for National Geographic News
Recently identified electrical activity on Saturn's largest moon bolsters arguments that Titan is the kind of place that could harbor life.
At a brisk -350 degrees Fahrenheit (-180 Celsius), Titan is currently much too cold to host anything close to life as we know it, scientists say.
But a new study reports faint signs of a natural electric field in Titan's thick cloud cover that are similar to the energy radiated by lightning on Earth.
Lightning is thought to have sparked the chemical reactions that led to the origin of life on our planet.
"As of now, lightning activity has not been observed in Titan's atmosphere," said lead author Juan Antonio Morente of the University of Granada in Spain.
But, he said, the signals that have been detected "are an irrefutable proof for the existence of electric activity."
Frozen, Prebiotic Casserole
Morente's team studied data returned from the European Space Agency's Huygens probe, which broke away from NASA's Cassini spacecraft in 2005 to become the first probe to go below Titan's clouds. (Read "Voyage to Saturn" in National Geographic magazine.)
As soon as the probe entered the moon's atmosphere, a strong wind tilted the device about 30 degrees.
This accidental motion enabled Huygens to detect the Earthlike electrical resonances that it otherwise would have missed, which Morente and colleagues describe their study, published in a recent issue of the journal Icarus.
Jeffrey Bada, of the Scripps Institution of Oceanography, believes the process that allowed lightning to spark life on Earth is universal and could happen in many environments—including on Titan.
Confirmation earlier this year of Titan's hydrocarbon lakes makes the Saturnian moon the first place other than Earth where open bodies of liquid have been found.
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