Life imitates art, or at least retro arcade games, as experts advise that Earth needs an ‘asteroid shield’.
A group of leading scientist have warned the UN that Earth needs an early warning system to deal with the threat of collisions with large extra-terrestrial objects, and more space craft to handle their destruction and deflection. The group, called the International Panel on Asteroid Threat Mitigation made its presentation at the UN’s building in Vienna.
Asteroid detection is currently a rather low priority of the international community, with only £2.7m spent annually. The system that the panel proposes is significantly more expensive, costing around £68m a year. Improvements in telescope technology mean that by 2020, it will be possible to track the movements of half a million asteroids, of which several dozen may be a risk to Earth. Unfortunately, it is nearly impossible to predict which asteroids will actually hit the Earth, meaning that missions will have to be launched to deflect or destroy objects with a chance to hit as low as 1% and these missions would have to launched far in advance of the object being anywhere near Earth.
The risk of a significantly sized asteroid, defined by the panel as being more than 45 meters in diameter, actually hitting the Earth has been calculated as two or three events every millennium, which seems like good odds, but the panel points to the asteroid that wiped out the dinosaurs and also to the Tunguska incident, now known to have been caused by a similar collision, as proof of the catastrophic outcome of such an occurrence.
The panel, chaired by former US astronaut Russell Schweickart, and including Royal Society president Lord Rees and environmentalist Crispin Tickell said, “The international community must begin work now on forging three impact prevention elements – warning, deflection technology and a decision-making process – into an effective defense against a future collision… We are no longer passive victims of the impact process, we cannot shirk the responsibility.”
Source: The Guardian
Published: Dec 7, 2008 04:58 pm