PLEASE NOTE:
*
CCNet 99/2000 - 2 October 2000
------------------------------
"Most astronomers believe Australia
will miss out altogether and
the [recommended 3m NEO] telescope will
end up in Chile, where the
European Southern Observatory is sited.
The president of the
Astronomical Society of Australia,
Professor Mike Bessell, says
astronomers were very concerned when the
Federal Government cut
funding for Australia's only asteroid
search in 1996, and they
would welcome a new telescope here.
Siding Spring Observatory,
near Coonabarabran, would be the best
site, he says, because
Woomera has problems with security
lights. 'But if the Europeans are
involved it is more likely it will go to
Chile.'"
-- Sydney
Morning Herald, 30 September 2000
(1) AUSTRALIA CONTEMPLATES IMPLICATIONS OF NEO TASK FORCE REPORT
Michael Paine <mpaine@tpgi.com.au>
(2) STATEMENT BY THE JAPAN SPACEGUARD ASSOCIATION
Syuzo Isobe <isobesz@cc.nao.ac.jp>
(3) BRIGHT METEOR OBSERVED OVER CALIFORNIA & ARIZONA
Ron Baalke <baalke@jpl.nasa.gov>
(4) KLET OBSERVATORY NEO FOLLOW-UP PROGRAMME
Klet Observatory <klet@klet.cz>
(5) SOLAR SCIENTISTS CONVERGE AS SOLAR ACTIVITY PEAKS
European Space Agency <sciweb@estec.esa.nl>
(6) SCIENCE AS USUAL: ASTRONOMER CHALLENGES ACEPTED VIEW OF
UNIVERSE
SpaceDaily, 2 October 2000
(7) MICKEY MOUSE SCIENCE
Alan T. Hagan <AHagan@dean.med.ufl.edu>
(8) HOW OFTEN IS THERE AN "NEA NEAR MISS"?
David Morrison <david.morrison@arc.nasa.gov>
(9) AND FINALLY: "THE END IS NIGH: TIME TO LEAVE THE SINKING
SHIP!"
STEPHEN HAWKING JOINS DOOMSDAY HYSTERIA OVER
GLOBAL WARMING
Yahoo! News, 30 September 2000
============
(1) AUSTRALIA CONTEMPLATES IMPLICATIONS OF NEO TASK FORCE REPORT
From Michael Paine <mpaine@tpgi.com.au>
From Sydney Morning Herald, 30 September 2000
http://www.smh.com.au/news/0009/30/text/features9.html
HIT OR MISS
IF A doomsday asteroid or comet was detected heading towards
Earth, what
could the world do?
The first obvious option would be to blow it apart with nuclear
weapons,
but this is likely to be attempted only as a last resort. An
explosion
would risk breaking the object into lots of pieces which could
still hit
earth and inflict even more damage.
Attaching solar-powered sails to the heavenly body so it drifted
off-course is another, remote possibility.
But the most promising way to avert global disaster, say the
experts,
would be to send up a spacecraft to nudge the asteroid or comet
into a
different orbit.
The spacecraft might have to fly alongside it for months or
years. And
gentleness would be vital, because these objects are held
together only
by weak gravitational forces.
But even a small nudge could be very effective, as long as it was
given
early enough, a British task force on potentially hazardous Near
Earth
Objects has concluded.
"This is not science fiction," notes the task force,
led by Dr Harry
Atkinson, past chairman of the European Space Agency's Council,
in its
recent report.
Four years from now, NASA intends to drop a lump of copper
weighing half
a tonne onto the surface of the comet, Tempel 1, in an experiment
that
will slightly change the comet's orbit.
Vigilance, however, is vital. If the planet is ever to be
protected by
any of these means, the world will have to improve its ability to
detect
threats well in advance. In particular there is a major gap in
coverage
of the skies from the Southern Hemisphere, the task force warns.
Comets and asteroids ranging in size from pebbles to massive
mountains,
travelling at speeds up to 100 times that of a Concorde jet, have
been
bombarding our planet since its formation 4.5 billion years ago.
The asteroid that slammed into Mexico 65 million years ago spelt
the end
for the dinosaurs. But until recently there was a reluctance to
accept
the significant risk to our own survival from similar impacts,
the task
force says.
The huge Barringer crater in Arizona, created 49,000 years ago by
an
asteroid about 50 metres in diameter, was dismissed for many
years as
the result of volcanic activity.
"Even the destruction of thousands of square kilometres of
forest in
Siberia in 1908 [by a similar-sized asteroid] was somehow brushed
aside," the report notes. Yet if a city had been hit, it
would have been
totally destroyed.
The first major project to search for asteroids and comets
heading our
way was begun only in 1988, by an American team.
Two years later Dr Duncan Steel began the first survey in the
Southern
Hemisphere for these very faint objects. Between 1990 and 1996
his
Australian team, based at the Anglo-Australian telescope in
Coonabarabran, discovered 38 near-Earth asteroids and nine
comets.
Despite this success, the Federal Government ceased funding the
project
in 1996 - a decision that went against a world trend.
During the '90s the US Congress has consistently backed a major
program
aimed at detecting 90 per cent of the objects above one kilometre
in
diameter within 10 years. NASA's budget for this is about $US3
million a
year. Japan also has a smaller survey program.
The British Government set up its task force in January and last
week it
recommended Britain too become involved in the search for
potentially
hazardous asteroids and comets.
Most notably it recommended that Britain seek partners,
preferably in
Europe, to build a large three-metre telescope in the Southern
Hemisphere dedicated to looking for bodies at least 150 metres in
diameter.
South Australia has been the first to declare an interest. State
Labor
leader Mike Rann said last week that every effort should be made
to try
to persuade the British to build the telescope at Woomera.
But most astronomers believe Australia will miss out altogether
and the
telescope will end up in Chile, where the European Southern
Observatory
is sited.
The president of the Astronomical Society of Australia, Professor
Mike
Bessell, says astronomers were very concerned when the Federal
Government cut funding for Australia's only asteroid search in
1996, and
they would welcome a new telescope here.
Siding Spring Observatory, near Coonabarabran, would be the best
site,
he says, because Woomera has problems with security lights.
"But if the
Europeans are involved it is more likely it will go to
Chile."
But it's not all bad news for Australia. Early next year a search
for
asteroids will resume here, paid for mostly by the Americans, but
run by
a leading Australian asteroid hunter, Dr Rob McNaught, of the
Australian
National University.
In a collaboration with the ANU, the University of Arizona is
refurbishing a little-used telescope at Siding Spring Observatory
with
modern detectors and computers to detect potentially hazardous
objects.
In the meantime, Dr McNaught, who was a member of the original
team in
the early 1990s, has been making follow-up observations of
asteroids
detected in the Northern Hemisphere that have travelled south,
out of
range of the northern telescopes, so their orbits can be
calculated more
accurately.
Dr McNaught also believes the chances of a British telescope
being sited
in Australia are slim, because of the European connection with
Chile and
the lack of commitment shown in the past by the Australian
Government to
the asteroid search.
The funding for the program that was halted in 1996 was a trivial
amount, he says, but asteroid hunting is now much more costly,
requiring
dedicated telescopes and sophisticated equipment.
The astronomer-in-charge of the Anglo-Australian Observatory, Dr
Fred
Watson, says that although it was astronomers who established the
hazard
posed by asteroids and comets, the issue has become one of
defence, not
funding for pure science. "The issue of saving the world ...
is in a
different political arena."
He says he may sound altruistic, but he would like the site for
any new
Southern Hemisphere telescope to be chosen solely on its
scientific
merits as the best place for observing asteroids.
If an object with a diameter of 10 kilometres or more hit us it
could
extinguish life on Earth, says the task force. The dust and water
thrown
into the air would cause freezing conditions for months or years,
crop
destruction, and widespread acid rain.
Fortunately, such events are very rare, typically occurring once
in 100
million years or more.
Most dangerous, says the task force, are objects with a diameter
of one
kilometre or more. Impacts occur more frequently - from every
500,000 to
10 million years. A collision with these large objects could
affect the
global climate as well as cause gigantic waves, or tsunamis,
around the
world, killing billions of people.
So far, the orbits of more than 400 near-Earth objects with
diameters
greater than one kilometre have been determined. "These
measurements
allow us to state with some confidence that none of these is
likely to
hit the earth over the next 50 years," says the task force.
However,
there are likely to be at least 400 more that haven't been
discovered,
it cautions.
Objects of a few hundred metres across could destroy cities, or
even
states, if they hit. Much less is known about them. For example,
fewer
than 10 per cent of 300-metre objects have been detected, the
task force
estimates. And it is these Britain would look for from the
Southern
Hemisphere.
With enough forewarning, it might be possible to move people to
safety,
away from the impact sight or coastal areas, says the task force.
With
decades or even longer notice of an asteroid's approach, new
technologies could be developed to knock it off course. On the
other
hand, we may have only as little as a year's notice that some
comets are
likely to hit.
International research should begin now on methods of deflection,
says
the task force. "If ever there was an issue affecting the
whole world it
is the threat from near-Earth objects."
It also recommends the establishment of an international panel,
like the
one on climate change, to direct the global response.
That we still have a lot to learn was underlined by a report last
week
on the potato-shaped asteroid, Eros, which a NASA spacecraft has
been
orbiting since February. The asteroid has lots of large rocks,
between
30 and 100 metres across, on its surface. This has puzzled
scientists
because its gravitational force should not be strong enough to
prevent
them drifting off into space.
In 2003 the European space agency also plans to launch a mission,
known
as Rosetta, to rendezvous with a comet as well as fly past two
asteroids.
The British task force report is available at www.nearearthobjects.co.uk
c2000 Sydney Morning Herald
==========
(2) STATEMENT BY THE JAPAN SPACEGUARD ASSOCIATION
From Syuzo Isobe <isobesz@cc.nao.ac.jp>
National Astronomical Observatory
2-21-1, Osawa, Mitaka, Tokyo 181, Japan
Tel: 81-422-34-3645, Fax: 81-422-34-3641
E-mail: isobesz@cc.nao.ac.jp
homepage http://neowg.mtk.nao.ac.jp/
September 30, 2000
Dear Dr. Peiser:
Since I was in hospital in the last four weeks, I was not able to
response in time to the UK Task Force report. Here, I would like
to say a
few words as the President of the Japan Spaceguard Association.
I am sorry for my late response to the report of the UK Task
Force on
NEOs. As many colleagues said in their comments, the Report is
most
welcome for us and is thoroughly written regarding NEO-related
topics.
However, I would like to make two comments.
The first concern is regarding the usage of nuclear power to
mitigate an
impactor. Although the report focuses on the nuclear bomb as one
of many
mitigation methods, it is mentioned explicitly. Some military
people use
the NEA problem to maintain the nuclear bomb. Yet, it is more
dangerous
to keep it than to have a NEA collision in the near future. If we
would
determine all the orbits of hazardous NEA, we could determine
their
collision time well in advance and could mitigate an threat by
some
methods except the nuclear bomb. In any case, it is the most
important
aspect of NEO resesarch to detect all the hazardous NEA since
otherwise
we cannot make any types of mitigation.
The second comment is about the recommended 3m class telescope to
detect
asteroids a few hundred metres across. In the Task Force Report,
there
does not seem to be any consideration of the difficulty to detect
asteroids fainter than sky brightness, usually 21 magnitude per
square
arc second. At the Torino meeting, there was a recommendation to
observe
down to 20.5 magnitude in order to detect up all the NEA larger
than 1
km in a short time. For a 300m asteroid, we would have to observe
down
to 23 magnitude which is much fainter than sky brightness. Then,
neccessary exposure time is much longer. Therefore, we are
currently
studying the prospect of introducing space-based and lunar based
NEA
detection telescopes.
Finally, I hope that UK Government will approve the
recommendations of
the Task Force Report and will also encourage similar action to
be taken
by other governments, especially the Japanese Government.
Yours sincererly,
Syuzo Isobe
===========
(3) BRIGHT METEOR OBSERVED OVER CALIFORNIA & ARIZONA
From Ron Baalke <baalke@jpl.nasa.gov>
http://www.sun-sentinel.com/news/daily/detail/0,1136,35000000000119903,00.html
Mysterious flash across California sky may have been an asteroid
chip
The Associated Press
September 27, 2000
LOS ANGELES -- A green and orange flash people saw streak from
the high
desert to the Pacific Coast across the night sky was most likely
a
meteor, according to an astronomer.
The flash was seen in the clear Southern California sky about 8
p.m.
Tuesday. It was visible more than 100 miles away, as far east as
the
Arizona line and as far south as the U.S.-Mexico border.
Full story here:
http://www.sun-sentinel.com/news/daily/detail/0,1136,35000000000119903,00.html
===========
(4) KLET OBSERVATORY NEO FOLLOW-UP PROGRAMME
From the Klet Observatory <klet@klet.cz>
Dear Benny,
we would like to mention a paper regarding Klet Observatory
NEO astrometric follow-up programme in PASS. It was originally
presented on the Torino IMPACT Workshop.
Best regards
Jana and Milos
----------------------------------------------------------------------
J. Ticha, M. Tichy, Z. Moravec: Klet' Observatory NEO follow-up
programme. PLANETARY AND SPACE SCIENCE 48: (9) 787-792, AUG. 2000
The number of known Near-Earth Objects (NEOs) has rapidly
increased in
recent years. The discovery effort must be succeeded by follow-up
observations to ensure astrometric data for determining orbits of
newly
discovered NEOs. The importance of follow-up astrometry of NEOs
increases with the rising number of discovered NEOs. The field of
follow-up astrometry includes the confirmatory observations,
early and
later follow-up observations, as well as the recoveries of NEOs
in the
second convenient opposition. We discuss here methods, techniques
and
results of the targeted NEO follow-up astrometry programme at the
Klet'
Observatory using the 0.57 m telescope, equipped with a CCD
camera since
1994. We point out that follow-up astrometry of NEOs is the
common
endeavour of the whole international community; this is also
based on
the continued improvement of communication tools. In the near
future we
are going to extend this programme to fainter objects and very
fast-moving objects using a 1.02 m reflector at Klet'. Copyright
(c)
2000 Elsevier Science Ltd. All rights reserved.
Address:
Klet' Observatory/Hvezdarna Klet', Zatkovo nabrezi 4,
CZ-370 01 Ceske Budejovice, Czech Republic
===========
(5) SOLAR SCIENTISTS CONVERGE AS SOLAR ACTIVITY PEAKS
From European Space Agency <sciweb@estec.esa.nl>
As the Ulysses spacecraft hurtles through space towards the Sun's
south
pole, more than 100 scientists from 16 countries will be speeding
their
way through airspace next week towards ESTEC, ESA's technical
centre
near Amsterdam. They will converge to discuss the very latest
results
from the intrepid spacecraft.
More at: http://sci.esa.int/content/news/index.cfm?aid=1&cid=1&oid=24656
=============
(6) SCIENCE AS USUAL: ASTRONOMER CHALLENGES ACEPTED VIEW OF
UNIVERSE
From SpaceDaily, 2 October 2000
http://www.spacedaily.com/news/darkmatter-00e.html
Accuracy of Astronomer's Predictions Challenges Accepted View of
Universe
College Park - October 2, 2000
An article published in the latest issue of the Astrophysical
Journal
lends strong support for a controversial theory that rejects the
cold
dark matter hypothesis central to what most scientists believe
about the
composition of the Universe.
In the October issue, which is now available online, University
of
Maryland astronomer Stacy McGaugh details cosmic microwave
background
predictions that he made last year and which subsequently proved
correct. The cosmic microwave background is the faint radiation
that
scientists believe to be a remnant of the energy released in the
Big
Bang. Measurements of cosmic microwave background matching
McGaugh's
1999 prediction were reported in the journal Nature in March of
this
year by scientists conducting an experiment known as Boomerang.
The accuracy of his predictions, writes McGaugh, points to a
universe
that consists entirely of "ordinary" matter. This
contradicts the widely
held paradigm that 90 percent of the universe is made up of
unseen
matter, termed cold dark matter. Cold dark matter is widely
thought to
consist of a new kind of particle rather than the protons,
neutrons, and
other known particles that constitute ordinary matter.
FULL STORY at http://www.spacedaily.com/news/darkmatter-00e.html
=====================
* LETTERS & OPINION *
=====================
(7) MICKEY MOUSE SCIENCE
From: Alan T. Hagan <AHagan@dean.med.ufl.edu>
Hi Benny,
Indeed, you did have discover.com and discovery.com confused as
to who
represented whom - but discover.com IS owned by Walt Disney as it
plainly says at the bottom of every page, and the article did
contain
several factual errors. I think you were right in your reporting
the
subject.
I was not a subscriber to the list at the time of the 1997 XF11
affair
but I have been steadily working my way through the entire CCNet
archives and have just finished 1998 and am well into 1999 so the
pertinent details are still fresh to me. The discover.com article
is
plainly a popularized gloss over of an issue that cannot be
adequately
explained in the single paragraph the author devoted to it. The
Y2K
paragraph was singularly lacking as well.
I've much enjoyed the list and hope you keep up the good work.
Alan
===========
(8) HOW OFTEN IS THERE AN "NEA NEAR MISS"?
From David Morrison <david.morrison@arc.nasa.gov>
as posted on NEO News 29/9/00
This month, two newly discovered Near-Earth Asteroids (NEAs),
2000
QW7 and 2000 RD53, were widely publicized as having come close to
the
Earth, often described as a "near miss". In fact, we
would expect
several NEAs of this size to come within this range every year,
as
explained below. These near misses were also used to dramatize
the
continuing danger of NEA impacts, and several commentators noted
that
they had been discovered too late for us to take any defensive
action
if they had been on a true collision course with our planet.
Following are two typical stories:
* 5 September -- THE Earth has had a cosmic near miss with an
asteroid one third of a mile wide, leading to new calls for an
international task force to devise ways of preventing a
devastating
impact. The 2000 QW7 asteroid which originated in the belt
between
Mars and Jupiter, passed within 2.4 million miles of the Earth on
Friday morning, astronomers said yesterday. It was detected at
Cornell University's Arecibo Observatory in Puerto Rico, six days
before it hurtled past the Earth. [Actually, it was discovered by
the
NEAT program]. The asteroid was only twelve times further away
than
the moon when it reached the nearest point to earth on its orbit
- a
close shave in cosmic terms.
* 11 September -- ASTEROID ALERT: Late last week the LINEAR
robotic
telescope in New Mexico discovered a bright Near-Earth Asteroid
(NEA)
that will pass 0.03 AU from Earth on Sept. 17 (approximately 12
times
farther from our planet than the Moon). The space rock, called
2000
RD53, is probably 300-400 meters across. There is no danger of a
collision, but the close encounter offers astronomers a chance to
study an NEA at close range.
Those who commented with surprise on the fact that these two NEAs
were not discovered until close to the Earth presumably are
thinking
in terms of a search program designed to pick up collision-bound
NEAs
on their final approach to Earth. But this has never been the
plan.
The Spaceguard strategy is to carry out a reasonably complete
inventory of NEAs, allowing a forward projection of their orbits;
such an approach would likely provide at least decades, and
perhaps
centuries, of warning of any future impact.
However, there were others who simply expressed surprise that any
NEAs were coming as close as 12 times the distance to the Moon,
let
alone two in one month. Just how remarkable was September 2000 in
this respect?
It is easy to calculate how often, on average, a NEA of a given
size
comes within any particular distance of the Earth. We use the
known
average impact rates on the Earth and Moon and correct for the
larger
cross-section of a target with radius 5 million km (12 times the
Earth-Moon distance). The answer is that a 300-500 m diameter
NEA,
such as 2000 QW7 and 2000 RD53, passes this close to Earth about
once
every 2 months on average. Finding two within a month is
therefore
not so unusual. Tunguska-size NEAs come this close at a rate of
one
every few hours, and even 1 km NEAs come this close nearly once
per
year. I would therefore suggest that we tighten the definition of
a
"near miss" -- perhaps using this phrase only for NEAs
that come
inside the orbit of the Moon.
David Morrison
============
(9) AND FINALLY: "THE END IS NIGH: TIME TO LEAVE THE SINKING
SHIP!"
STEPHEN HAWKING JOINS DOOMSDAY HYSTERIA OVER
GLOBAL WARMING
From Yahoo! News, 30 September 2000
http://dailynews.yahoo.com/h/ap/20000930/sc/hawking_1.html
Greenhouse Effect Worries Hawking
LONDON (AP) - Stephen Hawking says he fears the human race will
not
survive another millennium.
"I am afraid the atmosphere might get hotter and hotter
until it will
be like Venus with boiling sulfuric acid," the physicist
told Britain's
Press Association. "I am worried about the greenhouse
effect."
To ensure the survival of humans, he adds, efforts must be made
to
colonize other planets. Space travel would not solve every
problem, but
at least it would ensure that people don't become extinct.
"It takes too many resources to send each person into
space," he said.
"But unless the human race spreads into space, I doubt it
will survive
the next thousand years."
Hawking holds the Cambridge University post once held by Sir
Isaac
Newton and is the author of the best-selling "A Brief
History of
Time." Now 58, he has suffered from Lou Gehrig's disease, or
amyotrophic lateral sclerosis, since his 20s, and uses a
wheelchair.
Copyright © 2000 The Associated Press.
----------------------------------------
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