From: LARRY KLAES (ljk4@msn.com)
Date: Wed Nov 27 2002 - 18:21:16 PST
SCIENTISTS HURL ROCKS TO STUDY SPACE BACTERIA
>From The Daily Camera, 25 November, 2002
http://www2.dailycamera.com/bdc/science/article/0,1713,BDC_2432_1569238,00.html
By SUE VORENBERG
New Mexico Tech wants to see what happens when bacteria fly.
Scientists at the university are testing bacteria-filled rocks to see if the
organisms can survive the extreme pressures and temperatures involved in a
meteor impact on another planet that might send them to Earth. If the
bacteria prove hardy, it might mean that life could be widespread across the
universe.
"People kind of thought of this as crazy science fiction in the past, until
we found this meteorite from Mars and discovered evidence of life in it in
the 1990s," said Eileen Ryan, a research scientist at Tech's Magdalena Ridge
Observatory Project. "Studying these rocks has implications for how we view
ourselves and our place in the universe. It's an exciting idea that we're
not alone."
Meteor impacts, which can create large explosions, often send rocks from a
planet's surface hurtling through the atmosphere into space. If there were
bacteria or other micro-organisms in those rocks, they would be carried
along for the ride, Ryan said.
If the tiny critters can easily withstand the trip - which is what Ryan's
research shows so far - then it's possible that bacteria have hitched rides
on rocks to planets all over the galaxy. And if that's true, there's a good
chance they have evolved into myriad other life forms on some of those
planets, Ryan said.
"It would be much cooler if we found little green men instead of bacteria in
these rocks, but the presence of bacteria has far-reaching implications,"
Ryan said.
Scientists have already learned through experiments that bacteria can
survive quite well in a frozen vacuum, which bodes well for Ryan's theory.
Until recently nobody had tested how well they could survive the initial
impact conditions that would have sent them into space.
To test that, Ryan and students from Tech, New Mexico State University and
Highlands University have been blasting bacteria-filled sandstone rocks from
Arizona - which are similar to rocks that might be on Mars - with a really
big gun.
"What we hope to do is look at impacts and try our best to replicate the
environment, including the stress, pressure and temperatures of a
collisional event," Ryan said.
To see just how hardy the tiny critters are, Ryan and her students tested
how much bacteria was inside the rock before the experiment. Then they
placed the rock in a 9-foot-by-5-foot chamber that looks a bit like a small
submarine and fired a hunk of metal at it.
The projectile was shot from a 6-foot-long gun at about 60 miles a second.
At that speed, one could travel from Albuquerque to Santa Fe in less than a
minute.
"Even using the gun is pretty dangerous - we all have to clear the area and
go to a concrete bunker when it's fired," she said. "When the projectile
hits the rock it creates dramatic pressure and temperature inside, similar
to that of an impact."
After the rock explodes, Ryan and her students take samples of the fragments
and test how much bacteria has survived.
"The happy end to the story is that in our tests so far they all survived,"
Ryan said. "They're alive and doing fine."
Ryan's work is sponsored through a $1.5 million, three-year grant from the
National Air and Space Administration's Johnson Space Center. Her studies
will build on work done by David McKay, director of astrobiology at the
center, who made the initial discovery in the late 1990s of evidence of life
inside a Martian meteorite.
Ryan's work will also help scientists understand if bacteria can hitch rides
on comets and asteroids, another hot topic in the space science community.
Copyright 2002, The Daily Camera and the E.W. Scripps Company
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* LETTERS TO THE MODERATOR *
============================
(5) WHY IS EVERYONE FORGETTING THE IMPACT OF COMETS?, OR, REALLY BIG NEWS:
COMET SHOEMAKER-LEVY 9 HITS JUPITER
>From E.P. Grondine <epgrondine@hotmail.com>
Hello Benny -
It is quite remarkable to note that in the recent coverage of the
Brown/Worden/ReVelle/Tagliafero study nearly all science writers
conveniently forgot about the impact of comets as a part of the total impact
hazard. This is all the more remarkable when one considers that presumably
most of those science writers were around eight years ago when the fragments
of Comet Shoemaker Levy 9 impacted Jupiter between July 16-22, 1994, and
thus witnessed cometary impact with their own eyes.
Why did this lapse in memory occur? Was it simply that the science writers
were lazy, and thus simply re-wrote the press release which was handed to
them? I don't think so...
This failure to take into account the cometary impact hazard, even though it
has been personally observed, is also reflected in both Ed Weiler and David
Morrison's testimony before the Congress, as well as the Representatives
re-action to it. The cometary impact impact hazard was not
mentioned for over 2 hours, until Brian Marsden insisted on bringing it to
the Subcommittee's attention before the hearing closed. The Representatives
literally stopped in their tracks at Marden's comment; since the
Representatives had earlier requested NASA to report on both asteroids and
comets, apparently their own memories of Comet Shoemaker Levy hitting
Jupiter had failed them as well...
It is also interesting to note in this regard that some of the assumptions
made about comet impact hazard and reported as fact are simply nonsense. For
example, it is often reported
that an asteroid impact killed the dinosaurs, when the Pacific seabed sample
is now known to be a carbonaceous chondrite likely of cometary origin. Also
peculiarly, while there have been many pieces written about a "Nemesis"
gravitational body which no one can find, Clube and Napier's hypothesis on
the 26 million year periodicity of extinctions and the tie to comet influx
is simply generally unknown and unreport. Simultaneously, the role of comet
impact in the bulk of recent small impact events ( for a summary of these
see
http://abob.libs.uga.edu/bobk/ccc/ce091702.html) is also generally unknown.
Perhaps these two facts are related, and have some common cause.
Fallacies abound. It is asserted without any supporting evidence that any
long period comet will be massive enough to be detected quite early, while
by actually looking at the historic impact record such as it is (above) it
appears that comets may come in all sizes. It is also sometimes asserted,
again without evidence, that impacting comets would be impossible to
distinguish from the Oort Cloud, when in point of fact those on Earth
approach could be detected by a system such as Dr. Mazanek's COMET and
Asteroid Protection System (CAPS).
Since Earth impacting comets can both be detected and stopped from
impacting, if appropriate funds are spent, why is there this widespread
inability to remember, this failure of
memory on so massive a scale? Is it simply the scale of the event? Is
Jupiter too remote? I open the floor for discussion.
For Conference participants, while the new study will be of great use in
getting a better grasp on the asteroid impact threat, it is well known to
all here that the flux of comets is not constant over time. It will be
interesting to see how the authors of the study factored out the impacts of
carbonaceous chondrites (presumably dead comets) from the impacts of comets
from the outer solar system.
Best wishes,
Ed
=================
(6) AND FINALLY: "ASTEROID DANGER DISCOUNTED"
>From The Washington Post, 25 November 2002
http://www.washingtonpost.com/wp-dyn/articles/A28459-2002Nov22.html
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