Sunday, September 18, 2005
Titan's Seas found?
One of the things scientists were hoping to see on the Cassini mission to Saturn was a methane sea. There had been lots of tantalizing hints that large portions of Titan might be covered in liquid methane, and the Huygens lander had even been built to float on Methane, if it landed in such a sea. However, preliminary radar observations didn't detect large areas with liquid features, and Huygens landed in the equivalent of mud (the "dirt" was probably ice and the fluid probably methane). While Huygens imaged things that looked like rivers and shorelines, it looked as if the tide was out.
The latest radar imaging from Cassini shows something that looks a lot more like a sea (or at least a lake). There is a large, dark and above all smooth feature that could be lake, there are what looks to be a shoreline and drainage channels. While the large methane oceans are absent, there appear to be areas such as this one here there are methane lakes. They may be filled by periodically methane "rain" or seepage for underground reseviours, rather than being permanent features. There are many more close flyby's of Titan scheduled to observe the terrain in greater detail, to determine if these areas really are "lakes". The next close approach will target the Huygens landing area.