Enceladus, one of Saturn’s (62!) moons, has a global sub-surface ocean. Using pictures from the Cassini probe, P C Thomas of Cornell University and colleagues observed the object’s libration and found it so large as to imply a global ocean. Liquid water and vapour had been seen in jets from a south-polar depression, but the new work rules out a localised polar sea. Salts and organic material have been detected in the jets, so this now looks like an interesting place to search for life.


• dx.doi.org/10.1016/j.icarus.2015.08.037