The Solar System

The Solar System is a 4.6-billion-year-old gravitationally bound system comprising the Sun, eight planets, dwarf planets (like Pluto), moons, asteroids, and comets, all located in the Milky Way's Orion Arm. The Sun holds 99.8% of the system's mass. The four inner rocky planets are Mercury, Venus, Earth, and Mars; the four outer gas/ice giants are Jupiter, Saturn, Uranus, and Neptune. NASA Science (.gov) NASA Science (.gov) +5