Beneath an icy crust, Saturn's moon Enceladus (pictured) has an ocean that covers its entire globe.
NASA's Cassini spacecraft measured wobbles in Enceladus's rotation over more than seven years. The data confirm that the crust is moving separately from the rocky core, meaning that there must be a widespread layer of liquid between them, says a team led by Peter Thomas of Cornell University in Ithaca, New York.
Cassini had previously spotted jets of liquid spewing from the moon's surface, and other studies have suggested that Enceladus has an underground sea only near its south pole. This latest finding further highlights how Enceladus could be one of the most likely places for extraterrestrial life.
Icarus http://doi.org/7rf (2015)