Enceladus

Saturn’s sixth-largest moon, Enceladus measures in at roughly 500 kilometres - or 310 miles - in diameter. However, this is only a tenth of the size of Titan, Saturn’s largest moon.

Discovered by William Herschel in 1789, not much was known about the icy moon, however, until Voyager 1 flew by Saturn in 1980. Then, in 2005, Cassini-Huygens (a space-research craft) was sent to study Saturn and her moons.

This revealed the moon’s icy surface, complete with cryovolcanoes near the south pole. Later, in 2014, Cassini-Huygens discovered evidence of a subsurface ocean around the south pole, supplying the cryovolcanoes.