New Cassini findings show possible signs of methane-based life on Titan.

From PopSci:

Something is consuming hydrogen and organic molecules on Saturn's moon Titan, and the recipe matches astrobiologists' theories about possible methane-based life. Granted, there may be other chemical explanations -- it's just that no one knows what they are yet.

New data from the Cassini spacecraft show hydrogen is disappearing near Titan's surface. What's more, scientists have not been able to find acetylene, an organic molecule that should be pretty abundant in the moon's thick atmosphere.

All this fits very nicely with a theory from NASA astrobiologist Chris McKay, who proposed five years ago that microbial life on Titan could breathe hydrogen and eat acetylene, producing methane as a result.

Scientists emphasize that the findings are not proof of life, and there's plenty of work to do before non-biological causes can be ruled out. Scientific conservatism suggests that a biological explanation should be the last choice after all non-biological explanations are addressed," says Mark Allen of NASA's Jet Propulsion Laboratory in Pasadena, Calif., in a NASA release.

The good news is that even if life is ruled out, the non-biological explanations are still interesting. According to previous studies, hydrogen should be distributed pretty evenly throughout Titan's atmosphere. But it's disappearing at the surface.