Living In A Crowded Neighbourhood

So, you thought the people coming up with ideas for effectively blocking asteroids from hitting the Earth were being a bit paranoid? There’s a whole lot of those rocks out there, as shown by this map of the known asteroids within 3AU of the Earth – and that’s not counting the ones we haven’t spotted yet, of which there may be literally thousands more. Makes you realise how lucky we’ve been to survive this long.