Enceladus even hotter than thought

The mysteries of Saturn’s moon Enceladus just get more puzzling… it’s been known for a while now that the water vapour/ice geysers at the south pole emanate from fissures where heat is continuously leaking, more than was thought possible for such a tiny world. Now, new data from the Cassini spacecraft shows that much more heat than that even is coming out of Enceladus’ interior.

Credit: NASA/JPL/Space Science Institute
Credit: NASA/JPL/Space Science Institute

The expected heat energy output from tidal heating, based on a 2007 study, was about 1.1 gigawatts (averaged out over time). Plus maybe another 0.3 gigawatts from natural radioactive heating. But the new results indicate an energy output of 15.8 gigawatts, about 2.6 times the energy from all of the hotsprings in Yellowstone, or 20 coal-fueled power stations. For a tiny, icy body like Enceladus, that’s amazing, and also makes it even more likely that the geysers originate from a subsurface sea or ocean. A salty one at that, as salts have already been found in the vapour/ice plumes, as well as organic molecules. What else might be lurking below?

See also the Enceladus image gallery for more great photos.