NASA launch TODAY 'could help save millions of lives' in real-world doomsday scenario

However, this will not happen until late September 2022 when DART rendezvous with Didymos about 6.8 million miles (11 million km) from Earth.

And if all goes according to plan, Professor Womersley argued it will bolster NASA’s planetary defences.

He said: “The best result will be first, that DART successfully reaches and impacts Didymos, which is one of a pair of twin asteroids travelling together around the Sun; and then that this impact changes the way it orbits its twin just in the way that NASA scientists calculate and expect from computer simulations.

“If that happens it will give us confidence a future mission to redirect an asteroid away from Earth could in principle be designed and constructed should it ever be needed.”