Scientists have known for a while that Saturn's largest moon, Titan, has rivers and seas of liquid methane on its surface.

"There has been this sense that because Titan has such abundant organics, there is no shortage of food sources that could sustain life," Affholder said. "Not all of these organic molecules may ...

This artist's concept of a lake at the north pole of Saturn's moon Titan illustrates raised rims and rampart-like features as seen by NASA's Cassini spacecraft. | Credit: NASA/JPL-Caltech With ...