Illustration showing the core, mantle and crust of Saturn. There is no direct information about Saturn's internal structure, although, it is thought to have a similar interior to Jupiter, having a small rocky core surrounded mostly by hydrogen and helium. The rocky core is similar in composition to the Earth, but denser. Above the core there is thought to be a thicker liquid metallic hydrogen layer, with a layer of liquid hydrogen and helium above that, and a gaseous atmosphere in the outermost 1000 km.