Rogue Asteroids and Doomsday Comets: The Search for the Million Megaton Menace That Threatens Life on Earth

Steel estimates that a massive asteroid capable of wiping out a fourth of humanity can be expected to collide with Earth roughly once every 100,000 years. In the immediate offing, he maintains, we can expect smaller cataclysmic impacts similar to the Tunguska explosion of 1908, which devastated a vast expanse of Siberian forest (he believes that an asteroid blew up in the atmosphere above the Tunguska River). Written in clear prose for the layperson, this gripping report advocates the creation of an international search program to detect, intercept and divert Earth-menacing asteroids and comets. Steel, an English astronomer based in Australia, served on two NASA committees investigating potential impact hazards. He endorses the theory that asteroid collisions caused not only the dinosaurs' extinction but also many other mass extinctions during the past few hundred million years. Steel's hypothesis that the Taurid meteoroid stream poses the major risk to Earth is bound to be controversial, as is his speculation that the Taurid Complex of meteor showers produced huge storms and Tunguska-type explosions on Earth around 4500 years ago--and that Stonehenge was built to observe and predict these cataclysms. Newbridge Astronomy Book Club alternate. (May)