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

[Ron Baalke]

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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