Seven Wonders of Asteroids, Comets, and Meteors

From earliest times, humans have wondered about the sky above them and have studied all visible objects. People began to identify differences between stars and planets, and as technology advanced with telescopes and space probes, they sought deeper understanding of the millions of bits of debris rocketing through the solar system. Scientists determined that most of these objects are left over from the creation of the planets and their moons. They classified these leftovers into categories such as asteroids, comets, and meteors. In this book, we'll explore seven wonders of asteroids, comets, and meteors. Ceres is a huge mountain-sized asteroid that orbits with other asteroids between Mars and Jupiter. Other marvels include Ganymede, the largest asteroid in the group called Earthgrazers or Near-Earth Objects, and Halley's comet, a ball of ice, that passes Earth every seventy-five or so years.