Probe spots seas on Saturn's moon Titan

(CNN)-LOS ANGELES, California (AP) -- Scientists have discovered what appear to be sea-size bodies of liquid, probably methane or ethane, on the surface of Saturn's largest moon.

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 spotted only 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.