[meteorite-list] NASA Rover Finds Conditions Once Suited for Ancient Life on Mars

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Tue, 12 Mar 2013 11:17:32 -0700 (PDT)
Message-ID: <201303121817.r2CIHWFN027480_at_zagami.jpl.nasa.gov>

March 12, 2013

Dwayne Brown
Headquarters, Washington
202-358-1726
dwayne.c.brown at nasa.gov

D.C. Agle
Jet Propulsion Laboratory, Pasadena, Calif.
818-393-9011
agle at jpl.nasa.gov

RELEASE: 13-073

NASA ROVER FINDS CONDITIONS ONCE SUITED FOR ANCIENT LIFE ON MARS

WASHINGTON -- An analysis of a rock sample collected by NASA's
Curiosity rover shows ancient Mars could have supported living
microbes.

Scientists identified sulfur, nitrogen, hydrogen, oxygen, phosphorus
and carbon -- some of the key chemical ingredients for life -- in the
powder Curiosity drilled out of a sedimentary rock near an ancient
stream bed in Gale Crater on the Red Planet last month.

"A fundamental question for this mission is whether Mars could have
supported a habitable environment," said Michael Meyer, lead
scientist for NASA's Mars Exploration Program at the agency's
headquarters in Washington. "From what we know now, the answer is
yes."

Clues to this habitable environment come from data returned by the
rover's Sample Analysis at Mars (SAM) and Chemistry and Mineralogy
(CheMin) instruments. The data indicate the Yellowknife Bay area the
rover is exploring was the end of an ancient river system or an
intermittently wet lake bed that could have provided chemical energy
and other favorable conditions for microbes. The rock is made up of a
fine grain mudstone containing clay minerals, sulfate minerals and
other chemicals. This ancient wet environment, unlike some others on
Mars, was not harshly oxidizing, acidic, or extremely salty.

The patch of bedrock where Curiosity drilled for its first sample lies
in an ancient network of stream channels descending from the rim of
Gale Crater. The bedrock also is fine-grained mudstone and shows
evidence of multiple periods of wet conditions, including nodules and
veins.

Curiosity's drill collected the sample at a site just a few hundred
yards away from where the rover earlier found an ancient streambed in
September 2012.

"Clay minerals make up at least 20 percent of the composition of this
sample," said David Blake, principal investigator for the CheMin
instrument at NASA's Ames Research Center in Moffett Field, Calif.

These clay minerals are a product of the reaction of relatively fresh
water with igneous minerals, such as olivine, also present in the
sediment. The reaction could have taken place within the sedimentary
deposit, during transport of the sediment, or in the source region of
the sediment. The presence of calcium sulfate along with the clay
suggests the soil is neutral or mildly alkaline.

Scientists were surprised to find a mixture of oxidized,
less-oxidized, and even non-oxidized chemicals providing an energy
gradient of the sort many microbes on Earth exploit to live. This
partial oxidation was first hinted at when the drill cuttings were
revealed to be gray rather than red.

"The range of chemical ingredients we have identified in the sample is
impressive, and it suggests pairings such as sulfates and sulfides
that indicate a possible chemical energy source for micro-organisms,"
said Paul Mahaffy, principal investigator of the SAM suite of
instruments at NASA's Goddard Space Flight Center in Greenbelt, Md.

An additional drilled sample will be used to help confirm these
results for several of the trace gases analyzed by the SAM
instrument.

"We have characterized a very ancient, but strangely new 'gray Mars'
where conditions once were favorable for life," said John Grotzinger,
Mars Science Laboratory project scientist at the California Institute
of Technology in Pasadena, Calif. "Curiosity is on a mission of
discovery and exploration, and as a team we feel there are many more
exciting discoveries ahead of us in the months and years to come."

Scientists plan to work with Curiosity in the Yellowknife Bay area for
many more weeks before beginning a long drive to Gale Crater's
central mound, Mount Sharp. Investigating the stack of layers exposed
on Mount Sharp, where clay minerals and sulfate minerals have been
identified from orbit, may add information about the duration and
diversity of habitable conditions.

NASA's Mars Science Laboratory Project has been using Curiosity to
investigate whether an area within Mars' Gale Crater ever has offered
an environment favorable for microbial life. Curiosity, carrying 10
science instruments, landed seven months ago to begin its two-year
prime mission. NASA's Jet Propulsion Laboratory in Pasadena, Calif.,
manages the project for NASA's Science Mission Directorate in
Washington.

For more about the mission, visit:

http://www.nasa.gov/msl

You can follow the mission on Facebook and Twitter at:

http://www.facebook.com/marscuriosity

and

http://www.twitter.com/marscuriosity

-end-
Received on Tue 12 Mar 2013 02:17:32 PM PDT