Science: Since 2004 the Cassini-Huygens mission has been observing Saturn's moon Titan. The satellite moon, which is covered in a dense methane-based atmosphere, is unobservable in the visible spectrum, but based on the size of the moon and the pressure reached at the surface, for years it was generally believed to have a liquid hydrocarbon-based ocean. The radar on Cassini spacecraft, and the descent of the Huygens probe to the surface in January 2005 radically changed our perspective of the moon, to that of a planetary body that consisted of a solid surface, full of geological features such as dunes, channels, lakes, impact craters.

Now a research team led by Ralph D. Lorenz at Johns Hopkins University Applied Physics Laboratory, have announced a new startling conclusion. The features researchers saw three years ago have drifted position, which leads them to conclude that Titan has an ocean buried below several tens of kilometers of ice.

“I think the paper is basically sound,” said David J. Stevenson from the California Institute of Technology to the New York Times reporter Kenneth Chang. “They have data to support the idea that the outer shell of Titan is moving relative to the deeper part, and the cause of this movement is a stress exerted on the shell.”

Related Links
Report: Titan's Rotation Reveals an Internal Ocean and Changing Zonal Winds (Science)
Perspective: Titan's Hidden Ocean (Science)
Surf’s down on Titan, 50 miles below the surface, scientists say (New York Times)