This history of asteroids explains how ideas about asteroids have evolved and provides insights into the evolution of scientific ideas. The author describes how such phenomena as the Moon’s craters and dinosaur extinction were gradually, and by some scientists grudgingly, accepted as the results of asteroid impacts. He tells how a band of icy asteroids rimming the solar system, first proposed as a theory in the 1940s, was ignored for more than 40 years until renewed interest and technological breakthroughs confirmed the existence of the Kuiper Belt. Covering all aspects of asteroid investigation, Peebles also chronicles the discovery of Shoemaker-Levy 9, a comet with 22 nuclei that crashed into Jupiter in 1994, releasing many times the energy of the world’s nuclear arsenal.