Comets: Creators and Destroyers

The recent discovery of an asteroid seemingly on a near-collision course with Earth has heightened awareness of the real risk to our species and civilization posed by asteroids and their spectacular cousins, the comets. Levy, who was a discoverer of the comet Shoemaker-Levy 9 in 1994 (and who chronicled the comet's explosive demise in Impact Jupiter), has authored a host of other books about comets and is science editor of Parade. In his compact and literate new book, he notes that comet impacts on the early Earth were the likely source of the water and organic materials that developed into life. They were also the most likely cause of the demise of the dinosaurs (and other mass extinctions), paving the way for the rise of mammalian life. The book is rich in photographs and images, including three paintings by James V. Scotti, discoverer of the near-miss asteroid that made recent headlines. Science fiction buffs will appreciate the millennial doomsday scenario Levy offers, beginning with a terse scientific announcement heralding a train of disrupted comet pieces heading for a spectacular impact on Earth in July 2000. Those who prefer fact-based speculation to flights of imagination will appreciate his knowledgeable discussion of the possibility of comet-seeded life on other worlds in the solar system, the Milky Way and beyond. 40 b&w photos. (May)