[meteorite-list] NASA Researchers Claim Evidence of Present Life on Mars

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Wed Feb 16 14:50:12 2005
Message-ID: <200502161949.j1GJnvR08319_at_zagami.jpl.nasa.gov>

http://www.space.com/scienceastronomy/mars_life_050216.html

NASA Researchers Claim Evidence of Present Life on Mars
By Brian Berger
Space News
16 February 2005

WASHINGTON -- A pair of NASA scientists told a group of space officials
at a private meeting here Sunday that they have found strong evidence
that life may exist today on Mars, hidden away in caves and sustained by
pockets of water.

The scientists, Carol Stoker and Larry Lemke of NASA's Ames Research
Center in Silicon Valley, told the group that they have submitted their
findings to the journal Nature for publication in May, and their paper
currently is being peer reviewed.

What Stoker and Lemke have found, according to several attendees of the
private meeting, is not direct proof of life on Mars, but methane
signatures and other signs of possible biological activity remarkably
similar to those recently discovered in caves here on Earth.

Stoker and other researchers have long theorized that the Martian
subsurface could harbor biological organisms that have developed unusual
strategies for existing in extreme environments. That suspicion led
Stoker and a team of U.S. and Spanish researchers in 2003 to
southwestern Spain to search for subsurface life near the
Rio Tinto river - so-called because of its reddish tint - the product of
iron being dissolved in its highly acidic water.

Stoker did not respond to messages left Tuesday on her voice mail at Ames.

Stoker told SPACE.com in 2003, weeks before
leading the expedition to southwestern Spain, that by studying the very
acidic Rio Tinto, she and other scientists hoped to characterize the
potential for a "chemical bioreactor" in the subsurface - an underground
microbial ecosystem of sorts that might well control the chemistry of
the surface environment.

Making such a discovery at Rio Tinto, Stoker said in 2003, would mean
uncovering a new, previously uncharacterized metabolic strategy for
living in the subsurface. "For that reason, the search for life in the
Rio Tinto is a good analog for searching for life on Mars," she said.

Stoker told her private audience Sunday evening that by comparing
discoveries made at Rio Tinto with data collected by ground-based
telescopes and orbiting spacecraft, including the European Space
Agency's Mars Express, she and Lemke have made a very a strong case that
life exists below Mars' surface.

The two scientists, according to sources at the Sunday meeting, based
their case in part on Mars' fluctuating methane signatures that
could be a sign of an active underground biosphere and nearby surface
concentrations of the sulfate jarosite, a mineral salt found on Earth in
hot springs and other acidic bodies of water like Rio Tinto that have
been found to harbor life despite their inhospitable environments.

One of NASA's Mars Exploration Rovers, Opportunity, bolstered the case
for water on Mars when it discovered jarosite and other mineral salts on
a rocky outcropping in Merdiani Planum, the intrepid rover's landing
site chosen because scientists believe the area was once covered by
salty sea.

Stoker and Lemke's research could lead the search for Martian biology
underground, where standing water would help account the curious methane
signatures the two have been analyzing.

"They are desperate to find out what could be producing the methane,"
one attendee told Space News. "Their answer is drill, drill, drill."

NASA has no firm plans for sending a drill-equipped lander to Mars, but
the agency is planning to launch a powerful new rover in 2009 that could
help shed additional light on Stoker and Lemke's intriguing findings.
Dubbed the Mars Science Laboratory, the nuclear-powered rover will range
farther than any of its predecessors and will be carrying an advanced
mass spectrometer to sniff out methane with greater sensitivity than any
instrument flown to date.

In 1996 a team of NASA and Stanford University researchers created a
stir when they published findings that meteorites recovered from the
Allen Hills region of Antarctica contained evidence of possible past
life on Mars. Those findings remain controversial, with many researchers
unconvinced that those meteorites held even possible evidence that very
primitive microbial life had once existed on Mars.
Received on Wed 16 Feb 2005 02:49:57 PM PST