[X] My Assistant

[remcook]

..according to earth-based measurements

http://www.newscientist.com/article.ns?id=...dId=space_rss20

The surface doesn't look like an ocean anyway

[Guest_BruceMoomaw_*]

The question "Where has all the liquid gone (long time passing)?" has two different aspects on Titan, because there are two different types of liquid. Methane, as we now know from Huygens, rains down periodically on the surface and then has the ability to re-evaporate back into the air.

But the very slowly built-up liquid ethane -- which we now know was also detected on the surface by Huygens, although they haven't publicly released quantity data yet -- will not evaporate once it forms, and calculations of its formation rate over the eons have long predicted enough for a global layer over a kilometer thick. So it must have soaked down into Titan's subsurface. I suspect much of it has been permanently carried down into Titan's deeper interior by its cryovolcanism and its resultant crustal recycling. A.D. Fortes has an interesting abstract at the upcoming DPS meeting on the possibility of "mud volcanism" on Titan: http://www.aas.org/publications/baas/v37n3/dps2005/126.htm .

By the way, we now have confirmation from http://www.aas.org/publications/baas/v37n3/dps2005/31.htm that Huygens not only detected ethane from the surface when it was heated, but also cyanogen and -- really surprisingly -- carbon dioxide. (The first two were mentioned briefly by the Solar System Strategic Roadmap.)