All CCNet Digests and Debates can be found on the electronic archive at

    Carolyn Shoemaker

    Michael Gerrard <>

    Clark Chapman <>

    Sir Arthur C Clarke

    Uri Carsenty <>

    National Research Council


From Carolyn Shoemaker

Just for the record, since Gene and I were given credit as scientific
consultants for Deep Impact, I feel as though I should clarify our
contributions. Four years ago one of the script writers, Bruce Joel
Rubin, came to visit us during one of our observing runs at Palomar. 
We endeavored to show him how we made discoveries and discussed with
him at length about the story line he proposed for Deep Impact and ways
it could be developed. Our understanding was that Spielberg was
interested in having the science correct, but that doing it right might
stretch the truth. In other words, for theatre-sake the exception and
not the rule could be portrayed. Gene and I liked Rubin and felt he was
doing his best to get a good grasp of what might make the story work
and be acceptable to the scientists. We pointed him to a number of
people who might be worth consulting. Then, as far as we knew, Rubin
dropped out of sight and we figured that nothing was to come of his

Last April, everything was on again, and Dream Works asked the two of
us to serve as consultants.  We were sent a preliminary script and in
April a big meeting was held with producers and technical
people--sound, costumes, staging, the works.  We were not the only
consultants; there were some very good ones. Rubin seemed no longer to
be in the loop. We discussed the script for several hours--it was
generally like you saw it portrayed. (Happily, they clothed the nude
astronomer even before the meeting. I always thought astronomy was one
of the coldest professions, and envisioned frostbite at the least!) I
expressed my misgivings about the discovery process as portrayed (to no
avail). If I want to really pick at the film, I have to agree with
Brian Marsden's reservations. The consultants wanted to make the film
credible and each addressed different areas. We were all hung up on the
one big premise that astronauts are ready to and could go out and get
rid of the comet simply. Gene and I attended only the one meeting and
shooting began after we left for Australia. When I returned, I was
asked by Dream Works to give interviews on the movie and was told they
would send me the new revised script. They didn't and I didn't. I saw
the movie last Sunday for the first time.

I was not surprised that the beginning was not changed and that some of
the other flaws still existed. Most people are not that interested in
the intracacies of the regular observing process to get an orbit nor
even the naming process. Timing of events was something of a problem
but not necessarily to most viewers. I think the whole subject of
discovery, the nature of comets, how to ameliorate such a threat,
social/political aspects, space travel, and the physical results of an
impact like this are so involved that no movie can do justice to all
aspects. In the interest of covering all these topics, Deep Impact, of
necessity had to slight virtually all of these areas or we could have
been there for days.  Did Titanic go into correct ship-building
procedures, or the behavior and characteristics of icebergs, etc? In
science we each have our pet area of interest which we want credible,
but this was a story of people also. Overall, it was a pretty exciting
yarn and the science was not as badly flawed as we have all seen
before. It just might help to increase the public awareness of the
danger of impact, because most people think of dangers in relation to
themselves and this movie addressed the social implications of impact.

And to answer a question, yes, my name was on the envelope lost in the
truck collision.  Either I was keeping very quiet, or the envelope flew
out and was lost in the brush of that mountain or it burned.  I find
the latter explanations more realistic.  No doubt, the computer images
left behind by Biederman gave the story away to the investigating


From Michael Gerrard <>

All the main characters in Deep Impact proved themselves to be
altruistic, wise, or both. Mimi Leder is to be congratulated for
bringing such an uplifting vision to the screen. However, an only
slightly darker vision yields a more downbeat image of how society
would react to a year's warning of a catastrophic impact.

If one million of the 275 million Americans are to be saved by the
federal government, the remaining 274 million surely will include more
than a few who will not accept certain death for themselves and their
families with quiet resignation. The very rich will decide to build
their own shelters, and since other construction projects are likely to
stop anyway (who wants to execute or finance a building that may be
swept away before it's finished?), the nation's construction industry
will quickly be diverted to building private shelters for those who can

afford space -- and for the construction workers and their families,
who will rightly demand berths in what they have built. Some or all
states may also build their own shelters. (The State of Missouri may
have particular objections to hosting a national Ark to which very few
of its citizens are admitted.)

Because far more than one million people are likely to find shelter
under this scenario, it will be important to begin, immediately upon
warning, to shift as much of the nation's agricultural and food
processing capability as possible to foods that can be grown quickly 
and that can be preserved for the long underground siege (powdered
milk, canned or dried fruits and vegetables, etc.). Because of the long
lead time involved in this, it would be irresponsible (as well as
impossible) to delay very long the announcement of confirmation of
likely impact.

The nature of wealth will also be tested. Many of the richest people
have their money in stocks and in real estate -- two items whose value
will plummet. Those with construction equipment and materials; fuel;
and agricultural production capabilities will have the upper hand; a
billion dollars in computer stock won't go very far.

The Deep Impact scenario raises a host of other philosophical, ethical
and practical issues:

-- How many people should be sacrificed to accommodate two years' food
supply for mating pairs of all of the world's elephant species?

-- Will a religious group view the comet as the will of God, so that
efforts to intercept it must be stopped? What are the military
consequences if members of this religion control a country?

-- For those who win admission to the shelters, for themselves and
their families, what is the definition of a "family"? What about
unmarried, or same sex, or very underaged (and very newly married)
couples? What about second cousins?

-- At what point in the course of events do we unlock the doors to all
prisons in coastal states, to give the inmates at least a chance of a
way to safety?

-- Will the population admitted to the shelters resemble the ethnic
diversity of the population as a whole? If not, will there be attempts
under the equal protection and civil rights laws to redress the
imbalance? As an attorney who has studied the legal issues in NEO
defense, I can say it's not at all clear that imposition of martial law
suspends indefinitely all constititutional rights of civilians.
Moreover, there is no predicting what ruling might be issued by a 
judge who himself or herself was not among those  admitted to a shelter
-- or how that judge would enforce his or her ruling.

-- Even before the place of impact is known, it will be apparent that
the greatest risks are to those along coastlines. Thus there is likely
to be a massive migration inland. How will the inland states cope with
this huge flux of refugees? Will some of them try to erect barriers?

-- If the surviving population of the U.S. is now mostly west of the
Mississippi, does it make sense to rebuild Washington as the nation's
capital? More fundamentally -- who would decide? Would totally drowned
states still each have two Senators?

These are all U.S.-centered thoughts, but comparable questions will
arise in other countries. Obviously no two-hour entertainment film can
deal with these issues, some large and some small, but I am grateful to
Deep Impact for provoking these thoughts.


A review of the legal aspects surrounding the NEO threat can be
found in: Michael B. Gerrard and Anna W. Barber, "Asteroids and Comets:
U.S. and International Law and the Lowest-Probability, Highest
Consequence Risk," New York University Environmental Law Journal, vol.
6, no. 1 (1997). I will mail a copy of the reprint to anyone who sends
me their snail mail address. (The article is not available in an
electronically-transmittable form.)


From Clark Chapman <>

Dear Benny,

    A few comments about "Deep Impact," inspired by Brian Marsden's
remarks in yesterday's CCNet Digest: Brian's detailed criticism of the
early minutes of the movie are, of course, technically correct and
amplify on my own brief criticisms. Brian asks why I was critical of
him and more forgiving of the movie, and I would like to explain. 
First, the scientific process is inherently one of continually
critiquing the work of oneself and others, in order to reach a higher
standard than is typical of most human activities. That is why
scientific research is often internally reviewed within organizations,
externally reviewed before publication, and subject to after-the-fact
criticisms in the literature. In the world of astronomy, the review
process puts one in quadruple jeopardy: hiring and promotion decisions,
awarding of telescope time, funding decisions, and acceptance of
publications are all largely disjoint from each other.

   I believe that scientists enjoy especially high regard (although not
as high as we might like) in the public view because of these
standards. Sagas like the Lou Frank mini-comet hypothesis or the recent
"cure for cancer" announced in the New York Times by a reporter trying
to market a private book project on that topic undercut scientific
credibility. I entirely agree with Brian Marsden that a major
underlying problem in the 1997 XF11 matter was lack of adequate
funding. It has become clear (and Marsden agreed in his April 18th IAU
Circular) that people working for Marsden, Yeomans, or any other expert
orbit calculator could have calculated the virtual impossibility of an
Earth impact months before March 11th; moreover, adequate data for that
purpose (if not all of it) had been made available by Marsden. But XF11
wasn't examined carefully enough and it wasn't declared "safe". The
main problem was (and remains) lack of funding: there simply wasn't the
money to hire the manpower to critically evaluate all of the relevant
data all of the time. That is the excuse. But the announcement and
retraction deserved critical evaluation so that we, as a community, may
do better in the future, with whatever funding may be available.

  The purpose of movies is not science but entertainment. While I would
love to see a movie that, as a sub-purpose, adhered to strict
scientific accuracy, the standards in that industry are extremely low.
Most movies that have been made on this and other scientific topics
employ *no* technical advisors.  It is not that Hollywood directors
wouldn't prefer advice, everything else being equal.  But it is simply
not a priority, and it rarely makes the cut.  As Brian's essay makes
clear, there *were* efforts to make "Deep Impact" technically accurate.

   I spoke recently with Dr. Josh Colwell, a planetary scientist at the
University of Colorado here in Boulder.  He actually has a bit part in
the movie, as CAPCOM just before the shuttle launch.  But he also
worked as a scientific consultant to "Deep Impact" throughout, checking
various versions of the script. He told me that elements of the movie
were scientifically dreadful, in early versions. He, for example,
argued vociferously that the comet would have nearly-zero gravity and
that the space vehicle would have to dock with it.  The original
concept was to have astronauts land on it and bound about on the comet
as on the Moon, and Josh used up a fair number of his silver bullets in
getting that change accepted.

  I believe that we should encourage Hollywood to follow "Deep
Impact's" example, and do even better in the future. 

Clark R. Chapman
Institute Scientist
Southwest Research Institute
Boulder, Colorado


From Sir Arthur C Clarke

Dear Benny,

Herewith my contribution, written a couple of years ago... Thanks
for info on DEEP IMPACT, which will be v useful to my agent.

All best,   Arthur    



Space scientists recently completed an examination of orbital debris,
recovered after circling the Earth for several years. They discovered 
that much of it was coated with a thin film of what was delicately
described as `fecal matter', attributed to astronaut's sloppy

This may solve one of the mysteries of life's origin on Earth: it seems
to have arisen almost as soon as conditions were favourable, and not
after the billions of years of molecular trial and error required by
what Isaac Asimov called the 'unblind working of chance.'

Obviously, organised life-forms need have occurred only once in this
Galaxy, if the very first space-faring civilisation was as careless
about the environment as we are. Years ago, Hoyle and Wickramasinghe
suggested that life had a cosmic, and not terrestrial, origin. They
may be right, though not precisely in the way they imagined. It's a
humbling thought that we may  have arisen from dumped sewage; the
first chapter of Genesis would certainly require drastic revision.

On the other hand, if - as some philosophers have suggested - this
Earth does indeed harbour the only life in the Universe, that 
deplorable state of affairs is now being rectified. We may draw some
consolation - I hesitate to say inspiration - from  the fact that our
descendants are already on their way to the stars. But we certainly 
would not recognise them, and it might be tactless to ask exactly how
they got there.

Arthur C Clarke       


From Uri Carsenty <>

Dear Benny,

A colleague of mine had his vacation (April 1998) in the Maledives
Islands. He observed there a spectacular meteoritic event and asked to
whome he should submit a description. I am adding his description to
this note. Please forward it to who ever is interested in this events.

Uri Carsenty

During a trip to North Maledives in April we have seen a spectacular
appearance of a meteorite (or something else?) passing the upper
atmosphere. We would be happy to hear if their had been a registration
of the event and to get more information about it. 
A description of the observation:

the object moved horizontallysouth to south-west at about 25 deg.
elevation covering an azimuth angle of about 50 degrees. The duration
of the event was estimated to 1-2 seconds with three phases (no noise):

1. phase like a very bright falling star, white-red
2. phase lighting up to a bright green-white double track, pretty
3. phase white-red again with parts separating moving downwards
   while the main object moved on straight.

Date 18 April 1998, 15:40 (UT) or 20:40 local time
Observer pos. 73 deg. 13 min. East Greenwich, 6 deg. 55 min. North.

As no one of the twelve people their had ever seen such an event it
would very nice if we could get more about it.

Thanks for your help

Jochen Fries
DLR Oberpfaffenhofen
T: 08153/28-276
Fax:    /28-1337


From Andrew Yee <>

NOTE: The report cited in this release is available online at


National Research Council
Washington, D.C.

Contacts: Ellen Bailey Pippenger, Media Relations Associate
Dumi Ndlovu, Media Relations Assistant
(202) 334-2138; e-mail

Date: May 13, 1998

Publication Announcement

Policies Needed for Reporting Potential Hazards Of Asteroid Collisions
with Earth

Recent news of a possible asteroid collision with Earth in 2028 sparked
intense scientific and popular interest worldwide. When further data
revealed that the asteroid had virtually no chance of hitting this
planet, the episode prompted the astronomy community to re-evaluate how
they communicate such information to the public.

NASA and astronomers should develop protocols for reporting information
about asteroids that appear to pose a potential hazard to Earth, says a
new report from a National Research Council committee, which began its
work before the recent episode. These protocols will be important
because several telescope facilities and new instruments now coming
into operation will dramatically increase the rate by which scientists
are able to discover asteroids and comets whose orbits approach Earth.
With the flood of discoveries expected within the next decade also will
come the risk of false alarms.

Some 400 Earth-approaching asteroids and comets larger than one
kilometer in diameter have been discovered so far, but only an
estimated 10 percent of the objects this size have been identified. Of
the thousands that may be discovered, some initially -- for a few days,
weeks, or even years -- may seem likely to collide with Earth, until
enough data have been collected to determine accurate orbits and
interpreted to show otherwise. Policies for handling such potentially
important information will be needed. International scientific
organizations, such as the International Astronomical Union, could
play a role in this task, the report says.

Most asteroids orbit the sun in a belt between Jupiter and Mars, but
thousands have orbits that sometimes take them uncomfortably close to
Earth. Geological processes such as erosion tend to erase scars left
when asteroids and comets occasionally hit Earth, but there are some
notable exceptions, such as Arizona's Meteor Crater. Moreover, there is
evidence that an asteroid or comet some five to 10 kilometers in
diameter created an enormous crater in Yucatan, Mexico, some 65 million
years ago. That event has been implicated in the extinction of
dinosaurs and other living organisms. This information, coupled with
recent evidence of the collision of Comet Shoemaker-Levy 9 with Jupiter
in 1994, has led to increased scientific and public interest in
assessing the likelihood that a large object might hit Earth again.

Although asteroids and comets are potential hazards to Earth, these
tiny worlds offer a trove of clues to the solar system's birth and
early history, the report says. Exploration of asteroids also may be
used as stepping stones toward manned missions to Mars. Comets are
frozen chunks of ice and dust thought to be left from the formation of
the planets in the solar system. Asteroids are minor planets, some made
from almost pure mixtures of nickel and iron like those at the Earth's
core or from minerals similar to those found in the Earth's crust, and
others from exotic combinations of carbon compounds.

To better understand the scientific opportunities posed by asteroids
and comets, the report recommends that priorities be given to the
following areas:

Telescopic studies. NASA, other government agencies, and private
research organizations should further coordinate their programs using
ground-based telescopes to search for and study asteroids and comets.
Because a typical asteroid or comet is very faint and travels by Earth
so quickly, the opportunity to view it may last no more than a few days
or a week at most. To conduct the detailed observations that these
fleeting objects require, routine or priority access to existing
infrared and optical telescopes is needed. Otherwise, telescopes
dedicated to characterizing the asteroids and comets discovered by
ongoing search programs should be developed.

Laboratory investigations. More research is needed to increase
understanding of extraterrestrial materials, such as meteorites, which
are believed to come from asteroids. Laboratory studies can address,
for example, the puzzle of how the environment in space changes the
surfaces of asteroids to such an extent that the physical
characteristics of the most common varieties of asteroids and
meteorites do not match. NASA, other government agencies, and private
research organizations should support additional laboratory
investigations of samples of these space-borne objects. New analytical
instruments, such as those necessary to study very small samples of
meteorites, also are needed.

Robotic and manned spacecraft missions. Spacecraft that pass by,
rendezvous with, or obtain samples from asteroids orbiting near Earth
provide important information on the detailed physical characteristics,
composition, and geologic histories of planetary bodies that is
otherwise unobtainable. Moreover, Earth-approaching asteroids or comets
are among the most accessible objects in the solar system. Indeed, some
are easier to reach than the moon. NASA's Galileo missions, for
example, provided a wealth of information about asteroids Ida and
Gaspra orbiting between Mars and Jupiter. Last year, a NASA spacecraft
made detailed observations of another asteroid, Mathilde. The
spacecraft is currently en route to a February 1999 rendezvous with
Eros, one of the largest Earth-approaching asteroids. NASA should
continue such missions and improve spacecraft technology, such as
propulsion and navigation systems, to allow additional low-cost
rendezvous and sample-return missions.

Should the United States choose to undertake further manned exploration
beyond Earth, a strong case can be made for beginning with missions to
Earth-approaching asteroids, the report says. Because missions to these
asteroids represent deep-space exploration with moderate technical
challenges, they would be the least-expensive next step in human
exploration of space and could provide the experience and technology
needed for fruitful missions to Mars and beyond. Five percent of
Earth-approaching asteroids are readily accessible by relatively short
space flights.

A primary concern would be keeping the length of the mission as short
as possible to minimize hazards and risks to which astronauts are
exposed, including weightlessness, radiation, meteoroid impact, and
equipment failure. Further research should be conducted to study
specific technical requirements necessary for a six- to 12-month
round-trip expedition. With the anticipated increase in discoveries of
Earth-approaching asteroids, there likely will be opportunities for
missions to one or more asteroids each year.

The study was funded by the NASA. The National Research Council is the
principal operating agency of the National Academy of Sciences and the
National Academy of Engineering. It is a private, non-profit
institution that provides science advice under a congressional charter.
A committee roster follows.

Copies of The Exploration of Near-Earth Objects are available from the
National Academy Press for $10.00 (prepaid) plus shipping charges of
$4.00 for the first copy and $.50 for each additional copy; tel. (202)
334-3313 or 1-800-624-6242. Reporters may obtain a copy from the Office
of News and Public Information (contacts listed above).

Commission on Physical Sciences, Mathematics, and Applications
Space Studies Board

Committee on Planetary and Lunar Exploration

Ronald Greeley (chair)
Professor of Geology
Department of Geology
Arizona State University

Jeffrey R. Barnes
Associate Professor
College of Oceanic and Atmospheric Sciences
Oregon State University

Richard P. Binzel
Department of Earth, Atmospheric, and Planetary Sciences
Massachusetts Institute of Technology

Wendy Calvin
Astrogeology Team
U.S. Geological Survey
Flagstaff, Ariz.

Russell F. Doolittle*
Research Professor of Biochemistry
Center for Molecular Genetics
University of California
San Diego

Heidi Hammel
Principal Research Scientist
Department of Earth, Atmospheric, and Planetary Sciences
Massachusetts Institute of Technology

Larry A. Haskin
Professor of Chemistry and Earth and Planetary Sciences
Department of Earth and Planetary Sciences
Washington University
St. Louis

Bruce Jakosky
Associate Professor, Atmospheric and Space Physics
Laboratory for Atmospheric and Space Physics
University of Colorado

Kenneth Jezek
Director, Byrd Polar Research Center, and
Professor, Department of Geological Sciences
Ohio State University

George E. McGill
Professor Emeritus
Department of Geosciences
University of Massachusetts

Harry Y. McSween Jr.
Department of Geological Sciences
University of Tennessee

Michael Mendillo
Professor, Department of Astronomy, and
Professor, Department of Electrical and Computer Engineering
Boston University

Gerald Schubert
Professor of Geophysics and Planetary Physics
Department of Earth and Space Science
University of California
Los Angeles

Everett Shock
Associate Professor
Department of Earth and Planetary Sciences
Washington University
St. Louis


David H. Smith
Senior Program Officer

The CCNet is a scholarly electronic network. To subscribe, please
contact the moderator Benny J Peiser at <>.
Information circulated on this network is for scholarly and educational
use only. The attached information may not be copied or reproduced for
any other purposes without prior permission of the copyright holders.
The electronic archive of the CCNet can be found at

CCCMENU CCC for 1998