Titan, Saturn's largest moon, as seen by the spaceprobe Huygens during its successful descent on January 14th 2005. The linear feature could be an area where water ice has extruded onto the surface, whilst the short stubby dark channels may have been formed by liquid methane springs. Although the Huygens probe found no conclusive evidence of liquids on Titan, images like this would tend to imply that in the recent past there was liquid flowing on the surface. It is probable that it would have been liquid methane, or another hydrocarbon.