Extraterrestrial lakes

Io exhibits extraordinary
variations in color and brightness
as shown in this color-enhanced image.

At present the surface of the planet Mars is too cold and has too little atmospheric pressure to permit pooling of liquid water on the surface. However geologic evidence appears to confirm that ancient lakes once formed on the surface. It is also possible that volcanic activity on Mars will occasionally melt the subsurface ice, forming large lakes. Under current conditions this water will quickly evaporate or freeze unless insulated in some manner, such as by a coating of volcanic ash.

Jupiter's small moon Io is volcanically active due to tidal stresses, and as a result sulfur deposits have accumulated on the surface. Some photographs taken during the Galileo mission appear to show lakes of liquid sulfur on the surface.

There are dark basaltic plains on the Moon, similar to lunar maria but smaller, that are called lacus (singular lacus, Latin for "lake"). They were once thought by early astronomers to be literal lakes.

On July 24, 2006 photos brought in by the Cassini-Huygens spacecraft give a strong evidence for the existence of methane or ethane lakes on Titan.

From Wikipedia