Cassini’s last Titan flyby reveals deep methane lakes, Earth-like cycles

Titan, Saturn's largest moon, crosses the rings and the planet. credit: NASA/JPL-Caltech/Space Science Institute

By examining data from the Cassini spacecraft’s last close encounter with Saturn’s moon Titan, scientists have found that its methane-filled lakes are up to 300 feet deep, much deeper than previously thought.

The lakes also seem to feed underground reservoirs that pour into Titan’s seas – offering evidence of a hydrologic-like cycle on another place in the solar system, according to Cornell, Caltech and international researchers publishing in Nature Astronomy, April 15.

Titan is an exotic place. Think of it as an Earth-like, geologic wonderland made of hydrocarbon but with less gravity. It’s a world where methane raindrops the size of marbles fall slowly to a ground surface covered in organics. The rain fills the lakes. While the deep lakes are perched far above the orange landscape, the liquid methane seems to flow underground to fill Titan’s seas – which are as flat as paper. The 5-millimeter-high sea waves crest to a gnarly 1 centimeter.

“The lakes are stable on Titan. For long periods of time, these lakes are filled,” said CSI member Valerio Poggiali said. “While Titan should have a river-like phenomena, the methane travels from the lakes to the seas by subsurface. All the lakes we studied have the same composition. They are connected.”

“The big picture is reinforcing the idea of an Earth-like nature to Titan, in terms of landforms, but it has an exotic nature in terms of the working materials of the geologic processes.” said CSI member and co-author Jonathan Lunine, the David C. Duncan Professor in the Physical Sciences and director of Cornell’s Center for Astrophysics and Planetary Science.

Other co-authors of the study were CSI members Alex Hayes and Sam Birch.

Full story here story by Blaine Friedlander, Cornell Chronicle