Titan’s Inside Outed

Saturn’s moon Titan is unquestionably one of the most interesting objects in the outer solar system, and the Cassini-Huygens mission to Saturn continues to contribute to our ever-increasing understanding of this fascinating cold world.

Now, in findings published in the journal Science, scientists have determined that Titan’s internal structure is radically different from that of such other icy moons as Jupiter’s Ganymede, though perhaps more similar to Jupiter’s Callisto. In Cassini Data Show Ice and Rock Mixture Inside Titan, project scientists explain that “Titan, Saturn’s largest moon, is about half ice and half rock” and that “Titan’s interior is a sorbet of ice studded with rocks that probably never heated up beyond a relatively lukewarm temperature. Only in the outermost 500 kilometers (300 miles) is Titan’s ice devoid of any rock, while ice and rock are mixed to various extents at greater depth.”

“‘To avoid separating the ice and the rock, you must avoid heating the ice too much,’ said David J. Stevenson, one of the paper’s co-authors and a professor of planetary science at the California Institute of Technology in Pasadena. ‘This means that Titan was built rather slowly for a moon, in perhaps around a million years or so, back soon after the formation of the solar system.’”

One remaining question: does Titan have an interior ocean hidden beneath its surface? Stay tuned.

For additional perspectives on Titan, see our earlier posts Titan & Tethys and Sunglint on Titan.

For more on the Cassini mission, visit NASA’s Cassini mission page or NASA/JPL’s Cassini website.

Titan's Interior Structure, Artist's Conception (NASA/JPL)