CCNet 119/2001 - 13 November 2001

"The key points from Colin Hicks: The PPARC report will come in
later in the year, after the ESA science summit. There is no specific
slot set aside at the science summit for discussion of dealing with
the impact hazard, though Sir Colin emphasized the real improvement
since they first started on the problem 2 years ago: many researchers were
now highlighting the benefits which their existing proposals would bring
to dealing with the impact hazard.... As regards the ESA science summit,
on a more positive note there will be a spectacular meteorite display
co-incident with it, so perhaps discussions there may further focus on
dealing with the impact hazard."
--Ed Grondine, 13 November 2001

"Recent research results published by astronomers using data from
the Sloan Digital Sky Survey in the United States have been interpreted as
indicating that the Earth faces a reduced hazard from asteroids. This
is sadly not the case. The results, published in the November issue of
the Astronomical Journal, are not significantly different to the lowest
of others produced in the past five years, hardly justifying the headlines
that have appeared around the world. This can come as no comfort to
the British government who have spent a year pondering the 14
explicit recommendations of their NEO Task Force that were published in
September 2000. So far the BNSC has only announced the firm intention to
action one half of one of them. The impending establishment of a National
NEO Information Centre, probably at the NSC in Leicester, is a
welcome development, but is only the first step in the implementation
of the Task Force's recommendations. One of the main tasks of such an
institution should be to facilitate the implementation of the other
recommendations, but the BNSC appointed centre will probably be unable to do
so under the terms of its contract."
--Jay Tate, Spaceguard UK, 11 November 2001

    Robert Lunsford <>

    Daniel Fischer <>

    Spaceguard UK <>

    The New York Times, 13 November 2001

    Space Daily, 13 November 2001

    Washington Post, 12 November 2001

    Matthew Genge <>

    E.P. Grondine <>

    Gamezilla, 11 November 2001


>From Robert Lunsford <>

The Leonid meteor shower occurs every year between November 14 and the 21st
as the earth encounters particles left behind from comet Temple-Tuttle. This
comet orbits the sun every 33.25 years and leaves debris in a slightly
different path with every return. The debris the earth encounters is normally sparse
creating no more than 10-15 meteors per hour at best.

What makes this year exceptional is that the debris fields or paths orbiting
near the comet, which last passed the sun in 1998, has a much higher
concentration of material than in normal years when the comet is far from
the inner solar system. In 2001 the earth will pass close to
three separate paths of the comet. These paths were created by the comet in
1699, 1767 and 1866. When the earth passes close to each one of these paths
there is the chance of increased meteor activity.

The first encounter will occur when the earth will pass close to the path
created in 1767 near 10:00 Universal Time on November 18. Observers in
extreme northwestern South America, Central America and North America can
see this possible outburst. This time corresponds to 2:00 AM Pacific
Standard Time and 5:00 AM Eastern Standard Time. Rates as high as 30 per
minute have been predicted at this time.

The second possible outburst will occur some seven hours later near 17:30
Universal Time. This outburst will be caused by the path created in 1699 and
is best seen by observers in eastern Australia and all of the western
Pacific region including Japan, Korea, and eastern China. This time
corresponds to 1:30 AM in Korea and 4:30 AM in eastern Australia on the
morning of the 19th. Rates as high as 30 per minute have also been predicted
at this time. By this time the Americas' will have moved into daylight, with
the sun obscuring that region from seeing further activity.

The last possible outburst may be the best as the earth passes very close to
the path created by the comet in 1866. Closest approach occurs near 18:15
Universal Time which is only 45 minutes after the 1699 encounter. This time
favors the same regions mentioned above for the 17:30 outburst. Rates as
high as 100 per minute have been predicted at this time. Another reason the
predicted rate is so high is that there is the possibility that the material
from the 1699 path will still be active thus we have activity from both
sources occurring simultaneously. 

Please note that these times and rates are only estimates. We cannot predict
with 100 percent certainty the exact time and activity since we do not know
the exact location and intensity of each path. The actual times and
strengths may differ considerably. The key is to be out at least an hour
BEFORE these times just in case the outbursts occur early.

Leonid meteors cannot be seen during the early evening hours. These meteors
can begin to appear as soon as the radiant (the area of the sky the meteors
seem to originate) rises in the east. This occurs during the mid evening
hours for high northern latitudes, late evening hours for mid northern
latitudes, and after midnight for those located in equatorial regions and
the Southern Hemisphere.

When the radiant lies near the horizon the Leonid meteors cannot penetrate
far into the earth's atmosphere. At this time they are only able to skim the
upper atmosphere. Meteors seen at this time are called "earthgrazers" and
can be quite spectacular. They often last several seconds and can span a
great distance of the sky.

As the earth rotates and we move into the morning hours the Leonid radiant
will rise higher into the sky and the meteors will strike the atmosphere at
a more direct angle creating shorter paths. These meteors may be less
striking than the earthgrazers but they will certainly be much more numerous
as less of them will be obscured by the horizon.

Tips for watching the shower:

1. Watch near the times indicated above on the morning of the 18th for those
in the western hemisphere and on the morning of the 19th (local time) for
those watching from eastern Asia and the western Pacific region.

2. Watch from rural areas free from light pollution. While a few meteors may
be bright enough to be seen from cities, most of them will be fainter and
will be obscured by bright city lights.

3. Be comfortable! Don't stand and watch. Use a lounge chair and blankets to
make yourself comfortable.

4. Don't watch for 5 minutes and give up if you don't see much. Meteors
often appear to arrive in bursts. A few minutes may go by with little
activity and then you may see a sudden burst of activity the next minute.

5. Leonid meteors can be seen in any portion of the sky. It is probably best
if you face the darkest direction available at your location. The typical
Leonid meteor last much less than one second and often leaves behind a
persistent train. Leonid meteors seen close to the radiant and close to the
horizion (in any direction) will appear shorter and slower than those seen
high in the sky far from the radiant. Just be sure to look up at least
halfway into the sky so that none of your field of view is wasted on the

6. Make this a family event! Since this is a Sunday morning in the
Americas', get the entire family involved. Next year's shower is hampered by
a full moon and after that it will not be until 2099 that we see Leonid
activity this strong again.

Wishing you all clear and meteor-streaked skies!

Robert Lunsford
IMO Secretary-General


>From Daniel Fischer <>

Dear Benny,

I'm not sure I sent you this Leonids 2001 preview that may be of interest to
CCNet readers.

Regards, Daniel (already in Korea for the observations, typing from the

Here is the latest write-up of what four different models predict for the
Leonids next week - I've tried to be fair towards all parties ... This
article can be found at
with many links - to get 'into the mood' of meteor storms, I especially
recommend the eyewitness reports linked there!

Expect 7000+ Leonids per hour, (some) experts agree

With the 2001 return of the Leonids approaching fast, the discrepancies
between four detailled models that had become evident this summer have not
been resolved at all. All of the models have been published in great detail
in the literature now: Two of them predict a major meteor storm of 7000 to
9000 meteors per hour over Eastern Asia and Australia, together with a
lesser outburst over America, one predicts nice storms over both America and
the Far East - and one sees just one very extended maximum of activity that
barely reaches storm level (if defined as 1000 meteors/hour) over the
Pacific Ocean.

All four models are firmly based on the existence of dust trails, created by
the parent comet during every perihelion passage, which have permitted
successful predictions of the Leonids storm of 1999 and of the general
activity profile in 2000. But efforts to further improve the modelling have
been moving into different directions, with the resulting predictions for
2001 diverging to a surprising degree. And it's not just the strengths of
the maxima that differ between the models, also the times of the maxima are
no longer identical for different approaches. On November 19 we will know
who did the best job:

An outburst or small storm over America plus a big storm over Asia &
Australia is the prediction by the celebrated theoreticians who had re-discovered the dust
trail idea in 1999. Robert McNaught & David Asher are now including aging effects of the
dust trails, reducing the strengths of the maxima somewhat. Here are their
predictions (the time of the maximum on Nov. 18, how many revolutions the
respective dust trail is old, the expected maximum Zenithal Hourly Rate, and
for how many minutes before or after the peak the rate will be still at
least half the maximum value):

            9:55 UTC |  7 rev. | max.  800 | 45 m
           17:24 UTC |  9 rev. | max. 2000 | 65 m
           18:13 UTC |  4 rev. | max. 8000 | 35 m

The two maxima around 18 UTC will overlap and cause a maximum overall rate
of some 9000 around 18:10 UTC, twice as high as during the 1999 storm.
But the 10 UT maximum won't reach storm level any more in this model.

Esko Lyytinen et al. are worried primarily about the role of
non-gravitational forces on the orbits of the dust trails which can also
cause significant shifts of the times of the maxima. They predict:

           10:28 UTC |  7 rev. | max. 2000 | 29 m
           18:03 UTC |  9 rev. | max. 2600 | 31 m
           18:20 UTC |  4 rev. | max. 5000 | 21 m

Again the last two maxima will overlap, generating a combined peak ZHR of
about 7200, just before 18:20 UTC. And the Americas could still hope for a
small storm, albeit at only half the strength of the 1999 event.

A bigger storm over the Americas than over Asia is the prediction by Peter
Jenniskens who has drastically revised his forecasts for 2001 and 2002
repeatedly since mid-2000. He sees evidence (disputed by others) that some
of the dust trails have shifted towards the Sun, which would not affect the
times but the relative strengths of the 2001 maxima:

           10:09 UTC |  7 rev. | max. 4200 | 20 m
           17:08 UTC |  9 rev. | max. 1800 | 37 m
           17:21 UTC | 11 rev. | max.  510 | 38 m
           17:55 UTC |  4 rev. | max. 2700 | 24 m

The combined power of the three trails to be encountered from 17 to 18 UTC
(the 11 rev. trail has less effect in the other two models) would cause a
prolonged peak of perhaps 3000, while the Americas would face a short peak
of over 4000.

A very extended shallow peak that barely reaches storm level at no more that
1500 meteors/hour between 12 and 13 UTC is the forecast by Peter
Brown & Bill Cooke who have simulated the orbits
of millions of dust particles ejected from the comet under various
assumptions. The very different outcome of these calculations (neither the
10 UTC nor the 18 UTC peak are pronounced here) seems to come from the
greater degrees of freedom that the particles have to drift away from the
dust trails in this 3D world.

There are only three areas in which all four models agree:

a) There will be at least one meteor storm this year, some time between
9 UTC and 19 UTC on Nov. 18,
b) there will not be any storms over Europe, Africa and Western Asia,
c) the fluence of meteoroids, i.e. the number of dust particles hitting
the atmosphere per area per time, will be 5 to 10 times larger this
time than in 1999. Thus there is a somewhat higher risk for orbiting satellites,
but it's not as dramatic as stated in some media reports.

(McNaught & Asher, WGN 29 [Oct. 2001] 156-164, Lyytinen et al., ibid.
29 [Aug. 2001] 110-8, Jenniskens, ibid. 29 [Oct. 2001] 165-175, and Brown &
Cooke, MNRAS 326 [Sep. 11, 2001] L19-22)

Daniel Fischer, Koenigswinter, Germany (now off to Korea, to find out who's
got it right this time ...)


>From Spaceguard UK <>

SGC 01-06
11 November 2001

Recent research results published by astronomers using data from the Sloan
Digital Sky Survey in the United States have been interpreted as indicating
that the Earth faces a reduced hazard from asteroids. This is sadly not the
The results, published in the November issue of the Astronomical Journal,
are not significantly different to the lowest of others produced in the past
five years, hardly justifying the headlines that have appeared around the
world. The published risk estimate was based on observations of Main Belt
Asteroids that orbit the Sun between Jupiter and Mars.  These data were then
used to deduce the population of Near Earth Asteroids (NEAs), making
assumptions that most NEA experts regard as unsafe.  In addition, the new
risk estimate relies on only a single data point - the impact event 65
million years ago that caused the mass extinction of 75% of all living
This can come as no comfort to the British government who have spent a year
pondering the 14 explicit recommendations of their NEO Task Force that were
published in September 2000.  So far the BNSC has only announced the firm
intention to action one half of one of them.
The impending establishment of a National NEO Information Centre, probably
at the NSC in Leicester, is a welcome development, but is only the first
step in the implementation of the Task Force's recommendations. One of the
main tasks of such an institution should be to facilitate the implementation
of the other recommendations, but the BNSC appointed centre will probably be
unable to do so under the terms of its contract.
The Spaceguard Centre, as the International Spaceguard Information Centre
wishes the BNSC enterprise well, and offers its co-operation, should it be
JR Tate                           Tel:                   01547 520 247
The Spaceguard Centre             Fax:                   01547 520 247
Llanshay Lane                     Mobile:                07968 195 625
Knighton, Powys                   E-Mail:
LD7 1LW                           Website:


>From The New York Times, 13 November 2001

At a time when comfort is in short supply, here's some: the odds of a
civilization-ending collision with an asteroid have become longer.

Astronomers from Princeton and the University of Washington, using data from
a census of one- quarter of the sky, now estimate that there are 700,000
asteroids that are a kilometer or more in diameter - big enough to cause a
global catastrophe in a collision with Earth. That is about one- third of
earlier estimates, and reduces the chances of such an event in the next 100
years to about 1 in 5,000, from 1 in 1,500.

The astronomers based their calculations on data from the Sloan Digital Sky
Survey, which uses a telescope in New Mexico to search systematically for
objects near and far. The survey is able to detect extremely faint objects
and also provides information about an object's color, which allows
astronomers to determine composition and size.

The Princeton and Washington astronomers used information on 10,000
asteroids to come up with their new estimate of the total number, which they
report in The Astronomical Journal. Most of these asteroids will orbit
forever in the belt between Mars and Jupiter, but some are in Earth-
crossing orbits. The astronomers used common assumptions about the frequency
of large-scale collisions with Earth to calculate the chances that a large
Earth-crosser will become an Earth-collider.

Because of these assumptions, the researchers say, the estimate of odds is
only just that, an estimate. But it's clear, they add, that the risk is
lower than previously believed.

Copyright 2001, The New York Times


>From Space Daily, 13 November 2001

by Marc D. Rayman
DS1 Mission Manager

Pasadena - Nov 13, 2001

After introducing another member of the solar system family to Earth, Deep
Space 1, the little spacecraft that could -- and did! -- continues flying
contentedly in its orbit around the Sun. Meanwhile, scientists are analyzing
the fantastically rich harvest of data returned from the historic encounter
with comet Borrelly. More than two years after the end of its 11-month
primary mission, on September 22 DS1 stepped up to its greatest challenge of
all with the elegance and skill of a true master. The encounter certainly
did not go the way I expected -- instead, everything went perfectly!

The scientific analysis of the visible images, infrared spectra, ion and
electron energy and angle spectra, ion composition measurements, magnetic
field measurements, and plasma wave burst data will go on for quite some
time. After just the initial impressions of a subset of these data were
described in a press conference a few days after the encounter, the real
analysis began. DS1's images are the only ones in existence that are
detailed enough to allow geological analysis of the nucleus of a comet.
These images are still being processed to bring out additional details not
discernible in the raw images releases so far.

It literally will take years to mine everything from these data, but
preliminary results will be announced in press releases at the end of
November. They will contain some fascinating and exciting news, but in order
not to steal any of the impending thunder, let's focus instead on what
happened in the time between that last two logs (available as a special
discounted gift set at fine establishments throughout the halo of the Milky
Way), as the spacecraft closed in on its quarry. Following that admittedly
somewhat dry material, we'll turn back to more of the human experience. As
all corporeal readers know, DS1 has had to thrust with its ion propulsion
system even when we did not want it to change its course. This served to
reduce the consumption of its conventional chemical propellant. As a result,
DS1 thrusted at impulse power back and forth for many months, tacking its
way to Borrelly.

The push of the ion engine, as delicate as it is, adds up to problems for
the navigators who try to predict DS1's course with the accuracy needed for
the encounter. (During its normal interplanetary travels, the subtle
uncertainties that arise from the continuous acceleration are too small to
be of concern.)

As planned for many months, DS1 stopped firing its ion engine on September
15 and coasted most of the rest of the way to the comet. Following almost 15
months of being in powered flight nearly 100% of the time, the ship was
silently drawing near its destination.

A total of 11 times from August 25 until about 10 hours before the closest
approach on September 22 (still at a range of over 600,000 kilometers
(around 375,000 miles), or more than 1.5 times the distance between Earth
and the moon), DS1 took images of where it expected Borrelly to be. These
distant views were used to improve estimates of the location of the comet.

Although it has been observed many times from Earth since its discovery in
1904, as with all astronomical bodies there are significant limitations in
astronomers' ability to pin down the orbit. But by combining data from
Earth-based observations of Borrelly with DS1's views of the comet as they
raced toward their eagerly awaited appointment, it was possible to get a
better estimate of the comet's location.

These observations were complex, but, to our great relief, all of them
worked just the way they were supposed to. At first, the comet was so
distant that many images had to be electronically combined for the comet
even to be detected. What appeared in the images was the coma (the vast
cloud that cloaks the nucleus in gas and dust) and the tail.

As DS1 closed in on Borrelly, these images were used by navigators to
compute course corrections. Before routine thrusting stopped on September
15, the trajectory was altered by changing the planned direction and
throttle level of the ion drive. After September 15, the corrections were
accomplished by firing the engine only at specially selected times and
throttle levels.

Nearly every activity on the spacecraft represents an opportunity for a
problem to arise. As just two examples, when the probe turns, it might have
trouble locking to a new reference star, or any commands sent from Earth
might contain an error. (The extremely small mission control team, despite
the excellence shown during three years of complex and successful flight,
could -- gasp! -- make a mistake.) The closer the spacecraft was to the
comet, the more important it was to avoid actions that, if they did not go
as planned, could compromise the encounter. Less time to recover from
problems meant it was more important than ever to avoid them.

We devised a clever strategy over the summer that made it likely (but not
guaranteed) that most course corrections would require the spacecraft to
thrust while it was in nearly the same orientation needed for communicating
with Earth. In fact, this worked so well that all but one of the course
corrections required thrusting in exactly that orientation.

That meant that the spacecraft did not have to execute extra turns and did
not have to expend extra hydrazine. When it came time to modify the
trajectory, we simply told the spacecraft the duration and power level, and
it dutifully and calmly executed the thrusting as needed. We could
communicate with it at the same time, uploading more of the many files it
would need for the encounter and monitoring its health to be sure no
problems were brewing that might interfere with its chances of collecting at
least some of the data we sought at Borrelly.

One of the reasons that so much effort had been devoted to saving hydrazine
was that during the last day before the encounter, we expected not to be
able to use the ion engine for course corrections. The ion engine delivers
what I've often described as "acceleration with patience," but with only
hours before closest approach, patience was not a virtue: the spacecraft
needed to point its antenna to Earth most of the time.

But our strategy paid off handsomely, and we were able to make the final
corrections by firing the engine with no turns at all. As a result, we did
not have to use any extra hydrazine, and no time was lost in using the
reliable and efficient, if leisurely, ion engine.

A few days before the encounter, our old friend PEPE was activated, its
software loaded, and its operation verified. Its job would be to try to
measure the composition, energies, and directions of the charged particles
in the coma as well as how the comet and the solar wind affect each other.

Myriad other preparations were conducted in the remaining few days,
including finalizing plans for what to do in a variety of unplanned
circumstances too nerve-wracking to try to recall if I want to sleep well
tonight. In brief, however, we filled up the available time working as hard
as we could to give the spacecraft its best chances for success.

Everything went surprisingly smoothly in the days leading up to Saturday,
September 22. I had had myriad concerns before the encounter. Even casual
readers of these logs know that I did not have high confidence in this
daring undertaking, and many logs over the past few months have described
different aspects of the risk.

As I ate breakfast well before sunrise on Saturday, one of my fears was that
everything would continue to go well but for one mistake, one oversight, one
simple little thing that we should have done or not done. The encounter
would be conducted with 685 stored instructions, containing nearly 4000
parameters, relying on complex software that had been used for tests but
never for visiting a comet.

That represented an extraordinary number of opportunities for a mistake. I
prepared myself for coming home dejected that night, expecting to scold
myself for missing that one lurking error. It would be no worse that the
entire encounter going poorly, but just one simple error would make it
easier to devote excessive energy to repeating "If only..." for years to

It was an almost eerily calm day in DS1's mission control room, as the
spacecraft continued to be well behaved. Most members of the team had little
to do but make sure the spacecraft was healthy. We did have several critical
decisions to make, based on plans we had worked out carefully during the
preceding year.

When the final pre-encounter images were obtained, we analyzed them and our
earlier ones with a mathematical model of how the brightness of the scene
formed by the combination of the vast coma plus the tiny nucleus should
change as the distance to the comet diminished. This allowed us to make our
selection for the camera exposure times and to formulate our final estimate
of where the spacecraft should begin looking for the nucleus.

Some team members suggested we make other, unplanned changes, but that is
always dangerous. It is easy for late anxiety (augmented with the burritos
we had for lunch) to foster new ideas that, in the absence of calm
reflection, may seem meritorious.

But making changes to such an intricate plan in the final hours requires
very careful consideration, and, by definition, there probably is not time
for that. We did discuss some ideas but opted instead to trust the more
considered judgment we had exercised earlier and stayed the course. Shortly
before 1:30 pm PDT, signals confirmed the spacecraft had begun turning. The
main antenna would not point to Earth again until after the encounter (if
the spacecraft survived), and we had only very limited signals with which to
infer its progress.

The spacecraft had a tremendously complicated plan to follow, including
locking to a reference star for a while, then trying to obtain some views of
the nucleus while still more than 85,000 kilometers (53,000 miles) away,
then trying to point its very narrow-view infrared spectrometer at the
nucleus. Next it had to lock to another reference star in a special location
that would provide it information it would need later in the final

Finally, about 35 minutes before its closest passage by the nucleus, still
35,000 kilometers (22,000 miles) away, it turned to the 8-kilometer (5-mile)
long nucleus for the final time. It began taking two images per minute in
order to try to find it and lock on so it could track the mysterious core of
the comet.

The elaborate choreography continued with many changes in spacecraft modes
and constant measurements by PEPE and by the reprogrammed ion engine
sensors, smelling and hearing phenomena in the coma as the camera tried to
record the sights.

The indications we had on Earth were that everything was going well, but
that could have been deceptive. If the signals indicated the spacecraft were
having problems, we could have trusted that. But its belief that it was
tracking the nucleus was not proof that indeed it was; there were many ways
it could fail and not realize it.

Still, it was reassuring that no problems were evident. We later determined
that of the 53 pictures the spacecraft took, it managed to identify the
nucleus in 52 of them. In one of the pictures, a cosmic ray that struck the
electronic detector in the camera left a track that got most of the way
through the various software guards meant to eliminate spurious signals.

Although it prevented the system from finding the nucleus in that one image,
it did not disrupt or confuse the attempt to track the nucleus; rather, the
software ultimately discarded the picture, refusing to be fooled by the
deceptive information it contained.

There was tentative applause at JPL when signals showed that the spacecraft
had traveled half-way through the coma, completing its closest approach to
the nucleus. But it still had to survive its trip back out of the coma, with
potentially fatal dust impacts and more complex maneuvers. Finally the
spacecraft turned to point its main antenna back to Earth, and we waited
like expectant children listening as a masterful story teller begins to
unfold a tale of daring, mystery, and adventure.

As the spacecraft regaled us with its spine-tingling exploits, we gathered
around a few of the monitors on which the pictures would first be displayed.
We already had good reason to believe that the tremendously important PEPE
and ion propulsion system diagnostics sensor data had been acquired. They
would reveal much of great interest about the comet.

But, regardless of our technical or scientific interests, the roughly 100%
human controllers are visual creatures, and we frankly hoped for a cool
picture. Our goal had been to get a picture in which the nucleus spanned 50
pixels (a pixel is the smallest element of the digital camera's view).

This would be of great scientific value and would be good enough to give us
a feel for what this completely unknown body looked like. The images were
returned in a special order, but not in the order in which they were taken.

Still, the first images we saw had been taken from so far away that the
nucleus was still small, and the scene was dominated by a powerful jet of
dust. These showed that the comet was an unfamiliar and strange place

Why didn't the dust destroy the spacecraft
It appears that our prediction of a few hundred dust impacts, based on
analysis of Earth-based images of Borrelly, was tricked by this powerful
jet. Earth was too distant for the jet to show up; all that could be
inferred was the total amount of dust in the vicinity of the comet. But by
being concentrated in a jet that DS1 did not fly through, it left other
regions less dangerous. While we know DS1 was hit, it did not experience
enough blows to suffer damage. Indeed, the only effect of the encounter we
have been able to identify is the appearance on the spacecraft now of a big

After a few additional distant images were returned, the first image at
appeared on the monitors at about 5:30 pm, and the real celebration of the
Borrelly encounter began.

The spacecraft had managed to track the nucleus better than we had hoped and
took a picture when it was close enough that the body was about 170 pixels
across -- more than 3 times better than our goal. The purity of the human
joy that I shared with my colleagues there, as cheers and applause erupted
in mission control, is something I will never forget.

On behalf of our curious and noble species, we beheld the first detailed
views not only of a place, but of a kind of place, never seen before. Our
spirits soared to heights unachievable even with ion propulsion! Your
ever-devoted correspondent, normally of at least average eloquence, found
himself unable to say little more than "I just can't believe how incredibly
cool this is" every 30 seconds for the next few hours.

In the two years following the end of the primary mission, we had made many
thousands of difficult decisions, particularly, but by no means exclusively,
because of the failure of the craft's star tracker.

With the very small budget for Deep Space 1 (indeed, it is the lowest cost
interplanetary mission NASA has ever conducted), many times we simply did
not have the resources to analyze problems in as much detail as we might
have liked. With a small team and a very complex mission, too often we found
ourselves having to choose which problems we would penetrate.

For the others, it generally became necessary to go with our best estimate
through a combination of specific and limited technical information and a
strong dose of human judgment. But what if we had made a wrong choice in
which areas to focus our greatest attention, or what if the less well
considered decisions proved to be wrong in an important way? Well, in that
case, I wouldn't be writing about the jubilation that followed a truly
flawless encounter.

Coming at a time when so many of us were witness to the most shocking human
actions and were forced to confront our greatest fears, we felt that we were
taking humanity's highest ideals to its greatest reaches. More than just an
incremental step, in that one day we made an astronomical jump forward in
our cosmic view. While our grand news may have been largely lost in the
midst of these other terrestrial events, we were proud to accomplish
something beautiful, surprising, and inspiring on behalf of everyone who has
ever wondered about the universe.

Deep Space 1 completed its primary mission in 1999 and its extended mission
this autumn. So what is left? The hyperextended mission, of course.
Beginning in October, our attention shifted to retesting many of the
technologies that were the reason DS1 was built and launched.

Nine of the 12 technologies on board are hardware (three were autonomous
software systems), and each is being exercised more during this phase of the
flight, as we return DS1 to its roots.

With a mission that was intended to last 11 months, the opportunity to test
these systems after three years in space (celebrated a few weeks ago with a
yummy cake displaying the gleeful proclamation "3 sweet years!"), with
greater exposure to radiation and other hazards of the space environment,
many large swings in temperature, and other possible sources of wear, this
is an opportunity to add still more to our understanding of these systems
that are important for reducing the cost and risk of ambitious space and
Earth science missions of the future.

The focus of the hyperextended mission is on the ion propulsion system, and
we are performing many tests to quantify the effects of its having operated
for so long. We are also testing it in various modes that would have been
too risky or otherwise inappropriate earlier in the mission.

This amazing system has provided the equivalent of about 4.2
kilometers/second (9400 miles/hour) to the spacecraft, while consuming less
than 70 kilograms (157 pounds) of xenon propellant. The system has
accumulated more than 640 days of thrust time. (The requirement for "minimum
mission success" for DS1 included operating the ion propulsion system for
200 hours.

We have only exceeded that by a factor of 77; but don't despair, still more
hours of operation are ahead.) The results of these tests will represent
still greater bonus from the mission as it continues blazing trails in space

The hyperextended mission will conclude in December, and the next log will
describe what fate awaits the aged, wounded, intrepid, and very very happy

DS1 is now over 68 million kilometers, or 42 million miles, from its new
friend comet Borrelly. As they continue on their separate ways, we can be
sure each will retain a fond memory of their brief meeting, a special moment
of shared discovery in their very different solar system journeys.

Meanwhile, DS1 and Earth are continuing to get closer in their individual
orbits. Since launch in October 1998, DS1 has completed two orbits of the
Sun while Earth has completed three. By lapping the craft, Earth is now
catching up again. (See the June 30, 2001 log for more on DS1's orbit.) Deep
Space 1 is almost 1.2 times as far from Earth as the Sun is and over 460
times as far as the moon. At this distance of 177 million kilometers, or 110
million miles, radio signals, traveling at the universal limit of the speed
of light, take over 19 and a half minutes to make the round trip.

Copyright 2001, Space Daily


>From Washington Post, 12 November 2001

By Susan Okie

As recently as 20,000 years ago, North America had an array of large mammals
to rival the spectacular wildlife of modern Africa. Mammoths bigger than
African elephants, as well as smaller, pointy-toothed mastodons, ranged from
Alaska to Central America. Herds of horses and camels roamed the grasslands
while ground sloths the size of oxen lived in the forests and bear-sized
beavers built dams in the streams.

By about 10,000 years ago, all of these animals -- and others, such as
American lions, cheetahs, sabertooth cats and giant bears -- were gone. Some
70 North American species disappeared, three-quarters of them large mammals.

The question has fascinated archaeologists, geologists, biologists and
anthropologists for decades. One long-popular theory holds that the Clovis
people, Stone Age immigrants from Asia who appeared in North America about
11,000 years ago, swept across the continent and hunted most of its large
mammals to extinction.

But proponents of alternative theories suggest that the animals died of
natural causes. According to one view, rapid climate shifts at the end of
the Ice Age altered the pattern of North American vegetation, progressively
shrinking the habitats of the continent's big mammals until they became

Another recently proposed scenario casts human immigrants (or perhaps
animals or insects they brought with them) as unwitting deliverers of a
killer virus that devastated the continent's wildlife.

Did hunters wipe out the American megafauna? Did climate change do it? Or
was it a plague?

Scientists on all sides of the debate are hampered by the limits of what can
be proved by examining animal fossils and stone spear points. Fossils can't
tell researchers the size of animal populations at various times in
prehistory or pinpoint precisely when they died out, although they can
suggest an approximate chronology. Sophisticated chemical analysis of bones
can provide some clues about an animal's diet. In rare cases, genetic or
immunological tests on well-preserved soft tissues may be able to yield
evidence of infectious diseases.

Paul Martin, professor emeritus of geosciences at the University of Arizona
in Tucson, is the most vigorous proponent of the "overkill" theory. He
argues that because so many species of large American mammals disappeared
about 11,000 years ago, overhunting by the new arrivals is the most
plausible explanation. There are abundant examples of extinctions occurring
soon after humans arrived on islands, apparently caused by hunting, and
Martin believes the same thing could have happened on a continent-wide

"People can do it really fast and it won't leave much evidence behind," he
said. The Clovis people "found a favorable environment. Their numbers would
increase without serious limit, at a really rapid rate. Within 1,000 years,
our species can sweep through the Americas."

But critics respond that if Clovis hunters killed off the mammals, there
should be more fossil evidence of the deed. Clovis people's stone weapon
points have been found in association with mammoths, mastodons and bison but
not with other mammals, noted Russell Graham, chief curator at the Denver
Museum of Nature and Science.

Climate was probably paramount, according to Graham, who presented new
evidence to support his position last week at the Geological Society of
America's annual meeting in Boston. "I would argue that [mammoths' and
mastodons'] ranges were already collapsing" because of climate change when
the Clovis hunters showed up, he said. "I think they would have gone extinct
without people. . . . People arrived and killed the last few on the

Donald Grayson, a professor of anthropology at the University of Washington,
agrees. He points to recent archaeological evidence from Monte Verde, Chile,
that humans had settled in the Americas about 13,000 years ago, well before
the Clovis people arrived and the major wave of mammalian extinctions

Grayson said that at the end of the Ice Age, the melting of the glaciers
that had covered Canada and the northern United States caused dramatic
alterations in climate and vegetation. In the continent's interior, both
winters and summers became more extreme. Landscapes that had contained a
patchwork of trees and pasture became more homogeneous -- either all forest
or all grassland.

"There were complex combinations of plants that you don't find after that
period of time," he said. Many animals shifted their ranges in response to
changing habitat.

By constructing computer maps of the distribution of mammal fossils from
different time periods, Graham sees evidence that the ranges of species like
the Columbia mammoth and the Shasta ground sloth were steadily shrinking for
thousands of years before they became extinct.

"Large animals require larger geographic ranges, and as you reduce the
geographic range, the probability of extinction goes up exponentially," he
said. "With small distributions, local effects like fire, disease and
competition become very important."

But if climate change was severe enough to cause a wave of extinctions in
the Americas, it should have caused the same phenomenon globally, argues
Ross D.E. MacPhee, curator of vertebrate zoology at New York's American
Museum of Natural History. Yet most other regions were spared, even the
nearby West Indies. "Why weren't things falling down in droves in Africa?"
he asked.

Like Martin, MacPhee is impressed with the fact that extinctions in the
Americas and several other places seem to have closely followed the arrival
of humans. But he doubts that overhunting is the explanation, noting that no
whale or seal species has been driven to extinction in the past 200 years
despite extreme overhunting.

Instead, MacPhee is betting that a virus or other microbe new to the
Americas arrived with human settlers and killed off many mammal species that
had no natural resistance. He points to the devastation caused later among
Native Americans by smallpox, measles and other "European" infections.

"Nothing in nature is able to cause such levels of havoc except emerging
diseases," MacPhee said. "It was either the humans themselves that were
vectors, or parasites of humans, or it could have been parasites of animals
that came in with humans."

To fulfill MacPhee's "hyperdisease hypothesis," a new infection would have
had to spread quickly among individuals of all ages and sexes and would have
been able to cross species barriers. He suspects it would have spread
through the air. Candidates might include influenza and rinderpest, a
disease of cattle that also affects deer, antelope and related species.

MacPhee is searching for evidence of such infections in frozen tissue from
mammoths, ground sloths and other beasts that died out at the end of the Ice
Age. An infected animal's immune system would make antibodies against the
invading virus, chemicals that might be detectable. If antibody tests are
positive, MacPhee plans to search for viral genetic material.

"No extinction is a simple matter. There's always an environment in which it
happens," said MacPhee. "I need to show and convince people that disease by
itself could be considered a primary factor, rather than a secondary or
negligible one."

2001 The Washington Post Company



>From Matthew Genge <>

Professor Felix Catophilus and Dr Neophobius Snobbs suggest in CCNET (12
Nov) that white animals such as mice and rabbits pose less of a hazard to
human life than brown or golden animals such as lions, bears and tigers
(although they also suggest that cats present a lesser threat). I should
remind Felix Catophilus and Dr Neophobius Snobbs that the size determination
of mice and rabbits, like comets, is an imprecise art due to the presence of
abundant fluff. Models of atmospheric entry would suggest that a large
(100m) white mouse, like comets and weak primitive asteroids,
entering the atmosphere at hypervelocity over a large city could detonate
with an energy of several megatonnes devasting a large area and cause
enormous number of casualties.

Matthew Genge

I thought I better make a comment on this submission since I have already
been accused twice of being the anonymous correspondant.


>From E.P. Grondine <>

Hello Benny -

My closest neighbor called the morning of 11 September at about 9:30 and
woke me out of a sound sleep. "Well, Ed, you were right, we got hit." He was
slurring his words, as he had already started to work on a six pack of beer.
As I blinked my eyes open, I parted my dry mouth, exhaled, and asked,
"Nuclear, chemical, or biological?" "World Trade Center." "Nuclear, then?"
My neighbor paused, at a complete loss for words, "Oh - just go turn on your
television. You'll see" "Okay" "You'll see."

I hung up the telephone and went to turn on my television. Nothing but snow
appeated, as the local citizens band radio use was so intense that the
interference from it reduced every channel's signal to noise.

Faced with a white storm on the screen, with scattered words coming through
the hiss, I went to my desk and turned on my computer. By some strange twist
of fate I managed to get a connection to the internet, and by a further
stroke of luck, I also managed to get a video feed from the CSPAN
governmental affairs site.

That day I ended up watching the Pentagon attack and the building collapses
on the internet instead of on television.


Lest anyone be mistaken about the effects of small impacts, I ask that they
note very carefully what a remarkable difference a relatively miniscule .6
kiloton blast has had. In the NEO community, before the attacks we had
reasonable hopes that the British Parliament would soon be examining the
Blair government's response to the NEO Taskforce's recommendations. While
budgets were tight, the odds of obtaining at least one adequate NEO
telescope appeared good.

For myself, I was working towards completing a survey of relatively recent
historical Atlantic impacts, a work which I hoped to get off in time for the
questioning. Just when I had sat down to do a final draft of the material,
about a week and a half before the attacks, my computer had
failed. I had finally gotten it fixed late Sunday night, 9 September, but
when I got up Monday morning, 10 September, the water supply at my house
failed completely. Given just the e-mail, I decided that the best course of
action would be to call the plumber on Tuesday morning -

Suddenly, then, there was of course no pressing need to get the Atlantic
impacts historical  survey completed and circulated. There would be no
Parliamentary discussion, as all national budgets, including space budgets,
evaporated simultaneously into uncertainty.

My plumber was on vacation at the beach in South Carolina, and would not
return for a week.


As we've seen with the media coverage of even such relatively hard evidence
as the possible crater in Iraq, the public's attention to this day is
elsewhere. Any survey of written records and field excavations such as the
one I was working on for the coastal Atlantic region would  fare no better,
and most lkiely worse, in raising public awareness. (By the way, I propose
we name the crater after Saddam Hussein, as certainly the evil which he has
commited against both the people of Iraq as well as their neighbors has come
closest in recent history to matching the harm which this impact caused in
ancient times.)


About Saturday evening, when there was no indication that FBI was moving
quickly to shut down bin Laden's cells, I became "concerned", for lack of a
better word.

Here a little background on my "concern" is in order. I began covering the
space program of the Soviet Union in 1985. At that time, the Energia booster
was going into operation, and  the Soviet space establishment was busy at
work on a proposal for building a manned base on the Moon to
celebrate the 75th anniversary of the "Great October Socialist Revolution",
as that event was then known by the peoples of the area.

Following the collapse of the Soviet Union, the first reports of attempts to
steal nuclear materials began to surface in the European press. I attempted
to place articles on this topic at that time, but had remarkably little
luck: the big money then was in defense contracts, and the readers'
interests were there as well. While this may seem strange in retrospect, at
that time the possiblities of nuclear, chemical, or biological proliferation
were not considered by many to pose an immediate danger.

A period of even more intense frustration followed. I considered setting up
my own newsletter to focus on the proliferation problem, and came up with a
title for it, the "International Aerospace News"; but that option was
consumed along with my working capital by the need to replace my

By this time there were also no Soviet space plans to report, as there was
no longer any Soviet Union. I decided to use the period to gather my
research materials together into a "History of Cosmonautics", but once again
frustration ensued. While researching Hitler's plans to arm the V-2 rockets
with nerve gas, I stumbled across the fact that in their haste to
de-classify documents concerning war crimes, the US National Archive had
inadvertently de-classifed manufacturing information for the Tabun and Sarin
nerve gases.

I tried placing articles on this, but met with no success; this was about a
month before the Tokyo subway bombings. As of today, whether that particular
fanatic, with his long term interest in Hitler, ultimately got his nerve gas
manufacturing information from the National Archives, is a question which I
think very few may want answered: the financial responsibilities which might
ensue are something that many may wish not to bring up.

This reaction is something which it is well to keep in mind when considering
current Russian statements on the possibilities of diversions of their
weapons technologies.


A fact which may be hard for someone in the UK to understand, given the
pounding which London took, and the sacrifice of those good lives paid to
stop the V-2, is that von Braun is held with a certain reverence by many in
the US space community. Thus when I circulated the first draft of the volume
of my history of cosmonautics dedicated to the V-2, setting out in as much
detail as possible Hitler's strategic plans for use of the nerve gases, I
managed to alienate many of them.  They kept demanding more proof, as if 100
metric tons of nerve gas lying on the floor of the Baltic Sea in rusting
metal drums were not sufficient.

Skipping most of the details, I finally walked away from proliferation
matters shortly before the death of Deng Xaio Peng. bin Laden had just been
forced by the US to move from Sudan to Afghanistan, and he not started
operations in full yet - he went into full swing after I left the subject.

Allow me to walk you through the calculation which I performed at that time.
Let us compare the way the hazard of asteroid and cometary impact is dealt
with, with the way in which the proliferation hazard is dealt with. There
are many people paid full time to deal with proliferation; some
$10,000,000,000 in funding per year - I emphasize that this is only a part
of the amount spent per year now by the US alone; the budget for dealing
with the asteroid and cometary hazard isn't even enough to buy equipment,
little less pay people anything near their fair market value. Inddeed,
nearly everyone who I've met who has dealt with the asteroid and cometary
hazard has done it to a greater or lesser extent out of their own pocket,
and often at heavy emotional cost, motivated by nothing more than their
certain conviction that if they didn't deal with it, people would die.
Contrast this with proliferation hazard, where people are paid in full, and
paid well.

On the plus side, work on proliferation focuses on the evil that men do,
while asteroid and cometary hazard studies focus on what are generally held
to be the completely indifferent operation of the forces of nature. While
work on proliferation is necessarily nationalistic to a large degree,
dealing with the asteroid and cometary impact hazard can not by its nature
be done on a national basis. This work must be international in character,
as not only are the resources necesary for dealing with this hazard beyond
national scope, the plain fact of the matter is that we do not have the
slightest clue where the next one will hit, though most of us know with a
certainty that hit it will.

One consequence of this is that if anyone here has any doubts about the
propiety of my commenting on any government's or any government's official's
performance in dealing with the impact hazard, allow me to clearly state
that their objection is noted and ignored. Steel, this includes you.

Despite having a chunk of that $10,000,000,000 dollar per year US
expenditure for dealing with proliferation, the former head of the FBI's
counter-terrorism unit failed completely to stop bin Laden's cells from
carrying out their attacks. Fortunately, he resigned and went on to head up
security for the World Trade Center buildings, where he perished in the
attacks, and thus was spared any need to explain the failures.

Let us now examine some of the misleading comments in David Morrison's
recent note on the Sloan public relations release. "Impacts by NEAs of any
size are exceedingly rare, from the 5-megaton limit of atmospheric shielding
up to the hundreds of millions of megatons associated with mass

No they aren't. According to my estimates, in the recent past mankind has
suffered one continent-wide impact disaster at a rate of about 1 time per
1,000 years. 

"Statistically, no impact is to be expected within a human lifetime."

No, at least in recent times, smaller impacts have occured about once per
100 years. For example, anyone now just over 70 years old would have been
around for the impact which hit the jungle of Brazil in 1930.

"Since the mid-1990s, the most common estimate has been that the Earth is
hit by a "civilization threatening" impact (by a 1.5-km-diameter asteroid)
about twice per million years, which is equivalent to a 1-in-5000 chance per
century. But it is hard to tie down such estimates, in part because there is
also a range of uncertainty as to what constitutes a civilization
threatening impact,spreading over at least a factor of two in asteroid size
(from 1 km to 2 km diameter)."

No. While an astronomer might think that "civilization" is universal and
that there is only one, no anthropologist would do so. Anything from 75
meters up can take out any particular civilization, and they have done so in
the recent past by taking out key centers. Go up to 150 meters or so, and in
the recent past the ecological collapses from land impacts have led to
the simultaneous collapse of several civilizations.

"This impact rate depends on the population of near-earth asteroids (NEAs)
and occasional comets, and the dynamics of their orbits that ultimately may
bring them into collision course with our planet."

"Occasional comets"? On what grounds is David Morrison making the assertion
that comets strike only occasionally?

"Indeed, we have no way from a single example 65 million years ago of
estimating the average frequency of such [K-T sized] impacts."

"a single example" - In Morrison's statement it is as though all the work
which the geologists have carried out over the last 20 years on K-T sized
impact structures did not take place.

Growing old, and the aging of our knowledge of any scientific field, are
both inevitable and certain - they are certain that is, if we are fortunate.

But when that deficit in current knowledge endangers human life, do we not
have a moral responsiblity to act? If a physician has not kept current, and
his practice is actually endangering patients, certainly his colleagues will
try to ensure that his activities are limited to those areas where they have
a fair confidence that he will do good.

One can understand Morrison's focus on deriving estimates of impact rates
from astronomical observations, as that was one of the few techniques that
were available to early researchers, aside from the lunar crater counts for
limited areas. That was then; this is now, and the best estimates for the
frequency of large Earth impacts now come from geological and
paleontological data.

For the smaller impacts, for myself, I work quite hard to dig up what
information I can about possible historical impacts. I do that work as well
as I can with the resources available to me o if you want better work, find
somebody better at it and pay them to do it.

In blunt terms, my best guess, and the one I operate on, is that what
mankind faces is that "small" impacts equivalent to about 16,000 World Trade
Center attacks have recently been occuring about once per 100 years;
continent killing impacts equivalent in force to about 600,000 WTC attacks
have recently been occuring about once per 1,000 years; and dinosaur killer
impacts have occured chaotically at an interval centered around about 26
million years.


Now in my perambulations through the years, I once ran into a fellow who was
a chance  acquaintance of one of the physicians who worked at that
psychiatric facility where German espionage agents captured by Britain
during the Second World War were administered "truth serums". The techniques
worked very well, and gave Churchill that wonderous tool, the Double Cross
system. Why there is a hesitancy in the US to use such serums on capured
cell members is beyond my comprehension, as surely their after effects must
pale in comparison to the after effects of being set on fire with jet fuel
and then crushed by tons of concrete. I think that one must conclude that US
officials prefer guessing about the bin Laden organization's plans and
capabilities to certain knowledge of them...

No such serums were involved in my interview of Colin Hicks at the recent
International Space Symposium which was held in Washington, though I have
little doubt that what he told me was anything other than absolutely true.
We conversed over a delightful lunch provided by Japan's Mitsubishi
Corporation, who appear as determined as several other corporate
partnerships to offer turn key communication satellite systems. Generally,
these corporate partnerships appear to have formed as attempts to improve
product delivery in response to the weak communications market.  While the
business aspects of this trend are of interest to some, the key aspect of
this for the NEO community is that the current weak commercial demand for
launchers may be an opportunity to seek launchers for space based NEO

The key points from Colin Hicks: The PPARC report will come in later in the
year, after the ESA science summit. There is no specific slot set aside at
the science summit for discussion of dealing with the impact hazard, though
Sir Colin emphasized the real improvement since they first started on the
problem 2 years ago: many researchers were now highlighting the benefits
which their existing proposals would bring to dealing with the impact
hazard. It is important to note Hicks' mention of the beginning of their
work 2 years ago - they feel like they have pioneered the effort in the face
of indifference from other European governments, and this should be well
noted by French and German Conference participants.  I asked Colin Hicks
about the possibility of getting the Italian dynamicists' work funded on a
pan-European basis, but this was something not being considered at that
time. Colin Hicks concurred with my observation that due to the recent
events what the actual state of the UK space budget would finally turn out
to be was unclear, just as it was for every other country.

As regards the ESA science summit, on a more positive note there will be a
spectacular meteorite display co-incident with it, so perhaps discussions there
may further focus on dealing with the impact hazard.

Let's all hope there are no bigger pieces of junk in that debris stream.


I also had a conversation with Joe Pasulich from Boeing's Delta business
development section.  Things were tough. Aside from the weakness in the
communication markets, it must be remembered that most launch vehicle
manufacturers also manufacture aircraft, and this sector has been given a
real pounding by the recent events. Boeing had already laid off 30,000
employees. Passenger fears remain high, and the slow US government response
to improving airline security systems has already had a severe economic
effect. Consumers are worried about their future incomes, and they are
cutting back on their vacation spending adnthus on their vacation air

While UK Conference participants remain focused on the ground based
telescope proposal, for Conference participants in the US I think that this
may be a really good time to begin work toward getting funding for a space
based NEO telescope.


When the plumber installed the new water pump at my house, he moved some
pipes which had become severely worn with age. The high pressure from the
new pump combined with the pipes' weakness to cause a massive rupture, and I
went another week without water. Dan Goldin announced his resignation as
NASA Administrator about this time, which was also roughly about the time
the anthrax letter attacks began.

Despite the mud that some throw at him, Dan Goldin recieved a standing
ovation from the industry officials who heard him speak at the International
Sympoisum - they knew full well the difficulties he had faced during his
tenure as NASA Administrator. They gave Goldin this standing ovation after
he had lectured them continuously for about 30 minutes on their own poor
response to commercial concerns and their poor cycle time in getting their
products to market.

Goldin was surrounded by well wishers after his talk, and I did not seek to
ask him how the search for a new NASA Admistrator was going. For all of his
good points, one of Goldin's most glaring deficiencies has been that he had
a almost no understanding as to the severity of the impact hazard. But since
Goldin was under almost continuous attack, at the same time that he
had no good immediate counsel on the impact hazard about, I don't think we
can hold him too responsible for this. Who the next NASA Administrator will
be, and what will be his initial existing knowledge of the impact hazard,
are wide open questions. I also do not know whether or not a new NASA
Administrator pretty much selects his own chief space science officer, in
other words whether Ed Weiler will continue to hold that position or not.


All of us here know the key role the late Representative George Brown
(Democrat, California) played in getting the initial funding for dealing
with the NEO hazard. His death hit us severely, and we can see the result of
his absence in the lack of current congressional action on the impact

The good news from the Hill, as the Capitol Hill where the US Congress sits
is refered to, is that Representative Sherwood Boehlert (Republican, New
York) now heads up the House space sub-committee. To say the least, this man
is no dummy, and he reads. My estimate is that when he can get past dealing
with the current attacks, and gets on to the Iraq crater, and starts to look
into NASA's response to the impact hazard, he is going to be all over this
problem like syrup on pancakes. Boehlert has an inquiring mind and will not
be put off, accompanied by a predisposition to deal immediately with very
down to Earth concerns.

I don't know exactly when this will happen, but I feel certain that it will,
and not too far off into the future.

Here's hoping for better times ahead for all of us.

Best wishes,


>From Gamezilla, 11 November 2001

Reviewed by: Jim Weber

It started innocently enough as a technology that saved the planet,
originally designed to destroy an onslaught of asteroids from space. When
the developers of this new device discovered its potential for destroying
anything airborne, be it asteroid or jet fighter, they decided that it might
have a greater purpose and started a fierce offensive. Now an immense war
has begun and it's all the USAF can do to hold what positions they have
left. Although the momentum is currently behind the enemy and their new
technology, that appears to be changing as the USAF begins to amass multiple

Ace Combat 04: Shattered Skies is a flight simulator that shows off the
power of the PlayStation 2. Although some graphical elements are not what
they should be, others look amazing. In addition, there are eighteen
different jets with assorted armaments available, and they all handle well.
If you're into flight simulators, this isn't one to pass up.....

All contents 1996-2001 Gamezilla! Online Magazine, a publication of
Gamezilla, Inc. All rights reserved.
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please contact the moderator Benny J Peiser <>.
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>From, 13 November 2001

By Robert Roy Britt
Senior Science Writer

"...and the seven judges of hell ... raised their torches, lighting
the land with their livid flame. A stupor of despair went up to heaven
when the god of the storm turned daylight into darkness, when he
smashed the land like a cup."
-- An account of the Deluge from the Epic of Gilgamesh,
circa 2200 B.C.

If you are fortunate enough to see the storm of shooting stars predicted for
the Nov. 18 peak of the Leonid meteor shower, you'll be watching a similar
but considerably less powerful version of events which some scientists say
brought down the world's first civilizations.

The root of both: debris from a disintegrating comet.

Biblical stories, apocalyptic visions, ancient art and scientific data all
seem to intersect at around 2350 B.C., when one or more catastrophic events
wiped out several advanced societies in Europe, Asia and Africa.

Increasingly, some scientists suspect comets and their associated meteor
storms were the cause. History and culture provide clues: Icons and myths
surrounding the alleged cataclysms persist in cults and religions today and
even fuel terrorism.

And a newly found 2-mile-wide crater in Iraq, spotted serendipitously in a
perusal of satellite images, could provide a smoking gun. The crater's
discovery, which was announced in a recent issue of the journal Meteoritics
& Planetary Science, is a preliminary finding. Scientists stress that a
ground expedition is needed to determine if the landform was actually carved
out by an impact.

Yet the crater has already added another chapter to an intriguing overall
story that is, at best, loosely bound. Many of the pages are washed away or
buried. But several plot lines converge in conspicuous ways.

Too many coincidences

Archeological findings show that in the space of a few centuries, many of
the first sophisticated civilizations disappeared. The Old Kingdom in Egypt
fell into ruin. The Akkadian culture of Iraq, thought to be the world's
first empire, collapsed. The settlements of ancient Israel, gone.
Mesopotamia, Earth's original breadbasket, dust.

Around the same time -- a period called the Early Bronze Age -- apocalyptic
writings appeared, fueling religious beliefs that persist today.

The Epic of Gilgamesh describes the fire, brimstone and flood of possibly
mythical events. Omens predicting the Akkadian collapse preserve a record
that "many stars were falling from the sky." The "Curse of Akkad," dated to
about 2200 B.C., speaks of "flaming potsherds raining from the sky."

Roughly 2000 years later, the Jewish astronomer Rabbi bar Nachmani created
what could be considered the first impact theory: That Noah's Flood was
triggered by two "stars" that fell from the sky. "When God decided to bring
about the Flood, He took two stars from Khima, threw them on Earth, and
brought about the Flood."

Another thread was woven into the tale when, in 1650, the Irish Archbishop
James Ussher mapped out the chronology of the Bible -- a feat that included
stringing together all the "begats" to count generations -- and put Noah's
great flood at 2349 B.C.

All coincidence?

A number of scientists don't think so.

Mounting hard evidence collected from tree rings, soil layers and even dust
that long ago settled to the ocean floor indicates there were widespread
environmental nightmares in the Near East during the Early Bronze Age:
Abrupt cooling of the climate, sudden floods and surges from the seas, huge

Comet as a culprit

In recent years, the fall of ancient civilizations has come to be viewed not
as a failure of social engineering or political might but rather the product
of climate change and, possibly, heavenly happenstance. As this new thinking
dawned, volcanoes and earthquakes were blamed at first. More recently, a
300-year drought has been the likely suspect.

But now more than ever, it appears a comet could be the culprit. One or more
devastating impacts could have rocked the planet, chilled the air, and
created unthinkable tsunamis -- ocean waves hundreds of feet high. Showers
of debris wafting through space -- concentrated versions of the dust trails
that create the Leonids -- would have blocked the Sun and delivered horrific
rains of fire to Earth for years.

So far, the comet theory lacks firm evidence. Like a crater.

Now, though, there is this depression in Iraq. It was found accidentally by
Sharad Master, a geologist at the University of Witwatersrand in South
Africa, while studying satellite images. Master says the crater bears the
signature shape and look of an impact caused by a space rock.

The finding has not been developed into a full-fledged scientific paper,
however, nor has it undergone peer review. Scientist in several fields were
excited by the possibility, but they expressed caution about interpreting
the preliminary analysis and said a full scientific expedition to the site
needs to be mounted to determine if the landforms do in fact represent an
impact crater.

Researchers would look for shards of melted sand and telltale quartz that
had been shocked into existence. If it were a comet, the impact would have
occurred on what was once a shallow sea, triggering massive flooding
following the fire generated by the object's partial vaporization as it
screamed through the atmosphere. The comet would have plunged through the
water and dug into the earth below.

If it proves to be an impact crater, there is a good chance it was dug from
the planet less than 6,000 years ago, Master said, because shifting sediment
in the region would have buried anything older.

Arriving at an exact date will be difficult, researchers said.

"It's an exciting crater if it really is of impact origin," said Bill
Napier, an astronomer at the Armagh Observatory.

Cultural impact

Napier said an impact that could carve a hole this large would have packed
the energy of several dozen nuclear bombs. The local effect: utter

"But the cultural effect would be far greater," Napier said in an e-mail
interview. "The event would surely be incorporated into the world view of
people in the Near East at that time and be handed down through the
generations in the form of celestial myths."

Napier and others have also suggested that the swastika, a symbol with roots
in Asia stretching back to at least 1400 B.C., could be an artist's
rendering of a comet, with jets spewing material outward as the head of the
comet points earthward.

But could a single impact of this size take down civilizations on three
continents? No way, most experts say.

Napier thinks multiple impacts, and possibly a rain of other smaller meteors
and dust, would have been required. He and his colleagues have been arguing
since 1982 that such events are possible. And, he says, it might have
happened right around the time the first urban civilizations were crumbling.

Napier thinks a comet called Encke, discovered in 1786, is the remnant of a
larger comet that broke apart 5,000 years ago. Large chunks and vast clouds
of smaller debris were cast into space. Napier said it's possible that Earth
ran through that material during the Early Bronze Age.

The night sky would have been lit up for years by a fireworks-like display
of comet fragments and dust vaporizing upon impact with Earth's atmosphere.
The Sun would have struggled to shine through the debris. Napier has tied
the possible event to a cooling of the climate, measured in tree rings, that
ran from 2354-2345 B.C.

Supporting evidence

Though no other craters have been found in the region and precisely dated to
this time, there is other evidence to suggest the scenario is plausible. Two
large impact craters in Argentina are believed to have been created sometime
in the past 5,000 years.

Benny Peiser, a social anthropologist at Liverpool John Moores University in
England, said roughly a dozen craters are known to have been carved out
during the past 10,000 years. Dating them precisely is nearly impossible
with current technology. And, Peiser said, whether any of the impact craters
thought to have been made in the past 10,000 years can be tied back to a
single comet is still unknown.

But he did not discount Napier's scenario.

"There is no scientific reason to doubt that the break-up of a giant comet
might result in a shower of cosmic debris," Peiser said. He also points out
that because Earth is covered mostly by deep seas, each visible crater
represents more ominous statistical possibilities.

"For every crater discovered on land, we should expect two oceanic impacts
with even worse consequences," he said.

Tsunamis generated in deep water can rise even taller when they reach a

Reverberating today

Peiser studies known craters for clues to the past. But he also examines
religions and cults, old and new, for signs of what might have happened way
back then.

"I would not be surprised if the notorious rituals of human sacrifice were a
direct consequence of attempts to overcome this trauma," he says of the
South American impact craters. "Interestingly, the same deadly cults were
also established in the Near East during the Bronze Age."

The impact of comets on myth and religion has reverberated through the ages,
in Peiser's view.

"One has to take into consideration apocalyptic religions [of today] to
understand the far-reaching consequences of historical impacts," he says.
"After all, the apocalyptic fear of the end of the world is still very
prevalent today and can often lead to fanaticism and extremism."

An obsession with the end of the world provides the legs on which modern-day
terrorism stands, Peiser argues. Leaders of fundamentalist terror groups
drum into the minds of their followers looming cataclysms inspired by
ancient writings. Phrases run along these lines: a rolling up of the sun,
darkening of the stars, movement of the mountains, splitting of the sky.

It is in the context of such apocalyptic religions that a large meteorite,
enshrined in the Kaba in Mecca, became the most feared and venerated object
of the Islamic faith, Peiser said.

By using such language, radical fundamentalist leaders instill "absolute
commitment and fanaticism into their followers," Peiser said. "Once you
believe that the end is imminent and that your direct action will hasten the
coming of end-times, every atrocity is sanctioned."

No smoking gun yet

Despite the excitement of the newfound hole in the ground in Iraq, it is
still far from clear why so many civilizations collapsed in such a
relatively short historical time frame. Few scientists, even those who find
evidence to support the idea, are ready to categorically blame a comet.

French soil scientist Marie-Agnes Courty, who in 1997 found material that
could only have come from a meteorite and dated it to the Early Bronze Age,
urged caution on drawing any conclusions until a smoking gun has been
positively identified.

"Certain scientists and the popular press do prefer the idea of linking
natural catastrophes and societal collapse," Courty said.

Multiple cosmic impacts are an attractive culprit though, because of the
many effects they can have, including some found in real climate and
geologic data. The initial impact, if it is on land, vaporizes life for
miles around. Earthquakes devastate an even wider area. A cloud of debris
can block out the Sun and alter the climate. The extent and duration of the
climate effects is not known for sure, because scientists have never
witnessed such an event.

It might not have taken much. Ancient civilizations, which depended on
farming and reliable rainfall, were precarious.

Mike Baillie, a professor of palaeoecology at Queens University in Belfast,
figures it would have taken just a few bad years to destroy such a society.

Even a single comet impact large enough to have created the Iraqi crater,
"would have caused a mini nuclear winter with failed harvests and famine,
bringing down any agriculture based populations which can survive only as
long as their stored food reserves," Baillie said. "So any environmental
downturn lasting longer than about three years tends to bring down

Other scientists doubt that a single impact would have altered the climate
for so long.

Lessons for tomorrow

Either way, there is a giant scar on the planet, near the cradle of
civilization, that could soon begin to provide some solid answers, assuming
geologists can get permission to enter Iraq and conduct a study.

"If the crater dated from the 3rd Millennium B.C., it would be almost
impossible not to connect it directly with the demise of the Early Bronze
Age civilizations in the Near East," said Peiser.

Perhaps before long all the cometary traditions, myths and scientific fact
will be seen to converge at the Iraqi hole in the ground for good purpose.
Understanding what happened, and how frequent and deadly such impacts might
be, is an important tool for researchers like Peiser who aim to estimate
future risk and help modern society avoid the fate of the ancients.

"Paradoxically, the Hebrew Bible and other Near Eastern documents have kept
alive the memory of ancient catastrophes whose scientific analysis and
understanding might now be vital for the protection of our own civilizations
from future impacts," Peiser said.

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