‘It might blow up in the air, but the explosion is the main problem, because it would make a massive blast wave which would kill a bunch of people in the middle, and multistorey buildings for a few miles around would be knocked down.
Dr Andrews said that this method, where the asteroid was slammed into by a spacecraft the size of a van, had risks: ‘You don’t want to deflect it so it hits somewhere else on Earth, or breaks up into fragments that are still big and may hit random spots.’.
Nasa’s DART mission in 2022 was the first and only time humans ever deflected an asteroid, when 160m-wide Dimorphos was hit causing its orbit time to shrink by 33 minutes.
This woud break a current taboo against the use of nuclear weapons, but the explosion itself would not have negative consequences for us as ‘it would be so far away that we wouldn’t even see it.’.
Ultimately, if it hit any city, that city would know about it – so it’s good we have enough notice to either do something about it, or simply run away if it’s coming close.
