Hollywood blockbusters such as Deep Impact and Armageddon brought the possibility of earth being hit by an asteroid front and center. These asteroids, also called near earth objects (NEO), miss the earth regularly and there has not been anything detected on the horizon to hit earth within the next 2,000 years, unfortunately it will not take much to send an asteroid in our direction. In preparation for this possibility, a team of British engineers have designed a space craft to save the world.

The central part of this craft is the invention known as the “gravity tractor”, which would be used when a NEO or asteroid is detected as heading towards earth. The plan is to fly the space craft to the asteroid and fly alongside the object, just 160ft above its surfact. At this point the gravity tractor would be deployed, pulling the object closer towards the craft. By changing the course of the asteroid just slightly over a period of years, we can alter its course enough so it will miss the earth.

The entire process would depend on detecting the object very early on, and the actual size of the object. The larger the object, the farther out we would have to intercept, in order to have enough time to alter its trajectory sufficiently.

“Anything bigger than 30m (32 yards) across is a real threat to the Earth,” said Dr Ralph Cordey, science and exploration business development manager at Astrium.

“Unfortunately it is a matter of when rather than if one of them hits us.

“The gravity tractor exploits the principals of very basic physics – every object with a mass has its own gravity that affects objects around it. It can move fairly large objects 300 metres (984ft) to 400 metres (1,312ft) across.

“These asteroids are hurtling around our solar system at 10km per second, so when you scale that up, you just need a tiny nudge to send it off course.”

The scientists believe that in order to make a course correction on an average sized asteroid, it would need to be detected and intercepted 20 years in advance.