Exclusive: NASA Researchers Claim Evidence of Present
Life on Mars
By Brian Berger - Space News Staff Writer - 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 for
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.
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