[meteorite-list] Scientists Blast Rocks To Study Space Bacteria

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:06:17 2004
Message-ID: <200211261816.KAA23442_at_zagami.jpl.nasa.gov>

http://www.abqtrib.com/archives/news02/112502_news_bacteria.shtml

Scientists blast rocks to study space bacteria
By Sue Vorenberg
The Albuquerque Tribune
November 26, 2002

SOCORRO - 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.

Blowing up sandstone is just the first step in Ryan's research. Her next
goal is to shoot a harder rock with an even bigger gun, one that fires
projectiles about three times as fast as the one from her initial tests.

The ultimate goal is to test a variety of rock types and bacteria to see
how well they survive in a variety of situations, Ryan said.

"Mars, of course, is an interesting place where we think bacteria may
have traveled from," Ryan said. "But Europa, a moon of Jupiter that's
covered with ice, is also an interesting test for life developing in the
Solar System. I'd also like to do other impact tests with icy rocks and
see how well the bacteria survive."

Her work will also help scientists understand if bacteria can hitch
rides on comets and asteroids, another hot topic in the space science
community.

In the meantime, she says she's glad her tests so far bode well for the
bacteria - and not just because of the scientific implications of her
work.

"Actually, I feel kind of guilty because I'm taking these nice bacteria
from their comfortable environment and subjecting them to these
impacts and pressure," Ryan said. "It just sounds so cruel. But I'm
happy to see they're alive and doing well, and I hope they do as well
through our future tests."
Received on Tue 26 Nov 2002 01:16:43 PM PST