However, the announcement has triggered a bitter inter-departmental row among civil servants. In other words, when Armageddon arrives all we will able to do is send a policeman on a bicycle. The threat of an asteroid collision is now taken seriously by most astronomers, who point out that our planet is struck regularly by objects from outer space. The best recorded of these events occurred in 1908 when a small asteroid, about 300ft in diameter, exploded high above the Tunguska river valley in Siberia, producing a brilliant blue fireball that knocked people off their feet 40 miles away, and flattened millions of trees. It is thought similar-sized objects hit Earth every 100 years.
Larger objects are fortunately rarer.
For example, the asteroid that destroyed the dinosaurs 65 million years ago was probably a few miles in diameter. With the development of space rockets and nuclear bombs, however, Earth now has a chance to avoid such impacts. The UK initiative has already had an impact on European space programmes. It has been decided that two missions, the Bepi Colombo mission to Mercury, and Gaia, a probe to map stars, should be fitted with asteroid-spotting telescopes. Instead, he has asked Britain's Particle Physics and Astronomy Research Council to appoint a senior astronomer to cost the options outlined by the task force.