Saturn. Cassini spacecraft image of Saturn, its rings, and two of its moons Titan (upper right) and Tethys (bottom left). The rings, which consist of particles of nearly pure water ice, have become contaminated with meteoritic dust over time. It is this dust that causes differences in the rings colours. The CassiniHuygens spacecraft was launched in 1997 to investigate Saturn, its rings and its moons. This image was taken at a distance of 1.3 million kilometres from Saturn on 30th January 2008.