Saturn has the most moons of any planet in the solar system: 31, at the last count. The Cassini mission involves 45 close Titan fly-bys and the craft will also visit Enceladus, Hyperion, Dione, Rhea and Iapetus. It has already paid its only visit to the outer moon Phoebe.

In 2000, astronomers found 12 tiny moons in orbit at around the same distance from Saturn as Phoebe. It is likely that they are the remnants of a catastrophic collision, possibly involving Phoebe itself.

This picture shows icy Dione, which was discovered by Cassini in 1684. At 1,120 kilometres across, it is Saturn's fourth largest moon.