Cassini Probe Watches Methane Clouds Waft Over Titan's Seas

Image: Titan clouds
A projected image of Titan's north polar region shows clouds forming over Ligeia Mare.NASA / JPL-Caltech / SSI

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It's one thing to know methane clouds can form within the smoggy atmosphere of Titan, a mysterious moon of Saturn. It's another thing for NASA's Cassini spacecraft to watch those clouds wafting over the moon's hydrocarbon seas. On Tuesday, the science team behind Cassini's camera system released time-lapse imagery of the moving cloud formations, as seen in infrared wavelengths.

The clouds could mark the start of summer storms in the moon's northern reaches. "The lack of northern cloud activity up till now has surprised those studying Titan's atmospheric circulation," imaging team leader Carolyn Porco wrote in an email. "Today's reports of clouds, seen a few weeks ago, and other recent indicators of seasonal change, are exciting for what they imply about Titan's meteorology and the cycling of organic compounds between northern and southern hemispheres on this unusual moon, the only one in our solar system covered in liquid organics." Porco and her colleagues will be watching the clouds for a while: Each season on Titan lasts about seven Earth years.



— Alan Boyle