Saturn’s large moon, Titan–the potential fuel depot of the future if we continue to rely upon hydrocarbon technology–has been under scrutiny for some time, and recently NASA’s Cassini spacecraft has detected an unexplained, changing feature in Ligeia Mare, one of Titan’s largest hydrocarbon seas.
The feature hadn’t been detected prior to July 2013 and SAR images (Synthetic Aperture Radar) obtained in October 2013 also failed to recover the feature. However, the SAR observation from Cassini’s August 21, 2014 flyby shows the feature, although its appearance changed in size, doubling from about 30 square miles to about 60 square miles. Says NASA:
The Cassini radar team is investigating possible origins for the feature, including surface waves, rising bubbles, floating solids, solids that are suspended just below the surface or perhaps something more exotic. Researchers suspect that the appearance of this feature could be related to changing seasons on Titan, as summer draws near in the moon’s northern hemisphere. Monitoring such changes is a major goal for Cassini’s current extended mission.
It is probably not surprising that Titan’s environment is sufficiently volatile to yield such mysterious changes, and whatever we learn of it is bound to increase our understanding of this potentially very important body in our solar system. But for now, given that we have absolutely no direct experience with seas of hydrocarbon, the feature is fascinating and we look forward to noodling it through.
The Cassini-Huygens mission is a cooperative project of NASA, the European Space Agency and the Italian Space Agency. NASA’s Jet Propulsion Laboratory (a division of the California Institute of Technology in Pasadena) manages the mission for NASA. The Cassini orbiter was designed, developed and assembled at JPL. The radar instrument was built by JPL and the ISA, working with team members from the United States and several European countries.
J. C. Conway 
I wonder if Titan’s presumably dormant organics could come alive in the distant future as the sun’s energy output increases. Maybe all it needs is a spark!