Nasa's plan to deflect deadly asteroid will not work on asteroid that could collide with Earth, study finds

Nasa's plan to deflect deadly asteroids wouldn't be up to the job of keeping us safe from the deadly asteroid that could one day hit us, a study has found.

Experts have developed a technology called HAMMER that they hope could deflect rocks as they fly dangerously towards us. That should be able to keep us from being hit by asteroids like Bennu – which has a slim but significant chance of colliding with the Earth in 2135.

But the new study finds that for significant dangers like Bennu the plan would not be enough. As such, the world might have to opt for the "nuclear option", of shooting a warhead at the rock and destroying it.

But researchers found that plan would not be enough for asteroids like Bennu, which pose a considerable amount of danger. They found that it could take as many as 50 different rocket launches to safely deflect the rock away, and that success couldn't be guaranteed.

“The chance of an impact appears slim now, but the consequences would be dire,” said Kirsten Howley, LLNL physicist and coauthor on the paper. “This study aims to help us shorten the response timeline when we do see a clear and present danger so we can have more options to deflect it. The ultimate goal is to be ready to protect life on Earth.”

To do so, scientists might have to use a nuclear warhead. That would involve detonating the bomb some distance from an asteroid like Bennu, with the hope that the energy of the blast would deflect it off course.