A spacecraft capable of saving the world from a catastrophic asteroid collision has been designed by British space scientists. Heroic missions to stop life on Earth from being wiped out by an asteroid have become a favourite theme for Hollywood disaster films.
Now, a team of British engineers have designed a real-life spacecraft to save the world from destruction.
Their invention, called a "gravity tractor", would be deployed when an orbiting rock is detected on a collision course with Earth. The spacecraft would intercept the asteroid and position itself to fly alongside it, just 160ft from its surface.
From this position, the 10 tonne craft is able to exert a small gravitational force on the rock, pulling the asteroid towards it. By gradually modifying its course, over several years, the gravity tractor is able to slowly shift the asteroid's trajectory enough to ensure it misses the Earth.
Details of the planned craft come just weeks after an asteroid or comet was found to have ploughed into Jupiter, which is a giant gas planet, leaving behind a vast impact scar – estimated to be about the same size as the Earth – in its atmosphere.
Scientists believe it is only a matter of time before an asteroid comes close enough to the Earth to be a threat. Nasa, the US space agency, is so concerned that it has established an expensive monitoring programme to track every object in the sky that might come close to the planet.
It estimates there are more than 100,000 asteroids orbiting near the Earth that are large enough to destroy a city. So far the agency has only been able to identify and track 6,363 of them.
Just one football pitch-sized asteroid would be capable of obliterating a large city and could cause widespread destruction by also throwing flaming material into the atmosphere and triggering tidal waves.
In 1908, a meteor of this size exploded above Lake Tunguska in Siberia, destroying 770 square miles of forest. Such collisions hit the Earth every 100 years.
To avoid such a disaster, engineers at space company EADS Astrium, which designs and builds spacecraft for Nasa and the European Space Agency, have designed the gravity tractor.
