It's a small point but isn't a "near Earth impact" actually a "miss" ? And wouldn't the impact from a miss be zero?
Heh... good point... but he refers to impacts by Near-Earth objects.
I read a REALLY BAD sci fi novel about a near impact once. In the novel an asteroid or comet passed close over the north pole. Some strange gravatational effect caused a large part of our atmosphere to be draw up over the north pole in some kind of freak super high pressure system.
Long story short. The atmosphere suddenly snapped back causing thousand+ MPH winds across the planet wiping out mankind.