NASA scientists have released an image of a 400 km long river on Saturn's moon Titan, imaged by the Cassini Space Probe during a flyby on 26 September 2012. The river meanders for some distance across a flat plane before entering the Kraken Mare, a sea of hydrocarbons (probably methane and ethane) near to the moon's north pole described as being intermediate in size between the Caspian and the Mediterranean on Earth.
Titan is the only place in the Solar System, other than the Earth, where a cycle of liquid evaporation and precipitation is known to form a system of rivers and sea, though ancient sedementological structures suggest that Mars once had rivers of running water, and rivers of what appear to be sulphurous lava have been sighted on Jupiter's moon Io, though these last are thought to be fed by volcanic eruptions rather than rain.
Left: Cassini image of the new river on Titan. NASA/JPL.
See also New Cassini Images of Titan, Tethys and Methone, NASA releases new Cassini images of Saturn's moons Enceladus Janus and Dione, NASA releases new Cassini images of Saturn's moon Rhea, Saturn's moon Dione found to have an atmosphere and Saturn on Sciency Thoughts YouTube.
Follow Sciency Thoughts on Facebook.