What is the difference between a comet and an asteroid? What makes up each one? How do have they affected our world in the past--and how will they continue to do so in the future? These questions and more are answered in this volume, which offers a fascinating look at these celestial objects and their impact on our universe. Through stunning full-color photographs and detailed graphic organizers, readers learn about the history of comets and asteroids, their composition and structure, and how they have shaped the formation of our solar system.