System
Our planetary system consists of the Sun and everything bound to it by gravity—the planets Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune; dwarf planets such as Pluto; dozens of moons; and millions of asteroids, comets, and meteoroids.
The inner Solar System includes the four terrestrial planets—Mercury, Venus, Earth, and Mars—which are composed primarily of rock and metal. Beyond Mars lies the asteroid belt, containing millions of rocky remnants from the Solar System's early formation.
The outer Solar System is home to the gas giants Jupiter and Saturn, composed mostly of hydrogen and helium, and the ice giants Uranus and Neptune, consisting largely of water, ammonia and methane. Beyond Neptune lies the icy Kuiper belt and the Oort cloud.