[meteorite-list] Texas State Research Sheds New Light on Panspermia
From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue Feb 21 16:27:08 2006
Texas State research sheds new light on panspermia
By Jayme Blaschke
Texas State University-San Marcos
February 21, 2006
When the space shuttle Columbia broke apart during reentry Feb. 1, 2003,
more than 80 on-board science experiments were lost in the fiery descent.
Texas State University-San Marcos biologist Robert McLean, however, has
salvaged some unexpected science from the wreckage. A strain of
slow-growing bacteria survived the crash, a discovery which may have
significant implications for the concept of panspermia. The findings
will be published in the May 2006 issue of Icarus, the international
journal of solar system studies.
Panspermia is the idea that life--hitchhiking on rocks ejected from
meteorite impacts on one world--could travel through space and seed
other worlds with life under favorable conditions. Because the
conditions under which panspermia could function are so harsh, however,
there's been little direct testing of the hypothesis.
"That might have been in the back of my mind when we recovered our
payload," McLean said. McLean, along with a team of Texas State
researchers, had placed an experiment package aboard the Columbia to
investigate the interactions of three different bacterial species in
microgravity. When the shuttle broke up over Texas, they assumed the
experiment lost--until it turned up, relatively intact, in the parking
lot of a Nacogdoches convenience store. "My first thinking when we found
our payload was, 'Let's look for survivors.'"
And survivors he found--a bacteria called Microbispora. Ironically,
Microbispora wasn't one of the three species McLean expected to find.
The slow-growing organism is normally found in the soil, and McLean
determined that it had contaminated the experiment prior to launch. With
the Icarus publication, McLean anticipates request for samples of this
rugged strain to come in from researchers around the world.
"This organism appears to have survived an atmospheric passage, with the
heat and the force of impact," he said. "That's only about a fifth of
the speed that something on a real meteorite would have to survive, but
it is at least five or six times faster than what's been tested before.
"This is important for panspermia, because if something survives space
travel, it eventually has to get down to the Earth and survive passage
through the atmosphere and impact. This doesn't prove anything--it just
contributes evidence to the plausibility of panspermia. Realistically,
that's all it can do," McLean said. "Out of respect for the seven people
who gave their lives for this research, I feel it's very important these
results don't get lost."
Received on Tue 21 Feb 2006 04:25:07 PM PST