Animation of a flight towards Saturn and through its rings. Saturn is a gas giant planet, the sixth from the Sun, orbiting at a distance of some 1.5 billion kilometres. It is the second largest planet in the Solar System, with a diameter of around 120,000 kilometres. It has the largest and most prominent ring system of all the planets, with bright rings extending from just 6,600 kilometres above the clouds to more than 120,000 kilometres distant, and fainter rings much further out than that. Despite their great extent, the rings are extremely thin, only around 20 metres deep at their thickest. The rings are composed of countless small chunks of water ice.