What is the solar system?
The solar system consists of a central star, the Sun, and all of the smaller celestial bodies that continuously travel around it. The smaller bodies include eight planets: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune, which are themselves orbited by more than 140 moons. (Only Mercury and Venus have no moons.) In addition, the solar system contains millions of rocky asteroids and billions of icy comets. All of these objects are held together in a group by the Sun's gravity.
Our solar system officially has eight planets and one star: the Sun. In order from the Sun out, the planets are: Mercury, Venus, Earth, Mars, Jupiter, Saturn, Uranus, and Neptune. The discovery of an object larger than Pluto in 2005 rekindled the debate over whether such objects, belonging to the "Kuiper Belt" – a collection of icy bodies located beyond Neptune – should be called planets. Pluto and other large members of the Kuiper Belt are now considered "dwarf planets."