By Xinhua,
Washington : At least one of the large lakes observed on Saturn’s moon Titan contains liquid hydrocarbons, NASA scientists have said.
They have also identified presence of ethane. This makes Titan the only body in the solar system beyond Earth known to have liquid on its surface, National Aeronautics and Space Administration (NASA) reported Wednesday.
Scientists made the discovery using data from an instrument aboard the Cassini spacecraft.
Earlier, scientists had thought Titan would have oceans of methane, ethane and other light hydrocarbons.
More than 40 close flybys of Titan by Cassini showed no such oceans existed, but revealed the presence of hundreds of dark lake-like features.
Until this new study, it was not known whether these features were liquid or simply dark, solid material.
“This is the first observation that shows Titan has a surface lake filled with liquid,” said lead researcher Robert Brown of the University of Arizona’s Lunar and Planetary Laboratory.
Brown is the team leader of Cassini’s visual and mapping instrument. The results were published in the July 31 issue of the journal Nature.
The liquid ethane was identified using a technique that removed the interference from Titan’s atmospheric hydrocarbons.
The visual and mapping instrument observed a lake in Titan’s south polar region during a close Cassini flyby in December 2007. The lake is roughly 20,000 sq km in area, slightly larger than North America’s Lake Ontario.
“Detection of liquid ethane confirms a long-held idea that lakes and seas filled with methane and ethane exist on Titan,” said Larry Soderblom, a Cassini scientist.
“The fact that we could detect the ethane spectral signatures of the lake even when it was so dimly illuminated, and at a slanted viewing path through Titan’s atmosphere, raises expectations for exciting future lake discoveries by our instrument.”