The real threat isn't the planet killers. It's the city busters. He points to the 1913 meteorite train, a procession of fireballs that crossed the populated Northeast. If that stream had contained dozens of objects between one hundred and two hundred feet, each one could have delivered a Tunguska-scale impact. Not extinction, but millions of casualties. Entire cities leveled in minutes.
An event of that magnitude wouldn't end civilization, but it could collapse the global economy for years. The infrastructure damage, the cascading failures, the psychological shock. These are the scenarios that keep researchers awake at night. Not because they're impossible, but because they've already happened. The question isn't if, it's when, and whether we'll see it coming.