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16 Jan 2009 12:41
Plumes of methane gas detected on Mars could be a sign of geological or biological activity—and possibly the latest indication that life can be sustained on the “Red Planet”, according to a new study.
The presence of methane implies active geological, or possibly even biological, processes on Mars, and the amount of methane observed on the “Red Planet” is comparable to some active sites on Earth, the study published in the journal Science found.
“This is exciting because we have evidence that we need to think about in terms of the possibilities of life on Mars,” said Lisa Pratt, Professor of geological sciences at Indiana University in Bloomington, Indiana.
“It’s prudent that we begin to explore Mars looking for the possibility of a life form that’s exhaling methane,” she told a press conference.
“Right now, we do not have enough information to tell whether biology or geology—or both—is producing the methane on Mars,” said principal researcher Michael Mumma of Nasa’s Goddard Space Flight Centre.
“But it does tell us the planet is still alive, at least in a geologic sense. It is as if Mars is challenging us, saying, ‘hey, find out what this means.’
“On the planet Earth, microorganisms thrive in unlikely places like up to three kilometres beneath the Witwatersrand basin of South Africa, “where natural radioactivity splits water molecules into molecular hydrogen and oxygen”, Mumma said.
“The organisms use the hydrogen for energy.
It might be possible for similar organisms to survive for billions of years below the permafrost layer on Mars, where water is liquid, radiation supplies energy, and carbon dioxide provides carbon.”
Mumma said he believed the finding increases the prospects for finding life on Mars.
Researchers noted that living systems produce more than 90% of Earth’s methane, with the other 10% being geochemical in origin.
Researchers said that one primary plume of Martian methane contained an estimated 19 000 metric tons of the gas—about as much as is produced at a massive hydrocarbon seep at Coal Oil Point in Santa Barbara, California.
The scientists said they have detected seasonal variations of methane emissions over some locations on Mars, but remain uncertain about the source of the gas.
“The methane we detected is of unknown age.
“Both geochemical and biological origins have been explored, but no consensus has emerged.”
Mumma and a team of researchers used high-dispersion infrared spectrometers to monitor about 90% of the planet’s surface for three Martian years (the equivalent of seven Earth years) for their study. - Sapa-AFP
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