Cassini’s camera last month imaged a large, irregular feature stretching 680 miles long with a surface area similar to the landlocked Caspian Sea. Its radar instrument swept over the feature’s northern tip and determined it likely contains liquid methane or ethane because of its smooth appearance. However, scientists don’t know whether the entire area is filled with liquid. The spacecraft also discerned another body one-fifth the size of Titan’s “Caspian Sea.” With a surface area of about 46,000 square miles, it is larger than Lakes Superior and Ontario combined, scientists said. 160Want local news?Sign up for the Localist and stay informed Something went wrong. Please try again.subscribeCongratulations! You’re all set! Scientists for the first time have discovered what appear to be sea-size bodies of liquid on the surface of Saturn’s largest moon, including one about as big as the Caspian Sea on Earth. The discovery by the international Cassini spacecraft was welcomed by researchers, who have long theorized that Titan possessed hydrocarbon seas because of methane and other organic compounds in its thick, largely nitrogen atmosphere. Until now, Cassini had only spotted clusters of small lakes on the planet-size moon. “They’re very obvious. There’s nothing subtle about them,” said Cassini scientist Jonathan Lunine of the University of Arizona, Tucson. Researchers using visual and radar imaging uncovered evidence of at least two seas on Titan’s hazy north pole.