CCNet 127/2002 - 6 November 2002

"An asteroid photographed by a passing deep space probe proved twice
as large as expected, according to NASA scientists, who on Tuesday
released the first image of the encounter."
--Richard Stenger, CNN, 5 November 2002

"A tremendous amount of new data has been accumulated over the past
few years that points in the direction of multiple impacts."
--Gerta Keller, Princeton University, The New York Times, 5 November

"You wait an hour for a bus, then three come along all at once.
Maybe impacts are like that."
--Simon P. Kelley, Open University, The New York Times, 5
November 2002

    The New York Times, 5 November 2002

    Ron Baalke <>

    CNN, 5 November 2002

    Popular Mechanics, 5 November 2002


    David Morrison <>

    Reiner M. Stoss <>

    Christian Gritzner <>

    Hermann Burchard <>

     Andrew Yee <>

     Space Daily, 4 October 2002


>From The New York Times, 5 November 2002


For more than a decade, most scientists have believed that the extinction of
the dinosaurs was caused by a single event: the crash of an immense body
from outer space, its explosive force like a hundred million hydrogen bombs,
igniting firestorms and shrouding the earth in a dense cloud of dust that
blocked sunlight and sent worldwide temperatures plummeting.

The theory gained wide acceptance in 1991, after the discovery of a crater
buried under the tip of the Yucatán Peninsula. The giant gash stretched 110
miles from rim to rim, and its age was found to be 65 million years, the
same time as the death of the dinosaurs.

Now, however, scientists working in Ukraine have discovered that a
well-known but smaller crater, some 15 miles wide, had been inaccurately
dated and is actually 65 million years old, making the blast that created it
a likely contributor to the end of the dinosaurs.

So too, a British team has recently found a crater at the bottom of the
North Sea dating to the same era and stretching over 12 miles in a series of
concentric rings.

The discoveries are giving new support to the idea that killer objects from
outer space may have sometimes arrived in pairs or even swarms, perhaps
explaining why the extinctions seen in the fossil record can be messy
affairs, with species reeling before a final punch finishes them off.

"It's so clear," said Dr. Gerta Keller, a geologist and paleontologist at
Princeton, who studies the links between cosmic bombardments and life
upheavals. "A tremendous amount of new data has been accumulated over the
past few years that points in the direction of multiple impacts."

But Dr. Keller added that many scholars had staked their reputations on the
idea of a single dinosaur-ending disaster and were reluctant to consider the
new evidence. "Old ideas," she said, "die hard."

Her own research, Dr. Keller added, suggests the reality of multiple strikes
and raises doubts that the Yucatán rock, whose crater is known as Chicxulub,
was the event that sealed the dinosaurs' fate. Instead, she said, the main
killer "has yet to be found."

The ferment is prompting scientists around the globe to look for new craters
and to reassess the ages of old ones in search of clues to the wave of
global extinction that did in thousands of species - not only the dinosaurs
but many plants, fish and plankton - at the end of the Cretaceous period.

"There are over 170 confirmed craters on earth and we know the precise
impact age of only around half," said Dr. Simon P. Kelley of the Open
University in Britain, who found the dating error on the Ukraine crater,
along with Dr. Eugene P. Gurov of the Institute of Geological Sciences in
Ukraine. Even in the United States, he added, several craters are poorly

"In the U.K., we have a phrase, `You wait an hour for a bus, then three come
along all at once,' " he remarked in an interview. "Maybe impacts are like

The idea that a giant intruder from outer space killed off the dinosaurs was
proposed in 1980 by Dr. Luis W. Alvarez; his son, Dr. Walter Alvarez; and
their colleagues at the University of California at Berkeley. It was met
with great skepticism at first, but in time became the standard belief.

In his 1997 book, "T. Rex and the Crater of Doom," Dr. Walter Alvarez, a
geologist, said he had considered the possibility of multiple impacts until
1991 and the discovery of the huge Yucatán crater, which seemed big enough
to solve the mystery on its own.

Dr. Kelley and Dr. Gurov presented their findings from Ukraine in the August
issue of the journal Meteoritics & Planetary Science. In geologic time, the
twin birth throes of the Ukraine and Yucatán craters, they note, suggest
rather than prove "that they combined to lead to the mass extinction" at the
end of the Cretaceous period and raise questions of other possible cosmic

Known as Boltysh, the newly dated crater lies in eastern Ukraine in the
basin of the Tyasmin River, a tributary of the Dnieper. Though just 15 miles
wide, the buried crater, whose presence is revealed by deep jumbled masses
of melted and broken rocks, is surrounded by a ring of rocky debris that
extends over many hundreds of square miles, conjuring up a fiery cataclysm.
The two scientists say in their report that this kind of crash today would
have devastated a densely populated nation.

Over the years, scientists had analyzed rocky samples from the Boltysh
crater and found ages ranging from 88 million to 105 million years.

The new dating of the crater by Dr. Kelley and Dr. Gurov used a highly
accurate method that carefully measures the ratio of two isotopes of the
element argon, a colorless, odorless gas that makes up about 1 percent of
the earth's atmosphere. Argon-argon dating works because the isotopes decay
at different rates. By measuring the ratio, it is possible to estimate how
long ago the sample melted to trap atmospheric argon.

Dr. Kelley and Dr. Gurov report that seven samples of melted rock from the
depths of the Boltysh crater yielded an average age of 65.2 million years,
with an accuracy of plus or minus 600,000 years.

By contrast, Chicxulub (pronounced CHEEK-soo-loob) has been dated to 65.5
million years, plus or minus 600,000. Given the range of dating uncertainty,
the two impacts that made the craters may have occurred simultaneously or
been separated by thousands of years.

Scientists have recently looked more favorably at the idea that comets can
travel in packs. In the 1980's, a few speculated that comet showers might
produce strikes on the earth over a period of a million years or so to bring
on extinctions. The idea gained support in 1994 when the comet
Shoemaker-Levy 9 was fractured by the gravitational pull of Jupiter into 21
discernible pieces that then, one by one, bombarded the planet.

Dr. Kelley and colleagues at the University of Chicago and the University of
New Brunswick, writing in the journal Nature in 1998, gave precise dating
evidence to argue that a similar kind of celestial barrage hit the earth 214
million years ago. Spread over Europe and North America, the chain of five
craters, they wrote, indicated that a large comet or asteroid had broken up
and struck the earth in a synchronized assault.

Today, Dr. Kelley said, the odds of the Boltysh and Chicxulub craters'
having formed simultaneously, like the chain, are not great. Still, even if
their times of impact prove to have been only close, experts say, the
one-two punch could still have added to the global turmoil that did in the
dinosaurs and other creatures.

Beneath the North Sea, two British oil geologists have found another crater,
buried under hundreds of feet of ooze, that may have contributed to the
chaos. Writing in the Aug. 1 issue of Nature, Simon A. Stewart and Philip J.
Allen said they were able to date the 12-mile structure to a period 60
million to 65 million years ago. They named it Silverpit, after a nearby
sea-floor channel.

Experts say the new finds may answer an old criticism of the single-impact
theory. Critics, especially the paleontologists who specialize in dinosaur
extinction rates, had long noted that the fossil record of the late
Cretaceous shows a slow decline of many life forms rather than a single vast
die-off. That seemed inconsistent with a cosmic catastrophe.

But now, the emerging family ties among the Boltysh, Silverpit and Chicxulub
craters suggest that a series of impacts may have driven or contributed to
this slow decline.

Dr. Keller of Princeton and her colleagues have found signs of other
intruders from outer space that hit at slightly different times about 65
million years ago, strengthening the gradualist idea.

Working in northeastern Mexico, they discovered that glass spheres of melted
rock once thought to have been thrown out by the Chicxulub impactor were
more likely the result of at least two separate disasters, about 300,000
years apart. They recently presented their findings in a paper for the
Geological Society of America.

Moreover, Dr. Keller said, the evidence suggests that the earlier of the two
cataclysms formed the Chicxulub crater, making its arrival too early to
account for the killer punch of the dinosaur extinction.

Geologic clues that she and her colleagues are collecting from Mexico,
Guatemala, Haiti and Belize, Dr. Keller said, suggest that a barrage of
cosmic bodies hit the earth over the course of 400,000 years. The first was
the Chicxulub event, the second the unlocated impactor at the end of the
Cretaceous period and then a straggler some 100,000 years later.

Strong evidence exists for three impacts at the end of the Cretaceous era,
Dr. Keller said, followed by wide climate shifts that lasted through the
turbulent period.

While geologists hunt for other craters and impact events, they say the most
compelling evidence of all may have vanished. Since the earth's surface is
more than 70 percent water, it is likely that most signs of speeding rocks
from space disappeared long ago in the churning geological processes that
constantly renew the seabed. The North Sea, being relatively shallow, is an

Despite the inherent difficulties of the research, Dr. Kelley of the Open
University said he planned to redouble his hunt to "try to solve this

Copyright 2002, The New York Times

MODERATOR'S NOTE: For more background information on the multiple K/T
impacts theory see CCNet issues 107/2002 and 109/2002:

CCNet 107/2002 - 17 September 2002

CCNet 109/2002 - 19 September 2002


>From Ron Baalke <>

STARDUST Successfully Images Asteroid Annefrank During Dress Rehearsal
November 4, 2002

Late Friday evening Pacific time on November 2, 2002 at the Jet Propulsion
Laboratory (JPL) in Pasadena, California, and at Lockheed Martin Space
Systems - Astronautics (LMA) near Denver, Colorado, the NASA STARDUST flight
team pulled off a tremendously successful close flyby of the
main belt asteroid Annefrank. This flyby was used as an engineering test of
the ground and spacecraft operations that will be implemented at the primary
scientific target, Comet Wild 2 (pronounced "Vilt" 2) just over one year
from now.

STARDUST is a low-cost Discovery Mission that continues to perform as
expected after more than three and a half years into a planned seven-year
mission to rendezvous with Comet Wild 2 in January 2004. STARDUST will
collect cometary dust samples, flowing from the nucleus just hours before
spacecraft flyby, and return the samples to Earth in a Sample Return Capsule
in January 2006. The close flyby of Annefrank offered a unique opportunity
to thoroughly test all planned operations on the spacecraft and ground
support operations which will be used during the rendezvous with Comet Wild

"We performed a full dress rehearsal with the cometary dust collector
deployed as we flew STARDUST within 3,300 kilometers of Annefrank," said
Professor Donald Brownlee, the project's Principal Investigator from the
University of Washington. "The spacecraft was poised in its flyby attitude
with all the science instruments on. The flyby has exceeded all of our
expectations and provided us with unexpected data about the asteroid," said

The approach geometry to Annefrank was much more difficult than will be the
case for Comet Wild 2. The spacecraft was pointed over 60 degrees off of the
normal Sun and Earth pointing attitude and was running on its battery in
order to attempt to detect and capture images of Annefrank.

"The spacecraft performed every command perfectly and did everything asked
of it," said Allan Cheuvront, Spacecraft Engineer at Lockheed Martin Space
Systems near Denver. "We are thrilled with how well the entire operation
went. We couldn't have asked for better performance from STARDUST and the
images it captured of the asteroid exceeded everyone's expectations. The
spacecraft's pointing, attitude and flight operations were excellent. This
really adds to our level of confidence about how well the spacecraft will
perform when we reach Wild 2," added Cheuvront. Cheuvront and a team of
engineers at Lockheed Martin's spacecraft control center, known as the
Mission Support Area, control the spacecraft in conjunction with JPL and the
Deep Space Network.

The Navigation Camera was straining to see Annefrank during approach. "This
camera was operating at its limit of performance and seeing very dim stars
down to about 11th visual magnitude", said Ray Newburn, the Lead Scientist
for the camera at JPL.

However, the brightness predicted by Drs. Stephen Synnott and Donald Yeomans
of JPL was dimmer than 11th visual magnitude. "We tried everything we could
think of including taking multiple long exposures and adding these on the
ground", said Dr. T. S. Mike Wang, Optical Navigation Specialist at JPL,
"but Annefrank was not cooperating. It was just too dim."

Because of the high probability of not seeing Annefrank during the approach,
the flyby was designed to be successful without having to see it up to 20
minutes from encounter. "A flyby distance of 3,000 km (1,864 miles) was
chosen so that there was no risk of the spacecraft flying near any possible
dust environment or small satellites of Annefrank", said Ed Hirst, JPL
Mission Design Manager. "We also wanted to ensure that Annefrank would be in
the camera view at the start of the encounter sequence," added Hirst.

Since Annefrank was not seen in the approach images, the flight team felt
that the asteroid was at least as dim as predicted and possibly even dimmer.
The team decided to send up a new encounter configuration file and set the
initial flyby exposures longer. "We had a planned uplink six hours before
encounter for this very purpose," said Robert Ryan, Mission Manager at JPL.
"We had some communications problems the day before that gave us some
difficulty, but NASA's Deep Space Network gave us highest priority, and
excellent communications on Friday, allowing us to play back earlier images
we missed as well as sending our final encounter commands," added Ryan.

At 8:00 pm (PST) Friday evening, communications were established with the
spacecraft to watch its pre-loaded sequence command turn the spacecraft away
from the Sun and Earth into its flyby attitude. "We have built up over three
years of flight experience and a tremendous amount of confidence and respect
for our spacecraft to perform such operations routinely," said Joe Vellinga,
STARDUST Program Manager at Lockheed Martin who led the development and
manufacture of the spacecraft. "The spacecraft did not miss a beat during
its flyby and it maintained all critical thermal, power, attitude, memory
and reserves at or above design levels," added Vellinga.

The main function to be tested during flyby was a sophisticated flight
computer program that would take over control of the spacecraft to keep the
camera view locked on Annefrank during a 25-minute period around its closest
encounter. "This software was a derivative of the nucleus tracking software
successfully flown on the Deep Space 1 (DS1) flyby of Borrelly," said Dr.
Shyam Bhaskaran, developer of the algorithms at JPL. "Based upon my previous
experience on DS1, it performed up to my expectations with this encounter at
Annefrank with over 60 successful images having Annefrank right in the
middle of each image," added Bhaskaran. David Gingerich, Flight Software
specialist at LMA who implemented and tested the nucleus tracking software
said, "its performance was executed just like the coach drew it on the

Over 70 encounter images were obtained that show a typical small solar
system body, highly irregularly shaped and cratered. Annefrank is about
twice as large as predicted, at least 6 kilometers in diameter, but darker
than expected and therefore more difficult to detect in the early images.
Not only did the camera perform well but the University of Chicago Dust Flux
Measurement Instrument (DFMI) and the German Cometary and Interstellar Dust
Analyzer (CIDA) performed as expected.

Professor Tom Economou, DFMI scientist from University of Chicago, stated
"we ran for 28 minutes as we will at Wild 2 with DFMI performing all
expected functions". Dr. Jochen Kissel, Lead Scientist for CIDA from Max
Planck Institute in Garching, Germany, said "I will be able to put CIDA into
an even better configuration at Wild 2 based upon the Annefrank experience."
Both dust instrument teams are combing through their data to see if by
chance they may have seen a dust particle.

"Performing such flight testing before the primary encounter is a critical
part of reducing risks and significantly increasing the probability of
success when we reach Wild 2", said JPL Project Manager, Thomas Duxbury. "We
have performed exhaustive testing and training with LMA at their spacecraft
test laboratory and through flight simulations, but these cannot totally
replace actual flight operations testing. We learned a lot that will improve
our operations at Wild 2 based upon the lessons learned at Annefrank. The
bottom line is that if Annefrank had been Wild 2, we would have succeeded in
every respect," added Duxbury.

"I applaud the entire flight team," said Don Brownlee. "We could not have
asked for more, except possibly for Annefrank to be a little brighter.
However, for everything that we could control with the spacecraft, we were
nearly perfect.

Even though this was an engineering test, the flyby with Annefrank provided
new information previously unknown about the asteroid about its size, shape,
spin state and brightness as a function of viewing angle.

"It was an exciting Friday evening for those of us involved in this
mission," Brownlee said. "We captured images of a primitive asteroid with a
highly significant name and one whose size turned out to be similar to the
asteroid that likely killed the dinosaurs 65 million years ago. We have now
validated STARDUST's systems and operations and we are eagerly awaiting our
encounter with Comet Wild 2, just over one year from now".

Asteroid Annefrank images are available here:


Image of Asteroid 5535 Annefrank taken by the Stardust spacecraft just prior
to closest approach.  The gray scale figure on the right show a partially
illuminated, highly irregularly shaped asteroid, typical of all small bodies
imaged in our solar system.  The STARDUST camera resolution was sufficient
to show that Annefrank was about 8 km in length, twice the predicted size
from Earth-based observations.  The surface reflects about 0.1 - 0.2 % of
the sunlight, slightly less than predicted.  A few craters many hundreds of
meters are seen as well as surface brightness variations due to changes in
solar illumination as well as albedo variation.  These variations are
exaggerated in the false color image to the left.  Both images have been
digitally enhanced and resampled.

For more information on the Stardust mission -- the first ever comet sample
return mission -- please visit the Stardust home page:


>From CNN, 5 November 2002

By Richard Stenger
(CNN) -- An asteroid photographed by a passing deep space probe proved twice
as large as expected, according to NASA scientists, who on Tuesday released
the first image of the encounter.

After the Stardust craft passed within 2,000 miles (3,300 km) of asteroid
Annefrank, mission researchers determined that it is about 5 miles (8 km) in

The crater-pocked, oddly shaped boulder turned out to reflect much less
sunlight than originally thought, which accounted for the error of the
earlier size estimate.

"It was a challenge for the navigation camera to see Annefrank during
approach," said Stardust scientist Ray Newburn of NASA's Jet Propulsion
Laboratory in Pasadena, California.

Added Mike Wang, optical navigation specialist at JPL: "Annefrank was not
cooperating. It was just too dim."

The robot ship took dozens of images as it flew by the asteroid this weekend
at about 16,000 mph (26,000 km/h). More pictures and data should beam back
to Earth during the week.

Despite the obstacles, the robot ship's instruments and systems performed
well during the flyby, a dress rehearsal for its primary mission, an
encounter with a comet in 14 months, NASA said.

Launched in 1999, Stardust should return to Earth in 2006 with samples from
comet Wild-2 as well as interstellar dust particles near the asteroid belt.
The mission is the first designed to return with materials from beyond the

Annefrank was discovered in 1942. The asteroid was later named for Anne
Frank, a young Dutch girl and writer who died in a Nazi concentration camp
in 1945.

Copyright 2002, CNN


>From Popular Mechanics, 5 November 2002
Hundreds of shooting stars an hour, smoky trails in the sky, huge flashes,
and even sonic booms--these can be the effects of a meteor storm. And it
gets even more exciting. During the Leonids meteor shower of November 2001
some alert stargazers observed and documented on video a dazzling flash
coming from the moon's dark side.

David Palmer, an astrophysicist at Los Alamos National Laboratory, recorded
the explosion from his backyard in White Rock, N.M., using a portable
telescope and a low-light video camera. Even though it was twilight, the
flash was bright enough to be detected, Palmer says.

Leonid meteor showers are produced when particles from the tail of the comet
Tempel-Tuttle encounter the Earth's atmosphere at a speed of more than
60,000 mph. That causes the tiny grains of cometary dust to vaporize
instantly, creating the sudden flashes we see from the ground.

Unlike Earth, however, the moon doesn't have a protective atmosphere in
which meteoroids harmlessly disintegrate, says NASA's Bill Cooke. In fact,
when kilogram-size Leonids hit the lunar surface, they explode in
spectacular fashion, digging craters and melting the terrain with
temperatures reaching up to 200,000° F.
This is a composite of four successive frames (1/30 second each) showing the
impact of a meteor and its afterglow. NTSC video frames consist of two
fields (each 1/60 second) filling in first the even then the odd rows of
pixels. This causes the light-dark "Venetian blind" effect for rapidly
changing light sources such as this.
Throughout the 1970s, Apollo seismic stations recorded impacts from Leonids
and other annual meteor showers. But it's only since 1999 that explosions on
the moon have been seen from Earth, Cooke says. In fact, at least six
Leonids hit the moon in 1999, causing explosions visible from Earth.

The lack of any detectable atmosphere would deprive future lunar settlers of
both protection and the fiery shows we enjoy on Earth. For an astronaut, the
probability of being hit by a 10- to 5-gram Leonid while on the moon is only
0.00025:1, says Cooke. Nevertheless, such meteoroids have enough energy to
pierce a spacesuit and severely injure a person. "The probability of being
hit by something that might totally vaporize you, like a 10-kilogram
fragment, is a billion times less," says Cooke.
Copyright 2002, Popular Mechanics


>From, 5 November 2002
By Robert Roy Britt
Senior Science Writer

A father-daughter science team has found what they say are the oldest known
impact craters on Mars, ghostly structures that could only be discerned with
special software and the latest elevation data.

Images obtained by reveal hints of circular outlines and subtle
depressions that appear to be craters created during tremendous asteroid or
comet impacts that pummeled the Red Planet's original crust 4 billion years
ago or more. The features have since been mostly buried or eroded away. 

The global distribution of craters larger than 125 miles (200 kilometers).
Solid circles show visible craters. Dashed circles indicate older, mostly
buried craters found with elevation data in the new study.

If the entombed craters exist as suspected, then the current visible surface
of Mars does not represent the original crust, as some scientists have

The work began as a science fair project and was led by planetary geologist
Herb Frey of NASA's Goddard Space Flight Center. He and Erin Frey, his
daughter and a junior at South River High School in Edgewater, Md., used
altimeter data collected by the Mars Global Surveyor and ran it through
newly developed computer software.

A graphics program turned elevations into different colors. By shifting and
stretching the colors to study various ranges of elevation change, the
researchers spotted faintly detectable features they call quasi-circular
depressions, or QCDs. The Freys figure these depressions are craters from
early times before the Noachian period, which may date back about 4 billion
years and is the oldest identified geological time period on Mars.

"We are talking about crust that's actually older than what's seen at the
surface," Erin Frey said. "We can't assign absolute ages because we don't
know how far back these subsurfaces go."

Rocky history

Mars, Earth and the other planets are thought to have formed about 4.5 or
4.6 billion years ago. A period of heavy bombardment likely ensued, as
countless rocks were cleared from the fledgling solar system. A record of
the bombardment remains on the Moon, where little erosion or geologic
activity takes place.

But on Mars and Earth, figuring out what happened more than about 3 billion
years ago is very, very difficult. Until now, there was little firm evidence
about the original early crust of Mars.

Erin Frey's work focused on a region near the Hellas Basin of Mars,
considered by previous studies to be old. It suggests an intense period of
asteroid and comet impact preceded the Noachian period. Most of the evidence
was covered over by later impacts and billions of years of geologic

Herb Frey looked at the entire planet. He found large depressions, all more
than 125 miles (200 kilometers) in diameter, buried under dust, volcanic
material and other sediments in the relatively crater-free northern lowlands
of Mars, as well as in the visibly cratered southern highlands. He said it's
"a very squirrelly business" trying to assign ages to the features they've

He suggests, however, that the northern lowlands were formed very early by
massive impact events. "It fits in with the time scale," he said.

Surface meaning

"Erin's results show that the assumption many people have made that the
oldest visible surface units go back to 4.6 billion years ago is wrong," the
father told "That means the absolute time scales people have
tried to use are probably wrong. It also means there is a recoverable
history on Mars that we cannot easily see, except in terms of the crater
record. The surface we see is not the original crust of Mars, but something

How does a high school student get involved in such important work?

"Each year of high school I was required to complete a science project, and
my contacts at the Goddard Space Flight Center allowed me to study unusual
topics," Erin Frey said. "Beginning in freshman year, I was introduced to
the topography of Mars and completed research on a similar subject. I
continued my work through 10th grade, which eventually turned into this

The paper also won 1st Place at a county science and engineering fair. The
Freys presented their findings last week at a meeting of the Geological
Society of America in Denver.

Copyright 2002,


>From David Morrison <>

Triennnial Report for the International Astronomical Union


PRESIDENT: David Morrison
SECRETARY: Richard Binzel

MEMBERS:  Mike A'Hearn, Mark Bailey, Richard Binzel, Carlo Blanco, Andrea
Boattini, Ted Bowell, Andrea Carusi, Clark Chapman, Paul Chodas, Nikolaj
Chernykh, Julio Fernandez, Daniel Green, Gerhard Hahn, Alan Harris, Eleanor
Helin, Syuzo Isobe, Claes-Ingvar Lagerkvist, Steve Larson, A.C.
Levasseur-Regourd, Brian Marsden, Robert McMillan, Andrea Milani, David
Morrison, Karri Muinonen, Syuichi Nakano, William Napier, Steven Ostro,
Steven Pravdo, Hans Rickman, Hans Scholl, Ken Seidelmann, Peter Shelus,
Viktor Shor, Maria Sokolskaya, Duncan Steel, Grant Stokes, Gonzalo Tancredi,
David Tholen, Jana Ticha, Giovanni Valsecchi, Richard West, Gareth Williams,
Iwan Williams, Makoto Yashikawa, Don Yeomans.

CONSULTANTS: David Asher, Dave Balam, Mario Carpino, Steve Chesley, Chris
Chyba, Victoria Garshnek, Scott Hudson, Leon Jaroff, Alain Maury, Jacqueline
Mitton, Oliver Morton, Petr Pravec, David Rabinowitz, Geoff Sommer, Tim
Spahr, Jonathan Tate, Milos Tichy

REPORT: This Working Group is sponsored jointly by Division I and Division
III. The charge of the WG includes (1) Liaison with SpaceGuard Foundation
(2) Advise on coordination of NEO activities worldwide (3) Advise on
reporting of NEO hazards (4) Advise on research relevant to NEOs. The WG
also maintains a standing review committee to provide a voluntary technical
peer review of predicted close approaches of NEOs, where such predictions
include estimates of the possibility of collision with the Earth. The IAU
also provides partial sponsorship of the Minor Planet Center in Cambridge
MA, with orbital and other information on all known NEOs available at

During this triennium, the WGNEO met at the IAU General Assembly in
Manchester and held one additional formal meeting in Palermo, Italy, in
conjunction with the conference "Asteroids 2001: From Piazzi to the Third
Millennium" (June 11-16, 2001). More than half of the WGNEO
members were present at Palermo. The WGNEO reaffirmed its commitment to
providing accurate, timely, and responsible information to the public on NEO
impact risks. The WGNEO maintains a Technical Review Committee for the
purpose of providing rapid peer review of predictions of possible impacts.
However, the development of on-line computational tools at JPL and in Pisa
(see below) means in practice that such reviews are automatic and
practically instantaneous, so that the formal IAU procedure is unlikely to
be much required in the future. A new hazard metric, called the Palermo
Technical Scale, was approved to compare the risk from newly discovered NEAs
<>, although it does not
replace the Torino Scale for public communication (see below).

The past three years have seen a tremendous growth in the study of NEOs.
This period includes the one-year orbital study of 433 Eros by the NASA
spacecraft NEAR-Shoemaker, followed by a landing on the asteroid surface
<>. This mission has effectively resolved in the
affirmative the long-standing issue of the association between S-type
asteroids and the primitive ordinary chondrite meteorites. New radar studies
have provided images of NEAs and include the discovery of several binary
objects, which permit the calculation of densities
<>. Automated orbital calculation and risk estimates
are now continuously available on-line through the NEO Dynamics system at
Pisa <> and the Sentry system
at JPL <>. The Spaceguard Survey discovery
programs, led by the LINEAR MIT system <>, have
found more than 600 of the estimated 1100 +/- 100 NEAs brighter than
absolute magnitude H=18 (diameter approximately 1 km). The primary
Spaceguard search programs are supported by the United States government
(NASA and the U.S. Air Force), with an international team for astrometric
follow-up. The goal of the Spaceguard Survey is to find 90% of the NEAs
larger than 1 km diameter by the end of 2008.

Communication with the international scientific community and with the
interested public represents an important part of the WG efforts. One tool
for public communication is the Torino Impact Scale, which has been adopted
by the WG and other NEO scientists for this purpose. The Torino Scale is a
"Richter Scale" for categorizing the Earth impact hazard associated with
newly discovered asteroids and comets. The scale is described at
<>. Other
websites, although not formally endorsed by the IAU, also provide a valuable
communication functions. These include the NASA NEO Program Office
<>, the NASA impact hazard website
<>, the UK NEO Information Centre
<>, and the Spaceguard Foundation and its
on-line magazine Tumbling Stone <>.

David Morrison, November 4, 2002

NEO News is an informal compilation of news and opinion dealing with Near
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>From Reiner M. Stoss <>

 MACE 2003 - Meeting on Asteroids and Comets in Europe
      May 1-4   Costitx - Mallorca SPAIN 

Dear minor planet observers,
During the first MACE2002 held last year in Visnjan, Croatia, where
observers, orbit computers and other people involved of 13 different
countries shared an interesting scientific programme
and enjoyed a wonderful social plan,  some ideas concerning the role of the
european minor planet astrometry future were discussed and some objectives
were established. With the purpose of continuing the line drawn those days
and for improving and searching for new goals, we have the pleasure of
announcing the new MACE 2003 edition that will be held at OAM - Mallorca
Observatory, in Mallorca island, on the Mediterranean sea, Spain, during the
next  May 1-4,  2003. 

We look forward to seeing you in Mallorca !
   Yours sincerely      
                Salvador Sanchez
      On behalf of the Local Organizing Committee


         Gruppo Italiano Astrometristi 
         Spaceguard Spain
         NEODyS Univ. Pisa
         Grup d'Estudis Astronomics
         Spaceguard Foundation 
         FG Kleine Planeten VdS

         Consell de Mallorca
         Govern de les Illes Balears
         Ajuntament de Costitx

- To continue and improve the relations and the established projects.
- To connect to other observers over borders and language barriers.
- To improve the technology and techniques of observing.
- To search for goals of small observatories in the future.


The scientific programme will include invited, contributed talks and
posters.   The topics that will be covered at MACE 2003 include:
- Projects and scientific results on minor planets.
- Advances in telescope design.
- Observing methods and future projects for small observatories.
- Robotic and remote observation and tools for reduction data.
Also some observational and data reduction "live" sessions are


Luciano Bittesini   (Farra d'Isonzo Observatory) Italy
Korado Korlevic   (Visnjan Observatory) Croatia
Jaime Nomen   (OAM-Mallorca & Ametlla de Mar Observatories) Spain
Petr Pravec   (Ondrejov Observatory) Czech R.
Herbert Raab   (Linz Observatory)  Austria
Jure Skvarc   (Crni vrh Observatory) Slovenia
Stefano Sposetti   (Gnosca Observatory) Switzerland
Reiner Stoss   (Starkenburg Observatory) Germany
Juraj Toth   (Modra Observatory) Slovakia


Oscar Arratia   (NEODyS team) Spain
Manolo Blasco   (OAM-Mallorca Observatory) Spain
Vadim Burwitz   (Max Planck institute & OAM-Mallorca Observatory)
Antonio Garcia   (OAM-Mallorca Observatory) Spain
Joan Guarro   (OAM-Mallorca & Piera Observatories) Spain
Jose-Luis Ortiz   (Instituto de astrofisica de Andalucia) Spain
Gabriel Pieras   (Consell of Mallorca) Spain
Juan Rodriguez   (OAM-Mallorca Observatory) Spain
Salvador Sanchez   (OAM-Mallorca Observatory) Spain
Genny Sansaturio   (NEODyS team) Spain


OAM-Observatorio Astronomico de Mallorca
Cami del Observatori s/n
Costitx, 07144 Mallorca

Tel:   34-689686557
Fax:  34-971876022


MACE 2003 will be held in the Civic Center of the village of
Costitx, very close to the Observatorio Astronomico de Mallorca,
however, some observational sessions will take place at the
Observatory and the Planetarium.

More info at:

 Please send your answer to this address: 

   First name:
   Last name:
   Comments and suggestions:
   I will participate (yes/maybe/no):



>From Christian Gritzner <>

Dear Benny,

as mentioned in the JPL news about the fly-by of Stardust at the asteroid
(5535) Annefrank, the albedo of Annefrank is said to be extremely low: "The
surface reflects about 0.1 - 0.2 % of the sunlight, slightly less than
predicted". This would be an albedo of 0.001 - 0.002 which is much lower
than common asteroid albedo values. I suppose this is a typing error.

According to the Solar System Exploration Target Bodies page of JPL the
absolute magnitude of Annefrank is H = 14.2. see:

Using the MPC page Conversion of Absolute Magnitude to Diameter and the
measured diameter of 8 km by Stardust for a brief estimation an albedo of
0.05 or higher (about 0.1 to 0.2) seems to be appropriate. see:

Therefore, the cited text should read as "The surface reflects about 10 -
20% (albedo 0.1 - 0.2) of the sunlight...".


Dresden University of Technology
Institute for Aerospace Technology
Dr.-Ing. Christian Gritzner, Senior Engineer
D-01062 Dresden, Germany
Phone: +49-(0)351-463-38234 (Fax: -38126)


>From Hermann Burchard <>

Dear Benny,

some data on airbag/rocket push schemes for NEO defence.

The recent proposals for NEO-defence by laser ablation seem very promising.
It would be interesting to see what kind of energy supply is envisioned for
this scheme.

There must exist quite a few papers on the physics of NEO-defence, but I
have not tried to acquire that literature, and probably there are no
surprises here for experts in the aero-space world. Instead I have tried to
do some simple-minded computations to get first quantitive data on the
airbag idea. If you recall, in at least one version, the proposal is to send
up a spacecraft with an ample fuel supply for its rocket engine and some
inflatable airbags to use as dynamical coupling to nudge the rock over to a
new and harmless orbit.

One of the more iffy parts of the proposal is the need to perform gravity
assist "slingshot"  maneuvers to bring the craft on an orbit where it flies
along side the NEO. I will have nothing to say on this, as in each specific
case an astronomical calculation has to be done (which NASA's JPL people are
accustomed to doing) in order to determine possible trajectories of approach
of the craft to the NEO.  A sufficient amount of lead time of years may be
needed, unless Earth and Moon happen to be in favorable positions (my

My airbag data are based on using NASA's hydrogen-oxygen SME - Space Shuttle
Main Engine propulsion system to push the space rock aside. SME power
characteristics are easily retrieved from the web.  The unit of fuel is one
ET - External Fuel Tank, the large red tank so familiar from Shuttle launch
videos.  One ET carries 1,359,000 lb or 616,000 kg of its H-O fuel. That's
616 metric tons that must be boosted to beyond escape velocity per ET.

It turns out that a simple formula relates fuel need dMf to NEO mass MNeo:
   MNeo/dMf = 6920*t.

Here, t (=time to impact) is the time in years that we have available to
wait out for the effect of the initial rocket push to grow inertially prior
to the space rock flying by Earth.  To avoid Earth, the total deflection
=dRE at the end of the t years should be three Earth radii, dRE= 3*RE,
RE=6,400 km, which I thought was reasonable.  Here, I am avoiding any
complicated nonlinear orbital mechanics and instead use dead-reckoning: If
the initial impulse supplied to the rock is dp=dv*MNeo, with dv=the imparted
velocity perpendicular to the natural velocity vector of the NEO, then I am
estimating that dRE=dv*t.

Of course, in reality, this initial perturbation may be either enlarged or
diminished by gross effects of orbital mechanics. These would be quite
impossible to predict in any generality.  Thus, in effect, I am postulating
a model, where the space rock heads toward Earth along a straight line path
with no other bodies around to cause interference. The next refinement might
be to consider the curvature in orbits due to the Sun, in other words, try
to figure out the actual effects of an initial perturbation on elliptical
orbits.  Of course, as has recently been pointed out, chaotic orbits may
occur, in which case even elliptic predictions would be wholly inadequate.
Thus, we stick here to the dead-reckoning scheme.

To get going, NEOs are assumed to be asteroids or comet fragments of density
three times that of water. This should be in a range between a dirty
snowball and a chondrite, I am hoping. If an iron meteorite is to be dealt
with, adjustments will be needed. Diameters I looked at range from small to
moderate, 85 m, 350 m, and 900 m (in meters). Much larger rocks would
require special considerations due to rapid increase to megatonnage range of
Fuel required.

The bags need to be inflated to exert pressure against the space rock. It
turns out that the amount of gas required is trivial. Assuming the SME is
throttled down to where it can be safely coupled to the bag, we need a
throttle factor =trfac, perhaps in the range of .1 or even smaller.  Let
pres_at denote the bag pressure in atmospheres (=1,033 millibar), then the
force on the bag exerted by the throttled SME is

                      fbag = .209*10^7*trfac*m*kg/s^2
                           = 470,000*trfac*lb.

Here, we use a scheme to fix the bag radius at a value of

                      rbag = 2.563*(trfac/pres_at)^.5*m.

(Of course, x^.5 is just our abbreviation for the square root of x.) With
all this, the SME fuel need N_ET in number of ET units (see above) for the
350 m asteroid is (in terms of t=time to impact)
                              N_ET = 25.9/t.

The amount Mbag of gas (helium) in the bag is
                        Mbag = 27.6*(trfac^3/pres_at)^.5 kg.

Here, I used the ideal gas law at a temperature of 100 C.



>From Andrew Yee <>

ESA News

4 November 2002
Take a chance to write the future

The only way of discovering the limits of the possible is
to venture a little way past them into the impossible.
     - Arthur C. Clarke

>From Cyrano de Bergerac's 17th century trip to the Moon and Jules Verne's
19th century Nautilus submarine right up to William Gibson's navigations
through cyberspace and Kim Stanley Robinson's colonisation of Mars, authors
have always signposted the shape of things to come.
Now ESA is giving young science fiction writers the chance to showcase their
own future visions with a worldwide competition.

The Clarke-Bradbury International Science Fiction Competition is named in
honour of Arthur C. Clarke and Ray Bradbury, whose writings have inspired
generations of space scientists and explorers.

To highlight this vital connection between initial idea and later reality,
writers aged between 15 and 30 are invited to submit short (2500 word
maximum) stories dealing with the technologies of space travel, exploration
or settlement.

"I hope the competition will attract many entries, and inspire more and more
young people to take to writing science fiction," said Arthur C. Clarke.
"Today's youth take for granted the marvels of modern technology, many of
which were envisioned in the science fiction of my youth (and some of my own

"Last year ESA carried out a detailed survey of science fiction concepts in
search of those worth real-world development which culminated in a
beautifully illustrated brochure. Continual technological progress means
ideas that were once wild speculation may now have come within
the bounds of feasibility", noted ESA's David Raitt, organizer of the

Take the exotic concept of the 'space elevator'. In 1895 Russian theorist
Konstantin Tsiolkovsky was inspired by a trip to the Eiffel Tower to imagine
a tower reaching up to orbital altitude. Arthur C. Clarke brought the idea
up to date in his 1979 novel The Fountains Of Paradise.
Crews and cargo could ride elevators up the tower into space.

Now science has discovered a material called carbon nanotubes, strong enough
to withstand the tensile stresses an orbital tower would experience. Current
thinking suggests that a space elevator could be built within the next dozen
years or so. Seattle-based HighLift Systems is well advanced with
theoretical and initial development work and estimates that the space
elevator would reduce launch costs to a mere Euro 10/kg!

Solar or light sails are another SF concept -- first featured in the short
stories of Cordwainer Smith and the Arthur C. Clarke tale 'Sunjammer' and
set to become reality much sooner. Once unfurled, sails can either be
propelled by light from the Sun or alternatively a continuously-firing

Proving the basic concept, a bowl-shaped 'lightship' has been lifted 20
metres high by laser pulses in the USA. While in Europe, ESA and DLR have
designed a prototype 20 metre square solar sail for future space flight.

During the ESA study for closer examination more than 250 such technology
concepts were collected by scientists, engineers, science fiction writers
and laymen from science fiction literature and films. And the hope is that
the competition could uncover or generate yet more promising ideas.

Five stories will be selected by an international jury to receive prizes and
from these a Winner will be chosen who will be invited to present his/her
story at the 2003 International Astronautical Congress in Bremen, Germany.
All the best entries will be published in a book by ESA.

The deadline for entries is 28th February 2003. Anyone interested in giving
the competition a try can find out more here or contact:

David Raitt
Technology Transfer and Promotion Office
European Space Agency, ESTEC, The Netherlands

More information

* ITSF competition

Related articles

* BR-176 brochure: Innovative Technologies from Science
  Fiction for Space Applications (pdf)

Related links

* ESA's Technology Transfer Programme
* ITSF homepage
* HighLift Systems -- Space Elevator
* Maison d'Alleurs: Museum of science fiction, utopia and
  extraordenary journeys
* MoonFront
* The Ours Foundation


[Image 1:]
Artist impression of a climber being beamed up the carbon nanotube ribbon of
the Space Elevator. The track and roller climber system presses onto the
ribbon and provides traction for movement up and down the tether. The
circular base consists of photovoltaic cells and receives power from a laser
beaming station on the surface below. Credits: Brad Edwards and HighLift

[Image 2:]
As the environmental conditions on other planets may be harmful to
astronauts, artificial habitats or biospheres will be required in the early
stations of colonization. Credits: Jeam Tag

[Image 3:]
Interstellar sails rely only on the solar wind or starlight to propel them
through space. This means the spacecraft can be much lighter as it carries
no engine or fuel. Credits: Mark Garlick

[Image 4:]
Artist impression of an ocean-going refurbished oil platform, based on the
current Sea Launch programme, which would be used for the Earth anchor
station for the Space Elevator and located in the equatorial Pacific Ocean.
Credits: Brad Edwards and HighLift Systems


>From Space Daily, 4 October 2002

Huntsville - Nov 04, 2002

Like farmers across the nation bringing in their crops this season,
researchers in Wisconsin are carefully taking stock of a very special
harvest - one grown aboard the International Space Station.

They've measured and weighed plants, counted seeds, and collected additional
physical information from the first-ever soybean crop grown aboard the
orbiting research laboratory.

Now, the research team will begin several months of chemical and biological
tests on the plants that will reveal whether microgravity - the low-gravity
environment inside the Space Station -- has changed the chemical make-up of
the seeds.

Soybeans -- a leading source of protein in the human diet -- are used in a
wide variety of products, from oil to crayons. Finding improved varieties
could have a significant economic impact on a soybean business worth
billions of dollars each year.

"We want to examine the seeds produced by plants grown on the Station to see
if they have any unique, desirable traits," said Dr. Tom Corbin, a research
scientist for Pioneer Hi-Bred International Inc., a DuPont subsidiary with
headquarters in Des Moines, Iowa, and the industrial sponsor for the
experiment. "If we find changes, then we want to know if the positive traits
can be inherited genetically by future generations of plants for the benefit
of farmers and consumers."

Space Shuttle Atlantis visited the orbiting laboratory this month during the
STS-112 mission to deliver new experiment equipment and other supplies and
return with the soybean plants and other completed experiments.

Space Shuttle Atlantis visited the orbiting laboratory this month during the
STS-112 mission to deliver new experiment equipment and other supplies and
return with the soybean plants and other completed experiments.

"This experiment and others are paving the way for improving crops grown on
Earth, as well as potentially feeding people living in space," said Mark
Nall, director of NASA's Space Product Development Program at the Marshall
Space Flight Center in Huntsville, Ala. The program has helped companies fly
several experiments on the Station by working with one of NASA's 15
Commercial Space Centers located across America.

"The Space Station is giving companies a chance to grow plants that require
several months to mature," said Nall.

NASA International Space Station Science Officer Peggy Whitson took care of
the soybeans on the Station since the experiment began in June. In one of
her e-mail letters to family and friends this summer, she reported, "The
beans looked mature and the leaves are turning brown."

The plants and seed pods were turning brown because scientists wanted them
to dry out and be preserved for tests on Earth.

It turned out to be a very good crop.

"The first soybean crop grown in space returned in excellent condition, and
a total of 83 seeds were harvested from 42 seed pods," said Dr. Weijia Zhou,
director of the Wisconsin Space Center for Automation and Robotics at the
University of Wisconsin-Madison. "Since a plant's habitat plays a key role
in determining the physiological and biological characteristics of the
plant, we believe that reduced gravity may affect plant chemistry."

The Wisconsin center is a NASA Commercial Space Center, and was responsible
for building the Advanced Astroculture* plant growth chamber where the
soybeans germinated and grew for 97 days.

"We will analyze the oil, proteins, carbohydrates and secondary metabolites
in the seeds produced in space," noted Corbin, whose company is the largest
seed company in the world. "We will continue analysis of the soybeans at
Pioneer's laboratory in Johnston, Iowa, and we anticipate having results in
two to three months."

NASA is interested in the technologies that enable production of
commercially important crops like soybeans in space because these
technologies will be needed to produce vegetable crops that support a
long-term human presence in space.

Can new varieties of crops be produced using seeds produced by space-grown
plants? Do these space plants produce seeds with higher oil content or
improved nutritional value? Can elite seeds be produced that will improve
farmers' crop yields and the quality of plants products used in consumer

Zhou and Corbin hope to begin answering these questions by analyzing the
space-grown plants and seeds. On Earth, the development of naturally bred
crop seeds is time consuming, usually taking several years. If this process
can be accelerated with space-grown, plants, it would make the Station an
attractive research laboratory for industry to use in crop development.

"As a science company, DuPont knows that future research opportunities may
come from totally different venues and needs as we look ahead," said Dr.
Thomas M. Connelly, DuPont's chief science and technology officer. "The
discovery process often requires exploring in unprecedented avenues to
unleash the next wave of innovation, and we are committed to discovering new
and meaningful innovation wherever it is."

Growing plants in space could provide salads for future space crews, but
they also may bring other psychological and biological benefits. When she
first saw the growing soybeans, Whitson, an Iowa native, reported in an
e-mail letter home to family and friends, "It was surprising to me how great
soybean plants looked. I guess seeing something green for the first time in
a month and a half had a real effect. I think it's interesting that the
reaction was as dramatic as it was...guess if we go to Mars, we need a

Over the next few months, Whitson will continue her gardening duties,
tending a crop of mustard plants that will soon be growing inside the Plant
Generic Bioprocessing Apparatus -- designed and built by BioServe Space
Technologies, a NASA Commercial Space Center at the University of Colorado,
Boulder. The U.S. Department of Agriculture's Forest Products Laboratory,
Madison, Wis., and the NASA Ames Research Center, Moffett Field, Calif.,
which also has grown plants on the Station, and a consortium of industries,
are partners on the experiment.

"This is the first in a series of Space Station plant experiments that will
study the role of gravity in producing lignin, a substance that affects the
strength of plant stalks and stems," said Louis Stodieck, director of
BioServe Space Technologies. "Identifying the genes that control lignin
production in plants has broad applications in the timber and pharmaceutical

Plants need lignin for strength to stand upright under the force of Earth's
gravity. But this chemical must be removed to produce paper -- a costly
process that results in pollution. Reducing the lignin content of plants
could make it less expensive to produce paper and reduce pollution.

Another significant benefit of growing plants in space is the educational
benefit. Space Explorers, Inc., a commercial firm in Green Bay, Wis.,
produces Internet-based, space education programs. The company used data
from the ADVANCED ASTROCULTURE* experiments to create the "Orbital
Laboratory" educational software program. It allows students to design,
conduct and analyze plant experiments on the Space Station.

Then they can compare data through an online student experiment database.

After the experiment is finished on the Space Station, students can use
actual data from the experiment to recreate the experiment in a virtual

During Expedition Five, students from California to New York grew soybeans
and dwarf wheat plants, similar to those already grown on the Station, under
nine different growing conditions. Via the Internet, they shared their
results and how those results might affect plants grown on long-term space

Copyright 2002, Space Daily

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