Saturn. Artwork of the planet Saturn and its moons seen from space. Saturn is the sixth planet from the Sun. It has a diameter nearly ten times that of Earth and a volume of over 800 Earths. It is a gas giant and is mostly hydrogen and helium. High pressures and temperatures give rise to liquid hydrogen in the interior. The outer surface clouds are coloured by trace chemical elements. Saturn has a large ring system, consisting of thousands of rock and ice chunks, probably from a moon that disintegrated. Saturn has over 30 moons, of which the largest is Titan (centre left). The Milky Way is seen in the background.