Cassini probe may fly through Saturn moon's steamy plume

In a daring act of space-obatics, the Cassini probe is to buzz one of Saturn's stranger moons. If NASA opts for the most precarious of the trajectories under consideration, Cassini will approach within just 30 kilometres of Enceladus before flying through a plume of steam emanating from its south pole.

The aim of this exceptionally close encounter is to find out what is powering that plume. A dozen or so jets appear to be blasting water vapour and ice crystals out of fissures near the south pole (watch a sequence of four images showing the jets).