From: LARRY KLAES (ljk4_at_msn.com)
Date: Fri Apr 15 2005 - 10:22:10 PDT
>From Today's Boulder Daily Camera
Life may be possible on Saturn moon
Microbes may be responsible for hydrocarbon fuels
By Todd Neff, Camera Staff Writer
April 15, 2005
The European Space Agency's Huygens space probe plopped onto a soft surface of the Saturn moon Titan on January 14. It soon relayed a startling black-and-white image to Earth via NASA's Cassini orbiter, which had lugged Huygens about 900 million miles over seven years.
To the untrained eye, it looked like a rock-strewn marsh.
To an expert such as Jonathan Lunine, a University of Arizona planetary scientist on the Huygens science team, it looked like a methane-soaked bog with frozen-hydrocarbon rocks.
To David Grinspoon, a planetary scientist at Southwest Research Institute in Boulder, it looked like a possible haven for life.
Grinspoon said Thursday that the abundance of hydrocarbon fuels such as acetylene, ethane and methane on Titan could mean some of the liquid was melted by microbes acting like so many tiny heaters.
He and Washington State University professor Dirk Schulze-Makuch have created a presentation titled "Liquid Water-Ammonia Habitats on Titan from the Release of Biothermal Energy?"
Grinspoon presented it to more than 200 scientists Thursday, the final day of the biannual NASA Astrobiology Institute conference in Boulder. Lunine, the Huygens scientist, spoke immediately after Grinspoon, presenting the latest scientific conclusions emerging from Huygens data, which scientists are still poring over.
Titan, although cold - minus-290 Fahrenheit where Huygens landed - is not dead like Earth's moon. Titan experiences intense geological activity, active cycling of chemicals in the atmosphere and "flagrant chemical disequilibrium," as Grinspoon called it. By that, he meant the presence of methane and carbon dioxide in the same atmosphere.
There is tentative evidence of carbon dioxide near the moon's surface. Methane is found in abundance.
"The only thing we know of that creates mixtures like that is biology," Grinspoon said.
Lunine said Huygens and Cassini instruments have found enough methane that there must be a source on the moon itself. He said it is probably coming from the moon's interior. Scientists now think Titan has a core of rocky silicon enveloped by a mantle of ice, Lunine said.
Mixed with some ammonia - a potent antifreeze - the mantle's frozen water could take on the qualities of a frigid magma, erupting to the surface in a process called cryovulcanism.
In an interview after both presentations, Lunine said Grinspoon's biological theory hasn't been ruled out but geological theories would have to be exhausted, which hasn't happened yet.
Grinspoon says his ideas are speculative.
"I think it's important to keep in mind these sort of outside-the-box ideas because we really don't know what we're looking for," he said.
Contact Camera Staff Writer Todd Neff at (303) 473-1327 or nefft_at_dailycamera.com<mailto:nefft_at_dailycamera.com>.
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