PLEASE NOTE:


*

CCNet 6/2003 -  20 January 2003
-------------------------------

"Opinions about the NEO question range from a belief that the threat
is vastly under- appreciated, to a suspicion that it has been
exaggerated by some scientists and the media. The OECD workshop is being
designed to approach the subject without preconceptions about the level of
the threat or the needed actions. A sober, science-based, international
analysis under the aegis of the Global Science Forum, and with full
appreciation of the policy contexts, should bring clarity, rigour, and
political realism to this complex and still largely unfamiliar issue."
--Organisation of Economic Cooperation and Development,
January 2003


"The laws of physics are the only things controlling how fast we go
anywhere, what we do and whether we can survive the experience. So until
we beat the technical limitations, you basically end up arguing about
fantasy missions. We've been restricted to the same speed for 40
years. With the new technology, where we go next will only be limited by our
imaginations."
--Sean O'Keefe, NASA Administrator, 17 January 2003


(1) OECD WORKSHOP ON NEO HAZARD: WILL EUROPE CONTINUE FREE-RIDING OR JOIN
SPACEGUARD EFFORTS?
    Organisation of Economic Cooperation and Development, January 2003

(2) "KILLER ASTEROID APPROACHING THE EARTH?" PRAVDA SPREADING APPALLING
ASTEROID SCARE
     Pravda, 17 January 2003

(3) FIREBALL WATCH
    SpaceWeather.com <swlist@spaceweather.com>

(4) GOOD NEWS FOR PLANETARY PROTECTION: NASA PREPARES FOR NUCLEAR-POWERED
LEAP TOWARDS MARS
    The Times, 18 January 2003

(5) ASTRONOMY PROJECTS IN RUINS AS AUSTRALIAN OBSERVATORY IS OBLITERATED
    The Sydney Morning Herald, 20 January 2003
 
(6) RE: TUNGUSKA & THE 1953 LUNAR FLASH
    Jens Kieffer-Olsen [mailto:dstdba@post4.tele.dk]

(7) IS THE SOLAR SYSTEM DETERMINISTIC?
    Hermann Burchard <burchar@math.okstate.edu>

(8) AND FINALLY: THE LESSON OF EARTH'S INEVITABLE END - ENJOY LIFE
    Tallahassee Democrat, 19 January 2003


=========
(1) OECD WORKSHOP ON NEO HAZARD: WILL EUROPE CONTINUE FREE-RIDING OR JOIN
SPACEGUARD EFFORTS?

>From Organisation of Economic Cooperation and Development
http://www.oecd.org/EN/document/0,,EN-document-0-nodirectorate-no-20-35881-0,00.html

OECD Global Science Forum
WORKSHOP ON NEAR EARTH OBJECTS: RISKS, POLICIES AND ACTIONS
European Space Research Institute (ESRIN), Frascati, Italy
January 20-22, 2003

The Global Science Forum is convening a workshop that will allow government
officials and scientists to examine the threat from Near Earth Objects, and
possible actions that may be needed. The event will be held in Frascati,
Italy, on January 20-22, 2003.

Over the past several years, astronomers have learned a great deal about
asteroids and comets ("Near Earth Objects" or NEOs) that strike the Earth.
Small asteroids burn up harmlessly as meteors in the atmosphere, the Earth's
natural defence. Very large impacts have in the past been overwhelmingly
catastrophic but are, fortunately, very infrequent. However, detectable
misses by mid-sized asteroids are quite common. As observational techniques
improve, astronomers detect such near misses with greater frequency. These
events are the subject of media reports that create widespread curiosity and
concern.

In response to new scientific findings and the increased visibility of the
issue, the Global Science Forum of the Organisation for Economic
Co-operation and Development (OECD) will hold a workshop to review the state
of knowledge about the dangers posed by NEOs, to examine the level of effort
currently devoted to dealing with the hazards, and to consider the need for
new policies and possible actions.

The workshop will be hosted by the European Space Research Institute (ESRIN)
in Frascati, Italy, on January 20 - 22, 2003. Unlike many previous
scientific gatherings on this subject, this workshop will bring together
researchers and government policy makers from OECD countries, including
those who are responsible for the safety of the public. The workshop was
proposed by the delegation of the United Kingdom to the Global Science Forum
as part of its follow-on to the report of the Task Force on Potentially
Hazardous Near Earth Objects (chaired by Dr. Harry Atkinson with Sir Crispin
Tickell and Professor David Williams as members). The report was delivered
to the UK government in September 2000 (http://www.nearearthobjects.co.uk).
An international steering committee is in charge of organising the event
with the assistance of the secretariat of the OECD. Members of the steering
committee were appointed by eleven Global Science Forum delegations.

Workshop participants will focus on the following specific areas:

- An assessment of the threat posed by NEOs relative to other known natural
and man-made hazards.
- An appraisal of current responses to the threat.
- A review of the policy-level dimensions of NEO-related issues, on national
and international levels.
- A review of the state of scientific knowledge, including its accuracy and
completeness.
- An enumeration of possible actions and follow-on studies by the scientific
and policy communities.

Opinions about the NEO question range from a belief that the threat is
vastly under-appreciated, to a suspicion that it has been exaggerated by
some scientists and the media. The OECD workshop is being designed to
approach the subject without preconceptions about the level of the threat or
the needed actions. A sober, science-based, international analysis under the
aegis of the Global Science Forum, and with full appreciation of the policy
contexts, should bring clarity, rigour, and political realism to this
complex and still largely unfamiliar issue. Attendees to the NEO workshop
will be invited by governmental delegations to the Global Science Forum, and
by the international steering committee.

PROGRAMME
Chairman: Dr. Richard Crowther (United Kingdom)

Monday, January 20
Morning 09:15 - 12:30

Session 1 The Threat From NEOs Relative to Other Hazards
1 09:15-10:05 Welcome and introductory remarks. Background and purpose of
the workshop.
2 10:05-10:45 Effects of Land Impacts from NEOs, Jan Smit (Vrije
Universiteit, The Netherlands)
10:45-11:15 Coffee
3 11:15-11:50 Tsunamis from NEOs, Jack Gilbert Hills (Los Alamos National
Laboratory, USA)
4 11:50-13:00 How an NEO Impact Might Affect Society, Clark Chapman
(Southwest Research Institute, USA) Commissioned paper
13:00-14:30 Lunch
Afternoon 14:30 - 17:40
Session 2 Perceiving and Dealing with Hazards
5 14:30-15:30 Strategic Responses to the NEO Hazard: Lessons Learned from
Crisis Management
Patrick Lagadec (Ecole Polytechnique, France)
6 15:30-16:00 The Threat of NEOs: Reactions from the Public and the Press,
Oliver Morton (UK)
16:00-16:30 Coffee
7 16:30-17:10 Why Should Governments be Interested? Lembit Öpik (House of
Commons, UK)
8 17:10-17:25 Video presentation: Asteroids in Space Syuzo Isobe (National
Astronomical
Observatory of Japan)
9 17:25- 17:50 General Discussion
Dinner
Speech by Sir Crispin Tickell (University of Kent, UK)
15 January 2003
Tuesday, January 21
Morning 09:15 - 12:40
Session 3.A The Science of NEOs
10 09:15-10:15 Facts and Uncertainties About NEOs, Donald Yeomans (Jet
Propulsion Laboratory, USA)
Session 3.B Assessing and Managing the Risk
11 10:15-11:05 Asteroid Searches and Monitoring: Predicting Impacts, Andrea
Milani (University of Pisa, Italy)
11:05-11:35 Coffee
12 11:35-12:00 What Might Be Done to Prevent an Impact? Ivan Bekey (USA)
13 12:00-12:25 Technology Development for Diversion and Mitigation
Marcello Coradini (European Space Agency)
14 12:25-12:35 Trustworthy Deflection of an NEO, Russell Schweickart (B612
Foundation)
15 12:35-13:00 Security Perspectives on the Asteroid Threat, Simon P. Worden
(US Air Force)
13:00-14:40 Lunch
Afternoon 14:40 - 18:00
Session 4 International Aspects
16 14:40-15:20 Astronomers, Impacts and Society: the IAU Experience, Hans
Rickman (International Astronomical Union)
17 15:20-16:05 Coordination for Detection, Computation and Assessment,
Andrea Carusi (Spaceguard Foundation, Italy)
16:05-16:35 Coffee
18 16:35-17:00 International Co-ordination at the Minor Planet Center, Brian
Marsden (Smithsonian Astrophysical Observatory, USA)
19 17:00-17:30 The Legal Basis for International Cooperation, Evan R.
Seamone (University of Iowa, USA)
20 17:30-18:00 National Programmes for Dealing with Natural Hazards
(including NEOs)
Workshop participants
15 January 2003
Wednesday, January 22
Morning 09:30 - 12:00
Session 5 General Discussion and Conclusions for the Global Science Forum
21 Panel: Members to be announced.
 
===============
(2) "KILLER ASTEROID APPROACHING THE EARTH?" PRAVDA SPREADING APPALLING
ASTEROID SCARE

>From Pravda, 17 January 2003
http://english.pravda.ru/main/2003/01/17/42163.html

Robin Scagell, vice-president of the British Society for Popular Astronomy
said: "Now we start realizing that we are living in the world that is a real
shooting range in fact. Until now, the mankind was lucky." He added that
only when the last generation of telescopes appeared, astronomers understood
that the space was polluted with "tiny" meteorites and asteroids, each of
them may wipe a large city off the face of the Earth. Not so much time ago,
a meteorite called 2000YA passed by the planet, it was just 800 thousand
kilometers from the Earth, which is a short distance judging by the
astronomic standards. The meteorite moved at the speed of over 36 km/sec.
Scagell says that the meteorite could turn the central part of London into a
mess if it hit London. To tell the truth, there are even larger meteorites
that pass the planet.

Recently, on December 27, 2002 Ukraine's newspaper Pravda Ukraini (Ukrainian
Truth) published a sensation that attracted little attention in the fuss on
the New Year's eve. The newspaper reported that a meteorite called Eight (it
is called so by its shape) was approaching the Earth and would hit the
planet on January 25, 2003. It was also reported that "leaders and
scientists of the world largest countries started incredibly heated disputes
on the problem. The world practice witnessed such situation for the first
time. It was also for the first time that projects of astrophysicists were
discussed at parliamentary sessions in Central Europe. The reason to it was
a huge meteorite hundreds times larger than the famous Tunguska meteorite,
which can drop on the Earth on January 25, 2003. The most optimistic
forecasts say that if the meteorite falls, it may raze to the ground the
territory of several thousands of square kilometers."

The newspaper cited President of the Boston Center for Space Research and
Observation, Herbert Coliander who said that "no doubt that the meteorite
discovered four years ago will fall on the Earth." The problem was discussed
at a G7 session in Warsaw, where it was suggested that a special group for
averting a catastrophe must be created. The newspaper reported at that:
"However, the Council of Europe Parliamentary Assembly declared such hasty
actions were ungrounded."

Baikal Lake is one of the possible spots of the meteorite's falling; if the
catastrophe occurs, the lake will turn into one more ocean, not to mention
the accompanying climate cataclysms.

It is strange that the information about the approaching cataclysm caused
just slightest anxiety. Probably, the Ukrainian newspaper made a misprint,
and the meteorite may hit the Earth not in 2003, but in 2013 or even in
2113. This doesn't change the situation radically, as the mankind is not yet
ready for resistance to danger going from the sky and unlikely to be ready
for it very soon. Indeed, the above mentioned 2000YA meteorite was detected
when it already passed by the Earth. After that, a report of three
scientists warning of a real meteorite danger was published in Great
Britain. The report suggested that a system of anti-meteorite protection
covering the whole of the planet must be created.

On June 14, 2002, asteroid 2002MN of about 100 meters in length passed by
the Earth at a distance of 120 thousand kilometers (it is less than one
third of the distance between the Earth and the Moon). And the asteroid was
detected only in three days after it successfully passed the planet. The
problem is that the "space guards" still have no equipment to detect such
"small" objects.

A meteorite threat is not a myth, but reality. Let's remember the Tunguska
meteorite which explosion in 1908 was equivalent to the explosion of 500
nuclear bombs. Fortunately, the meteorite blew up over the Siberian taiga.
What would happen if it didn't? There is a hypothesis saying that dinosaurs
were killed with an asteroid of 5 kilometers in diameter. About 40 meteorite
craters with the diameter of more than 20 kilometers were discovered on the
planet. It means that large celestial bodies collided with the Earth and
will do in the future as well.

Famous journalist and researcher Yaroslav Golovanov wrote: "90% of all
asteroids are orbiting between Mars and Jupiter. There are thousands, if not
millions of asteroids. They are large and small; judging by calculations,
17% of the large asteroids have tiny satellites of their own. (About one
billion of comets outside the Solar system are not taken into consideration
at that. 20% of celestial bodies that are dangerous for the Earth are just
exactly new comets that are difficult to predict). Some asteroids de-orbit
and approach the Earth under the influence of the Solar system planets'
gravitation. It is currently considered that there are 1000-1100 asteroids
of this kind. It was determined that about 400 of them are approximately of
one kilometer in size." Astronomers calculated that about 160 asteroids
cross the Earth orbit, 125 of them are potentially dangerous. According to
other information, about two million asteroids of over 50 meters in diameter
cross the Earth orbit.

What can be done? We must seek new modern methods of detection of killer
asteroids and instruments of liquidation of these asteroids. These are the
main objectives of Russia's Space Shield Foundation in the city of
Snezhinsk, the Federal Nuclear Center of Russia; the international
organization Space Guard is working on the problem in Europe; space
protection is developed in the USA on the governmental level. However, it is
too early to speak about complete space safety of the Earth. For better
security, not only systems of detection must be created, but also systems of
interception of dangerous objects, that certainly costs a lot. It will be
possible only if the mankind joins the efforts for creation of a space
shield. Meanwhile, it is highly likely that the killer asteroid is
approaching the Earth, but we still don't realize this fact.

Andrey Lubensky
PRAVDA.Ru

Copyright 2003, Pravda

MODERATOR'S NOTE: It is disturbing to see that one of Russia's main
newspapers can publish such totally fabricated impact scares  - and other
nonsense - without being taken to task. Are any of our Russian colleagues
and CCNet subscribers monitoring these miserable developments? BJP

==========
(3) FIREBALL WATCH

>From SpaceWeather.com <swlist@spaceweather.com>

Space Weather News for January 19, 2003
http://www.spaceweather.com

The glittering Starshine 3 satellite, built by schoolkids and launched in
Sept. 2001, will soon re-enter Earth's atmosphere. Can you spot the
fireball? Re-entry estimates vary from 0500 UT (midnight EST) to 1330 UT
(8:30 EST) on Tuesday, Jan. 21st. Although Starshine is likely to re-enter
above some unpopulated stretch of ocean, the satellite's final orbit does
carry it over North America and eastern Europe where sky watchers might see
it.

"There's no danger to anyone on the ground," says Prof. Gil Moore, the
director of Project Starshine. "We designed the satellite so that it will be
100% consumed about 80 km up." Except for a few small steel screws the body
of the spacecraft is made entirely of aluminum--a substance that will
vaporize during the bright and fiery descent.

Visit spaceweather.com for more information about Starshine 3 as well as
links to the latest re-entry predictions (they will improve between now and
Tuesday) and photo tips, too!

==========
(4) GOOD NEWS FOR PLANETARY PROTECTION: NASA PREPARES FOR NUCLEAR-POWERED
LEAP TOWARDS MARS

>From The Times, 18 January 2003
http://www.timesonline.co.uk/article/0,,3-546536,00.html

>From Chris Ayres in Los Angeles
 
PRESIDENT BUSH is to authorise Nasa to develop a hugely expensive
nuclear-powered spacecraft that would take just two months to reach Mars.

The spacecraft used a small nuclear generator for power and scientists have
speculated that it would be capable of travelling at up to 54,000mph - three
times the speed of conventional craft - although Nasa officials said
yesterday that this was still theoretical.

The generator would not power the craft's initial take-off - this would
still require conventional rockets - but would be switched on after it left
the Earth's atmosphere.

As well as providing electricity for propulsion, the generator would power
on-board scientific experiments and communications with Houston.

The development of space-based nuclear power is unlikely to go down well
with other nations, who may fear that the United States will use the project
- unofficially named Prometheus, after the mythological Greek figure who
stole fire from the gods - for military purposes. China is the most likely
to retaliate with its own space-based nuclear programme, which would prompt
comparisons with the space race between the US and the Soviet Union during
the Cold War.

Scientists are excited about the prospect of nuclear- powered space travel.
It could lead not only to human missions to Mars but also to the
construction of a permanent lunar base and the exploration of Jupiter's icy
satellite, Europa. It would also allow an unmanned craft to be sent beyond
the Earth's solar system, in a mission that could last for more than a
decade.

Nasa also hopes that the ambitious project will inspire American
schoolchildren to take a greater interest in science and technology. The US
is already beginning to suffer from a shortage of young engineers.

Project Prometheus will involve dusting down a programme that many regarded
as a relic of the Cold War. It was last backed by President Bush Sr more
than a decade ago, before the first Gulf War. It was dropped after
opposition from Congress and a lack of public interest.

It is not clear how the American public will react this time, especially
given the recession in the United States and the estimated $200 billion
(£125 billion) cost of going to war with Iraq. The state of the economy,
however, has not always been a factor in big Nasa space projects. Analysts
have pointed out that President Nixon started the Space Shuttle programme
during a recession.

With this in mind, Nasa is thought to be pushing for a significant increase
in funding for Project Prometheus, which has already been allocated $1
billion (£620 million) of funding for the next five years.

Speculation that the President will make an announcement on Nasa funding
during his State of the Union address to the American people on January 28
was being played down yesterday.

"We're talking about doing something on a very aggressive schedule to not
only develop the capability for nuclear propulsion and power generation but
to have a mission using the new technology within this decade," Sean
O'Keefe, the Nasa administrator, said.

The move is a significant shift in strategy for Nasa, which, since the end
of the space race with the former Soviet Union, has been forced to request
funding on a mission-by-mission basis. Now it wants the freedom to develop
so-called "enabling technologies" that could be put to any number of future
uses.

"The laws of physics are the only things controlling how fast we go
anywhere, what we do and whether we can survive the experience," Mr O'Keefe
said. "So until we beat the technical limitations, you basically end up
arguing about fantasy missions. We've been restricted to the same speed for
40 years. With the new technology, where we go next will only be limited by
our imaginations."

Nuclear-powered spacecraft have long been seen as the only serious way to
give manned spacecraft enough power to explore beyond the Moon. Existing
spacecraft use the momentum of the launch to simply "coast" through space.

Even before that, however, the United States had spent billions trying to
build a space-based nuclear reactor and several prototypes had been tested
in the Nevada desert. One of the reactors was launched in 1965, operated for
only 43 days and remains in orbit to this day. The nuclear project was
eventually discontinued.

There are still concerns over the safety of using a nuclear-powered craft in
space. The protection of astronauts would have to be improved, for example.

Astronauts return from space with a 30 per cent decrease in muscle mass and
a 10 per cent loss of bone mass. The radiation in a spacecraft is the
equivalent of getting eight chest X-rays every day.
 
Copyright 2003, The Times

===========
(5) ASTRONOMY PROJECTS IN RUINS AS AUSTRALIAN OBSERVATORY IS OBLITERATED

From, The Sydney Morning Herald, 20 January 2003
http://www.smh.com.au/articles/2003/01/19/1042911270928.html

By Richard Macey and Michael Bradley
 
A third of Australia's world-leading astronomy program was wiped out at the
weekend when the Canberra bushfires gutted the Mount Stromlo Observatory.

The flames destroyed five telescopes, the workshop, eight staff homes and
the main dome, causing more than $20million in damage.

The historic 1.3 metre-diameter Great Melbourne Telescope, built in 1868 and
upgraded a decade ago to become one of the most sophisticated in Australia,
was lost, as was a larger, 1.9-metre instrument.

"Our telescopes have been obliterated ... and most importantly, our
workshops have been gutted," said a shattered Professor John Norris, Mount
Stromlo's associate director, who spent several hours yesterday inspecting
the damage.

"It is just tragic."

The inferno devastated Australia's hopes of becoming a world leader in the
building of advanced technology used in the world's biggest telescopes.

Destroyed was a $5million imaging spectrograph in Mount Stromlo's workshop
that was almost ready to be installed in Hawaii's gigantic Gemini
Observatory, one of just two 8.1-metre-diameter telescopes in the world.

"It was ready to be delivered," said another shocked astronomer, Brian
Schmidt.

Just last month, Mount Stromlo won an international competition to build a
second instrument, a $6.3million camera to be fitted to the second Gemini
telescope, in Chile.

"It was a big win ... and now we have lost the workshop it was to be built
in," Professor Schmidt said.

The camera, to be delivered in 2005, would be able to cancel out distortions
caused by the atmosphere, allowing the Chilean telescope to take pictures
"as good as the Hubble Space Telescope".

The refurbished Great Melbourne Telescope made history in the 1990s,
discovering proof that some of the universe's missing matter is tied up in
dark MACHOs - massive astronomical compact halo objects, such as "brown
dwarfs" - stars lurking on the edge of our Milky Way galaxy that failed to
ignite and shine.

Since 2000, Mount Stromlo has also been involved in a search for swarms of
small "Pluto-like" planets believed to dwell on the edge of the solar
system.

"That search, I guess, is now complete," said a dismayed Professor Schmidt.

The astronomer recently began a $1.1million project to make a complete
digital map of the entire southern sky.

"We started only 19 days ago," he said.

Professor Schmidt realised the observatory was doomed on Saturday, when he
went to the home of a friend in Duffy, just two kilometres from Mount
Stromlo. At first he thought he would be able to help his friend by putting
out spot fires.

"But there were no spot fires. There was just a wall of flame."

Asked if Mount Stromlo, which employs 20 astronomers, 60 support staff and
25 students, could be rebuilt, he replied: "We can only hope and pray."

Copyright 2003, The Sydney Morning Herald

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

(6) RE: TUNGUSKA & THE 1953 LUNAR FLASH

From: Jens Kieffer-Olsen [mailto:dstdba@post4.tele.dk]

Dear Benny Peiser,

In CCNet 5/2003 -  17 January 2003 you wrote:

> MODERATOR'S NOTE: I'm afraid that if we were to follow
> Stephen Schneider's notorious scare tactics, we would inevitably
> (and rightly so) lose all credibility and respect in the eyes of the
> interested public. I am proud to say that the NEO community has
> been extremely self-critical with regards to those few (and
> inadvertent) asteroid scares of our own making. It is evident that
> disingenuous exaggeration of a low-probability risk for political
> or funding purposes is absolutely unacceptable even to those of
> us who genuinely feel that more should be done to address the
> impact hazard.

Noone can disagree with your above comments - but in one area we do seem to
choose our reference term in such a way, that we unnecessarily understate
the danger and, in fact, confuse the public.

I'm referring to the habit of measuring asteroids by diameter. There is
nothing scientifically dishonest at all about measuring their size instead
by volume. The point being that volume is proportional with damage, whereas
any comparison of asteroids by diameter leaves it to the more or less
educated reader to lift the ratio to the power of 3. Also the deflection
effort is proportional with volume/mass.

In my experience generally well-informed people tend to lump Tunguska-sized
objects, country-killers, and dinosaur-killers together in just two groups -
small and large - since they find a difference of some hundreds of meters
unimportant.  This is unfortunate, since the middle group of  >300m objects
is a natural next target to search for.

It is another issue, whether it would be prudent to measure asteroids by
footprint in case of impact.  But in my view journalists ought to do so as a
matter of routine.  Shouldn't scientists provide them with a reasonable
conversion formula for this purpose?

And finally, for the benefit of the educated layman emphasis should be given
to the power law governing the relative occurence of asteroids by size.
Although we do not have precise values for NEAs, I understand that it is
believed to be approximately 2.3?  That is, if we double the diameter ( or
8-double the volume ) the population drops by a factor of 6 or so.  Such
information helps to highlight the fact that the cumulative risk from
asteroids stems from all size groups, not exclusively from very large ones.

Yours sincerely
Jens Kieffer-Olsen, M.Sc.(Elec.Eng.)
Slagelse, Denmark

===========
(7) IS THE SOLAR SYSTEM DETERMINISTIC?

>From Hermann Burchard <burchar@math.okstate.edu>

Dear Benny,

Jens Kieffer-Olsen is of course correct when he makes the interesting remark
that "coming impact dates and hours are already determined by the lay of the
solar system," CCNet 17 Jan 2003.  I had ignored this, the omniscience of
the Laplacian demon, when I wrote a "probability law was
first recognized by Ernst J. Öpik," CCNet, 13 Jan.  Actually I'm not sure
what Öpik wrote himself.  In Target Earth (Duncan Steel) I found: "..reckon
a crude probability of an impact by..", and the stochastic language is
commonly used all the time when discussing ET impacts.

Here are some reasons why thinking of the solar system as deterministic may
not be a good idea:

1.  Jens remarked himself: "Even though future impacts by comets are just as
determinable as those by asteroids it is obvious that at our current
technological level we are unable to identify the associated dates, and that
we are therefore reluctantly forced to address the risk as probabilistic".

It seems unlikely that we will ever do better than a probabilistic model for
comets entering the inner solar system from the outer reaches, from the
Edgeworth-Kuiper Belt, and from the Oort cloud (anticipated by Öpik). This
requires consideration of the Sun's oscillations perpendicular to the
Galactic plane.

2. Comets are known to break up in the inner solar system for reasons known
only to them. This may happen in the outer reaches also without our
knowledge. Quite possibly, these  fragmentations are truly random events.

3. Dead comets are converted to asteroids, making the totality of asteroids
as stochastic an ensemble as are comets.

4. Recent discovery of chaotic orbits leaves the Laplacian demon in a lurch,
even merely considering NEAs.

Regards,
 Hermann

=============
(8) AND FINALLY: THE LESSON OF EARTH'S INEVITABLE END - ENJOY LIFE

>From Tallahassee Democrat, 19 January 2003
http://www.tallahassee.com/mld/democrat/news/opinion/4964353.htm
 
The lesson of Earth's inevitable end: Enjoy life
By Paul K. Driessen

KNIGHT RIDDER TRIBUNE

Here's some new ammo for those who believe in global warming - or nuclear
winter. Both views may be right. Unfortunately, there's little we can do
about it, it is all part of a natural cycle - the Death of Planet Earth.

In fact, that's the partial title of a new book by two University of
Washington scientists who contend the end of the world has already begun.
Fortunately, it's still billions of years away - give or take a few
millennia - so relax, sit back and enjoy that cinnamon-spiced hot toddy
during this winter's current cold spell.

In "The Life and Death of Planet Earth," Donald Brownlee and Peter Ward note
that in its 4.5 billion years of existence, Earth has evolved from a molten
mass into the beautiful blue-green planet photographed by our astronauts in
outer space.

Like every beauty, however, the Earth now finds itself entering the
relentless process of decay.

"The disappearance of our planet is still 7.5 billion years away," says
Brownlee, an astrophysicist based in Seattle, "but people really should
consider the fate of our world and have a realistic understanding of where
we are going."

His advice: Stop worrying and enjoy life.

"We live in a fabulous place at a fabulous time. It's a healthy thing for
people to realize what a treasure this is in space and time, and fully
appreciate and protect their environment as much as possible," he adds.

In their book, Brownlee and co-author Ward, a University of Washington
geologist, use the latest scientific understanding of the planets and stars
to provide us with a fascinating calculated guess about what lies ahead for
planet Earth as it orbits into middle age. The two experts point out that
human civilization has flourished during an 11,000-year warm interlude in a
recurring cycle of ice ages. In their view, the current cycle of global
warming - slightly less than one degree over the last 100 years - may help
postpone the inevitable return of ice.

But the next Ice Age will begin not too many thousands of years from now,
Brownlee and Ward contend. Civilization as we know it will be driven toward
the equator, and - if we get really lucky, perhaps - out into space to form
new colonies on a yet-unknown, inhabitable planet in a distant universe.

On the Doomsday clock, their calculations show Earth's "day in the sun" is
approaching 4:30 a.m., as it nears 4.5-billion years of age. In another
half-hour - relatively speaking - it will be 5 a.m. and the 1-billion-year
reign of animals and plants will come to an end.

"The Life and Death of Planet Earth," is the long-awaited sequel to Brownlee
and Ward's best-selling book, "Rare Earth," where they advanced the
hypothesis that simple life is relatively abundant throughout the universe,
but Earth's highly complex life is exceedingly rare.

In their new book, the authors contend that complex life eventually will
disappear from the Earth in much the same way as it arrived - ecosystem by
ecosystem. The planet's numbingly cold ice ages, they say, will be relived
in the period of devolution.

Rather than ratify a Kyoto Treaty on Climate Change, which would devastate
the U.S. economy by requiring huge cutbacks in energy use, we may have to
actually encourage some man-made warming. "If we do begin to slide into the
next glacial cycle," Ward observes, "there probably are grand,
planetary-scale engineering projects that might stop or lessen the effects.

"The big unknowns are whether we can afford to do such projects and would we
really know what to do. If the planet was cooling, we could, in principle,
begin painting the surface black to collect more heat. Could we afford it?
And what would be the many possible ramifications of a planet suddenly
covered in black paint? Any planetary remediation project would always run
the risk of making things worse."

If there's no cause for celebration in "The Life and Death of Planet Earth,"
there's little cause for despair, either. Brownlee and Ward have no desire
to be cast-type as doomsayers. And neither should we. The end of Earth, they
note, is still 7.5 billion years distant.

As Americans we should be constantly striving to improve life on Earth for
our fellow 6.2 billion humans. More than a third of those now subsist on
less than $2 a day. Over 2 billion still don't have electricity. Millions
are starving in Africa and Asia. The AIDS pandemic will kill millions more.
We need to harness our technological genius to provide better foods and
medicines, and more abundant energy for everyone.

Even as we contemplate the death of our planet, we should resolve to live
our lives to the fullest, and not be taken in by every passing catastrophe
theory. After all, 7.5 billion years - while not an eternity -is a long way
off.

------
Paul Driessen is a senior fellow at the Committee for a Constructive
Tomorrow. Readers may write him at P.O. Box 65722, Washington, D.C. 20035;
Web site: www.cfact.org

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