PLEASE NOTE:


*

CCNet DEBATE, 25 September 1998
-------------------------------

(1) NO TO PLANETARY DEFENSE: DON'T MESS WITH OUR NATURAL HERITAGE
    Paolo Farinella <paolof@keplero.dm.unipi.it>

(2) SPACE ELEVATOR: NUDGING ASTEROIDS INTO EARTH ORBIT
    Jens Kieffer-Olsen <dstdba@post4.tele.dk>


================
(1) NO TO PLANETARY DEFENSE: DON'T MESS WITH OUR NATURAL HERITAGE

From Paolo Farinella <paolof@keplero.dm.unipi.it>

Hi Benny. I don't know who is the anonymous author of the Space Command
text that you have circulated [it's James Oberg who submitted the text
for circulation on the CCNet, BJP], but I have found it quite amazing.
I have always thought that the polemics of the green fundamentalists
against the 'Baconian' hubris of scientists and technologists was based
on the old tactics of extremizing the other side's position, but
clearly some Strangelove-minded members of the military are still
around, at least in the US.

I will not comment on the philosophy behind the `interventionist'
approach of the author on different environmental issues. Basically,
this seems to me a badly conceived propaganda piece, which doesn't make
a good service to NASA (I don't know about the Space Command). But
specifically, I would like to point out that:

1. I don't see where the prediction that by 2025 we will have a list of
asteroids on collision course with the Earth comes from. Almost
certainly, this will NOT be the case for bodies larger than 1 km, which
on average hit the Earth every 200,000 years or so, and whose orbits
cannot be predicted for so long in the future. The only plausible
possibility to realize this prediction would be that the ongoing
surveys discover a large fraction of the millions of bodies 50 to 100 m
in size, for which the impact time scale is of the order of a century.
But I think this is very unlikely.

2. The argument given against the late Carl Sagan's and Steve Ostro's
warning that NEO deflection technologies may prove dangerous is not
convincing at all. If you have the technology to deflect a NEO away
from an Earth-bound trajectory, you can also deflect one into hitting
the Earth. Maybe you would need more than one hit, at different levels
of energy, to control the NEO trajectory, but this is not a fundamental
difficulty if the technology is available. The analogy with spacecraft
rendez-vous is misleading: they are difficult and delicate mainly because
one needs to achieve an extremely low relative speed, which is not the
case here!

3. No argument is given to show that non-nuclear deflection
technologies are not workable. They include mass drivers, solar
collectors, kinetic-energy projectiles and directed-energy beams, as
discussed in detail in the chapter by Melosh et al. of the volume
"Hazards due to Comets and Asteroids" (T. Gehrels ed., Univ. of Arizona
Press, 1994). Most of these technologies have not been fully developed
yet, but very probably they will be before the need will arise.

4. As a member of the International Dark-Sky Association (IDA, see
http://www.darksky.org) and of the IAU (which has often expressed a
concern for these projects), I fully agree with the people opposing the
light-polluting and astronomy-threatening big reflectors in space. The
night sky is a part of our natural heritage which should be protected and
preserved for the future generations, and also for future astronomers.

Best regards,

                                    Paolo Farinella

Paolo Farinella               Tel. +39-050-844254                   
Dipartimento di Matematica    Fax  +39-050-844224                   
Universita` di Pisa                                                  
Via F. Buonarroti 2           e-mail paolof@dm.unipi.it             
I-56127 Pisa, Italy           WWW: http://tycho.dm.unipi.it/~paolof 

=========================                           
(2) SPACE ELEVATOR: NUDGING ASTEROIDS INTO EARTH ORBIT

From Jens Kieffer-Olsen <dstdba@post4.tele.dk>

I'm sorry to have used a bad example. It was the suggested size of
Swift Tuttle which prompted me to post. I gather there is also doubt as
to whether it is, in fact, larger than 10km?

I think it is time NOW to consider WHICH asteroid to use for a future
space elevator. Once the job is under way I guess it's too late to
reconsider. Even with the best of techniques it's bound to be fraught
with danger to extend a base by 'docking' another asteroid to it.

The choice will depend on size, composition, and date of availability. 
Once a shortlist has been established, probes should check out each
candidate. The process of nudging the object into Earth orbit should
then start ASAP, since it may well take centuries to complete the job. 
Over that period the technology to build the actual space elevator
could then be developed, such that mankind is ready when the orbital
base is.

Let's envisage, say Toutatis, hovering 36,000km over Equador in the
year 2525 with that country's capital soon to become
Quito-the-Universe.

Jens Kieffer-Olsen, M.Sc.(Elec.Eng.)


*

CCNet DIGEST, 25 September 1998
-------------------------------

(1) NEW THEORY ON THE ORIGIN OF MULTI-KILOMETER NEAR-EARTH ASTEROIDS
    Alessandro Morbidelli <morby@obs-nice.fr>

(2) PRESSURE ON AUSTRALIAN GOVERNMENT IS GROWING TO RE-ESTABLISH
    SPACEGUARD PROGRAMME
    Michael Paine <mpaine@tpgi.com.au>

(3) SPACEDEV/NEAP UPDATE
    Jim Benson <Jim@SpaceDev.Com>

(4) IN SEARCH OF THE ORIGINS OF LIFE ON EARTH
    Andrew Yee <ayee@nova.astro.utoronto.ca>

(5) UNALTERED COSMIC SPHERULES
    A. Deutsch et al., UNIVERSITY OF MUNSTER



==================
(1) NEW THEORY ON THE ORIGIN OF MULTI-KILOMETER NEAR-EARTH ASTEROIDS

From Alessandro Morbidelli <morby@obs-nice.fr>

Dear Dr. Peiser

I would like you to diffuse this press release (not before Sept. 25!)
on a new paper appearing in SCIENCE on Friday.

Thanks

A. Morbidelli

-------------------

Origin of Multi--kilometer NEAs: New Quantitative Scenario

F. Migliorini, P. Michel, A. Mobidelli, D. Nesvorny and V. Zappala

According to the usually accepted scenario, Near Earth Asteroids (NEAs)
are fragments of main belt asteroids that were collisionally injected
into either the 3:1 or the nu_6 resonance. The 3:1 occurs at 2.5 AU,
where the orbital period of an asteroid is 1/3 of that of Jupiter,
while the nu_6 occurs when the precession rates of the asteroid's
and of Saturn's perihelia are equal, and bounds the inner edge of the
main belt. Under the action of either resonance, the injected fragments
increased their  orbital eccentricity until crossing the terrestrial
planets' orbits. Subsequent close encounters with the planets then
spread them all over the region where they are now observed and
categorized as NEAs.

However, a paper by Gladman et al.  (July 11, 1997 issue of Science)
showed that a population of bodies initially injected into the nu_6 or
3:1 resonance decays by a factor 2 every 2 million years, because most
of its members are forced to collide with the Sun. This implies that,
to sustain the NEAs population in steady state by this route, the
number of asteroids injected into resonance per Myr should  be about
25% of the total NEAs population. This supply rate is unrealistic for
multi--kilometer NEAs, because asteroids of this size can be injected
into resonance only during very energetic and rare break--up events,
such as those leading to the formation of asteroid families.
Therefore, a new scenario for the origin of large NEAs --a serious
space--menace for our planet-- needed to be designed.

The new idea came to the mind of Fabio Migliorini, an extremely bright
26 year old Ph.D. student and already co--author of the Gladman et al.
paper. To check his intuition, he started a large number of computer
simulations of the orbital evolutions of main belt asteroids and
of Mars--crossing asteroids. Unfortunately, Fabio died on November 2,
1997, hiking in the italian Alps, before having the opportunity
to see that the results of these simulations supported the scenario that he
had imagined. His work has been recently completed by his friends and
colleagues, leading to a report (Migliorini et al.) in the Sept. 25,
1998 issue of Science and two more technical preprints submitted to
Icarus by Morbidelli and Nesvorny and by Michel et al. The results will
also be presented at the 1998 DPS meeting.

According to the new scenario, numerous weak resonances, densely
located in the main belt, slowly increase the asteroids' eccentricity
until they start crossing the orbit of Mars. For instance, at least ~50
asteroids larger than 5 km should become Mars--crosser in the next 25
Myr, the real number being probably the double. Mars--crossers, in
turn, evolve to Earth--crossing orbit under the combined effect of
close encounters with Mars and of strong resonances. Simulations show
that the present number of multi--kilometer Mars--crossers is large
enough to keep the Earth--crossing asteroidal population in steady
state for the next 50 Myr, despite of the high collision rate that the
latter have with the Sun. In this scenario, therefore, the main belt
appears as a huge reservoir of asteroids that leaks through a very
large number of small holes (the weak resonances); Mars--crossers and
Earth--crossers represent the two subsequent evolutionary states of
asteroids that have recently leaked out of this reservoir. The Sun
is the main sink.

This unexpected leak--out process must have largely eroded the main belt
asteroidal population during the history of the Solar System. It is
estimated that the number of multi--kilometer asteroids that ``leaked
out'' during the past 3 billion years should be equivalent to the
number of those still presently existing in the main belt, which has
important implications for the cratering history of the terrestrial
planets.

For more information contact:

A. Morbidelli
CNRS, Observatory of Nice, B.P. 4229, 06304 Nice Cedex 4, France
Tel: 33-4-92003126; E--mail: morby@obs-nice.fr

=======================
(2) PRESSURE ON AUSTRALIAN GOVERNMENT IS GROWING TO RE-ESTABLISH
    SPACEGUARD PROGRAMME

From Michael Paine <mpaine@tpgi.com.au>

Space interest groups in Australia have stepped up pressure to
re-establish a Spaceguard Program in Australia. The timing co-incides
with a TV science program which criticized the withdrawal of Australian
government funding in 1996.

The press release in now available on the web at
http://www1.tpgi.com.au/users/tps-seti/pr980925.html

Michael Paine
New South Wales Co-ordinator
The Planetary Society Australian Volunteer Co-ordinators

=========================
(3) SPACEDEV/NEAP UPDATE

From Jim Benson <Jim@SpaceDev.Com>

Greetings "Friends of NEAP"

This is an informal update on activities related to NEAP and SpaceDev.

To each of you who has helped SpaceDev and supported NEAP -- thank you!

As you may have heard, at the recommendation of space scientists and
Tony Spear's study, SpaceDev has decided to change targets to 4660
Nereus, a carbonaceous near earth asteroid discovered by Glo Helin.

Thanks to great work by Drs. Alan Schneider, Bob Farquhar and Chauncey
Uphoff, we now intend to launch around April 3, 2001, and may include
6 or 7 flybys of the lunar poles. We are seeking appropriate
instruments to fly in the vicinity of the moon. Details are subject to
change.

Three proposals were eventually sent in for Discovery and MIDEX from
Carnegie Mellon, Utah State and UC Berkeley for JPL nanorover with
APXS, 3D mapping LIDAR and gamma ray burst detector, respectively. We
have done all we can in that area, so now we move on to other areas.

Room for more space physics and planetary science experiments is still
available, so we are now ready to start marketing to the international
science community, and we also intend to market to other national space
agencies.

I am proud to announce that I have been elected to the Board of
Directors of the National Space Society (www.nss.org). I hope to give
practical guidance to the organization.

The SEC matter is moving forward, but is needlessly wasting a large
amount of time and money that we would rather be applying directly to
accomplishing this commercial science mission. We had our first little
legal skirmish with them and won. We said we had received no specific
allegations, and the administrative law judge required the SEC to
provide us with details, which we are still waiting for. I believe the
hearing date has been set for November.

SpaceDev was mentioned by NASA Administrator Dan Goldin during a recent
TV interview, along with George Washington University Space Policy
guru Dr. John Logsdon, on the McLaughlin "One on One" show. After the
show, people wrote to tell me about it, so we ordered a copy of the
tape. When asked what NASA is doing about asteroids, Dan Goldin
mentioned SpaceDev. Here is a piece of the transcript, slightly edited
for ease of reading:

McLaughlin:  Is NASA the best existing agency to [protect against
asteroids], or is there any commercial space outfit that can do it for
us?

Goldin:  We're working with a commercial space outfit called COMDEV
(sp?). This outfit is founded by a wonderful man named .

Logsdon:  SpaceDev

Goldin:  SpaceDev, I'm sorry.

McLaughlin:  S-p-a-c-e capital D-e-v

Goldin:  Yeah.

McLaughlin:  A fellow by the name of Benson.

Goldin:  Benson. He's going to have a mission to an asteroid in NASA.
He has a couple of proposals in to us.

I found this a most interesting exchange. Note the question from
McLaughlin itself. Note that Dan says I am a "wonderful man.." Quite a
compliment from the guy running our $13 billion space program. Note
that McLaughlin knows the correct spelling of SpaceDev. When Goldin
mentions the proposals, he means the three universities that have sent
in NEAP-related proposals under the NASA Discovery and MIDEX programs.

I believe the Discovery decisions will be made and perhaps announced
within the next six to eight weeks or so, but with a bureaucracy, one
never knows. So, while we wait, we are continuing our sales strategy of
marketing instrument and technology rides to the military, other
agencies, and other countries.

I am about to leave for Australia and France to present invited papers
at the International Astronautical Federation (IAF) in Melbourne, and
at a private "think tank" in the South of France. The latter should be
interesting because the invited participants are European industrialist
futurists.

My three papers in Melbourne are for the IAF, the International Academy
of Astronautics (IAA) and for the International Institute on Space Law
(IISL).

The first paper is for the "Space Exploration Symposium" and concerns
a description of NEAP and its goals.

The second paper is for the "Economics and Commercialization of Space
Activities Symposium" and concerns the benefits and economics of
commercial space activities, with NEAP as an example.

The third paper is for the "41st International Colloquium on the Law of
Outer Space" and concerns my ongoing efforts to generate global
discussions about property rights in space. This is a fun issue, as I
thought it would be, and we have recently been covered in MIT
Technology Review, the Harvard International Review and in the Air &
Space magazine. As expected, none of the authorities can agree on
anything, confirming that the issue is up for grabs. I am looking
forward to further stirring things up during this prestigious
international gathering.

I will return to California in time for part of the Space Frontier
Foundation conference, my absolute favorite. If you want to attend a
really good conference that is totally dedicated to entrepreneurial
space commercialization, this is your only choice. Find out more by
visiting:

http://www.space-frontier.org/EVENTS/SFC7/

Each year more investment banking and venture capitalists attend, and
this year the Space Frontier Foundation has expanded the conference to
three days: Friday October 9 through Sunday October 11 at the Sheraton
Gateway hotel near the LA airport..

The first day features full day parallel tracks on "Cheap Access to
Space (CATS) and a session organized by SpaceDev adviser Dr. John
Lewis, titled "Asteroid Symposium: 2002 Vision."

John Lewis has lined up some of the world's leading experts, including

Dr. Glo Helin of JPL (Discoverer and namer of Nereus -- our NEAP target)

Jeff Kargel of the US Geological Survey -- an early friend of NEAP

Dr. Larry Lebofsky of the Lunar and Planetary Lab

Dr. Tom Gehrels of SpaceWatch

Dr. David Morrison: NASA Ames Research Center

Jan King, our own Vice President of Space Engineering

And many others.

This is THE place to be if you want good information about real science
and engineering related to near earth asteroids, and from an
entrepreneurial viewpoint. I am very sorry my travel plans do not allow
me to attend and participate in this great program. I strongly urge you
to go, if this is where your interest is.

I return from France to LAX on Saturday afternoon, October 10 and am
hoping to participate in some Foundation session on Sunday. In any
case, I am very happy I will be able to attend part of this great
conference and see many friends and supporters there. Please visit the
web site above and try to put this conference on your calendar today.

I have been nominated to be the sole industry representative on NASA's
national Space Grant Review Panel, and will be attending my first
meeting at NASA HQ November 12 & 13. I am looking forward to further
helping university students involved in space engineering and science,
and am quite proud to have been appointed to this unique position.

Later this year I will be participating in workshops sponsored by the
European Space Agency (ESA). I will be attending as a consultant to
ESA. One is on the island of Sardinia off the coast of Italy, and the
other is in Vienna, Austria. I might try to fit a sales visit to Turkey
between those. My schedule is already getting interesting for next
year. So far, I have been invited to participate in prestigious
conferences in three countries, with all the conferences dealing with
mining in space. These are sponsored by universities and international
mining companies like International Nickel. It appears that space
mining might become real before I thought it would. It is encouraging
to see large respected companies and universities getting involved so
early.

Comments and suggestions are always invited and welcome. If you are
attending any of the above conferences, please be sure to say hello.

   To the Moon, asteroids, and Mars, and beyond to the stars.

          SpaceDev - NEAP (Near Earth Asteroid Prospector)
-o-  Commercial Space Exploration & Development of Space Resources  -o-
             http://www.spacedev.com  -o-  Info@SpaceDev.Com
       To the Moon, asteroids and Mars, and beyond to the stars.

==========================
(4) IN SEARCH OF THE ORIGINS OF LIFE ON EARTH

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

Carnegie Institution
Washington, D.C.

Contact:
Jay Brandes, brandes@gl.ciw.edu, (202) 686-2410, ext. 2485
Or
Bob Hazen, hazen@gl.ciw.edu, (202) 686-2410, ext. 2470
Or
Pat Craig, (202) 939-1120

Ammonia From The Earth's Deep Oceans: A Key Step In The Search For
Life's Origins

New high-pressure research by scientists at the Carnegie Institution's
Geophysical Laboratory, announced in this week's Nature magazine, reveals
that unexpected chemical reactions occur in deep hydrothermal vents of the
sea reactions that may have played a key role in the origin of life.

Jay Brandes, Bob Hazen, and their Geophysical Lab colleagues* in
Washington, D.C. report that one of the necessary first steps for life
to begin the conversion of nitrogen to ammonia may have occurred
readily in deep ocean vents. Nitrogen is an essential ingredient of
amino acids and nucleic acids. But molecular nitrogen, N2, is
relatively inert and unlikely to have given rise to the first vital
signs of life. Most scientists believe instead that nitrogen in a more
reduced, reactive form, i.e., ammonia, or NH3, was required. How did
nitrogen, then, become ammonia?

Brandes and colleagues suggest that the most likely sites for ammonia
production to occur were in the early Earth's crust and in hydrothermal
vents, where iron-bearing minerals act as catalysts. The group
conducted experiments investigating what happens when nitrogen, both as
N2 and as its oxidized forms, NO2 and NO3 (all forms presumed to be
present in the ancient oceans), react with iron oxides, iron sulphides,
and basalt at high temperatures and pressures. Basalt is the
predominant rock type at ocean ridge systems, and iron sulfides and
oxides are ubiquitous in hydrothermal vents.

Using iron sulfides, they found that at 500C, up to 89% of the nitrogen
converted to NH3 within 15 minutes! Iron oxide converted up to 46% of
the nitrogen to ammonia, while powdered basalt converted up to 20%
under these conditions. Reduction of N2, the largest reservoir of
nitrogen on Earth, was slower but still resulted in up to 17%
conversion to ammonia within 24 hours. The ammonia is stable, they
found, to temperatures up to 800C, but only nitrogen gas survives
temperatures above that temperature. Thus, N2 or its oxidized forms
would have provided raw materials for an important and plentiful source
of ammonia in the ancient oceans, perhaps providing oases of NH3 for
the production of amino acids and nucleic acids in early life
forms.

Brandes and coauthors point to two important conclusions, in addition
to the unexpectedly high production of ammonia. The observation that
ammonia does not survive at temperatures above 800C indicates that
nitrogen on the Earth's surface would have been present only as
nitrogen gas (N2) during the early phase of the Earth's development,
when asteroid bombardments raised the surface temperature well above
800C. Thus, the ammonia necessary for the origins of life must have
been generated after the initial formation of the Earth.

A second important conclusion of the work relates to a long-standing
problem regarding the early atmosphere, known as the early faint-sun
paradox. The radiation output of the Sun has increased gradually over
the past several billion years. During the Earth's formation, the Sun's
radiant energy does not appear to have been sufficient to maintain
liquid oceans unless, that is, a significant amount of a greenhouse gas
was present to trap the Sun's energy and keep the planet warm. Ammonia
is one of the most efficient greenhouse gases. If the oceans maintained
a steady production of ammonia from hot vents, that ammonia would have
also enriched the atmosphere through water-gas exchange at the ocean's
surface, perhaps resolving the paradox.

Surprisingly, this research does little to settle an ongoing debate
regarding the most probable site of life's origins. The prevailing
paradigm for almost half a century has been that life began near the
ocean's surface, bathed in sunlight. The rival hypothesis, that life
arose near deep hydrothermal vents, is now being investigated at the
Geophysical Laboratory and several other labs around the world. The
present work demonstrates that high concentrations of ammonia might
occur near vents, possibly making them sites for some interesting
pre-life chemistry. But this ammonia will spread throughout the ocean
and enter the atmosphere as well, thus providing a source of reduced
nitrogen for almost any conceivable origin environment.

The Carnegie Institution, through its Geophysical Laboratory and
Department of Terrestrial Magnetism co-located in upper northwestern
Washington, D.C., is a member of NASA's new Astrobiology Institute, an
effort to blend astronomy, biology, chemistry, and physics in the
search to identify and understand the origins of life in the universe.
NASA funded the research reported here.

The experiments were conducted at the Geophysical Laboratory using a
technique developed years ago by Lab director emeritus Hatten S. Yoder,
Jr. for the study of the origins of basalt. The nitrogen, water, and
minerals are encapsulated in small gold containers and then subjected
to high pressures and temperatures in Yoder's high-pressure apparatus.
Capsules are opened and ammonia yields are determined by wet chemical
techniques.

The Geophysical Lab, led by its new director, Wesley T. Huntress, Jr.
(who arrives in October), is one of five departments of the Carnegie
Institution of Washington, a nonprofit organization devoted to advanced
research and education in the physical and biological sciences. The
institution's president is the biologist Maxine F. Singer.

* Brandes is a postdoctoral fellow at the Geophysical Laboratory. Hazen
is a staff member. The other authors are visiting investigator Nabil Z.
Boctor, staff member George D. Cody, student intern Benjamin Cooper,
and director emeritus Hatten S. Yoder, Jr. Benjamin Cooper was killed
in an auto accident during the completion of research on the project.
The Nature paper is dedicated to his memory.

========================================
(4) UNALTERED COSMIC SPHERULES

A. Deutsch*), A. Greshake, L.J. Pesonan, P. Pihlaja: Unaltered cosmic
spherules in a 1.4-Gyr-old sandstone from Finland. NATURE, 1998,
Vol.395, No.6698, pp.146-148

*) UNIVERSITY OF MUNSTER, INST PLANETOL, WILHELM KLEMM STR 10, D-48149
   MUNSTER, GERMANY

Micrometeorites-submillimetre-sized particles derived from asteroids
and comets-occur in significant quantities in deep sea sediments, and
the ice sheets of Greenland and Antarctica. The most abundant
micrometeorites are cosmic spherules, which contain nickel-rich spinels
that were crystallized and oxidized during atmospheric entry, therefore
recording the oxygen content in the uppermost atmosphere. But the use
of micrometeorites for detecting past changes in the flux of incoming
extraterrestrial matter, and as probes of the evolution of the
atmosphere, has been hampered by the fact that most objects with
depositional ages higher than 0.5 Mpr show severe chemical alteration.
Here we report the discovery of unaltered cosmic spherules in a 1.4-
Gyr-old sandstone (red bed) from Finland. From this we infer that red
beds, a common lithology in the Earth's history, map contain
substantial unbiased populations of fossil micrometeorites. The study
of such populations would allow systematic research on variations in
the micrometeorite flux from the early Proterozoic era to recent times
(a time span of about 2.5 Gyr), and could help to better constrain the
time when the atmospheric oxygen content was raised to its present
level. Copyright 1998, Institute for Scientific Information Inc.

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