Extraterrestrial liquid water
The Gliese 581 planetary system contains multiple planets that may be candidates for surface water, including Gliese 581c, Gliese 581d, might be warm enough for oceans if a greenhouse effect was operating, and Gliese 581e.
Lakes of Titan
According to Cassini data, scientists announced on February 13, 2008, that Titan hosts within its polar lakes "hundreds of times more natural gas and other liquid hydrocarbons than all the known oil and natural gas reserves on Earth." The desert sand dunes along the equator, while devoid of open liquid, nonetheless hold more organics than all of Earth's coal reserves. It has been estimated that the visible lakes and seas of Titan contain about 300 times the volume of Earth's proven oil reserves. In June 2008, "Cassini" Visible and Infrared Mapping Spectrometer confirmed the presence of liquid ethane beyond doubt in a lake in Titan's southern hemisphere. The exact blend of hydrocarbons in the lakes is unknown. According to a computer model, 3/4 of an average polar lake is ethane, with 10 percent methane, 7 percent propane and smaller amounts of hydrogen cyanide, butane, nitrogen and argon. Benzene is expected to fall like snow and quickly dissolve into the lakes, although the lakes may become saturated just as the Dead Sea on Earth is packed with salt. The excess benzene would then build up in a mud-like sludge on the shores and on the lake floors before eventually being eroded by ethane rain, forming a complex cave-riddled landscape.Salt-like compounds composed of ammonia and acetylene are also predicted to form. However, the chemical composition and physical properties of the lakes probably varies from one lake to another (Cassini observations in 2013 indicate Ligeia Mare is filled with a ternary mixture of methane, ethane, and nitrogen and consequently the probe's radar signals were able to detect the sea floor 170 m (557'9") below the liquid surface).