Comets are made of dust, rock and frozen gases that vaporize as they near the Sun, forming a coma and tail. Comets eventually break apart after passing by the Sun multiple times. Small pieces of comets are called meteoroids, which appear as meteors or "shooting stars" when burning up in Earth's atmosphere, or meteorites if they reach the ground. Asteroids are rocky bodies like planets that mainly orbit in a belt between Mars and Jupiter.