Chunks of rock and metal from planetary bodies that survive their journey through the atmosphere and fall to the ground are called meteorites and scientists have found over 50,000 on Earth's surface. Of these, 99.8% come from asteroids and evidence suggests that they are very old, 4.5 to 4.6 billion years. Asteroids and the meteorites that fall to Earth are the original diverse materials from which the planets formed. Because of this, what information can astronomers gain about the beginnings of the solar system?