Saturn. Computer artwork of the planet Saturn seen from space. Saturn is the sixth planet from the Sun (upper left). 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 of thousands of chunks of rock and ice, probably from a moon that disintegrated. Saturn has over 30 moons, of which the largest is Titan (upper right). The bright band of stars in the background (at right) is our Milky Way galaxy seen from the inside.