Don't fear apocalyptic asteroids

摘要

On 30 June 1908, an asteroid struck Earth, devastating an area the size of a large city. Luckily the Tunguska region of Russia where it landed was mainly forest. On the anniversary of the Tunguska blast next Tuesday, a group led by astrophysicist and Queen guitarist Brian May and film-maker Grigorij Richters will host Asteroid Day, a celebrity-studded event in San Francisco and London designed to raise awareness of the potentially catastrophic risk of an impact. So should we be concerned about apocalyptic asteroids? May and Richters think so. They and other supporters of Asteroid Day-including Chris Hadfield, Brian Cox and Richard Dawkins - have signed a declaration calling for a 100-fold acceleration of efforts to detect near-Earth asteroids in the next decade and increased funding to achieve this goal.