Scientists call for killer asteroid hunt
by Richard Waters in San Francisco<
©ESO/L. Calçada/M. Kornmesser/Nick Risinger
An international group of astronauts, scientists and others have called for a rapid expansion of efforts to detect asteroids capable of causing widespread destruction on earth, warning that this is one of the biggest threats to humanity in the coming centuries.
Led by Lord Rees, Britain’s royal astronomer, and Brian May, a PhD in astrophysics as well as guitarist with the rock band Queen, the group said a hundredfold increase in the number of objects detected each year was necessary over the next decade.
Academic projects to detect and track asteroids that might one day collide with earth have been under way for more than 50 years. The work was boosted in 1998 when Nasa was given a decade to identify near-earth objects with a diameter of more than 1km — a size that would turn a collision into a potentially extinction-level event.
However, astrophysicists warn that asteroids and meteors as small as 50m across could still cause devastation on earth, with a direct hit capable of wiping out a city and killing millions. An undetected meteor estimated to be 20m in diameter entered the atmosphere over Russia last year and exploded at a height of several miles, causing a shockwave that injured 1,500 people (pictured). Even the devastating 1908 impact at Tunguska in Siberia, the largest in human recorded history, was caused by an object of only around 50m, said Lord Rees.
Only around 1 per cent of the 1m asteroids, meteors and comets that could cause massive damage on earth have been detected so far, according to a declaration by the group issued on Wednesday.