あまり続報が流れないので外信から http://www.nytimes.com/ 【Titan's Big News: A Mysterious Shoreline】 If this evidence of possible liquids on Titan's landscape is confirmed it would support widely held pre-mission conjecture that the planet-sized moon has lakes and perhaps seas of liquid methane or ethane. It could thus prove to be the mission's most consequential discovery: that not only is Titan the only moon in the solar system with a substantial atmosphere, but it also appears to have flowing surface liquids, putting it in the company of only Earth and possibly Jupiter's moon Io, with its lava flows.
Another hypothesis has been that frozen water is also a significant component of Titan's surface, because the moon's mass would be greater if not for a considerable amount of water ice. The first pictures appeared to show that some of the ice lies in chunks on a surface that may be underlain with deeper layers of ice.