[meteorite-list] Notre Dame Geologist Lends Skill in Mars Probe

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:32:46 2004
Message-ID: <200403051641.IAA06726_at_zagami.jpl.nasa.gov>

http://www.southbendtribune.com/stories/2004/03/05/local.20040305-sbt-MARS-A1-ND_geologist_lends_s.sto

ND geologist lends skill in Mars probe

NASA asks scientists to develop ways to study rocks for signs of past life.

By DAVID RUMBACH
South Bend Tribune (Indiana)
March 5, 2004

SOUTH BEND -- University of Notre Dame scientist Clive Neal hopes to join the
search for life on Mars -- without ever leaving the Midwest.

Neal said the way to follow up on a recent discovery by the rover Opportunity
is to scrutinize some Earth rocks similar to those the robotic laboratory
found on Mars.

NASA officials announced Tuesday that data sent back from Opportunity confirmed
that the environment where it had landed was once watery and conducive to life.

Neal said the next step is to search for rocks on Earth that are chemically
similar to those analyzed by the rover's sophisticated scientific instruments.

The telltale Mars rocks contain various sulfur salts that, on Earth at least,
are always the product of evaporation.

"We have evaporate deposits like this in Michigan,'' Neal said, indicating
that candidate Earth rocks might be found nearby. "They used to mine it.''

Opportunity and its robot twin, Spirit, are never coming back, and their
instruments cannot conclusively test for evidence of past life.

Those tests will have to wait for a future NASA mission in which a robot is
to scoop up some Martian soil and return it to Earth, Neal said.

That mission is scheduled for completion in 2013.

Between now and then, NASA is asking scientists at universities on Earth to
begin developing ways of studying Mars rocks to look for signs of past
microbial life.

Neal said he hopes to do some of that work at Notre Dame, possibly in
conjunction with planetary scientists from other universities.

"We will start this in earnest this summer,'' he said.

The first step will be to find "analogs,'' that is, rocks from Earth that
are just like those that will be brought back from Mars nine years from
now. They may be as close as Michigan.

The most straight-forward evidence of past life would be for scientists to
find fossils of bacteria in the Mars rocks. But they may not be that lucky,
or they may not be able to recognize the shapes of bacteria that evolved
on Mars.

The next best thing would be to find indirect evidence of bacterial activity,
Neal said, sort of like detectives finding forensic evidence at a crime scene.

One possible avenue for indirect evidence stems from the fact that bacteria
are known to metabolize sulfur compounds in a way that, even eons later,
leaves a characteristic pattern of isotopes (variations of elemental
atoms).

Neal, an associate professor of civil engineering and geological sciences,
said he has been studying a meteorite that originated in the interior of Mars.
That study was aimed at learning how the planet was formed.

But now he's planning to put aside that line of research and focus on the hot
topic: looking for signs of past life on the surface.
Received on Fri 05 Mar 2004 11:41:02 AM PST