It wouldn't be instant.

Well, it would for a lot of people, but depending on the size of the impact (and actually a close-enough near-miss is just as deleterious to ongoing existence) it'd be a slow and lingering death from hunger, radiation sickness, violence from the total collapse of civilisation, or similar that would do it for the majority of us. We wouldn't see the sun for months, years maybe, from the dust of the impact and airbourne ash from planet-wide uncontrollable forest fires. All plantlife not already incinerated would die off, and we'd follow shortly after.

Posted By: Arizona Bay, May 3, 11:30:27