Raisin’ Mountains on Saturn’s Moon Titan -
Saturn’s moon Titan ripples with mountains, and scientists have been trying to figure out how they form. The best explanation, it turns out, is that Titan is shrinking as it cools, wrinkling up the moon’s surface like a raisin.
A new model developed by scientists working with radar data obtained by NASA’s Cassini spacecraft shows that differing densities in the outermost layers of Titan can account for the unusual surface behavior. Titan is slowly cooling because it is releasing heat from its original formation and radioactive isotopes are decaying in the interior. As this happens, parts of Titan’s subsurface ocean freeze over, the outermost ice crust thickens and folds, and the moon shrivels up. The model is described in an article now online in the Journal of Geophysical Research.
"Titan is the only icy body we know of in the solar system that behaves like this," said Giuseppe Mitri, the lead author of the paper and a Cassini radar associate based at the California Institute of Technology in Pasadena. "But it gives us insight into how our solar system came to be."
An example of this kind of process can also be found on Earth, where the crumpling of the outermost layer of the surface, known as the lithosphere, created the Zagros Mountains in Iran, Mitri said.
(image: mosaic of Titan’s northern hemisphere taken by Cassini. NASA/JPL-Caltech)
via NASA Jet Propulsion Laboratory