[X] My Assistant

[Palomar]

Best evidence yet

*...for a shoreline on Titan; they're calling it "dramatic." Area measures 1,060 by 106 miles. Is from Cassini radar, obtained during the latest flyby. Speculation continues regarding seepage of liquid from the ground/ground springs and/or rainfall.

[Guest_BruceMoomaw_*]

It isn't that the dark stuff falls out of the atmosphere in large amounts in the raindrops -- it's just that it continually very slowly drifts down and coats the surface, and then gets washed off the higher areas and into the riverbeds by the rare but violent rains. Most of it gets washed into the playas, but a little bit remains on the bottoms of the arroyos as they empty and then dry out (mixed, perhaps, with ground-up water-ice "sand" accumulated on the bottoms of the arroyos).

Always keep in mind how VERY slowly the dark stuff is thought to accumulate on the surface. We're talking about 1 micron total of ALL methane radiolysis products every 25 years -- and most of that is ethane (which is liquid and trickles down into the soil) or solid acetylene (which is light-colored).