Part of the Cassini probe to study Saturn - Huygens specifically was sent to land on Titan so that we can learn more about it. Titan has a very thick atmosphere (approximately 1.5x thicker than Earths at the surface) Which has teased scientists since Voyager first flew by. Due to its thick atmosphere, we knew practically nothing about its surface until Huygens landed there. The best we could manage was some radar imaging, and even then I think we weren't able to do that until Cassini reached Saturn.Originally Posted by SomethingBig
From the descriptions, it seems the moon is geologically active; Huygens landed in something like mud, and the aerial photographs look sort of like there are channels feeding into an ocean. The data is still being studied (and will be for a while; we're still studying voyager's data) but if what we see is in fact an ocean, it's almost certainly made of ethane.
