[meteorite-list] University of Alabama Scientist Searches For Life on Mars - Microbes May Eat Iron

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu Apr 22 10:31:58 2004
Message-ID: <200401052240.OAA22719_at_zagami.jpl.nasa.gov>

http://www.al.com/news/birminghamnews/index.ssf?/base/news/107329771346791.xml

UA scientist searches for life on Mars

Microbes may eat iron, may use it to breath

KENT FAULK
The Birmingham News
January 5, 2004

Life on Mars, if it exists, could have iron constitutions.

Crawling beneath the rust-colored Martian soil could be tiny microbes that
feed off iron. Other microbes could use iron to breathe.

University of Alabama researcher Eric Roden believes such odd life forms could
or could have once existed on Mars. Such microbes exist in many earthly places,
including Alabama.

"It's well-known that organisms that use iron to gain energy for life are present in
many different kinds of geologic environments on Earth," Roden said.

He has gotten nearly $500,000 from NASA to study these tiny microbes over
the next five years as part of the BioMars project.

The University of California at Berkeley-led project is identifying sites
on Mars where water - and life - may be or may have once been. Then, researchers
will look at places on Earth with similar environments to determine under what
conditions creatures could exist there.

"There's very little reason to expect there are now or ever were plants or
animals," on Mars, Roden said. "We're talking about microbial life."

If such microbial life does exist, it'll have to be just below the surface,
Roden said. The planet doesn't have an atmosphere like Earth's that can protect
it from constant zaps by dangerous doses of ultraviolet radiation, he said.

To survive, life would need to have water, Roden said. The planet - where
temperatures average 81 degrees below zero - does have ice, and from time to
time it could melt and turn into water just below the surface.

As for food, Roden believes some microbes could be feeding off Mars' abundance
of iron. This kind of microbe takes reduced iron, which is in a form that contains
electrons that may serve as a source of energy, from rocks like basalt, he said.

Oxidized iron is what gives Mars its rust-colored appearance.

Mars' atmosphere is made up of about .2 percent oxygen - about 100 times less
than that of Earth but still probably enough to sustain tiny iron-eating microbes,
Roden said.

But there's another kind of microbe Roden is looking at - one that breathes
oxidized iron and eats hydrogen. Mars does have some hydrogen in its atmosphere
and there could be hydrogen coming from fissures in the planet's surface.

Iron-breathing and iron-eating microbes can be found in all kinds of geologic
systems on Earth, Roden said.

One of the best places to find iron-eating microbes is in the acid drainage that
comes from coal mines, he said. There's also evidence they feed off the iron
from basalt rock found near the volcanic vents in the sea floor on Earth, Roden said.

Iron-breathing microbes exist in all kinds of environments, such as deep within
the iron rich soils of Alabama where no oxygen is available.

For more than a decade, Roden has been studying iron, the microbes that use it to
sustain life, and the role it might one-day play in cleaning up pollutants. He's
studied iron-breathing and iron-eating microbes found in swamps of the Talladega
National Forest.

He's worked on U.S. Department of Energy funded projects to look at the potential
for iron-breathing microbes to control waste such as uranium and cobalt from
nuclear weapons manufacturing sites. The iron-breathing microbes could keep the
waste from migrating farther in the subsurface soils and getting into underground
water supplies.

The hopes that iron-eating and -breathing microbes could be or could have at one
time been at work on Mars were bolstered during the late 1990s when it was reported
that a meteorite found on Earth had minerals that could have been produced by
mineral-breathing microbes.

Roden and undergraduate student Ryan St. John will hike into areas around Abert
Lake in Oregon later this year on the first trip out west to get samples from
formations similar to those found on Mars. A mountainous rim with basalt rock
surrounds the closed-in lake, Roden said.

Samples from rocks and water from their trips will be brought back for analysis
to see whether such iron-eating and -breathing microbes are living, or can live,
in such conditions, Roden said.

Roden and other researchers working on BioMars projects won't be playing a role
in the missions of the Spirit and Opportunity rovers, the first of which landed
on the red planet this weekend.

But the hope is one day the BioMars research will help NASA guide robots - and
maybe even one day astronauts - to the most likely places to find life on Mars,
Roden said.

Among the other thrusts of BioMars are public education and training a new
generation of astrobiologists who can understand a broad range of subjects they'll
need to look at environments on other planets.

"It may be the next generation that might be able to determine whether there is -
or was - life on Mars," Roden said.
Received on Mon 05 Jan 2004 05:40:23 PM PST