[meteorite-list] Study: Martian soil may contain life

From: Mike Groetz <mpg444_at_meteoritecentral.com>
Date: Thu, 23 Aug 2007 17:11:00 -0700 (PDT)
Message-ID: <999448.31258.qm_at_web32910.mail.mud.yahoo.com>

http://www.cnn.com/2007/TECH/space/08/23/mars.soil.life.reut/index.html

Study: Martian soil may contain life
Story Highlights
Signs of weird life on Martian surface, scientist
suggests

Mars may contain microbes made of hydrogen peroxide
and water

Data studied was originally collected in 1976 by
Viking landers

LONDON, England (Reuters) -- The soil on Mars may
contain microbial life, according to a new
interpretation of data first collected more than 30
years ago.

The search for life on Mars appeared to hit a dead end
in 1976 when Viking landers touched down on the red
planet and failed to detect biological activity.

But Joop Houtkooper of the University of Giessen,
Germany, said on Friday the spacecraft may in fact
have found signs of a weird life form based on
hydrogen peroxide on the subfreezing, arid Martian
surface.

His analysis of one of the experiments carried out by
the Viking spacecraft suggests that 0.1 percent of the
Martian soil could be of biological origin.

That is roughly comparable to biomass levels found in
some Antarctic permafrost, home to a range of hardy
bacteria and lichen.

"It is interesting because one part per thousand is
not a small amount," Houtkooper said in a telephone
interview.

"We will have to find confirmatory evidence and see
what kind of microbes these are and whether they are
related to terrestrial microbes. It is a possibility
that life has been transported from Earth to Mars or
vice versa a long time ago."

Speculation about such interplanetary seeding was
fueled a decade ago when researchers said an ancient
meteorite found in Antarctica contained evidence of
fossil life on Mars. Doubt has since been cast on that
finding.

Houtkooper is presenting his research to the European
Planetary Science Congress in Potsdam, Germany.

While most scientists think our next-door neighbor in
the solar system is lifeless, the discovery of
microbes on Earth that can exist in environments
previously thought too hostile has fueled debate over
extraterrestrial life.

Houtkooper believes Mars could be home to just such
"extremophiles" -- in this case, microbes whose cells
are filled with a mixture of hydrogen peroxide and
water, providing them with natural anti-freeze.

They would be quite capable of surviving a harsh
Martian climate where temperatures rarely rise above
freezing and can fall to minus 150 degrees Celsius.

Houtkooper believes their presence would account for
unexplained rises in oxygen and carbon dioxide when
NASA's Viking landers incubated Martian soil. He bases
his calculation of the biomass of Martian soil on the
assumption that these gases were produced during the
breakdown of organic material.

Scientists hope to gather further evidence on whether
or not Mars ever supported life when NASA's
next-generation robotic spacecraft, the Phoenix Mars
Lander, reaches the planet in May 2008 and probes the
soil near its northern pole.




       
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Received on Thu 23 Aug 2007 08:11:00 PM PDT