JPL-Caltech/NASA, Space Science Institute
A satellite of Saturn joins the club of moons with possible oceans. A subsurface sea of water might hide beneath the icy crust of Dione, one of Saturn’s moons, researchers report online October 9 in Geophysical Research Letters. That puts Dione in good company alongside Enceladus (another moon of Saturn) and several moons of Jupiter, as well as possibly Pluto (SN Online: 9/23/16).
Dione’s ocean is about 100 kilometers below the surface and roughly 65 kilometers deep, Mikael Beuthe, a planetary scientist at the Royal Observatory of Belgium in Brussels, and colleagues report. They inferred the ocean’s presence from measurements of Dione’s gravity made by the Cassini spacecraft.
M. Beuthe, A. Rivoldini and A. Trinh. Enceladus's and Dione's floating ice shells supported by minimum stress isostasy. Geophysical Research Letters. Published online October 9, 2016. doi: 10.1002/2016GL070650.