[meteorite-list] NASA Funded Research Shows Existence Of Reduced Carbon On Mars

From: Ron Baalke <baalke_at_meteoritecentral.com>
Date: Thu, 24 May 2012 14:06:35 -0700 (PDT)
Message-ID: <201205242106.q4OL6ZoA021085_at_zagami.jpl.nasa.gov>

May 24, 2012

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

Natasha Metzler
Carnegie Institution of Washington
202-939-1142
nmetzler at carnegiescience.edu


RELEASE: 12-171

NASA FUNDED RESEARCH SHOWS EXISTENCE OF REDUCED CARBON ON MARS

WASHINGTON -- NASA-funded research on Mars meteorites that landed on
Earth shows strong evidence that very large molecules containing
carbon, which is a key ingredient for the building blocks of life,
can originate on the Red Planet. These macromolecules are not of
biological origin, but they are indicators that complex carbon
chemistry has taken place on Mars.

Researchers from the Carnegie Institution for Science in Washington
who found reduced carbon molecules now have better insight into the
chemical processes taking place on Mars. Reduced carbon is carbon
that is bonded to hydrogen or itself. Their findings also may assist
in future quests for evidence of life on the Red Planet. The findings
are published in Thursday's online edition of Science Express.

"These findings show that the storage of reduced carbon molecules on
Mars occurred throughout the planet's history and might have been
similar to processes that occurred on the ancient Earth," said Andrew
Steele, lead author of the paper and researcher from Carnegie.
"Understanding the genesis of these non-biological, carbon-containing
macromolecules on Mars is crucial for developing future missions to
detect evidence of life on our neighboring planet."

Finding molecules containing large chains of carbon and hydrogen has
been one objective of past and present Mars missions. Such molecules
have been found previously in Mars meteorites, but scientists have
disagreed about how the carbon in them was formed and whether it came
from Mars. This new information proves Mars can produce organic
carbon.

"Although this study has not yielded evidence that Mars has or once
may have supported life, it does address some important questions
about the sources of organic carbon on Mars," said Mary Voytek,
director of NASA's Astrobiology Program at the agency's Headquarters
in Washington. "With the Curiosity rover scheduled to land in August,
these new research results may help Mars Science Laboratory
scientists fine-tune their investigations on the surface of the
planet by understanding where organic carbon may be found and how it
is preserved."

Scientists have theorized that the large carbon macromolecules
detected on Martian meteorites could have originated from terrestrial
contamination from Earth or other meteorites, or chemical reactions
or biological activity on Mars.

Steele's team examined samples from 11 Martian meteorites from a
period spanning about 4.2 billion years of Martian history. They
detected large carbon compounds in 10 of them. The molecules were
found inside grains of crystallized minerals.

Using an array of sophisticated research techniques, the team was able
to show that at least some of the macromolecules of carbon were
indigenous to the meteorites themselves and not contamination from
Earth.

The team next looked at the carbon molecules in relation to other
minerals in the meteorites to see what kinds of chemical processing
these samples endured before arriving on Earth. The crystalline
grains encasing the carbon compounds provided a window into how the
carbon molecules were created. Their findings indicate that the
carbon was created by volcanic activity on Mars and show that Mars
has been doing organic chemistry for most of its history.

In a separate paper published by American Mineralogist, Steele and his
team report their findings on the same meteorite announced in 1996 to
contain possible -- but subsequently discounted -- relics of ancient
biological life on Mars. Called ALH84001, the meteorite was found to
also contain organic macromolecules of non-biological origin.

The Steele team's research indicates that Mars does have a pool of
reduced carbon. Their findings should help scientists involved in
current and future Mars missions distinguish non-biologically formed
carbon molecules from potential life.

For an image and more information about the meteorite, visit:

http://1.usa.gov/mars052412
        
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Received on Thu 24 May 2012 05:06:35 PM PDT