Astronomers hash out defense against asteroids

A billion dollars needed to spot potential killer impacts.

Jeff Kanipe

Crash landing: how do we stop this from happening? Don Davis/NASA

Astronomers trying to save the world from Earth-threatening asteroids have this week composed a white paper outlining the threat and what needs to be done about it.

Although it isn't their first white paper on the subject - that was released in 2004 - it is the first mandated by Congress. This, scientists hope, may mean that their conclusions will be taken more seriously by decision-makers in Washington.

In 2005, Congress passed a bill authorizing NASA to search for asteroids as small as 140 metres that could possibly strike the Earth. The bill, however, provided no money for the search. Scientists at the Planetary Defense Conference, held 5-8 March in Washington DC to compose the new white paper, were quick to point this out.

On Monday, Simon 'Pete' Worden, director of NASA's Ames Research Center, said that the cost of finding at least 90% of the 20,000 estimated potential Earth-killers by 2020 would cost about $1 billion. US government employees, including NASA scientists, don't usually make public requests for more cash, but Worden was clear: "We know what to do, we just don't have the money."