Once such a deadly asteroid is discovered to be barrelling on a collision course with Earth, Mr Nye explains how they can be deflected.
He said: “We have got to deflect these asteroids, by just a tiny amount.
‘An asteroid might be travelling 10 km/s, and we want to change its speed about 2 mm/s.
“This will change the asteroid’s speed by a 10 millionth its total.
“But asteroids can come in at 10,000 – 100,000 tonnes, requiring a significant force to alter it by a 10 millionth of its speed.
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