COSMIC IMPACT: Understanding the Threat to Earth

Bart Simpson's solution to the risk of an asteroid impact was to "party hard and wreck the place", and many people would echo that fatalistic judgment. The author concludes this no-nonsense guide by detailing the ways in which cosmic impact could be avoided, arguing that rather than seeking to explode the space invader with possible disastrous consequences to its destination as well, deflection is the modern scientific alternative. Earth has only one easily recognisable impact crater, the Meteor Crater in Arizona which is less that fifty thousand years old. For those who know what to look for, however, Earth has many more craters, for instance the 200 km-wide Chikxulub Crater on Mexico's Yucatan Peninsula from 66 million years ago, which landed in an explosion five billion times worse than Hiroshima and extinguished the dinosaurs. Famous comets have often been considered to be bad omens, for instance Halley's Comet which appeared before the Battle of Hastings, though as the author points out, it must have been seen by both sides. Halley's is predictable, but in our own time Hale-Bopp of 1997 emerged as a surprise out of its elongated orbit. Pseudo-scientists have had a field day misinterpreting comets, for instance Immanuel Velikovsky in the 1950s, who based his theories on the belief that Jupiter had created a comet by colliding with Saturn. There is now a worldwide effort to protect our planet by monitoring the risk of comet impact. 168pp, paperback, black and white photos and diagrams.