There are 8 planets and 5 dwarf planets in our solar system. Mercury is closest to the sun while Neptune is farthest. Jupiter is the biggest planet and Saturn has the largest and most visible rings. The asteroid belt orbits between Mars and Jupiter. The sun is at the center of the solar system and the inner planets are made of rock and metal. Comets have icy tails and orbit the sun, and Mars is nicknamed the "red planet".