Thursday, 31 July 2008

NASA Says Scientists Find Liquid Lake on Saturn's Biggest Moon


By Ed Johnson

July 31 (Bloomberg) -- Scientists have found liquid on Saturn's largest moon, Titan, making it the only body in the solar system other than Earth known to have fluid on its surface, NASA said.

The discovery was made using data from an instrument on board the Cassini spacecraft, which traveled more than 2.2 billion miles before entering orbit around Saturn in 2004.

``This is the first observation that really pins down that Titan has a surface lake filled with liquid,'' said University of Arizona scientist Bob Brown, team leader of Cassini's visual and mapping instrument. At least one of the lakes on the moon contains liquid hydrocarbons, NASA said in a statement yesterday.

Titan, with a diameter of about 3,200 miles (5,150 kilometers), is the second-largest moon in the solar system after Jupiter's Ganymede. It orbits at a distance of about 745,000 miles from Saturn and is one of at least 56 moons of the ringed planet.

The lake, Ontario Lacus, in Titan's south polar region, was spotted during a flyby in December, the National Aeronautics and Space Administration said. It is about 7,800 square miles in area, slightly bigger than North America's Lake Ontario.

Scientists concluded the area is liquid by studying the way it absorbed and reflected infrared light.

Saturn's moons have long been of interest to scientists, who say Titan may resemble an early version of Earth, providing clues to how the planet developed. In 2005, scientists detected a ``significant atmosphere'' on another moon, Enceladus.

Cassini was launched from Cape Canaveral, Florida, in 1997, bearing the Huygens probe. Huygens was sent down through Titan's atmosphere in 2005, gathering data on the moon's physical, chemical and electrical properties.

The $3.2 billion Cassini-Huygens mission is a collaboration between NASA, the European Space Agency and the Italian Space Agency.

To contact the reporter on this story: Ed Johnson in Sydney at


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