April 9, 2009
(June 7) -- There may be life on Titan, Saturn's hazy, red moon.
While there are no signs of aliens just yet, some scientists say findings from a NASA spacecraft suggest the existence of extraterrestrial life is possible on Titan.
NASA's Cassini spacecraft found Titan lacking in hydrogen and acetylene, two ingredients vital to methane-based life, scientists say. The discovery sparked theories among researchers that a life form could be consuming the compounds as food.
Hydrogen is "the obvious gas for life to consume on Titan, similar to the way we consume oxygen on Earth," said Chris McKay, a NASA astrobiologist.
A paper published in Icarus, Cornell University's journal of solar system studies, reports that hydrogen molecules were disappearing on Titan's surface. And a second study in the Journal of Geophysical Research found the planet short on acetylene, which methane-based life forms would use for energy -- that is, of course, assuming they exist. NASA was quick to note today that methane-based life forms are so far entirely hypothetical.
That's one of the reasons why some NASA scientists are cautioning that the existence of alien life on Titan is just one explanation for the moon's curious lack of hydrogen and acetylene, and is probably the least likely theory to be correct.
"Scientific conservatism suggests that a biological explanation should be the last choice after all non-biological explanations are addressed," said Mark Allen of NASA's Astrobiology Institute. "We have a lot of work to do to rule out possible non-biological explanations."
If there is life on Titan -- which is Saturn's largest moon and even bigger than the planet Mercury -- it won't be like anything humans have ever seen before. With temperatures of minus 290 degrees Fahrenheit, the moon is far too frigid to support the kinds of water-based life forms that roam Earth.
"If these signs do turn out to be a sign of life, it would be doubly exciting because it would represent a second form of life independent from water-based life on Earth," McKay told NASA.
Yet that's exactly what has some experts, including Stephen Hawking, concerned. In April, the famous astrophysicist warned that seeking out other life forms could be dangerous.
"To my mathematical brain, the numbers alone make thinking about aliens perfectly rational," he said. "The real challenge is to work out what aliens might actually be like."
Filed under: Nation, Science
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The Few assume to be the deputies, but they are often only the despoilers of the Many.
Georg Wilhelm Friedrich Hegel