Originally Posted by anonytmouse
Meteorites that could cause major damage if they hit a city are relatively common on a geological time frame. Fortunately a large meteorite has a good chance of hitting somewhere on the 95% of the earth's surface that isn't covered by a city. Meteorites that could wipe out human life on earth are much much rarer.
>> Interesting to entertain the thought that the whole of human existence could be wiped out in a matter of hours. <<
Unfortunately, this is many times more likely to be caused by a full scale nuclear conflict than a mega-meteorite.