Life On Titan?

New studies of Saturn's huge moon Titan, using Cassini data, suggest to some scientists, including NASA's Chris MacKay, that methane-based life might exist there. The studies document the absence of hydrogen and acetylene on Titan's surface. Those elements do exist in the atmosphere, so one explanation of their disappearance near the surface is that they are being consumed in some way by living things. Indeed, scientists believe that methane-based life in Titan's frigid environment would in fact use hydrogen and acetylene.

Of course, other scientists aren't jumping on the bandwagon. They say there are non-biological processes that could explain the situation, and embracing the biological explanation-- which, after all, would rank with the greatest discoveries in human history-- should only be done after all other possibilities have been ruled out. MacKay agrees. Still, the vanishing hydrogen and acetylene constitute two more tantalyzing mysteries of the intriguing world of Titan.