Beyond size, shape and rotation, we know relatively little about these objects. We think that asteroids are the remainders of planetismals , early pieces of the solar system, that formed between Mars and Jupiter. Some of the planetismals began to form into planets, but were smashed apart by Jupiter's immense gravity. Many questions remain about asteroids, because we have never been able to study them closely. Inc. All rights reserved.
Meteors burn up when they hit the earth's atmosphere.