Saturn moon Enceladus may have massive hidden 'habitable ocean'
A potentially habitable ocean surrounds the whole of Saturn's small moon Enceladus beneath an icy surface, new research suggests.
The way the moon wobbles as it orbits the ringed gas giant can only be explained by an outer crust floating freely from an inner core, say scientists.
This points to a global ocean, rather than any kind of regional sea.
In 2006 the Cassini probe exploring the Saturnian system detected water vapour and simple organic molecules erupting from fractures near the moon's south pole.
More geyser particles detected in 2009 proved that they must emanate from a liquid reservoir. Later analysis demonstrated the possibility of a regional sea underlying the entire south pole region of Enceladus.
The new results, published in the journal Icarus, indicate that every square inch of the moon is likely to lie above a global ocean, warmed by the pulling and stretching tidal forces of Saturn's gravity.
Cassini scientist Dr Matthew Tiscareno, from the Seti (Search for Extraterrestrial Intelligence) Institute in Mountain View, California, said: "This exciting discovery expands the region of habitability for Enceladus from just a regional sea under the south pole to all of Enceladus.
"The global nature of the ocean likely tells us that it has been there for a long time, and is being maintained by robust global effects, which is also encouraging from the standpoint of habitability."