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(meteorobs) Excerpts from "CCNet 53/2001 - 5 April 2001"




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From: Peiser Benny <B.J.Peiser@livjm.acdot uk>
To: cambridge-conference <cambridge-conference@livjm.acdot uk>
Subject: CCNet, 5 April 2001
Date: Thu, 5 Apr 2001 10:38:44 +0100 

CCNet 53/2001 - 5 April 2001
----------------------------

 
[sic] "Duncan Steel, a physicist at Salford University, believes that he
has found a way for these chemicals to reach the Earth safely. As comets
approach the Sun, they spawn vast amounts of dust and meteoroids.
Astronomers usually assume that these meteoroids, which burn up as
shooting stars or meteors in the atmosphere, are made of rock or metal. With
Christopher McKay of the Nasa-Ames Research Centre in California, Mr Steel
has shown that 	many may contain heavy organic compounds similar to tar.
They would burn up at a lower temperature and a far higher altitude than
lumps of rock or metal, releasing organic chemicals into the atmosphere,
and they would take decades to float down to the surface and into oceans."
		--David Derbyshire, The Daily Telegraph, 5 April 2001

"To me the most striking aspect about all this work presented here
is how little we still know about the distribution and composition of
organic molecules in outer space. The scientific community has really just
barely scratched surface. There are going to be many compounds identified
in next few years that should give us better insights. It's really the new
frontier."
		--Peggy O'Day, Arizona State University, 5 April 2001



(1) METEORITE 'SEEDS' CLUE TO ORIGINS OF LIFE ON EARTH
    The Daily Telegraph, 5 April 2001

(2) LIFE COULD HAVE COME FROM SPACE
    United Press International, 5 April 2001 

[...]

(5) BAAMS MEETING NOTICE
    Neil Bone <bafb4@central.susx.acdot uk>

[...]

(7) EM EFFECTS CAUSED BY IMPACTS OF LARGE METEOROIDS
    S. Fred Singer <singer@sepp.org>

[...]

========================================================================

(1) METEORITE 'SEEDS' CLUE TO ORIGINS OF LIFE ON EARTH

>From The Daily Telegraph, 5 April 2001
http://www.telegraph.codot uk/et?ac=004712090541739&rtmo=VkFF51Vx&atmo=rrrrrrrq
&pg=/et/01/4/5/wcom05.html

By David Derbyshire, Science Correspondent
 
SMALL tarry meteorites from comets "seeded" the Earth with the building
blocks of life billions of years ago, according to a new study.
 
Meteorites may have brought the building blocks of life to Earth 

British researchers working with Nasa say they have evidence that organic
chemicals from space rained upon the lifeless Earth, providing the
ingredients for the first simple organisms. Many scientists think that
comets began to deposit water and carbon molecules on the Earth four billion
years ago. 

Comets are made mostly of ice and are relatively rich sources of organic
chemicals. Water can survive a fiery descent into the Earth's atmosphere and
explosive impact with the surface, but organic chemicals are far more
fragile.

Duncan Steel, a physicist at Salford University, believes that he has found
a way for these chemicals to reach the Earth safely. As comets approach the
Sun, they spawn vast amounts of dust and meteoroids. 

Astronomers usually assume that these meteoroids, which burn up as shooting
stars or meteors in the atmosphere, are made of rock or metal. With
Christopher McKay of the Nasa-Ames Research Centre in California, Mr Steel
has shown that many may contain heavy organic compounds similar to tar. 

Mr Steel, who presented his findings at the National Astronomical Meeting in
Cambridge yesterday, said these tarry lumps would survive being heated by
the Sun as they floated through the inner solar system. 

They would burn up at a lower temperature and a far higher altitude than
lumps of rock or metal, releasing organic chemicals into the atmosphere, and
they would take decades to float down to the surface and into oceans.

Using radar he has shown that tarry meteoroids are continually entering the
atmosphere. He said: "These organic chemicals have been raining down on the
atmosphere for billions of years. Each year the Earth accumulates 40,000
tons of material from space."

All the essential amino acids needed for life have been identified in
meteorites, he said. If comets and meteorites played a role in life on
Earth, then it raises the prospect that life could be fairly common
throughout the universe.

Copyright 2001, The Daily Telegraph
 
========================================================================

(2) LIFE COULD HAVE COME FROM SPACE

>From United Press International, 5 April 2001 
http://www.vny.com/cf/News/upidetail.cfm?QID=174432

Scientists: Life could have come from space
By KELLY HEARN, UPI Technology Writer

SAN DIEGO, April 5 (UPI) -- Leading astrophysicists and chemists presented
research, to varying degrees, bolsters the theory that life came to Earth
from outside the solar system.  They presented their findings Wednesday at
the annual meeting of the American Chemical Society in San Diego.

"In our mind there is a line, however direct, connecting molecules in the
interstellar medium 4 or 5 billion years ago and the delivery of organic
compounds from space," said Max P. Bernstein of the astrochemistry group at
SETI International in Moffet Field, Calif. "The theory helps to alleviate
the difficulty of making organic compounds on Earth."

SETI or the Search for Extra Terrestrial Intelligences a non-profit
corporation of researchers who study forms of life in the universe.

The so-called exogenous delivery theory challenges an earlier one that
lighting caused a primordial soup of gases in the Earth's earliest
atmosphere to form amino acids and other compounds that evolved into higher
life.

Two scientists at the University of Chicago -- Stanley L. Miller and Harold
C. Urey -- birthed that theory in the 1950s when they ran an electric
current through a mixture of gases believed to have been present in
prebiotic Earth. The current simulated lighting and caused parts of the
mixture to form amino acids, which build proteins and are the basis of life.

Today researchers focus on determining the amount of space-born chemicals
formed 4 to 5 billion years ago, how they changed during volatile journey to
Earth and what they did once they arrived.

"Studies show that organic chemistry in the universe has mostly formed in
dense clouds and then later become incorporated into the formation of
planetary systems, comets and asteroids," said Jean E. Chiar of NASA Ames
Research Center in Moffett Field, Calif.

She uses infrared detectors to see fluxes in infrared waves caused by dust
between the Earth and the waves' source in space. Organic compounds absorb
infrared energy, causing such fluxes.

Dr. Pascale Ehrenfreund of the Leiden Observatory in the Netherlands
reported that she had subjected amino acids to ultraviolet photolysis
(decomposition by radiant energy) in the laboratory and found they hold up
poorly, decreasing the chance they could survive some areas in space with
high levels of ultraviolet rays.

But Ehrenfreund has noted in a written summary of her work that amino acids
could form in a number of ways, including chemical alterations in certain
meteorites, photochemical reactions in dust grains and gas reactions in
interstellar clouds.

Vladimir Basiuk of the National Autonomous University of Mexico in Mexico
City presented evidence countering claims that the white-hot entry into the
Earth's atmosphere would have kill most organic compounds hitching a ride
with meteorites.

In laboratory experiments, Basiuk subjected a range of compounds to
temperatures up to 1000 degrees Celsius and found that even at 500 to 600
degrees Celsius some survive.

"This strongly favors the hypothesis that extraterrestrial delivery could
have been an efficient way of supplying simple biomolecules to the primitive
Earth in amounts sufficient for the emergence of life," he wrote in a
summary of his work.

Extending those findings, a researcher from the University of Tokyo, Dr.
Seiji Sugita, reported experiments showing that just-arrived carbon embedded
in a meteorite undergoes chemical reactions with the Earth's ambient
atmosphere, creating sizable amounts of organic material from which life
could evolve.

"To me the most striking aspect about all this work presented here is how
little we still know about the distribution and composition of organic
molecules in outer space," Peggy O'Day, professor of geological sciences at
Arizona State in Tempe, Ariz. told United Press International. "The
scientific community has really just barely scratched surface. There are
going to many compounds identified in next few years that should give us
better insights. It's really the new frontier."

Copyright 2001 by United Press International.
All rights reserved.

========================================================================

(5) BAAMS MEETING NOTICE

>From Neil Bone <bafb4@central.susx.acdot uk>

Further to advice from BAA Head Ofice, the notice for the meeting on
Saturday should now read as follows:

BAA Meteor Section Meeting Saturday 2001 April 7

John Stripe Lecture Theatre, King Alfred's College, Winchester 1415-1730

The meeting is being held as an integral part of the BAA's Winchester
residential weekend, but is, of course, open to day-visitors. Participants
arriving on the day should register at the BAA desk at the lecture theatre
(for administrative purposes only!); there is a #5 charge for admission, to
cover hall-hire costs and tea. Those requiring meals and/or accommodation
should do so via the BAA Office: Tel. 020 7734 4145.

The meeting will offer the chance to review the recent strong Leonid
returns, and also look ahead to some interesting activity which we can hope
to observe under relatively moonless conditions in the year ahead As the
first meeting of the Section in the south of England for some time, we hope
that this event will be attended by a few new faces, too.

Programme as at 2001 April 4:

1415: Welcome/opening remarks.
1420-1450: The 1999 Leonids from Sinai - Nigel Evans
1450-1500: A brief VS diversion - Roger Pickard
1500-1530: Video Observations of Meteors - Andrew Elliott

TEA 1530-1600

1600-1610: Video of the 2000 Leonids from Andalucia - Steve Evans
1610-1640: Analysis of the 2000 Leonids - Dr John Mason
1640-1710: Radio Observations of Meteors - Nick Quinn
1710-Close: Prospects for the coming year - Neil Bone

Neil Bone, Director, BAA Meteor Section, 'The Harepath', Mile End Lane,
Apuldram, Chichester, PO20 7DZ. Tel. (01243) 782679
Home e-mail: neil@bone2.freeserve.codot uk

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