Rogue asteroids and doomsday comets

Could a giant asteroid or comet crash into the Earth and destroy life as we know it? Many astronomers who formerly discredited the risks are now convinced there is a grave danger. In Rogue Asteroids and Doomsday Comets, astronomer Duncan Steel explores the scientists' fascinating and often chilling findings. Director of one of three global asteroid and comet search programs, Steel is one of the world's leading experts. He tells the intriguing story of the scientific detection work that pieced together mounting evidence to uncover a stunning history of impacts. Massive comet and asteroid impacts scarred our planet frequently in the past - a comet was almost surely responsible for the extinction of the dinosaurs. Recent advances in telescope tracking technology show at least 2,000 objects now orbiting the Earth that are large enough to hit with the force of a nuclear weapon. Based on the best calculations, it is certain that the Earth will sooner or later find itself on a disastrous collision course once again. . In the event of a collision, evidence suggests outcomes such as three-mile-high ocean waves capable of obliterating coastal communities worldwide, a massive conflagration an