The sun hurtles through space with a huge family of bodies large and small – planets, moons, asteroids, comets, and meteoroids. We call this family of the sun the solar system. The four planets closest to the Sun-Mercury, Venus, Earth, and Mars – are called the terrestrial planets because they have solid rocky surfaces. The four large planets beyond the orbit of Mars – Jupiter, Saturn, Uranus, and Neptune – are called the gas giants. Beyond Neptune, on the edge of the Kuiper Belt, tiny, distant, dwarf planet Pluto has a solid but icier surface than the terrestrial planets.