Amundsen and co-author Andrew Steele, of the Carnegie Institution's Geophysical Laboratory, suggest that a similar reaction occurred on Earth in Svalbard, Norway, about a million years ago.
Svalbard's prehistoric Arctic climate was possibly analogous to the hostile conditions found on ancient Mars.
(Related news: "Mars Volcanoes May Re-Erupt, Hawaii Comparison Shows" [October 18, 2007].)
Comparisons of organic material in rocks from Svalbard with those in the Martian meteorite suggested that the same process for forming organics was at work in both locales.
"We know that in Svalbard, when the climate was even colder than today, these eruptions [caused] hot lava [to] erupt through a very thick ice sheet," Amundsen said.
"The lava cooled rapidly, trapping minerals from the Earth's mantle, and that's when you had the reactions that formed these organic compounds."
The analysis is described in the current issue of the journal Meteoritics and Planetary Science.
The study authors also suggest that organics could be forming on scores of other cold, rocky planets across the universe.
"If you have volcanic activity on such planets, and water and carbon dioxide present, you could have the same reaction going on anywhere," Amundsen said.
"Homegrown" or Not?
But not everyone is convinced by the new analysis.
Jeffrey Bada, an expert on life origins at Scripps Institution of Oceanography at the University of California, San Diego, suggests caution.
"My take is that these meteorites are so complicated that to make bold claims on what the organic material is, where it came from, and what its implications might be is just not very credible," he said.
Much of the meteorite's carbon, Bada reports, is from contamination when it smashed into Antarctica's Allan Hills.
"You do see a tiny amount of carbon that does appear [to be different] than you'd expect from a terrestrial material," he added.
But Bada reiterated the longstanding theory that such organics were not homegrown and were likely delivered to Mars by meteorites.
"How [one] can tell that these organic compounds are not due to meteorite infall is perplexing."
Based on his studies of the meteorite's contamination, study co-author Steele remains convinced the carbon has a Martian origin.
"It is very difficult to see how the carbon came from meteorite infall," he said. "The carbon itself and the magnetite it is associated with would have to penetrate the minerals within the meteorite. That is impossible." NASA's 2009 Mars Science Laboratory mission, of which Steele is a member, could help resolve the debate.
"One of the goals is to detect organic compounds on Mars," study co-author Amundsen said.
"Now that we know they are there, and what kind of setting they are in, it's a matter of guiding that robot when it gets up there to hopefully find the same stuff."
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