The Solar System, sometimes referred to as Sol, is the planetary system based around the star Sol, more commonly known as "The Sun", a stable, middle aged G2 star. The Solar System is the home system of the human race, which originated on Earth, the third planet of the system.
The Solar System consists primarily of eight planets, plus several dwarf planets, their moons and a large asteroid belt. Generally, the system is divided into two sectors, the inner planets — consisting of Mercury, Venus, Earth and Mars — and the outer planets — including Jupiter, Saturn, Uranus and Neptune. A large asteroid belt, containing the dwarf planet Ceres, lies between the two sectors, while several other small bodies orbit Sol beyond Neptune, including the dwarf planets Eris, Pluto and Charon. The inner planets are comparatively small, rocky worlds, whereas the outer planets are large gas or ice giants.
- For many years, Pluto was classified as the ninth planet of the Solar System. However, it was reclassified in 2006 when it was discovered to be just one of several dwarf planets in the system. Some scientists continue to argue Pluto should be designated a full planet.