Jupiter orbits between Mars and Saturn at an average distance of 778 million km from the sun. Although it has an equatorial diameter of 142,800 km the planet rotates in less than ten hours. Its upper atmosphere consists mainly of hydrogen with swirling clouds of ammonia and methane, with a circulation system that results in a number of distinct latitudinal bands. There are at least sixteen satellites, four of which (the Galilean moons) are visible through binoculars, and a faint ring system.
Latin, from Jovis pater, literally 'Father Jove'