In addition to comets, two other relatively small bodies can be found floating around the solar system. They are known as asteroids and meteorites. Asteroids are smallish bodies that orbit the sun, mainly in the area between Mars and Jupiter. Though not large enough to be thought of as planets, asteroids can range from the size of a small boulder to several hundred miles in diameter. They are rocky bodies made up of various metals and other substances. Now and then something will jar an asteroid out of its orbit. Then it may approach or-very rarely-hit Earth.