Year in review: Global ocean spans Enceladus
Geyser chemistry offers hints of alkalinity
As it winds up its studies of Saturn’s moon Enceladus, NASA’s Cassini spacecraft is offering the best evidence yet that this moon’s buried ocean could be a great place to search for extraterrestrial life.
Cassini, which has orbited Saturn since 2004, has swooped past Enceladus more than 20 times. But only recently have measurements confirmed that, beneath the moon’s icy shell, an underground ocean spans the entire globe (SN: 10/17/15, p. 8). Scientists had suspected for a decade that the moon had a smaller sea, based on geysers spurting near its southern pole, but a widespread ocean means more room for otherworldly microbes to thrive.