NASA scientists said they had found liquid on Saturn's moon Titan, the second body in the solar system after Earth to have fluid on its surface.

The discovery was made after analysis on the US-European Cassini probe, the spacecraft orbiting Saturn since 2004.

NASA said that information from Cassini indicated that large lakes on Titan contained liquid hydrocarbons and ethane.

"This is the first observation that really pins down that Titan has a surface lake filled with liquid," said scientist Bob Brown, Team Leader.

NASA said large dark areas on Titan's surface had been spotted during numerous close flybys of the moon.

Scientists were able to conclude the areas were liquid after studying data from a Cassini instrument able to distinguish chemically different materials.

The visual and mapping instrument spotted a lake, Ontario Lacus, in Titan's south polar region during December.

The lake is roughly 7,800 square miles, slightly bigger North America's Lake Ontario.

"This raises expectations for future lake discoveries by our instrument," said Larry Sorderblom, Scientist, US Geological Survey in Flagstaff, Arizona.