Saturn is a giant planet with a diameter of over 58,000 km. It has a hydrogen and helium atmosphere and a core made of metallic hydrogen. Saturn has over 60 moons, the largest being Titan which has a thick nitrogen atmosphere and landscapes resembling those found in Tolkien's books, with rivers and lakes of methane. Another notable moon is Mimas, which resembles the Death Star from Star Wars and shakes internally in a mysterious way.