PLEASE NOTE:
*
CCNet 23/2002 - 14 February 2002
-------------------------------
"Our most serious obstacle was the Clinton Administration --
who
felt quite clearly that NEO work was some sort of subterfuge for
space-based missile defense. This attitude resulted in Mr.
Clinton's
1997 line-item veto of the (republican) Congress' appropriation
of
resources for a Clementine II spacecraft -- which was devoted to
addressing
the NEO impact threat."
--S. Pete Worden, 14 February 2002
"But what good is all this observing if there are no plans
for
averting disaster? Claudio Maccone at the Centre for
Astrodynamics in
Turin claims to have worked out the best way to deflect an
asteroid.
In the past, studies have assumed missiles will be launched from
Earth, but Maccone says space-based missiles would be far more
effective.
"You are in the worst possible situation to deflect a body
when it's
pointing at you," he says." So he recommends putting
space-based
missile launchers at "Lagrangian points". These are
locations in space
where the gravity of the Earth and Moon balances out in such a
way that
a satellite maintains its position relative to each body with
minimal
correction from its thrusters."
--Eugenie Samuel, New Scientist, 16 February 2002
(1) INCOMING! TO DEFLECT AN ASTEROID, CHOOSE YOUR SHOT CAREFULLY
New Scientist, 16 February 2002
(2) ASTRONOMER SAYS SPACE ROCKETS MAY BE EARTH'S BEST DEFENSE
Ananova, 14 February 2002
(3) PLANETARY DEFENSE FROM THE NEAREST 4 LAGRANGIAN POINTS
Acta Astronautica, Volume 50, Issue 3,
February 2002, Pages 185-199
(4) RE: US POLICIES FOR DEALING WITH THE IMPACT HAZARD
S. Pete Worden <spw21oct@earthlink.net>
(5) RE: UK ASTRONOMY FUNDING SQUEEZE
Michael Bode <mfb@astro.livjm.ac.uk>
(6) ASTEROID SCALE
Loren Ball <elo843@charter.net>
(7) EXTENDING WARNING TIMES
Jens Kieffer-Olsen <dstdba@post4.tele.dk>
(8) BRAVO
Andy Smith <astrosafe@yahoo.com>
(9) AND FINALLY: BRITISH PLANETARY SCIENTIST WINS £350,000 PRIZE
Ananova, 14 February 2002
=====================
(1) INCOMING! TO DEFLECT AN ASTEROID, CHOOSE YOUR SHOT CAREFULLY
>From New Scientist, 16 February 2002
STRANGE as it may seem, averting Armageddon isn't the top
priority for most
asteroid hunters. They'd be happy just to know where the rock
that could
wipe out life on Earth will come from. But an astronomer in Italy
thinks he
can save the world - with space-based missiles.
By the end of the decade, astronomers will have located over 90
per cent
(sic) of the near-Earth asteroids capable of causing a global
catastrophe.
Last week, NASA's Spaceguard Survey reported that over 100 rocks
more than a
kilometre across were discovered in 2001, bringing the total
known to 587 of
the estimated 1743 (sic) whoppers out there.
But what good is all this observing if there are no plans for
averting
disaster? Claudio Maccone at the Centre for Astrodynamics in
Turin claims to
have worked out the best way to deflect an asteroid. In the past,
studies
have assumed missiles will be launched from Earth, but Maccone
says
space-based missiles would be far more effective. "You are
in the worst
possible situation to deflect a body when it's pointing at
you," he says.
An incoming asteroid would approach the Earth on a curved,
hyperbolic path.
Simple mathematics shows that for every such hyperbola, there's
an
elliptical orbit around the Earth which intersects it at 90
degrees - the
ideal angle for a missile strike because even a small impact
should deflect
the asteroid from its collision course (see Graphic).
To get a missile into the right elliptical orbit would require
several long
burns from Earth, but just one tiny push from certain orbits in
space, says
Maccone. So he recommends putting space-based missile launchers
at
"Lagrangian points". These are locations in space where
the gravity of the
Earth and Moon balances out in such a way that a satellite
maintains its
position relative to each body with minimal correction from its
thrusters.
It will be hard to convince governments to prepare planetary
defences that
might never (sic) be needed, but Maccone feels it's not too soon
to start
discussing what form they might take. Although we're likely to
become aware
of an impending collision with one of the rare, large asteroids
many decades
in advance, numerous asteroids smaller than one kilometre across
could still
cause a local disaster, and those are thought to hit Earth once
every couple
of centuries.
That makes surveillance all the more of a priority, says Brian
Marsden of
the Minor Planet Center in Cambridge, Massachusetts, especially
in the
southern hemisphere where none is currently undertaken. "The
important thing
in any military operation is to know your enemy."
Eugenie Samuel
More at: Acta Astronautica, vol 50, p 1851
Copyright 2002, New Scientist
============
(2) ASTRONOMER SAYS SPACE ROCKETS MAY BE EARTH'S BEST DEFENSE
>From Ananova, 14 February 2002
http://www.ananova.com/news/story/sm_520279.html
An astronomer in Italy wants to save the planet with space-based
missiles.
He thinks he has worked out the best way to deflect an incoming
asteroid.
He says missiles in orbit will be more effective than land-based
launches
because they could hit the rock side-on and deflect it.
Claudio Maccone, at the Centre for Astrodynamics in Turin, says
Earth-based
defences would be haphazard.
Mathematicians agree there are specific orbits from which a
missile launch
would be guaranteed to hit at 90 degrees.
Mr Maccone told New Scientist that even a small impact from this
angle
should deflect an asteroid from its collision course.
This is why he prefers the space-launched rocket to the
land-launched
rocket. He said: "You are in the worst possible situation to
deflect a body
when it's pointing at you."
He recommends putting space-based missile launchers at points
where the
gravity of the Earth and Moon balance each other out because from
here very
little fuel would be required to fire the rockets on their
course.
Copyright 2002, Ananova
==============
(3) PLANETARY DEFENSE FROM THE NEAREST 4 LAGRANGIAN POINTS
Acta Astronautica, Volume 50, Issue 3, February 2002, Pages
185-199
http://www.sciencedirect.com/science?_ob=ArticleURL&_udi=B6V1N-451DFVJ-2&_us
er=777686&_coverDate=02%2F28%2F2002&_rdoc=7&_fmt=full&_orig=browse&_srch=%23
toc%235679%232002%23999499996%23283378!&_cdi=5679&_sort=d&_acct=C000043031&_
version=1&_urlVersion=0&_userid=777686&md5=450686ef01162ec5ea57c5c04dc88cb0
Planetary defense from the nearest 4 lagrangian points plus
rfi-free
radioastronomy from the farside of the moon: a unified vision
Claudio Maccone, clmaccon@libero.it
Via Martorelli 43, I-10155 Torino (TO), Italy
Received 15 January 2001. Available online 29 January 2002.
Abstract
A unified system of five space bases is proposed to achieve both
the
Planetary Defense of the Earth against dangerous asteroids and
the RFI-free
Radioastronomy from the farside of the Moon.
We show that the layout of the Earth¯Moon system with the five
relevant
Lagrangian points in space leads naturally to only one,
unmistakable
location of space bases within the sphere of influence of the
Earth.
Article Outline
1. Introduction to both planetary defense and rfi-free
radioastronomy
2. A short review about the five lagrangian points
3. Confocal trajectories for the best deflection of dangerous
asteroids
4. Political problems for planetary defense from the lagrangian
points
5. Jean heidmann's crater saha proposal (1994) for rfi-free
searches
6. Selecting crater daedalus at 180°E for all rfi-free searches
7. This author's vision of planetary defence and rfi-free
searches
8. Proposing "radiomoon": a new space mission to set up
and operate the
space base in crater daedalus robotically
9. Conclusion
References
Copyright © 2002 Published by Elsevier Science Ltd. All rights
reserved.
============================
* LETTERS TO THE MODERATOR *
============================
(4) RE: US POLICIES FOR DEALING WITH THE IMPACT HAZARD
>From S. Pete Worden <spw21oct@earthlink.net>
Benny,
Ed Grondine's review of the NASA budget and focus on the small
object threat
is admirable. However, his fine work is flawed by his
emotional reaction to
all things "Republican" and slavish devotion to all
things "Democratic." Al
Gore's contribution to the NEO hazard and making it
public is about as significant as his contribution to inventing
the
Internet. I have been involved in over a decade in working to
de-classify
military satellite data relevant to the NEO threat. This effort
began to
bear fruit in the early 1990s -- even before Mr. Gore burst upon
the
national scene. The ultimate declassification has been due to a
small number
of very dedicated individuals inside the national security
community. Our
most serious obstacle was the Clinton Administration -- who felt
quite
clearly that NEO work was some sort of subterfuge for space-based
missile
defense. This attitude resulted in Mr. Clinton's 1997 line-item
veto of the
(republican) Congress' appropriation of resources for a
Clementine II
spacecraft -- which was devoted to addressing the NEO impact
threat.
Respectfully
S. Pete Worden
================
(5) RE: UK ASTRONOMY FUNDING SQUEEZE
>From Michael Bode <mfb@astro.livjm.ac.uk>
Dear Benny,
Unfortunately, the recent BBC Online article (CCNet 13 Feb)
contained quotes
attributed to me that were incorrect. I was particularly
concerned to nail
the "myth" that the growth in the UK astronomy
community is due to small
groups springing up. The recent survey conducted by the Standing
Conference
of Astronomy Professors (which I led) clearly shows the growth is
dominated
(as one would logically expect) by the large, long-established
groups.
Furthermore, it is well known that I recognise that the
"newer" groups
(including my own!) contain researchers of the highest
international calibre
researching and teaching at the highest levels. An amended
version
has now been posted on the BBC online website, and I thank David
Whitehouse
for doing so. Overall, I was also concerned that the article
could give the
impression that the growth in the community did anything other
than reflect
the increasing significance of astronomy to the UK's
physics departments. This is a subject area in which we excel
internationally, but, as impled in the article, lack of funds are
threatening this position.
Mike
------------------------------------------------------------------------
Professor Michael F.
Bode
| email: mfb@astro.livjm.ac.uk
Head, Astrophysics Research Institute | Tel: +44
(0)151-231 2920 (direct)
Liverpool John Moores University |
2919(secretary)
Twelve Quays
House
| FAX: +44 (0)151-231 2921
Egerton
Wharf
| WWW: www.livjm.ac.uk/astro/
Birkenhead L41
1LD
|
United
Kingdom
|
===============
(6) ASTEROID SCALE
>From Loren Ball <elo843@charter.net>
Hello Benny,
I take great pleasure in speaking to local schools about
astronomy in
general and asteroids in particular. A scale model I have used is
as follows:
At 1 mile = 1 mm, an 8,000 mile dia Earth is 8,000 mm or 26.25
ft.
At 1 mile = 1 mm, a 1 mile asteroid is 1 mm or about a # 9
birdshot.
It is a little hard to believe that such a small asteroid can in
fact create
not just local, but global destruction. I would be hard pressed
to prove
mathematically the dire results, but others have convinced me
that this is
so. Now I have only to convince these same students that a
fraction of a
second after the Big Bang, the entire universe was smaller than
the same
# 9 bird shot. Typically, a 5th grader will want to know what it
weighed in pounds and ounces. :>)
Thank you,
Loren C Ball
Emerald Lane Observatory 843
Decatur, Alabama
elo843@charter.net
============
(7) EXTENDING WARNING TIMES
>From Jens Kieffer-Olsen <dstdba@post4.tele.dk>
Dear Benny Peiser,
>From the Duncan Steel and Mark Bailey report on the December
2001 Meeting:
> "By identifying the next potential NEO impact we can
> ameliorate its effects or maybe obviate it altogether.
> But lots of warning time is needed and that is where
> astronomy comes in. We must scour the skies, catalogue
> all Earth-approaching asteroids above a certain size ...
Concerned about warning times for comets as we must all be and
inspired by
Ed Grondine's call for Discovery mission-type proposals, may I
suggest that
a telescope be delivered into halo orbit around the L3 point,
such as to
double the warning time in a worst-case scenario.
Yours sincerely
Jens Kieffer-Olsen, M.Sc.(Elec.Eng.)
Slagelse, Denmark
============
(8) BRAVO
>From Andy Smith <astrosafe@yahoo.com>
Hello Benny and CCNet,
It is just great to read the excellent meeting report and
situation
summaries being published in your newsletter. Ed Grondine did an
excellent
job of investigating and reporting on the status of NEO things,
in
Washington.
It is this low-level of support which has caused us to emphasize
the
importance of being sure the NEO hazard is identified and
addressed by the
newly formed Natural Hazards Caucus (NHC)of the U.S.Senate. We
are having
some luck with the NHC Working Group (WG), but we still need at
least one
expert, who lives/works in that area (Washington, Virginia,
Boston, etc.).
to attend the WG meetings.
We are trying to get representation from the National Space
Society and/or
the AIAA to help.
Unity Is Vital
Because advocates for planetary defense are such a small group,
it is
extremely important for us to work togeather. We were delighted
to see the
cooperation reflected in the recent letter to the Australian
leaders and we
appreciate the work involved and those who organized it. We would
like to
see more of this kind of thing and one letter could certainly go
to the NHC,
mentioned above.
Asteroid Impact is a Hundred-Year Event
As many of you know, the next NEA hit (Tunguska of larger) is a
100 year
event...a disturbingly high risk, in the light of the possible
consequences.
As a result, we find it disturbing to see it being suggested that
the job of
NEA hunting is almost done.
NEA larger that a kilometer are a very small portion of the
dangerous
population (2% or so) and most of the 100,000 or so NEA remain
unidentified.
We also think, as mentioned in an earlier note, to the net, that
the
threshold an asteroid winter is in the 300 meter NEA range (1000
megatons),
based on a comparison with the Tambora volcanic explosion of 1815
(and the
year-without-a-summer of 1816). The greatest danger and the
ngreates
discovery need is in the sub-kilometer range....and we need to
get larger
survey telescopes involved ASAP.
We continue to see a major role for the very inexpensive liquid
mirror
instruments, as NEA spotters and we are continuing to work with
the pioneers
of this technology. We invite any others who share this interest
to contact
us.
We Represent The Public
Because we are volunteers, acting in the interest of the millions
of
possible impact victims, we are giving a high priority to civil
asteroid/comet emergency preparedness and we are devoting
significant effort
to finding ways to survive an impact. The top priority, in this
area, is
food stores and production.
We Are It
It would be nice if there were major and well-funded programs,
around the
World....all working to help to prevent the next NEA hit and to
be prepared
for survival, if we fail. However, the CCNet members and a few
hundred other
specialists are all there are...and it is truly up to us to do as
much as we
can, individually and collectively, to "get the train on the
right track".
We appreciate all that you are doing, friends, and we pray that
we will have
the time we need to prepare and that each of you will be given
the
determination and strength you need.
Cheers
Andy Smith
===========
(9) AND FINALLY: BRITISH PLANETARY SCIENTIST WINS £350,000 PRIZE
>From Ananova, 14 February 2002
http://www.ananova.com/news/story/sm_521051.html?menu=news.scienceanddiscovery
A Cambridge don has been named as this year's winner of the
£350,000
Crafoord Prize for work that has contributed to understanding how
and why
continents move.
Dan McKenzie, 59, also developed a method to predict earthquakes
and
provided new insights into the evolution of Mars and Venus.
The Professor of Earth Sciences at Cambridge University said
"a whole load
of people made huge contributions.
"It has changed our whole view of how the planet has
evolved, and that
doesn't happen very often."
The annual award by the Royal Swedish Academy of Sciences is
named after
Holger Crafoord who designed the first artificial kidney. It was
established
in 1980 for scientific research in areas not recognised by the
Nobel Prizes.
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