Saturn's rings. Cassini spacecraft image of the Cassini Division in Saturn's rings. The Cassini Division is between rings A and B. It was originally thought to be empty, but is now known to contain broad belts of material separated by empty rifts. The particles in Saturn's rings are mainly made of water ice. Particles range from microns to metres in diameter. This image was taken by the narrow angle camera on the Cassini spacecraft after its entry into Saturn orbit on 1 July 2004. The spacecraft will spend four years collecting data about Saturn, its rings and its moons.