CCNet 07/2000, 20 January 2000


     "No known NEO has yet had a Torino number greater than one. This  
     is just as well because we presently have no coherent plan of action
     should a real threat arise."
        -- David Jewitt

    Ron Baalke <>

    Ron Baalke <>

    David Jewitt, in NATURE 403, 145 - 148 (2000)

    Mark Kidger <>

    Michael Paine <>

    Jonathan TATE <>  

    Andrew Yee <>

    Bob Kobres <>   


From Ron Baalke <>

Meteor explodes in air near Alaska, Yukon border
January 18, 2000

WHITEHORSE, Yukon (Reuters) - A meteor exploded over the mountains of
southern Yukon Tuesday, shaking houses and providing residents of the remote
region with a dramatic light show, the Geologic Survey of Canada said.

The meteor is believed to have exploded in the atmosphere midday between
Carcross, Yukon and Skagway, Alaska, at about 9 a.m. according to the
agency, which received witness reports and sonic data on the event.

Full story here:


From Ron Baalke <>

Forwarded from Peter Brown (

Fireball Detection

On 18 January 2000, sensors aboard DOD satellites detected the impact
of a meteoroid at 16:43:43 UTC near Whitehorse in the Yukon territory,
Canada. The object detonated at an altitude of 25 km at 60.25 degrees
North latitude, 134.65 degrees West Longitude. Optical sensors detected
the same event at 16:43:42 UTC. The event  lasted 2 seconds at 1 micron
wavelength.  Estimates of total radiated power (assuming a 6000K
Blackbody model) are 1.1 x 10 exp 12 Joules.

Assuming a 10% energy conversion, this corresponds to approximately 2-3
kT TNT equivalent total equivalent energy.




Dr. Peter Brown
Meteor Physics Lab
Department of Physics and Astronomy
University of Western Ontario
London, Ontario
N6A 3K7

Voice:1-519-661-2111 x86458


From NATURE 403, 145 - 148 (2000) (c) Macmillan Publishers Ltd.

Astronomy: Eyes wide shut


Astronomers like to forget that the roots of their subject
lie in ancient superstitions about the influence of the
cosmos on everyday affairs. In fact, astronomy and astrology
were closely intertwined as recently as four centuries ago, when Tycho Brahe
laid the foundations of modern astronomy while simultaneously
maintaining a lucrative business in personal horoscopes.
Modern astronomers generally scoff at such superstitious beliefs, so it is
somewhat ironic that science has in the past few decades uncovered
compelling evidence for celestial interference in terrestrial matters.

It is now clear that asteroids occasionally wander from the main belt beyond
Mars because of chaotic instabilities caused by Jupiter. Some of these
errant asteroids strike the Earth with terrible consequences.
On page 165 of this issue, Rabinowitz et al.1 report that the number of
threatening near-Earth objects (NEOs) larger than 1 km in diameter is only
half the previous estimates. But we still have no effective means of
detecting them all, and no form of self-defence.

The Earth bears the scars of previous encounters with NEOs. Hundreds of
impact craters, some the size of small American states, have been discovered
on the surface of our planet. Each was produced by a
devastating explosion that must have been fatal to life in the surrounding
areas on scales from local to global (Fig. 1). The Cretaceous-Tertiary mass
extinction of 65 million years ago seems to have been triggered by the
impact of an asteroid 10 km in diameter2. Ten
thousand people killed by 'falling stones' in Shanxi Province, China, in
1490 were possibly the victims of a much smaller and thoroughly fragmented

Still more recently, on 30 June 1908, 1,000 square kilometres of Siberian
pine forest in Tunguska were blown flat by a 10-megaton atmospheric blast
caused by a 70-metre asteroid.

The gradual acceptance of the evidence for impacts by asteroids (and comets)
has led naturally to questions about the magnitude of the threat posed by
NEOs to life on Earth3,4. Rabinowitz and colleagues1 provide
the most recent and best controlled estimate of the number of large,
potentially Earth-threatening NEOs.They report that there are nearly 1,000
NEOs larger than 1 km in diameter and that, given the present rate of
discovery, it will take 20 years for 90% of these objects to be found.
Should we worry?

The answer depends on the number of fatalities to be expected, but also on
personal assessments of risk. The number of NEOs found by Rabinowitz et al.
is within a factor of two of previous estimates based on
less-controlled samples, so published estimates of impact mortality are
essentially unchanged. Considering events of all energies there is about 1
chance in 20,000 of being killed by an impact during the course of a
human lifetime4, similar to the likelihood of being killed in an airplane
accident. The perception of risk from impacts is smaller than for being
killed in a plane crash because planes crash at a steady rate with
(relatively) few deaths per event, whereas lethal impacts are rare but kill
a lot of people. At the very least, the potential consequences of impact are
large enough to cause concern.

In the past decade, thanks to several reported near-miss encounters with
small objects, the impact threat has become a subject of intense interest to
the general public (spawning the popular movies Deep Impact and
Armageddon). In 1994, the United States House Committee on Science and
Technology went so far as to order the US space agency NASA to "catalogue
within 10 years the orbital characteristics of all (Earth-orbit-crossing)
comets and asteroids that are greater than 1 km in diameter". This
particular cut-off diameter was picked in part because 1-km NEOs are
thought to be the smallest objects capable of wreaking global havoc (for
example, by disrupting the climate and shutting down photosynthesis).
Smaller objects cause regional damage but would be unlikely to precipitate a
major extinction like the Cretaceous-Tertiary event.

Last summer, astronomers devised a new risk-assessment scale, similar to the
Richter scale used for earthquakes, to help the public understand the hazard
posed by a given NEO. The so-called Torino scale ranges from zero (no chance
of a collision) to 10 (certain collision causing global devastation). No
known NEO has yet had a Torino number greater than one.
This is just as well because we presently have no coherent plan of action
should a real threat arise.

The simplest option -- massive evacuation of the impact site -- would be
impractical because of the positional uncertainties and large numbers of
people involved, and would be ineffective because the damage from large NEOs
will be global. One option that has been discussed is the thermonuclear
destruction of the incoming NEO (a bad idea because the shower of debris
produced by the exploding NEO might be as damaging as
the initial object, and would be radioactive). Given enough time, the NEO
might be deflected from an Earth-intersecting path by a series of smaller
explosions, or by attaching rockets or solar sails that use radiation
pressure from the Sun.

The focus on NEOs larger than 1 km ignores the threat from smaller but much
more numerous objects. The Earth's atmosphere offers little protection
against objects larger than 100 metres in diameter4. These smaller objects
outnumber NEOs larger than 1 km by a factor of 100, so they are much more
likely to strike in our lifetimes. There is a 1% chance that the Earth will
be struck by a 300-metre NEO in the next century4. Such an impact would
deliver a withering 1,000-megaton
explosion and cause perhaps 100,000 deaths. If the impact occurred in or
near a densely populated region -- the eastern seaboard of the United
States, for instance, or Western Europe or coastal Asia -- the fatalities
could easily rise into the tens of millions.

Neither can we take refuge in the fact that 70% of the Earth is covered by
oceans. Impact-induced tsunamis could wipe out coastal cities over a wide
area. So, to have practical value, surveys should not be limited to the
(observationally easy but numerically rare) 1-km NEOs, but should instead
catalogue objects at least down to the fewhundred-metre size range5. What is
needed is a more ambitious survey to completely identify the population of
small, potentially threatening NEOs.

The strategy for such a survey has been explored by Alan Harris of the Jet
Propulsion Laboratory6. He argues that the whole sky must be surveyed on a
monthly basis with a sensitivity about 100 times greater
than current NASA-sponsored surveys. How can this be done? A large
(6-8-metre) telescope is required, with a wide field of view tiled with CCD
(charge-coupled device) optical detectors and connected to a massive
computer array capable of meeting the huge data-processing demands. The
technology exists and tentative designs are beginning to appear7-9. Such a
telescope, which would have many applications in other branches of
astronomy, is projected to cost about $100 million (about half the price of
a Jumbo jet). What is missing is any sign that such a facility will be
funded by governments and their agencies. Perhaps astronomers can attract
the interest of private donors in the search for threatening NEOs. If not,
it seems we will have to face the asteroidal impact hazard with our eyes
wide shut.

David Jewitt is at the Institute for Astronomy,
University of Hawaii, 2680 Woodlawn Drive, Honolulu,
Hawaii 96822, USA.


     1.Rabinowitz, D., Helin, E., Lawrence, K. & Prado, S.
       Nature 403, 165-166 (2000). Links
     2.Alvarez, L. W., Alvarez, W., Asaro, F. & Michel, H.
       Science 208, 1095-1108 (1980). Links
     3.Morrison, D. The Spaceguard Survey: Report of the
       NASA International Near-Earth Object Detection
       Workshop (Jet Propulsion Laboratory, Pasadena, 1992). Links
     4.Chapman, C. R. & Morrison, D. Nature 367, 33-40 (1994). Links
     5.Binzel, R. P. et al. From the Pragmatic to the
       Fundamental: The Scientific Case for Near-Earth Object
       Surveys (1999). Links
     6.Harris, A. Planet. Space Sci. 46, 283-290 (1998). Links
     7. Links
     8. Links
     9. Links

Copyright 2000, Macmillan Publishers Ltd.


From Mark Kidger <>

Hi Benny:

Josep Corbella's request for info on iceballs is down to me, I think.
I am firmly of the opinion that they come from a faulty plane (the
fact that three of them fell in a line not far from a major airport is
suggestive!). He called me yesterday asking about the comet hypothesis
and I pointed out that it is not exactly reasonable that the blessed
things (the biggest was of several kilograms), would fall only on

In fact, I was talking to an Iberia technician on a Spanish astronomy
mailing list on Friday evening and he confirmed that the aeroplane
hypothesis is almost certainly right. In fact, the last Spanish
iceball case (some three years ago, in Galicia, in the extreme
north-west of the Spanish mainland) was later and very quietly proved
to have fallen from an aircraft.

The very cold temperatures in Spain in the last week are almost
certainly a factor. I also suspect that some of the most recent
iceballs are of the "home made" variety, given the publicity that they



From Michael Paine <>

Dear Benny,

You may consider this too political for CCNet but...
U.S. Missile Test Was 'Very, Very Close' -Pentagon

...The failed $100 million test, which followed a successful intercept
last October, could have a negative impact on President Clinton's
planned decision this summer on whether to begin  building the
anti-missile base in Alaska at a cost of more than $12 billion despite
objections from Russia...

Just the $100 million would have paid for 10 years of Spaceguard

Michael Paine


From Jonathan TATE <>  

Welcome to Impact 9 and to the year 2000. Over the festive season things
have been moving on apace.  We now have news that the government task force
that was ordered by the Under-Secretary of State, Department of Trade and
Industry (Lord Sainsbury) at our meeting with him in July has been
established, and will be starting its investigation early in the New Year. 

Since July things have not proceeded smoothly. The job of setting up the
task force was given to the British National Space Centre (BNSC), more
specifically to Richard Tremayne-Smith.  Sadly Richard suffered a heart
attack in the early autumn, and this work was placed on a back burner.
However, I am glad to report that Richard has now recovered. The task was
then passed to Dr Richard Crowther at the Defence Evaluation and Research
Agency at Farnborough, where he works on space debris studies. Richard has
been involved in Spaceguard UK since its inception, so that seemed like good
news. However, the goal posts moved yet again shortly thereafter, and the
task fell to Dr. David Hall of the BNSC. Dr Hall has greatly impressed those
who have met him with his open minded and enthusiastic attitude, and, along
with the encouragement of the new Director General of the BNSC, Dr Hicks,
there is cause for cautious optimism over the contents of the report. As a
result of Dr. Hicks' report the formal task force has been established, and
will have until the summer to produce its findings for the Minister.

The information that we have on the task force can be found later in this

There has been a recent upsurge in press interest over the proposed National
Spaceguard Centre. This began with interest from the Sunday Times over the
reported impacts of Leonid meteoroids on the Moon.  However, the NSC
proposal must have been a juicier titbit. A rather inaccurate report
appeared in the Sunday Times of 28th November, followed by interviews on
Radio 4 with Mark Bailey and Lord Sainsbury. During the latter, the minister
reiterated the government's view that the impact threat is significant
enough to warrant further work, but that this must be carried out as part of
an international programme. He also pointed out, not surprisingly, that the
Sunday Times report was premature to say the least.

So far so good. The Daily Telegraph then published a short piece on 29th
November which gave the impression that the BNSC report was imminent, and
that the government was likely to approve its recommendations. 

My first fear was that this sort of publicity at this time might rejudice
the progress that has been made over the past year or so. A jaded view could
be that we are trying to force the government's hand by using the press.
Actually, nothing could be further from the truth, but it might be
difficult to persuade them of that! However, I think that this little
upsurge in interest could serve as a timely reminder to those in power that
this is an issue that won't just go away if ignored, and that public
interest is sufficient for the press to keep returning to the subject.
Anyway, time will tell, and I would like to say a big thank you to all of
you who wrote to their MPs on this matter. I have received a number of
replies, all of which have been sympathetic to the Spaceguard UK proposals.

As I said in my letters to you all, when the issues are as important as this
one, I need to rally the considerable support that the membership of
Spaceguard UK represents.

Finally I would like to wish all of you the very best for the New Year. 

Jay Tate

By the time that you receive this issue of "Impact" the BNSC will have
formally announced the establishment of the government task force that Lord
Sainsbury, the Science minister, instructed to investigate the impact threat
and what the UK should do about it. The details as we know them at the
moment are:


Dr. H H (Harry) Atkinson (Chairman)
Professor David Williams
Sir Crispin Tickell
Secretary: Richard Tremayne-Smith (BNSC)

Terms of Reference:

Confirm the nature of the hazard.
Identify current UK activities in the field.
Advise Her Majesty's Government on future action.


The Director General of the BNSC is to report to the minister by 31 May

As you all know, we believe that any Spaceguard project should have broader
remit than just space research (BNSC) involving matters of the environment,
defence, insurance etc. There is a general move towards interdisciplinary
subjects at the moment that might be to our advantage.  An example is the
current interest (and investment) in bio astronomy.  This interdisciplinary
emphasis makes something of a mockery of some old, established lines of
demarcation between the responsibilities of the research councils. A classic
example is the arbitrary boundary between PPARC and NERC, which is an
altitude of 100 kilometres above the Earth's surface. Anything above that is
PPARC's responsibility and everything below that of NERC. That puts those of
us concerned with cometary and asteroidal impacts in a tricky position!

It is clear that Lord Sainsbury is keen on the international (European)
angle, but the nightmare scenario would be getting tangled up with the
bureaucracy of Europe, especially the European Space Agency.  We could then
expect years of studies, committees, meetings, reviews and so on before any
sort of decision.

One of the points that we have emphasised, particularly after the sometimes
heated debates at the Turin symposium, is that of national interest. At the
moment single nation dominates the field, and can decide, with virtual
impunity, what data to release to the public, and how. The United Kingdom
has no official organisation capable of advising government or the public on
matters related to the impact threat. With the increase in public interest,
and the huge number of new asteroid and comet discoveries it is inevitable
that we will see repeats of the XF11 and AN10 affairs in ever increasing
numbers. Embarrassed silence from government departments is no longer an

The US is doing stunningly well with discovery programmes such as LINEAR,
but there is a huge gap in the ability to follow up their discoveries.
Follow-up is less "sexy" than discovery, but just as important - without it,
discoveries are totally wasted. It is in this field that the UK could
contribute the most. The establishment of a National Spaceguard Centre,
hopefully followed by the commissioning of a suitable 1.5-metre class
telescope devoted to follow-up observations would be a substantial
contribution to the global effort.


From Andrew Yee <>

Carnegie Mellon University

Anne Watzman
Carnegie Mellon University

Susan Griffith
Case Western Reserve University

January 17, 2000

Carnegie Mellon Researchers Deploy Robot in Antarctica to Search
Autonomously for Meteorites and Classify Them in the Field

PITTSBURGH -- Researchers from Carnegie Mellon University's Robotics
Institute have deployed a four-wheeled robot named Nomad to a site in
Antarctica, where it will autonomously search for meteorites and
classify them in the field with scientific instruments contained in a
newly developed manipulator arm. The expedition marks the first time
a robot will be used to discover extraterrestrial material that has
fallen to Earth and could serve as a prototype for future scientific
missions to Mars and the Moon.

The Nomad research program and the expedition are funded by grants
from the Cross Enterprise Technology Development Program of NASA's
Office of Space Science. Additional support for a related public
outreach program comes from the Heinz Endowments, the Henry C. Frick Fund of
the Buhl Foundation and the Grable Foundation, all in Pittsburgh.

The expedition is the result of a collaboration between Carnegie Mellon
researchers and the National Science Foundation's (NSF) Antarctic Search
for Meteorites (ANSMET) program, which funds the work of ANSMET
scientists through its Office of Polar Programs. Since ANSMET was
established in 1976, its members have collected more than 10,000
meteorites during their annual expeditions to Antarctica. They
subsequently have been made available to the world's scientists for

The robotic search for meteorites is taking place at Elephant Moraine, a
remote area in eastern Antarctica, 160 miles northwest of the United
States base at McMurdo Station. Nomad and the Carnegie Mellon/ANSMET
team were transported to the site from NSF's staging ground at McMurdo
via light aircraft and helicopter.

Nomad will perform autonomous searches and classification of rock
samples at Elephant Moraine in an effort to discover meteorites. Its
search will include driving, looking, choosing and testing to select
meteorite candidates it encounters in the area. The robot will use high-
resolution imagery and spectroscopy to gather scientific data about the
rocks it finds. Its arm will enable precise placement of the scientific
instruments on the rocks it chooses to study.

The ANSMET member of the field team will serve as a guide to the region
and collect any meteorites that Nomad successfully locates. The
expedition will last about three weeks, depending on the weather.

Elephant Moraine looks like a small elephant with a very long trunk.
It's considered to be one of the more important sites for meteorite
discovery, with nearly 2,000 specimens recovered during seven previous
visits, including the first meteorite identified as definitely being from

This year's expedition takes place near the end of the "elephant's trunk,"
which was last searched in 1979.

The principal investigator on the Nomad project is William L. "Red"
Whittaker, the Fredkin research professor and founder of the Field
Robotics Center at Carnegie Mellon's Robotics Institute. The project
manager is Robotics Institute Systems Scientist Dimitrios Apostolopoulos.

A six-member Carnegie Mellon team will be supporting the experiments
on the ice. The group includes Robotics Institute doctoral students
Stuart Moorhead, Liam Pedersen and Kim Shillcutt, Mark Sibenac and Michael
Wagner, who are studying for master's degrees in electrical and computer
engineering, and Ben Shamah, a senior research engineer at the Robotics

The head of the ANSMET program is Ralph P. Harvey, assistant professor
of geological science at Case Western Reserve University. His associate,
John Schutt, will be collecting Nomad's meteorite choices in the field.

"This expedition will showcase the ability of a robot to discover
meteorites, distinguish them from surrounding rocks and do it in an
autonomous, self-reliant, self-contained manner," said Whittaker. "The
breakthrough technologies are robotic classification and search. Humans
classify every time they sort pennies from nickels, and they search every
time they lose their car keys. But these are new skills for robots.
Classification and search both must succeed for the autonomous meteorite
discovery to succeed.

Until now, explorative robots have taken pictures, gathered data and
returned what they viewed to scientists who made judgments and decisions.
This time Nomad will make its own judgments and inferences about the rocks
that it encounters."

Nomad has been programmed with navigation strategies for driving. It
will move in patterns similar to those people use when they're operating a
lawn mower. As it moves, machine vision will enable it to search for rocks
distinguished by their dark color against the white ice background.
Then, the robot's high-resolution camera can zoom in on a rock, determining
size and color as evidence that it's a meteorite. As Nomad explores an area,
it must choose which rocks to examine and in what order. It will have to
decide whether it should drive, use its arm or employ both capabilities to
reach its goal.

"The compelling element of this expedition is the prospect of meteorite
discovery by a robot," Apostolopoulos said. "Nomad will demonstrate for
the first time the ability of a science robot to autonomously search for
and distinguish meteorites from terrestrial rocks. Robotic technologies
demonstrated by this project could set a new precedent on the state of
the art in space robotics and impact how missions to the planets are
designed and carried out."

As the expedition in Antarctica unfolds, the public will be able to
follow the action on the Web. Southwestern Pennsylvania K-12 science
students and teachers will follow Nomad's adventures in real time through
Carnegie Mellon's interactive Web site known as the Big Signal Project.

This is Nomad's third trip to a locale on Earth analogous to an
extraterrestrial world. In the summer of 1997, it made an unprecedented
130-mile trek through the Atacama Desert in Chile while being teleoperated
by researchers in Pittsburgh and at NASA's Ames Research Center. Last
winter, it was taken to Patriot Hills in the Chilean section of Antarctica,
where its navigation capabilities were tested under polar conditions.

Experience Nomad's robotic search for Antarctic meteorites:

* The expedition
* Education and outreach


From Bob Kobres <>   

Sir Fred & company are hacking again! If they prove to be correct then,
according to Nigel Calder (The Comet is Coming, 1980, p-115), we should soon
see pigs flying about. ;^)


Flu comes from outer space, claim scientists
Flu epidemic: special report

Stuart Millar
Wednesday January 19, 2000
The Guardian

It made the festive season a misery for many and threw NHS policy into
crisis. But the flu may have worse in store, according to scientists who
claim to have discovered an alarming explanation for the epidemic - a virus
from outer space.

Dismissing as dogma the conventional medical wisdom that flu is a virus
passed by human contact, the distinguished astrophysicist Sir Fred Hoyle,
and his colleague at Cardiff university, Chandra Wickramasinghe, warn that
we may be on the brink of a global epidemic.

In a report to be published in the journal Current Science, they claim the
outbreak was caused by dust deposited high in the atmosphere by passing
comets being forced down to earth by energy generated by cooler patches on
the sun's surface, known as sunspots.

They reach the peak of their activity, the maxima, every 11 years,
coinciding, the scientists say, with all major flu outbreaks since 1761,
including the 1918 Spanish flu pandemic blamed for 20m deaths worldwide. The
latest cycle began to peak in September and the maxima is due sometime this

Copyright Guardian Media Group plc. 2000


From Bob Kobres <>

Speaking of pigs flying to soaring markets--it seems that the mystery of
why people focused so much attention on the Pleiades star cluster has
been solved.  It was potato futures!

I guess the rest of the world's Subaru gawkers must have been pretty far
sighted because the spud didn't escape the Americas until the mid 1500s!
;^) See:

--A couple of additional books DjVued (new verb?) on my web-site:

A discussion of the historicity of the Mahabharata, edited by S.P. Gupta
and K.S. Ramachandran (1976):

Mahabharata: Myth and Reality, Differing Views

An early (1882) discussion, by Ignatius Donnelly, of the possibility of
Earth being hit by a comet:

Ragnarok: The age of fire and gravel

There is some interesting annotation from October of 1896 at the head of
chapter 13, Genesis Read by the Light of the Comet (p-316):

It's a little hard to see but it reads:
This chapter will weaken the average mans ideas as to the Christian
religion.  If you don't want yours weakened, Don't Read. (The "don't
read" is underscored twice.)

Actually, Donnelly felt that cosmic crashes were the work of God and
served to keep us marching in step toward our divinely planned destiny.

I doubt that this notion is totally passe, even today.

Bob Kobres
Main Library
University of Georgia
Athens, GA  30602

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