Lakes of Titan
The Cassini-Huygens probe, flew very close to Titan in December 2007, and took infrared pictures of the chemicals on the surface and found a lake called Ontario Lacus near the south pole. Scientists studying the infrared pictures decided that one or more of the large lakes in the pictures of Saturn's moon Titan does hold liquid and that the liquid is made of hydrocarbons. They have also found ethane on Titan.  This mission proves Titan to be the only other planet known to have liquid on its surface. The lakes make Titan a very important planet for studying weather science. Liquids, gases and temperatures are at play on Titan.  This should help the science of weather forecasting.