Seas of liquid gas on Saturn's moon Titan seen in great detail

NASA says its Cassini spacecraft is providing scientists with key clues about Saturn's moon Titan and its unique hydrocarbon lakes and seas. Titan is the only place in the solar system other than that has stable liquid on its surface, although in Titan's case it's not water by hydrocarbons like liquid methane. Cassini has made increasingly close flybys over the moon's northern hemisphere that contains almost all of Titan's seas and lakes, allowing scientists to put together the most detailed multi-image mosaic of that region to date, NASA reported Thursday. "Learning about surface features like lakes and seas helps us to understand how Titan's liquids, solids and gases interact to make it so Earth-like," Steve Wall at NASA's Jet Propulsion Laboratory in Pasadena, Calif., said. "While these two worlds aren't exactly the same, it shows us more and more Earth-like processes as we get new views." Nearly all of the lakes on Titan fall into an area of about 600 miles by 1,100 miles, with only 3 percent of the liquid on Titan existing outside this area, researchers said. "Scientists have been wondering why Titan's lakes are where they are," said Randolph Kirk, a Cassini radar team member at the U.S. Geological Survey in Flagstaff, Ariz. "These images show us that the bedrock and geology must be creating a particularly inviting environment for lakes in this box." Cassini's radar revealed Ligeia Mare, Titan's second-largest sea, is about 560 feet deep. This is the first time scientists have been able to plumb the bottom of a lake or sea on Titan, NASA said.