NASA reported on Jan 8, 2013 that the Cassini probe, currently orbiting Saturn, has found indications of hydrocarbon ice floating on the seas of liquid methane and ethane on the moon Titan. Hitherto, scientists had concluded that any such ice would sink because solid methane is denser than liquid methane and therefore would sink. However it is surmised that these ice floes contain at least five percent Titan a ”air” making them buoyant enough to float.
Scientists came to the conclusion because imaging by Cassini indicated differences with reflection from Titan’s hydrocarbon bodies of water. This surmise will allow Cassini to study the climate cycle of Titan. As temperatures change, ice will form or melt as it goes lower and higher, changing the reflective properties of the hydrocarbon seas.
How the cycle of freezing and melting of hydrocarbon ice plus the interaction of ice with liquid affects the possibility of exotic life on Titan likely will remain speculation at least until space probes visit the moon’s surface for extended periods of time. Methane and ethane are organic molecules and thus might indicate more complex chemistry leading to life on Titan.