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Titan's Lakes of Methane and Ethane
Rob Carr writes "During the most recent Cassini fly-by, the surface-mapping radar spotted what appear to be lakes in the high northern latitudes of Titan. From the article: 'The channels have a shape that strongly implies they were carved by liquid. Some of the dark patches and connecting channels are completely black, that is, they reflect back essentially no radar signal, and hence must be extremely smooth. In some cases rims can be seen around the dark patches, suggesting deposits that might form as liquid evaporates.' At Titan's temperatures, water is a solid; the lakes would be comprised of methane and ethane. The fluids are different, as are the temperatures, but these lakes cement Titan's status in the solar system as the place with the most earth-like weather — except for Earth, of course."
I remember that when the Huygens probe landed there were lots of pictures of dark areas presumed to be lakes with channels leading into them from higher ground. But the probe landed close to a channel and didn't see any liquid.
Later the consensus was that the channels seen from Huygens were dry channels left over from flows in the past.
The evidence in this case seems to be the darkness (in radar) of the "lakes", which imply that we are seeing liquid Methane or Ethane. So why are these areas different from the Huygens landing site? It is in a polar area (gee I wish we had a second probe now) but most of the heat on Titan comes from internal sources anyway so having the sun close to th horizon won't make it much colder.
In any event Arthur Clarke is looking more right then wrong at the moment, We should be on the lookout for a Methane Monsoon.
http://michaelsmith.id.au
We are pretty certain it has liquid lakes, but it may
have caves as well.
We know so little about our solar system.