CCNet, 17 September 1999


     "The odds are that a comet with Earth's name on it is lingering in
     deep space, already on a course that will kill millions"
     (Matthew Genge, The Times, 17 September 1999)

    THE TIMES, 17 September 1999

    S P A C E V I E W S, 15 September 1999

    Mark Bailey <>

    Mark Eby <>

    Andrew Yee <>

    Andrew Yee <>


From THE TIMES, 17 September 1999
The British Association for the Advancement of Science conference -
Nigel Hawkes and Nick Nuttall report

Killer comet 'lurks in space'

THE odds are that a comet with Earth's name on it is lingering in deep
space, already on a course that will kill millions, a researcher has

Calculations by Matthew Genge, of the Natural History Museum in London,
to be presented at the British Association meeting today, show that
impacts large enough to cause enormous damage occur on average
once a century.

The last collision occurred in Siberia in 1908, when a comet fragment
60 metres in diameter devastated 2,000 square kilometres of forest. "If
this event occurred today over an urban area such as London, fatalities
of several million could be expected," Dr Genge said. Smaller
fragments, up to ten metres in diameter, hit the Earth at the rate of
about five a year, but burnt up harmlessly high in the atmosphere, he

Asteroids were a potential hazard, but it was the much more fragile
comets we needed to worry about most, he said. Comets broke up easily
as they reached the atmosphere, instantly converting all their kinetic
energy into a flash of radiation and a shockwave. Nothing solid
reached the Earth, he said, so such impacts left few traces other than
the damage they caused - which may mean the number of impacts has been

Long-period comets from the Oort cloud, which lies at the fringes of
the solar system, were most likely to take us by surprise, Dr Genge
said. There were 10,000 comets in the cloud, in orbits that brought
them close to the Sun, and Earth, only once every 30 million years.
This meant we could not predict their arrival.

"Comet Hale-Bopp, which is 40 kilometres in diameter, is one of these,"
he said. "We had less than a year's warning that it was coming."
Hale-Bopp made a spectacular display in the sky as it passed the Sun,
but came nowhere near the Earth. Smaller long-period comets could be
less obliging.

The size of the comet was critical, the researcher said. One 50 metres
in diameter would burn up so high in the atmosphere that it would have
no discernible effect at ground level. But a fragment 70 metres in
diameter would explode four kilometres above Earth, and the blast and
heat would cause enormous damage.

The first effect on the ground would be a blinding flash of light and a
wave of heat so intense that everything combustible would burst into
flames. A fraction of a second later, a blast wave would blow out the
flames, and demolish buildings over a wide area. The destruction
would fan outwards from the point of the explosion.

Given sufficient time, Dr Genge said, action might be taken to prevent
disaster. A rocket sent to rendezvous with the incoming comet could
nudge it off course with a nuclear explosion. But long-period comets
may not give sufficient warning to allow such action.

Astronomical searches are concentrating on objects more than 500 metres
across. When these have been catalogued, the search can move to smaller

But the chances of spotting them were not high, especially if they came
from the south, Dr Genge said. There were no telescopes in the Southern
Hemisphere looking for objects on a collision course for Earth.

Copyright 1999 Times Newspapers Ltd.
[see also: bobk]


From S P A C E V I E W S, 15 September 1999

The House of Representatives approved NASA's fiscal year 2000 budget
Thursday, September 9, keeping intact more than $900 million in
cuts to the space agency.

The House approved H.R. 2684, the appropriations bill for the
Departments of Veterans Affairs (VA) and Housing and Urban Development
(HUD) as well as independent agencies like NASA, by a margin of 235 to
187.  The vote was largely along party lines, with 39 Democrats
joining 196 Republicans to approve the bill.

Among the 18 Republicans voting against the bill were Reps. James
Sensenbrenner (R-WI), chairman of the House Science Committee, and Dave
Weldon (R-FL), whose district includes the Kennedy Space Center.

Just prior to the final vote on the bill, the House narrowly turned
back an effort to send the bill back to the House Appropriations
Committee for reconsideration.  That vote failed 207-212, almost
strictly along party lines.

Debate on the Bill began Wednesday, September 8. During the debate,
which lasted for over seven hours, members of the House rejected a
series of amendments that would have both restored some funding cut
earlier by the House Appropriations Committee, as well as efforts to
further cut NASA's budget and redistribute the funding to other

As expected, an effort to cancel the space station, proposed by Reps.
Tim Roemer (D-IN) and Mark Sanford (R-SC), was soundly defeated by
representatives.  Their amendment would have redistributed space
station money to fully fund NASA's space science budget, with the rest
going to VA and HUD programs and debt reduction. The amendment was
defeated 121-298.

The House also rejected an amendment by Rep. Jerrold Nadler (D-NY) to
take $305 million from space station and use it to fund additional
public housing vouchers.  That amendment failed on a 154-267 vote.

Rep. Luis Gutierrez (D-IL) proposed taking $30 million from various
NASA programs and using it to support HUD projects, including
reclamation of former industrial "brownfields" into new commercial
projects.  Although that amendment initially passed on a voice vote, a
recorded vote was requested and the amendment lated failed 152-269.

However, members of the House also defeated efforts to take money from
other programs and use it to restore NASA's budget. On a 185-235 vote
the House rejected an amendment proposed by Reps. James Rogan (R-CA)
and Herbert Bateman (R-VA) to take $105 million of administrative
funding from the Environmental Protection Agency and move it to NASA's
science, aeronautics, and technology account.

Weldon introduced an amendment to move $445 million from HUD's capital
development fund to NASA, fully restoring cuts to human space flight
and mission operations and partially restoring the science,
aeronautics, and technology budget.

However, facing parliamentary points of order from Rep. James Walsh
(R-NY), chair of the House Appropriations subcommittee, and its ranking
minority member, Rep. Alan Mollohan (D-WV), Weldon withdrew the

Most of the debate Thursday afternoon on the bill focused on amendments
relating to non-NASA portions of the bill, notably Veterans Affairs. 
However, two amendments were introduced in an effort to restore or
redistribute funding for NASA.

Reps. Steven LaTourette (R-OH) and Dennis Kucinich (D-OH) introduced an
amendment to transfer $67.9 million from NASA's Human Space Flight
account into its Science, Aeronautics, and Technology account.  The two
introduced the amendment in an effort to secure additional funding for
NASA's Glenn Research Center, located in Ohio. After objections from
Walsh, the amendment was withdrawn.

Rep. Sheila Jackson-Lee (D-TX) later introduced an amendment to add
$924.6 million to NASA's budget -- fully restoring the amount cut by
the Appropriations committee in July.  Walsh raised a point of order
against the amendment, noting that there was no money available to
allocate the extra funds, and Jackson-Lee withdrew the amendment.

Both amendments were proposed more as effort to bring attention to the
significant budget cuts in the NASA budget than as a realistic attempt
to restore the space agency's funding.  LaTourette said he intended his
amendment to "serve as a bookmark" for future reference later in the
budget process.

Jackson-Lee said her amendment was designed to "make the record for the
American people that this [cut] essentially halts the American space

While Walsh blocked both amendments from consideration, he was not
unsympathetic to his fellow representatives' efforts.  "This is a major
concern to the subcommittee as well," he said.  "I will work with you
and others to see that NASA's budget is accommodated in conference," he
added, referring to the conference committee that would hammer out any
differences between the House and Senate versions of the appropriations

The next step in the NASA budget battle will be in the Senate. The
Senate has yet to take up its version of the VA-HUD-independent
agencies appropriations.  A markup by a Senate appropriations
subcommittee of its version of the VA-HUD-independent agencies
appropriations is scheduled for September 15.

Pressure on the budget has been unusually strong this year, despite
predictions of a significant budget surplus, because of spending caps
placed into effect by a 1997 budget agreement. Some members of Congress
called on the caps to be abandoned to keep departments and programs
from fighting against each other for the artificially-scarce funds.

Copyright 1999, SpaceViews


From Mark Bailey <>

Dear Benny,

       Users of CC-Net may like to know that the journal Earth, Moon
and Planets has revised its scope as follows:

"Earth, Moon and Planets", an international journal of solar system
science, publishes original contributions on subjects ranging from star
and planet formation and the origin and evolution of the solar and
extra-solar planetary systems, to asteroids, comets, meteoroids and
Near-Earth Objects, including the terrestrial impact hazard and solar
system -- terrestrial relationships. The journal also publishes relevant
special issues and topical conference proceedings, review articles on
problems of current interest, and book reviews. The Editor welcomes
proposals from guest editors for special thematic issues.

Further details on the journal can be obtained from



From Mark Eby <>


Your group is probably aware of this already but I haven't noticed
anything recently.

New Comet/Asteroid Impact Hazard Book With Disaster Simulation Program
on CD

Just published!

Where to buy it


ISBN: 0124467601
Title: Comet and Asteroid Impact Hazards
Author: John S Lewis
Cover: CaseBound
Published: September 1999
Computer Modeling

John S. Lewis University of Arizona, Tucson

Comet and Asteroid Impact Hazards explores the anticipated consequences
of comet and asteroid impact. It presents the first computer
simulations of the hazards of comet and asteroid bombardment of a
populated Earth. Previous estimates of fatality and damage rates on the
100 to 10,000 year time scale are shown to be too low because they
neglect rare, highly lethal outriders of the populations of bombarding
objects, those with exceptional strength, unusually low entry velocity,
and near-horizontal entry angles. This is the first realistic
assessment of both the mean casualty rate and the expected statistical
fluctuations in that rate. A breakdown of fatality and damage rates by
impactor energy and compositional class suggests lessons for both
asteroid search strategies and interdiction techniques. This book is
written so that anyone with college level experience in the physical
sciences can understand it. It includes a disk that allows the reader
to simulate impact catastrophes. It serves as a useful resource in
various physical sciences courses such as astronomy, planetary science,
and environmental science.


Quantitatively rigorous treatment of the state of impact hazard
prediction, including structural blast damage, firestorm ignition,
tsunami generation.

Realistic treatment of the impact on population, composition,
and orbits.

Attention to economic and public policy issues of warning,
interdiction, and asteroid and comet search strategies.

Comparison of simulation results to historical records

Detailed and realistic Monte Carlo simulation software included


Preface. Introduction. The Impact Flux. The Impactor. The
Impact Process. The Target. Method of Calculation. Results. Hazard
Abatement. Areas Requiring Further Study. Conclusions. References.
Appendix I: Program HAZARDS Owner's Manual. Appendix II:
Program HAZARDS Listing. Appendix III: Program HAZARDS Sample Output.
Subject Index.

Mark Eby


From Andrew Yee <>

Office of News and Public Affairs
University of Wisconsin-Madison


Tracks in iron provide an insightful map of microbial world

Reading the narrow bands of iron found in some sedimentary rocks,
scientists may have found a way to assess microbial populations
across time and space, opening a window to the early history of life
on Earth and possibly other planets.

Writing in the Friday, Sept. 17 issue of the journal Science, a team
of scientists led by UW-Madison geochemist Brian L. Beard describes a
geochemical signature in iron indicative of life. If the technique is
confirmed and refined, it could be used to trace the distribution of
Earth's microorganisms in the distant past, and could help resolve
disputes about the existence of past life on other planets such as

"This could be an ideal biosignature," Beard says in describing a set
of iron isotope-sorting experiments designed to determine if iron
found in different kinds of rocks has been metabolized by

Iron is vital to plant, animal and microbial life. Nearly all
organisms ingest it in the course of daily life. If scientists can
devise a method to distinguish between iron that has been processed
by a living organism and iron that has not been metabolized, they
will have a way to measure the distribution of microbes on Earth
billions of years ago.

Because iron is common on the moon, planets and other objects in
space, the technique could be used to detect signs of past life
beyond our own planet.

Beard's group measured the isotopic composition of iron from two
distinct sources: sedimentary rock and igneous rock. Sedimentary rock
reflects the accumulation of sediments, including organic material
and trace elements such as iron. Igneous rock is forged deep in the
Earth at very high temperatures where life is absent. It also can
contain iron.

Working in collaboration with scientists from NASA's Jet Propulsion
Laboratory and the Institute for Great Lakes Study at UW-Milwaukee,
the Wisconsin team sampled the isotopic composition of iron from the
two sources by incinerating samples of iron and measuring charged
particles from the reaction is a mass spectrometer, a device that
sorts and counts ionized particles.

"Measurable isotopic variations can be seen," says Beard. "The mass
differences are small, but large enough that a microorganism could
have made the difference."

Isotopes from sedimentary rock, says Beard, match the isotopic
signature of iron ingested and metabolized by bacteria in the lab:
"What we found in the biological experiments was that microbes
produce a measurable iron isotope fractionation. We wondered if
inorganic processes might have the same effects, but we found that
the isotopic composition of iron in igneous rocks is constant."

Knowing this, it may now be possible for scientists to look at
sedimentary rock and gain a sense of the worldwide ebb and flow of
microbial populations in the distant past, perhaps as far back as 2
billion years ago, when the Earth's oceans were full of soluble iron.
Such insight may help show how life evolved on Earth.

"Iron has had a dramatic effect on how organisms have evolved," Beard
says. "Microorganisms fight for iron and some have developed a
chemical compound that allows them to grab iron and store it for
future use."

Beard says his group next plans to apply the technique to a piece of
the Mars Rock, a controversial meteorite that some scientists believe
harbors evidence of past microbial life on the Red Planet. It could
also be used to screen samples brought back to Earth from planned
NASA missions to Mars.

Co-authors of the paper published in Science include Clark Johnson, a
professor of geology and geophysics at UW-Madison; Lea Cox, Henry Sun
and Kenneth Nealson of NASA's Jet Propulsion Laboratory in Pasadena,
Calif.; and Carmen Aguilar of the Institute for Great Lakes Study at


From Andrew Yee <>

John Bluck
NASA Ames Research Center Sept. 16, 1999
Moffett Field, CA
650/604-5026 or 604-9000

Marsha Karle and Cheryl Matthews
National Park Service
Yellowstone National Park, WY
307/344-2015 and 344-2010



NASA scientists are planning to use 'mini-monster cams' as a bold new
step in preparation for the search for extraterrestrial life on moons
and planets.

On Sept. 17 – 26, researchers will conduct an experiment at Yellowstone
National Park, WY, in an effort to find tiny multi-cellular organisms
that may be living in the Hot Springs. Conventional wisdom says that
only single-celled life, such as bacteria, could exist in Yellowstone's
boiling waters, according to scientists at NASA's Ames Research Center,
Moffett Field, CA.

"We are hoping to locate multi-cellular organisms living in Hot Springs
at temperatures well above the 150 degrees Fahrenheit that scientists
now believe to be the upper limit at which that kind of life can
exist," said Jonathan Trent, team leader of the Ames Yellowstone

The main tools Principal Investigator Trent and his team will use to
seek "odd" new life forms in the Yellowstone Hot Springs are two
special "baitable" salt shaker-size video cameras built by Deep Sea
Power and Light, Inc., San Diego, CA. The cameras are in a
NASA-designed package including sensors able to detect temperature,
acidity, oxygen and carbon dioxide levels as well as depth below the

"Part of our ability to anticipate what kind of life may exist on other
worlds depends on expanding our knowledge of the ability of Earth life
to adapt to extreme conditions," said Trent, an Ames astrobiologist.
Astrobiology is the study of the origin, evolution, distribution and
destiny of life in the universe.

"As far as we know, nobody has baited video cameras to try to attract
life forms living within the Hot Springs," he said. "We plan to bait
our 'mini-monster cams' with local food, such as insects, algae or
leaves -- things that normally fall into the spring."

Scientists will stretch a rope across each hot spring they investigate,
and then slowly lower the cameras and instruments into the middle of
each pool of hot water. Wires will carry computer signals and TV
pictures to the surface where scientists will record data and images.

In other efforts to prepare to later search for extraterrestrial life
forms, investigators across the world have been looking for living
things that exist under extreme conditions. Those conditions include
extremes of heat and cold. Scientists have found single cell archaea
growing at temperatures as high as 234 degrees Fahrenheit.

"By increasing our knowledge of the physical and chemical limits that
are favorable to life, we'll expand the possibility of predicting where
complex extraterrestrial life forms may exist," Trent said.

"One of Jupiter's moons, Europa, is very cold, but because of the
strong tidal pulls of the huge planet's gravity, there could be a lot
of volcanic activity under kilometers of water ice on that moon," he
said. "The heat may create conditions that are extreme, yet conducive
to some forms of life. These possibilities stimulate the imaginations
of astrobiologists in search of complex extraterrestrial life."

"If we spot multi-celled life forms in the Hot Springs, we want to know
how extreme the conditions are in the immediate vicinity," Trent said.
"Without the sensor array, perhaps we could be fooled by a flow of cold
water if we were to use just the cameras."

Scientists of the Ames Sensors 2000! Project were tasked with
developing a probe housing and electronics capable of surviving the
boiling water, and yet able to detect and transmit data to the
scientists in the field near the Hot Springs.

"The real challenge has been to develop a probe that can survive in
extreme environments of boiling, acidic water," said Fred Martwick, an
Ames Sensors 2000! lead engineer for the Yellowstone project.

Trent will usually be available to meet with media representatives at
the Grant Village Lodge in Yellowstone after 7 p.m. MDT each day of the
expedition. No media representatives will be permitted in the research
area because of safety concerns and possible impact on natural resources.

Yellowstone information is on the Internet at:

General Astrobiology information can be obtained on the Internet at:

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