Book excerpt: Hurtling through the atmosphere, in a blaze of light and reverberating percussions, the arrival of a meteorite on Earth is a magical, rare, and precious sight. These characteristics have accordingly ensured a long, yet often controversial history. For all this, meteorites are cosmic messengers. They tell us about the entire history of the solar system, their story carrying us from the very earliest moments, when solid material first began to form in the solar nebula. Indeed, meteorites played a key role in the origins of Earth's oceans and the genesis of life. Meteorites additionally tell us about the origin and evolution of the asteroids, and they tell us about impacts upon the Moon as well as the volcanic history of planet Mars. Much is known about the structure and chemistry of meteorites, but for all this, they still harbor many scientific mysteries that have yet to be resolved.