Thought I'd start a thread on the Titan encounter, for us to post informed speculation, wild-ass guesses, and general awe at seeing this strange new world for the first time.

NASA coverage at 9:30pm Eastern tonight, a press conf tomorrow at 12:00pm Eastern, then a science briefing Thursday at 12:00pm.

So far this is about the coolest pic:

Two thoughts that occur to me:

1. It sure looks like the dark material at center-left embays a few craters. It might even be sort of filling in a large basin with central peak of light material sticking out, in the lower-right part of the dark region. That suggests fluid emplacement of some sort, but what the fluid was, who the heck knows.

2. If we're seeing that many craters -- even if partially modified -- out where the cratering rate is as low as it must be at Saturn's orbit, that suggests Titan's surface is fairly old. If you have an active cycle of precipitation and runoff into oceans, or much volcanic/tectonic activity, I would think you would erode craters pretty quickly. There especially shouldn't be many large craters or ringed basins left.

So, I hearby conclude that the dark patches are were emplaced as fluid -- hydrocarbon sludge as a sort of lava? -- but are not liquid now and that Titan does not have a terribly active fluid cycle. Thus end my wild-ass guesses for the night.