PLEASE NOTE:


*

LETTERS TO THE MODERATOR, 9 June 1999
-------------------------------------


(1) INTERSTELLAR COMETS AND METEOROIDS
    Duncan Steel <dis@star.arm.ac.uk>

(2) PLANETARY DEFENSE & ASTEROID MINING
    Steve Weintz <indy@the-line.com>

(3) SPACEGUARD DOWN UNDER
    Michael Paine <mpaine@tpgi.com.au>

(4) '60 MINUTES' ON 1999 AN10 & AUSTRALIAN TAXES
    Michael Paine <mpaine@tpgi.com.au>

(5) ASTEROID POSES GREATER FUTURE THREAT
    Jens Kieffer-Olsen <JKO@dst.dk>

(6) IMPACT EARTH
    Larry Robinson <lrobinsn@ix.netcom.com>

(7) PUBLICATION ON CLIMATE & HISTORY
    Ken Hsu <ken@erdw.ethz.ch>

=================
(1) INTERSTELLAR COMETS AND METEOROIDS

From Duncan Steel <dis@star.arm.ac.uk>
 
Dear Benny,
 
With regard to the interesting insertion:
  
J.Q. Zheng and M.J. Valtonen: On the probability that a comet that
has escaped from another solar system will collide with the Earth.
MONTHLY NOTICES OF THE ROYAL ASTRONOMICAL SOCIETY, 1999, Vol.304, No.3,
pp.579-582
 
...I note that the interstellar comet problem has been a long-term
puzzle.  That is, why have we not seen any?  One *might* expect a
detection rate of one per century or thereabouts.
 
Now, that is a small count rate, whereas the flux of smaller particles
(meteoroids and dust) from other stellar/planetary systems into the
solar system, and perhaps striking the Earth, would be expected to
be much higher.  Sub-micron dust on hyperbolic orbits has been detected
out near Jupiter e.g. with the Ulysses spacecraft.  However, using a
radar system in New Zealand we have detected a terrestrial influx
of small meteoroids (15-40 micron sizes) apparently from interstellar
space:
 
A.D. Taylor, W.J. Baggaley & D.I. Steel,
'Discovery of interstellar dust entering the Earth’s atmosphere,'
Nature, 380, 323-325 (1996).
 
Having written that I note that NZ is about the worst place to have tried
the experiment, because the declination of the apex of the Sun's 
galactocentric orbit is at plus 48 degrees. That is, a northern
hemisphere radar site would be favoured. To tie this down I would
very much like to conduct a search for such an interstellar meteoroid
influx using the radar near Aberystwyth, and operated by the
University of Wales. Although designed for lower atmosphere studies
it would be ideal for such observations, using much-improved
speed-determination techniques developed by Andrew Taylor (now
working in Durham) and myself. The results would in turn have
implications for the flux of interstellar comets.
 
Duncan Steel
Armagh Observatory
dis@star.arm.ac.uk

================
(2) PLANETARY DEFENSE & ASTEROID MINING

From Steve Weintz <indy@the-line.com>

Hi Benny,

I have been giving some thought to solution packages for planetary
defense and asteroid mining. I am currently engaged in launching a
studio, so I can't be specific on delivering a sketch, but when I do,
I'll post some web pages on the concept at
http://www.the-line.com/CanyonStudios/skyrocks/

In brief, I propose a systemic approach, in which planetary defense
becomes integrated into a larger Solar System economy using
large-scale infrastructure akin to the U.S. interstate highway system
or, for that matter, the Internet. Once an array of laser cannon is
set up to deflect/pulverize/whatever hazardous objects, it can be
used to push cargo lightsails to the planets, launch interstellar
probes, facilitate hi-gain System-wide communiations, etc., just as
the myriad commerical applications of the interstates and the
Internet piggyback on originally-military infrastructures.

Regarding asteroid mining, we are designing a computer game that puts
players at the controls of a mining spacecraft and pits them against
rival miners and real celestial objects. Our goal is to create a game
as compelling as Doom or Quake without the now-unacceptable personal
violence associated with those games. My hope is that we can create
something good for you that's a blast to play.

Best Regards,

Steve Weintz
Canyon Studios
indy@the-line.com

===============
(3) SPACEGUARD DOWN UNDER

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

Dear Benny,
 
Things are picking up here. The current affairs TV show "60 Minutes"
is researching a story on NEO detection and the lack of funding in
Australia. Of course, it would help if the US and UK Governments pointed
out, at a high level, the need for Australian Government support!
 
By chance while glancing through old issues of National Geographic I
came across the following:

Sept 1986, p390 "Meteorites: Invaders from Space" including the
discovery of meteorites in Antartica, the Tunguska event, early
detective work on the K-T extinctions (e.g. tektites in the Caribbean
- oh so close!), an illustration of the global effects of a major
impact (from modelling by LANL), an estimate of 1,000 earth crossers
1km or larger and this quote:

"Can the Earth be saved from such cataclysms in the future? Gene
Shoemaker thinks maybe it can, although the hazard for mankind is
remote. His scheme involves careful observations of the Earth
crossers to determine when one is on a collision course with Earth.
Then spacecraft sent under international auspices to rendezvous with
the asteroid would attach a future mass driver - just adequate to
nudge the object into a non-threatening orbit."

June 1989, p662 "Extinctions" includes more evidence of a K-T impact
(but still no crater), an excellent illustration of the effects of a 
large impact (immediate to long-term, including tsunami) and the case
for cycles in mass extinctions (Raup & Sepkoski, Rampino) including
the oscillation of the Sun through the galactic plane (also mentioned
by Carl Sagan and Ann Druyan in the 1985 book "Comet").
 
Also, I have added a section "Notes for Journalists" to the Australian
Spaceguard Survey Homepage
http://www1.tpgi.com.au/users/tps-seti/spacegd.html

The website is becoming rather large and I wanted to help journalists
zero in on some key issues (sorry about the attention grabbing headlines
;) ).
 
Michael Paine
NSW Coordinator
The Planetary Society Australian Volunteers

===========================
(4) '60 MINUTES' ON 1999 AN10 & AUSTRALIAN TAXES

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

Dear Benny,

Here is the transcript of the tongue-in-cheek 60 Minutes item
on Spaceguard (60 Minutes is a Sunday night current affairs
program in Australia).

Michael Paine
 
PAUL LYNEHAM, 60 MINUTES, 30 MAY 1999
Have you noticed how asteroids seem to have been overlooked in
the tax debate?
 
Well let me assure you they have. Indeed I'll bet that neither
John Howard nor Meg Lees have mentioned the subject since they
began their negotiations.
 
Income tax scales, diesel fuels, food-free-GST ... all that,
but not a word about asteroids.
 
Which is odd, given that an asteroid called 1999 AN10 - a
kilometre long chunk of rock, is heading towards us right now
at a speed of 45 kilometres per second.
 
When it arrives, in 28 years, a direct hit would mean a global
catastrophe with major climatic and taxation effects plus a
billion fatalities - including, of course, many taxpayers,
accountants and Australian Democrats.
 
Fortunately, however, it's expected to miss us by an
interplanetary whisker, a mere 39-thousand kilometres.  This
time.
 
So since Meg Lees is such a powerful political star right now,
how can she save the day?  Well, if she can get the GST off
food it should be easy for her to convince her new friend, John
Howard, to revive the Australian component of the Spaceguard
Survey, which was abandoned in '96 when the government scrapped
its funding.  Spaceguard is an international effort todetect
and monitor near earth asteroids. Labor's Martyn Evans has
tried, in vain, to alert a Parliament preoccupied by tax.
 
Martyn Evans
"If we do not know where these objects are, we will never know
what is going to happen nor will we be able to take any
mitigating action in defence of the planet."
 
And with no planet left so much for John Howard's beloved GST. 
Thankfully, though, the Americans have recently trebled their
funding for Spaceguard and, as we saw in the movie Armageddon,
they can always call on Bruce Willis and his team to save us
all. Remember that fiscally infamous line when Willis was
telling the top brass of his mens' demands for the job?
 
Bruce Willis: "None of them want to pay taxes again. Ever."
 
Who does Bruce? Mind you, with a GST we Aussies won't have any
choice. Unless, of course, the flying Ayres Rock gets us first.

=================
(5) ASTEROID POSES GREATER FUTURE THREAT

From Jens Kieffer-Olsen <JKO@dst.dk>

>In an interview with MSNBC, Don Yeomans, head of NASA's Near-Earth
>Object Program Office at JPL, said that asteroid 1999 AN10 has a
>1-in-500,000 chance of hitting the Earth in 2044.
>That probability is still less than that for a unknown asteroid.
>Astronomers estimate a 1-in-100,000 chance that an undiscovered
>asteroid one kilometer or larger in diameter will strike the Earth in a
>given year.
 
Dear Benny
 
1999 AN10 is bound to generate interest for years to come, since the
background risk is poised to sink below the 1:500,000 threshold well
before the year 2027.
 
Assuming that 90% of all objects of similar size are discovered by
2010 and that future observations will not affect current estimates
with respect to the 2027 encounter, isn't it fair to expect 1999 AN10
to loom ever more ominously over our mental horizon?
 
Yours sincerely
Jens Kieffer-Olsen, M.Sc.(Elec.Eng.)
Slagelse, Denmark

==============
(6) IMPACT EARTH

From Larry Robinson <lrobinsn@ix.netcom.com>

Benny:
 
I just returned to Kansas from our London holiday. I must say the
highlight of my visit was meeting Austen Atkinson at a local London
book signing for his just released, Impact Earth, Asteroids, Comets,
and Meteoroids, The Growing Threat (1999 Virgin Publishing Ltd. Thames
Wharf Studios, Rainville Road, London W6 9HT  ISBN 1 85227 789 0).   I
learned of Austen's book signing from CCNet a few days before our
departure to London.
 
At the small Books Inc side room in Bayswater, I watched as about
twenty, mostly young people, listened captivated to Austen present the
basic ideas of his book in a short audiovisual presentation.  Sales of
the book afterward were brisk. I bought two copies myself and will be
donating one to the Astronomical Society of Kansas City library.
 
After a pleasant, but too short, chat with Austen, my family and I
returned to our hotel and I spent most of the night reading Impact
Earth, straight through. Besides being a captivating subject I was
impressed by the way Austen researched the subject so thoroughly and
gave a chillingly detailed and logical treatment of a subject we have
all been increasingly concerned with for years. This book is a call to
action on a par with Rachel Carlson's Silent Spring, in my opinion.  It
should be required reading for every legislator, teacher and anyone
under the age of 30 with hopes of seeing middle and later life.  We
must get the word out on this book.
 
Austen did something very unique in Impact Earth. He added a second
book to the end, a fictional account of what it might be like to
experience a major impact. If the first book does not get attention,
the second surely will. It adds a human element that is missing from
other more technical books on this subject. Both parts if Impact Earth
are expertly done and written for the lay person in a manner that makes
the impact risk clear and obvious to anyone able to read. Austen is a
great writer.  His style is easy reading and his development is
extremely logical and captivating.
 
This is one for every middle school library and a great gift item for
the skeptic on your list.
 
Larry Robinson
Sunflower Observatory
IAUC/MPC Observatory Code 739
Olathe, KS
email: lrobinsn@ix.netcom.com
homepage: http://members.tripod.com/~btboar/
************************************************************************
ASKC Asteroid and Supernova Patrol Program
Powell Observatory
IAUC/MPC Observatory Code 649
Louisburg, KS
hompage: http://everstar.com/askcasteroids/index.html

==================
(7) PUBLICATION ON CLIMATE & HISTORY

From Ken Hsu <ken@erdw.ethz.ch>

Dear Benny:

The article on climate and history was published by the Neue
Züricher Zeitung on Wednesday, June 2, 1999, p. 71  (Forschung
und Technik section). A copy is available on request. The
English text, as I recall, was sent to you and distributed by
you already.

With best regards,  Ken Hsu

-----------------
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CCCMENU CCC for 1999

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