Saturn's frigid moon Titan was long suspected to have seas of liquid methane and ethane: the existence and extent of these seas has been determined by the Cassini spacecraft, and sea state, depth and the physical properties of the liquid are being learned. Titan's meteorology leads to concentration of liquid in the polar regions: two major northern seas, Kraken and Ligeia, and one shallow lake in the south, Ontario Lacus, are particularly well-studied to date. Titan serves as a new laboratory for physical oceanography, with familiar processes occurring under very alien conditions.
展开▼