London - A fleet of kamikaze spacecraft could be used to defend Earth against asteroid strikes.
The robotic vessels would change the direction of any threatening space rock to prevent it from crashing into the planet.
The prediction came as the UN discussed plans for an international asteroid defence network.
Under the plans, member nations will share information in an International Asteroid Warning Group, allowing space agencies to pool their brainpower to come up with the best way of deflecting any incoming objects.
A meteor, or asteroid fragment, that exploded over Russia in February injured more than 1 000 people. Scientists estimate there are a million asteroids big enough to destroy New York, and that an object big enough to threaten civilisation comes along once every few million years.
The veteran Nasa astronaut Tom Jones advocates defending the planet by using “a fleet of robot spacecraft to slam into the asteroids” to deflect them.
Other options include using a “gravity tractor” to tow asteroids off course and pummelling them with paintballs.
The option of blowing them up, as in the Bruce Willis film Armageddon, is likely to be the last resort.
But Sergio Camacho-Lara, of the UN Office for Outer Space Affairs, said: “The asteroids are there. It’s a question of finding them before they find us.”
Professor Richard Crowther, of the UK Space Agency, said: “It is always good to rehearse these things well in advance.” - Daily Mail