Bokelskere.no

So why, out of all the thousands of impacts Earth has endured, was the KT event of 65 million years ago, which put paid to the dinosaurs, so singularly devastating? Well, first, it was positively enormous. It struck with the force of 100 million megatonnes. Such an outburst is not easily imagined, but, as James Lawrence Powell has pointed out, if you exploded one Hiroshima-sized bomb for every person alive on Earth today you would still be about a billion bombs short of the size of the KT impact.