweat trying to retain their position and yet backpedal.
It's a mixed and confusing signal to the public."

The decision not to call Pluto a planet because it does not fall into
terrestrial and gas giant categories "is really skirting a very fine line
with the facts," he said.

But "planet" does not have a well-defined scientific meaning, said Dr. Neil
deGrasse Tyson, director of the museum's Hayden planetarium. For example,
some suggest that planets are bodies large enough for their gravity to pull
them into spherical shapes but not large enough to become stars. But that
definition would include some of the larger asteroids and Kuiper Belt
objects.

"Our view here is the concept of planet has little to no scientific meaning
or pedagogical value," Dr. Tyson said.

Instead, the exhibits group the solar system into families: the terrestrial
planets of Mercury, Venus, Earth and Mars, the asteroid belt between Mars
and Jupiter, the gas giant planets of Jupiter, Saturn, Uranus and Neptune,
the Kuiper Belt and the even more distant Oort Cloud of comets.

"Don't count planets," Dr. Tyson said. "Count families." He said many
prominent planetary scientists, including Dr. Scott Tremaine, chairman of
the astrophysics department at Princeton University, agree with the museum's
presentation of the solar system.

"I think the Rose Center has done a real service by focusing the public's
attention on the fuzzy boundaries between the different constituents of the
solar system," Dr. Tremaine said.

Both Dr. Shara and Dr. Tyson say they expect that over the next few years,
surveys of the outer solar system will turn up Kuiper Belt objects larger
than Pluto.

"By the time they find the 10th one," Dr. Shara said, "the debate will
become uninteresting."

Copyright 2001, The New York Times

==========
(6) BUCKBALLS AND GASES *MAY* MARK MASSIVE EXTINCTION

From PSRD DISCOVERIES, 28 February 2001
http://www.psrd.hawaii.edu/Feb01/permianImpact.html

Written by G. Jeffrey Taylor
Hawai'i Institute of Geophysics and Planetology 

The Permian period ended with a massive extinction event that might have
lasted only several thousand years. Over 90% of marine species, 70% of
vertebrate land dwellers, and most land plants perished. Scientists have
proposed several hypotheses to explain this environmental catastrophe,
including massive volcanic eruptions, meteoroid impact, large changes in sea
level, and severe climate changes. A huge volcanic complex in Siberia
occurred at about the time of the extinction (251 million years ago). Now a
group of scientists led by Luann Becker (University of Washington, Seattle)
report evidence for an asteroid impact. They discovered fullerenes
(nicknamed "buckyballs"), which are cage-like carbon compounds consisting of
60 or more carbon atoms, at the boundary between the Permian and Triassic
periods. The buckyballs at the Permian-Triassic boundary contain trapped
helium and argon with isotopic compositions like those in meteorites called
carbonaceous chondrites, and very different from those on Earth. This led
Becker and her colleagues to conclude that impact of a 9-kilometer asteroid
deposited the buckyballs. An unanswered question is whether this impact
caused the mass extinction by itself or did so in collaboration with the
Siberian volcanism and possibly unrelated climate changes.

Reference:
Becker, Luann, Robert J. Poreda, Andrew G. Hunt, Theodore E. Bunch, and
Michael Rampino (2001) Impact event at the Permian-Triassic boundary:
evidence from extraterrestrial noble gases in fullerenes. Science, vol. 291,
p. 1530-1533.

Impacts and Extinctions: The Dinosaur-Killing Example

Fossil experts recognize the end of the Cretaceous Period by the extinction
of about half the species on Earth, including the dinosaurs. Scientists
still debate the cause of this mass extinction, but we now know that two
dramatic events took place at about the same time, 65 million years ago:
massive volcanic eruptions and the impact of a large (about 10 kilometers)
asteroid.

The volcanic event took longer than the asteroid impact, but is nevertheless
very impressive. Layers of lava cover over 500,000 square kilometers of
India. They might have covered three times as much before erosion. The total
volume of the lava was an astonishing 8 million cubic kilometers. That's
enough to cover the state of Texas under a layer of lava about 10 kilometers
thick or the entire surface of the Earth under a meter and a half of lava.
Rock ages indicate that most of the lava erupted over a period of about a
million years beginning before and ending after the big extinction event 65
million years ago.

In 1980, Walter Alvarez and his colleagues at the University of California,
Berkeley, advanced the idea that an asteroid whacked into the Earth causing
the end of the Cretaceous Period. They had found exceptionally high
concentrations of the element iridium at the boundary between the Cretaceous
and Tertiary periods. Iridium is rare in the crust of the Earth, but much
higher in abundance in meteorites. This led Alvarez to propose that the
enrichment is due to an asteroid or comet impact. Since then geochemists
have found iridium anomalies at the Cretaceous-Tertiary boundary worldwide.
It is often accompanied by shock-damaged quartz, an unequivocal indicator of
meteorite impact. To top it off, in 1991 A. R. Hildebrand and his colleagues
identified the crater buried under a kilometer of sediments. Called
Chicxulub, it straddles the Yucatan peninsula and the Gulf of Mexico.
Samples of the impact melt collected by drilling into the crater give an age
of 65 million years. (For more information about Chicxulub, go to the
Chicxulub Scientific Drilling Project.)

Last year, Luann Becker (then at the University of Hawai`i), Robert Poreda
(University of Rochester), and Ted Bunch (NASA Ames Research Center)
reported finding fullerenes at the Cretaceous-Tertiary boundary. Fullerenes
are unique carbon molecules with structures that resemble geodesic domes.
Because of this they were named "buckministerfullerenes" after R.
Buckminster Fuller, inventor of the geodesic dome. The long name is usually
shortened to fullerenes or buckyballs. Buckyballs have two important
properties: they seem to be very stable, even surviving arrival by impact;
and they have a large volume in their interiors that can trap gases.

The soccer-ball structures of fullerenes allow the molecules to trap gases
inside. Luann Becker and her coworkers have found that the gases in
buckyballs from the Cretaceous-Tertiary and Permian-Triassic boundaries are
similar to those in extraterrestrial buckyballs. 

Measurements of the gases in Bob Poreda's laboratory showed that the
Cretaceous-Tertiary samples contain helium and argon with isotopic
abundances like those in meteorites. The compositions are much different
from those in typical Earth rocks or sediments. In fact, Becker and her
coworkers argue that the isotopes and the buckyballs that house them must
have formed in stars, long before our star and its Solar System formed. In
any case, the discovery of buckyballs and unusual isotopes at the
Cretaceous-Tertiary boundary, where an asteroid impact definitely took
place, indicates that buckyballs and their gases can be used as a
fingerprint for cometary or asteroidal impact.

Impact at the Permian-Triassic Boundary?

Whatever happened at the end of the Permian Period nearly wiped out all life
on Earth. Over ninety percent of ocean-dwelling species perished. Seventy
percent of land species died off. Paleontologists call it "The Great Dying."
It was Armageddon. It may have been fast, too. Recent work suggests that it
might have taken only several thousand years, or less--a snap of the fingers
in geologic time. Some scientists disagree, arguing that it took half a
million years.

The Permian ended 251 million years ago, at the same time the huge Siberian
flood basalts formed. These lava flows are not quite as voluminous as the
Deccan lavas that erupted at the Cretaceous-Tertiary boundary. Their volume
is a mere 1.5 million cubic kilometers versus 8 million for the Deccan.
Nevertheless, if spread evenly on the surface of the Earth, they would make
a layer about 30 centimeters thick. You'd be up to your knees in lava. Like
the Deccan episode, most of the Siberian lavas erupted during an interval of
about a million years.

Could there have been an impact at the Permian-Triassic boundary, too?
Geochemists have searched carefully for iridium anomalies in places where
the boundary is accessible, but they did not find any enrichments in
iridium. Nor has anyone found other indicators of impact, such as shocked
quartz. This has led many investigators to favor volcanism as a major
contributor to the massive extinction event, but Becker and her colleagues
put impact back in the running by finding buckyballs with extraterrestrial
noble gases in them.

To search for the buckyballs, Becker crushed each sample and used acids to
dissolve most of the rock. She then used organic solvents to extract
fullerenes from the residue. She found not only buckyballs with 60 carbon
atoms, but those with 70 to 160 carbon atoms as well.

The detection of buckyballs by themselves is ambiguous. They can be made on
Earth by forest fires. Analysis of samples from just above and below the
boundary in Japan, China, and Hungary indicate that the buckyballs are
concentrated there. More importantly, there is a sharp increase in the
abundance of helium-3 at the boundary. The ratio of helium-3 to helium-4 is
typical of helium trapped in carbonaceous meteorites, and much different
from Earth rocks or atmosphere. The ratio of argon-40 to argon-36 is well
below that measured in our atmosphere, and trends towards values typical of
buckyballs in meteorites. Becker and colleagues conclude that the gases and
their buckyball containers are extraterrestrial. A big impact spread them
all over the world.

Buckyballs extracted from sediments at the Permian-Triassic boundary have
very different abundances of the isotopes of helium and argon than Earthly
materials, such as the atmosphere. They appear to fall on a line between
abundances in carbonaceous meteorites and air.

A Tangled Web of Processes?

Becker and her collaborators make an excellent case for an impact having
taken place at the end of Permian, 251 million years ago. Certainly more
research needs to be done, especially a search for independent evidence such
as an enrichment in iridium or the presence of impact-damaged minerals.
Nevertheless, the case seems strong.

But does it have anything to do with the great extinction at the
Permian-Triassic boundary? That's the big question. It appears that huge
volcanic eruptions occurred around the same time as the huge impact. Other
studies show that the end of the Permian was accompanied by an astonishing
change in sea level--a drop of about 100 meters. Could all these have
combined to cause life to be almost wiped out? Perhaps the largest
extinction events happen only when two or more dramatic geologic events
coincide, such as huge outpourings of lava and the impact of a large
asteroid.

Impacts of multi-kilometer asteroids are not very common. Neither is the
formation of flood basalts. Nevertheless, the two could happen at the same
time surprisingly often. There have been ten huge flood basalt eruptions on
the continents starting with the Siberian eruptions 251 million years ago.
Each lasted about one million years (actually somewhat longer, but the
majority of the lava squirted out in a relatively short span of time). This
means that for the past 251 million years, large eruptions have been going
on for 10/251, or 1/25 (4%), of the time. For any random large impact there
is a 4% chance it will hit during a huge eruption. For two impacts, the
chance of one of them hitting is double that, 8%.

Studies of the ages of impact craters on Earth and the number of asteroids
in orbits that cross Earth's orbit indicate that impactors 10 kilometers or
larger hit the Earth once every 100 million years. Thus, during the past 250
million years, Earth would have been smacked by two or three 10-kilometer
asteroids. The chances are 8 to 12% that one of them would have corresponded
to a flood basalt eruption. Five-kilometer asteroids hit once every 6
million years. In this case, it is extremely likely that one will happen
during a flood basalt eruption. However, impacts of five-kilometer asteroids
have a much smaller affect on Earth than do larger ones (roughly in
proportion to the cube of the radius).

This means that we should not be too surprised that both the
Permian-Triassic and Cretaceous-Tertiary extinction events have both huge
volcanic eruptions and large impacts associated with them. (It also means
that the impacts did not cause the volcanism, though it does not rule that
out, of course.) Possibly the largest extinctions occur when two or more
geologic processes operate at the same time. This would not occur
frequently, and neither do immense extinction events--fortunately for us.

Acknowledgement: PSRD would like to thank Gerald Fryer and Ralph Moberly
(both at the University of Hawai`i) for an enlightening email discussion
about the probabilities of impacts and huge volcanic eruptions occurring
together.

================
(7) DOUBTS EMERGE ABOUT P/T IMPACT HYPOTHESIS

From Benny J Peiser <b.j.peiser@livjm.ac.uk>

In his presentation at the recent Liverpool Symposium, Iain Gilmour (Open
University) pointed out that there is no hard evidence for the existence of
fullerenes at the K/T boundary. A lack of fullerenes in a confirmed impact
boundary, however, raises serious doubts about whether or not fullerenes are
an impact signature at all. What is more, according to Iain, there are
serious doubts about the reliability of the analytical approaches adopted in
the K/T fullerenes studies as well as in Luann Becker's Laser Ablation (P/T
and Sudbury). A much more rigorous method, mass spectrometric analysis,
recently used by R. Taylor and A.K. Abdul-Sada to test the fullerenes-impact
connection for the K/T event, did not find any support for the hypothesis:
"Careful re-examination of the Cretacous-Tertiary boundary layer material
that was reported earlier to contain C-60, confirms that there is a peak in
the HPLC of the extract having a retention time similar to that of C-60 (the
basis of the earlier claim). However, mass spectrometric analysis shows this
to be merely a mixture of hydrocarbons. No traces of either C-60 or C-70 are
present under conditions capable of detecting as little as 50 pg (0.001 part
per billion in the original material), this sensitivity being four times
greater than that given in the earlier report. These findings are entirely
consistent with the known high oxidative instability of fullerenes." (R.
Taylor and A.K. Abdul-Sada (2000), There are no fullerenes in the K-T
boundary layer, Fullerene Science and Technology 8(1-2), 47-54).

I think Iain Gilmour is right to ask for more convincing evidence - in
particular evidence of shocked materials - before he is prepared to accept
the rather weak P/T impact hypothesis.

BJP

=========
(8) NEW TASK FORCE ON EUROPEAN STATEGY FOR SPACE

From ESA <esaweb@esa.int>

ESA Press Release, Nr. 12-2001 - Paris, 1 March 2001

ESA-EC Joint Task Force on European Strategy for Space meets for the first
time in Brussels

Today ESA and the EC have set up a Joint Task Force to implement the
European Strategy for Space endorsed by the European Research Council and by
ESA's Council at Ministerial level in Brussels on 16 November 2000 (see ESA
press release N° 74-2000 of 16/11/2000).

The main objectives of the European Strategy for Space - jointly prepared by
the EC and ESA - are (1) to strengthen the foundation for space activities
in Europe, (2) to enhance scientific knowledge for a better understanding of
our planet, the solar system and the Universe, and (3) to reap the benefits
for markets and society through exploitation of technical space
capabilities.

The main missions of the Joint Task Force are to monitor the implementation
of this strategy, to propose a framework enabling ESA to act as implementing
agency with respect to EU policy on space, and to prepare a report on
European space activities for submission to the EU and ESA Councils and the
European Parliament by the end of 2001.

At today's meeting the work plan for the coming year was endorsed. The
group's first concrete activities consist of a thorough analysis of the
present situation concerning the Galileo project and a common effort to
deepen the initiative for Global Monitoring for Environment and Security
(GMES).

On this occasion, Antonio Rodotŕ, Director General of ESA, made the
following statement: "The Joint Task Force is continuing and developing our
shared effort in 2000, effort which led to joint endorsement of the European
Strategy for Space by the ESA and EU Councils. With the Joint Task Force,
Europe is taking another step towards a new era in which space systems will
become an integral part of the overall political and economic drive to
promote the interests of Europe's citizens".

On the EU side the Research Commissioner, Philippe Busquin, declared :"The
set-up and work of this Joint Task Force illustrate the role that I see for
the Commission in developing a true space policy for Europe and in getting
everyone to work together around common goals. It is a concrete step in
building a European Research Area, in a field that is of strategic interest
to Europe and can bring concrete benefits to citizens, for example in
improved monitoring of our environment or a more efficient transport system".

For additional information:

Géraldine Naja
ESA, Directorate of Strategy
Tel: +33.1.53.69.69.75
Fax: +33.1.53.69.7382
e-mail : geraldine.naja@esa.int
For more information on ESA, visit our web site at : www.esa.int

============================
* LETTERS TO THE MODERATOR *
============================

(9) THE YORK "METEORITE" AND OTHERS

From Andrei Ol'khovatov <olkhovatov@mtu-net.ru>

Dear Dr. Peiser, and All,

I would like to make a methodological comment regarding the latest York
"meteorite" story.
Besides magic power of electric phenomena, the story reveals some tendency
of practically  automatically attribution of almost every event associated
with "something flew or exploded" to a "meteorite fall".  Another good
example is the Dec.7, 1999 Guyra, Australia "meteorite fall", which later
was discovered to be terrestrial origin (see:
www.geocities.com/olkhov/gr1997.htm#13). Initially just a few experts
doubted that it was a meteorite fall. It is also possible to recall the
Dec.4, 2000 Salisbury, USA "meteorite" fall, having nothing to do with a
meteorite. Our Nature is much more complex (and interesting), and we should
not forget about this.

Sincerely,
Andrei Ol'khovatov
Moscow, Russia

=============
(10) GEOLOGY KEEPER RUSHED CONCLUSIONS

From Ron Baalke <baalke@zagami.jpl.nasa.gov>

 
> SPACE ROCK FALLS ON YORK
>
> >From BBC, 1 March 2001 (16.00 GMT)
> http://news.bbc.co.uk/hi/english/sci/tech/newsid_1196000/1196688.stm

> A meteoroid has landed in a field in York, UK, narrowly missing a woman
> walking her two dogs.
> Officials from the Yorkshire Museum have confirmed it was made by a rock
> falling from space. It is almost 10 years since any such similar event
> has been recorded on the UK mainland.
 

Hmmm...I'm curious how they confirmed it was a meteorite when no rock was
recovered. Also, they have now determined that the hole was created when an
underground electrical cable short-circuited. See the updated BBC article:

from BBC, 1 March 2001 (16.06 GMT)
http://news.bbc.co.uk/hi/english/sci/tech/newsid_1196000/1196688.stm

===========
(11) "BACKGROUND RADIATION": ANOTHER FALSE ALARM?

From Phil Plait <badastro@badastronomy.com>

AHA! The electric cable snapping would explain the smoke too. That was
bothering me; meteorites are usually cold when they hit, so there shouldn't
be smoke.

I am still baffled by the claim of "background radiation", and why that
would make a sound. Another flase alarm?

-Phil

The Bad Astronomer 

================
(12) THE "CHRISTMAS" COMET

From Jonathan Shanklin <jdsh@bas.ac.uk>

Dear Benny,

Readers might also like to look at
http://cfa-www.harvard.edu/cfa/ps/Ephemerides/Comets/2000WM1.html and the
associated magnitude estimates. This ephemeris uses m = 6.5 + 5 log d + 10
log r (ie n = 4) and predicts that the comet will be closest to the Earth on
December 2 at a distance of 0.32 AU; it also predicts that the comet will be
brightest at 4th magnitude, on January 18 a few days before perihelion.
Recent CCD magnitude estimates are broadly consistent with the ephemeris, at
around 17th magnitude.  It should also be noted that the IAU are considering
using n=3 for routine prediction of comet brightness. It is unusual for a
long period comet to brighten as rapidly as n=7, though some comets do have
an even higher coefficient. Generally CCD magnitudes for distant, well
condensed comets are in good agreement with visual estimates, though this is
not the case for diffuse objects that are closer to the Earth.

I appreciate that in order to attract media attention it is necessary to
give objects a catchy title, however this object is not brightest at
Christmas, it is not most easily visible at Christmas, it was not discovered
at Christmas, it is not closest to the Earth at Christmas and it is not
closest to the Sun at Christmas. The phase angle is greatest within a week
of Christmas, but this is unlikely to be of significance to the public.
Given that it will be another six months before we can begin to say with any
confidence how it might behave, and that it is not impossible that other
objects will be discovered, it is a little premature to give the comet the
title 'Christmas comet'.

I quoted comet Kohoutek at least in part because this is the best known
example of media hype.  It would be unfortunate if the same thing happened
with this comet.

Jonathan Shanklin
j.shanklin@bas.ac.uk
British Astronomical Association, Comet Section
http://www.ast.cam.ac.uk/~jds

===========
(13) PALEOECOLOGY & MAMMOTHS

From Bas van Geel <vangeel@bio.uva.nl>

Dear colleagues,

March 11th (20.00 or 21.00) the film 'Land of the Mammoth' will be aired by
Discovery Channel. Part of the film will be about the environment of the
'Jarkov Mammoth' (reconstruction based on the study of fossil pollen, seeds
and mosses by Bas van Geel, Jan Peter Pals and Guido van Reenen). The Jarkov
Mammoth (which lived ca 24000 years ago) was recently found in permafrost on
the Taymyr Peninsula (N-Siberia). The main conclusions of the study were:
the climate in N-Siberia during the coldest part of the last Ice Age was
very dry. The mammoth and contemporaneous large herbivores were living in a
steppe, dominated by grasses and Artemisia. The reconstruction of the
vegetation is confirmed by palynological studies of lake deposits, published
by colleagues in Potsdam.

Best wishes,
Bas van Geel

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*

THE COMET/ASTEROID IMPACT HAZARD: A SYSTEMS APPROACH

From David Morrison <dmorrison@arc.nasa.gov>

NEO News (01/03/01) Chapman White Paper

Dear Friends & Students of NEOs:

This edition of NEO News features a new "white paper" on the NEO
impact hazard by Clark Chapman, Dan Durda, and Robert Gold. I have
reproduced here only the Executive Summary, Introduction, and
Recommendations. The full paper, including table and references, is
available on the Web at
(http://www.boulder.swri.edu/clark/neowp.html).

Also included in this message is an announcement of a community forum
this month on the proposed NASA Dawn mission to orbit main-belt
asteroids Ceres and Vesta.

David Morrison

================================================

THE COMET/ASTEROID IMPACT HAZARD: A SYSTEMS APPROACH

Clark R. Chapman and Daniel D. Durda

Office of Space Studies
Southwest Research Institute
Boulder CO  80302

Robert E. Gold
Space Engineering and Technology Branch
Johns Hopkins University Applied Physics Laboratory
Laurel MD  20723

24 February 2001

EXECUTIVE SUMMARY

            The threat of impact on Earth of an asteroid or comet,
while of very low probability, has the potential to create public
panic and -- should an impact happen -- be sufficiently destructive
(perhaps on a global scale) that an integrated approach to the
science, technology, and public policy aspects of the impact hazard
is warranted.  This report outlines the breadth of the issues that
need to be addressed, in an integrated way, in order for society to
deal with the impact hazard responsibly.  At the present time, the
hazard is often treated -- if treated at all -- in a haphazard and
unbalanced way.

            Most analysis so far has emphasized telescopic searches
for large (>1 km diameter) near-Earth asteroids and space-operations
approaches to deflecting any such body that threatens to impact. 
Comparatively little attention has been given to other essential
elements of addressing and mitigating this hazard.  For example, no
formal linkages exist between the astronomers who would announce
discovery of a threatening asteroid and the several national
(civilian or military) agencies that might undertake deflection. 
Beyond that, comparatively little attention has been devoted to
finding or dealing with other potential impactors, including
asteroids smaller than 1 km or long-period comets.  And essentially
no analysis has been done of how to mitigate other repercussions from
predictions of impacts (civil panic), how to plan for other kinds of
mitigation besides deflection (e.g. evacuation of ground zero,
storing up food in the case of a worldwide breakdown of agriculture,
etc.), or how to coordinate responses to impact predictions among
agencies within a single nation or among nations.

            We outline the nature of the impact hazard and the
existing ways that a predicted impact would be handled at the present
time.  We describe potential solutions to existing gaps in the
required approaches and structures (both technical and governmental)
for dealing with impacts, including the kinds of communications links
that need to be established and responsibilities assigned.

            We recommend crafting, adoption, and implementation of
improved procedures for informing the broader society about the
impact hazard, notifying the public and relevant officials/agencies
about an impact prediction, and putting in place (in advance of such
predictions) procedures for coordination among relevant agencies and
countries.  We recommend that pro-active steps be taken, perhaps
through a high-visibility international conference and other types of
communication, to educate the broader technical community and public
policy makers about the impact hazard and the special aspects of
mitigating this atypical hazard.  For example, the most likely
international disaster that would result from an impact is an
unprecedentedly large tsunami; yet those entities and individuals
responsible for warning, or heeding warnings, about tsunamis are
generally unaware of impact-induced tsunamis.  We also recommend that
additional attention be given to certain technical features of the
hazard that have not received priority so far, including the need to
discover and plan mitigation for asteroids smaller than 1 km and for
comets, study of the potential use of space-based technologies for
detection of some kinds of Near-Earth Objects, study of chemical
rockets as an approach to deflection that is intermediate between
bombs and low-thrust propulsion, and further evaluation of the risks
of disruption (rather than intended deflection) of an oncoming object.

            Finally, we believe that international human society (and
elements of it, like the U.S. government) needs to make an informed,
formal judgement about the seriousness of the impact hazard and the
degree to which resources should be spent toward taking steps to
address, and plan for mitigation of, potential cosmic impacts.  The
existing unbalanced, haphazard responses to the impact hazard
represent an implicit judgement; but that judgement does not
responsibly address the extraordinary and unusual consequences to
nations, or even civilization, that could result from leaving this
hazard unaddressed in such an arbitrary, off-hand way.  For example,
we believe it is appropriate, in the United States, that the National
Research Council develop a technical assessment of the impact hazard
that could serve as a basis for developing a broader consensus among
the public, policy officials, and governmental agencies about how to
proceed.  The dinosaurs could not evaluate and mitigate the natural
forces that exterminated them, but human beings have the intelligence
to do so.

{This SWRI White Paper is also available at: 
www.boulder.swri.edu/clark/neowp.html}

INTRODUCTION

            The impact hazard from near-Earth asteroids and comets
has evolved from a science fiction scenario to a serious societal
issue during the past twenty-five years.  The scientific community
began to understand the implications for life on Earth of errant
small bodies in the inner solar system in 1980 when Nobel Laureate
Luis Alvarez and his colleagues published an epochal paper in Science
(Alvarez et al. 1980) advocating asteroid impact as the cause of the
great mass extinction 65 million years ago that led to the
proliferation of mammal species.  The same year, the NASA Advisory
Council advocated study of a modern-day cosmic threat to
civilization, leading to a formal study (The Spacewatch Workshop,
chaired by Eugene Shoemaker) the following year.

            A decade later, these scientific issues first received
significant public consideration when lobbying efforts by the
American Institute of Aeronautics and Astronautics (AIAA) and others
resulted in action by the U.S. House of Representatives, which
directed NASA to study the impact hazard.  NASA responded by
organizing an International Conference on Near-Earth Asteroids and
two study workshops, one (chaired by David Morrison) leading to
recommendations (Morrison 1992) for a telescopic "Spaceguard Survey"
of the larger Near Earth Asteroids (NEAs) and the second (chaired by
John Rather) evaluating a host of potential approaches to mitigation
of an impending hazard should an asteroid be found to be on a
collision course with Earth (Rather et al. 1992).

            During the 1990s, numerous scientific and engineering
conferences have been held worldwide concerning the impact hazard
(including one held at United Nations headquarters, Remo 1997) and
public interest groups were established in several nations, mostly
associated with the Spaceguard Foundation
(http://spaceguard.ias.rm.cnr.it/SGF/).  Despite official notice
being taken by several national and international entities (e.g. the
Council of Europe), little serious attention has yet been given by
governments to evaluation of the NEO hazard or preparations for
dealing it (NEO = Near Earth Objects, including comets in addition to
NEAs).  NASA, in collaboration with the U.S. Air Force, is the major
supporter of NEO research, with a few million dollars per year
devoted almost solely to the use of existing telescopes to search
for, and find by 2008, 90% of the NEAs larger than 1 km diameter
(http://neo.jpl.nasa.gov).  In late 2000, a task force recommended
that the British government consider taking initial steps to support
efforts to research the impact hazard (Atkinson 2000;
http://www.nearearthobjects.co.uk/index.cfm); in late February 2001,
however, the government responded not with concrete action but only
promising to study the matter further and formulate an international
approach to the issue.

            Other major elements of the impact hazard remain
unaddressed.  Searches for comets and for smaller NEAs are in their
infancy.  And little or no serious, official actions have been taken
by governments to be prepared to respond to any announcement of a
specific impact threatened in the years or decades ahead.  For
example, Dr. Brian Marsden, who directs the International
Astronomical Union's Minor Planet Center (where most astronomical
data concerning NEOs is cataloged:
http://cfa-www.harvard.edu/cfa/ps/mpc.html), recently said that he
had no idea who in the United States government would be
receptive to serious information he might have one day about an
impending impact.  Surely some agencies would be interested, but
communication pathways, responsibilities, and implementation plans
have yet to be established.

            This White Paper has been supported primarily by a
Presidential Discretionary Internal Research and Development grant
from Southwest Research Institute.  Its purpose is to outline
elements of a systematic approach, with various options, for dealing
with the full breadth of the impact hazard -- starting with issues
about discovery of potentially dangerous bodies, proceeding through
societal issues about evaluating the hazard and taking appropriate
advance measures, to actual mitigation of potentially threatening
impactors.  We conclude with some recommendations that might lead to
a more comprehensive and balanced approach for twenty-first-century
society to take toward a very real, if low probability, threat that
could conceivably doom everyone we know and everything we care about.

DETECTION AND IMPACT EFFECTS (omitted here)

EVALUATION AND WARNING (omitted here)

MITIGATION (omitted here)

RECOMMENDATIONS

            Our primary recommendation is that much broader groups of
people need to be educated about impact hazard issues, beyond the
superficial and often incorrect impressions they may have gotten from
their chief exposures to these matters: exaggerated/retracted news
stories about impact predictions and "near misses," and movies like
"Armageddon."  A much broader segment of the technical community,
beyond astronomers and space engineers, needs to appreciate and
become familiar with technical aspects of this hazard.  These
segments include the natural hazards community and experts in risk
assessment, meteorological storms, seismicity, climate modelling,
etc.  In addition, public officials responsible for mitigation of
(and response to) emergencies and disasters need to understand the
basic attributes of the impact hazard.  These include the
chains-of-command in the military and in the law-enforcement/civil
defense infrastructures.

            Research, planning, and preparation need to commence now,
although it remains to be determined how far such activities should
go, given the low probabilities of having to address any real, major
impacts in our lifetimes.  We believe that several issues need to be
addressed in the near future.

*  The notification system (concerning a predicted potential impact)
needs to be cleaned up, expanded, and officially adopted and
implemented.

*  Official clearinghouse/s for the best information need do be
developed (potential nuclei for such functions, including fledgling
web sites or analogous capabilities, already exist at Jet Propulsion
Laboratory, NOAA, Spaceguard Foundation, and the IAU Minor Planet
Center, among others).

*  Serious connections need to be developed with the hazard
mitigation community, including agencies like FEMA.

*  More objective approaches to communications need to be developed
to minimize misunderstanding of this hazard, which is so mismatched
to our personal experience base (extreme rarity or low chances of
happening vs. extreme potential consequences).  In other words, the
Torino Impact Hazard Scale needs to be further developed, extended,
distributed, and explained.

*  Official international channels for exchanging information about
NEO hazard-related issues and events need to be developed.

*  Within the United States, an interagency approach, and assignment
of responsibilities, for dealing with the NEO hazard needs to be
developed; the Global Change Program may provide a template. 
Analogous steps need to be developed in other nations and to
coordinate among nations.

*  Education about the NEO hazard would be facilitated by conducting
a high-visibility, international conference on the NEO hazard,
emphasizing the non-astronomical, non-NEO-deflection issues that have
so far been treated as backwater concerns in previous NEO hazard
conferences.  Perhaps a newsletter should be instituted.

*  Given widespread interest in extending the Spaceguard search down
to bodies much smaller than the 1 km goal of the U.S. search efforts,
a thorough evaluation of ground- vs space-based approaches needs to
be made.  Although spacebased efforts are usually vastly more
expensive, they have advantages that may balance the costs in some
cases; in other cases, the cost of spacebased efforts may not be
relevant (e.g. the searches may be piggy-backed onto other endeavors
that pay most of the costs).

*  We consider the case of comets to be astonishingly intractable
(they are difficult to detect, there is a short time between
detection and impact so the object can't be studied carefully, a
comet may be difficult or time-consuming to get to so it may not be
possible to "blast" it until it is almost here, a comet's motion is
difficult to predict, and the structural nature of comets is poorly
known -- they break-up independently and unpredictably).  So we
recommend more detailed study of the nature of comets and of cometary
detection/mitigation strategies.  At a minimum, we must quickly
assess how large a part of the impact hazard comets are.

*  Chemical rockets may have quite wide applicability to deflection
scenarios; we recommend more study of that technology.

*  In certain cases of attempted mitigation, disruption is more
likely than deflection.  More research needs to be done in this area,
including studies of the potential consequences of disruption.

*  All of these recommendations are predicated on a political
decision about the importance of the NEO hazard and about the
level-of-effort that should be expended in addressing it.  The
technical community needs to identify potential criteria (beyond
simple comparisons of death rates from various hazards) for making
this judgement.  We recommend that official, objective study/ies by
bodies like the National Research Council be done for this purpose. 
Ultimately, society's decision about how seriously to address the
impact hazard will have to involve broad segments of the public,
beyond the technical community.

REFERENCES (omitted here)

TABLE (omitted here)

===============================================

PROPOSED DAWN MISSION TO CERES & VESTA

from Chris Russell

Community Forum - March 11 on Dawn: A Discovery Mission to Vesta and Ceres

NASA has selected the proposed Dawn Discovery mission for a concept
study leading to a Step 2 proposal. Dawn uses solar electric
propulsion to fly to both Vesta and Ceres orbiting each for a period
of nine months. The spacecraft carries a framing camera, a mapping
spectrometer, a gamma ray/neutron spectrometer, a laser altimeter and
a magnetometer. Vesta is a dry, differentiated asteroid with a
basaltic crust and is the presumed parent body of the HED meteorites.
Ceres appears to be wet and have less distinct features. It has no
known associated meteorites. It has been postulated that Vesta
accreted dry and Ceres wet and that the water kept Ceres cool enough
to avoid differentiation. Thus these two asteroidal neighbors
represent two quite different end members of solar system evolution.

The top level science objectives, the measurement suite, and the
science team were approved during the Step 1 selection process. Over
the next several months the Dawn team will demonstrate to NASA that
we can safely achieve those objectives within the constraints of the
Discovery program. It is the intent of the Dawn science team to
engage the scientific community throughout the mission, with
community forums on our plans as we build the spacecraft and
instruments, and with participating scientist programs and data
analysis programs when we are obtaining data. The first community
forum will be held in Houston, TX on Sunday, March 11, 2001 from 1:00
to 4:00 p.m. in Admiral Room A at the Hilton Nassau Bay Hotel across
from the Johnson Space Center. The purpose of this meeting is both to
inform the community of our plans and to initiate meaningful
interactions as we execute the various mission phases. If you wish to
make a formal presentation, please contact amcglynn@igpp.ucla.ed!
u by March 1, 2001.

+++++++++++++++++++++++++++++++++++++++++++

NEO News is an informal compilation of news and opinion dealing with
Near Earth Objects (NEOs) and their impacts.  These opinions are the
responsibility of the individual authors and do not represent the
positions of NASA, the International Astronomical Union, or any other
organization.  To subscribe (or unsubscribe) contact
dmorrison@arc.nasa.gov.  For additional information, please see the
website: http://impact.arc.nasa.gov.  If anyone wishes to copy or
redistribute original material from these notes, fully or in part,
please include this disclaimer.



CCCMENU CCC for 2000

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