3 ms·

For comparison, the asteroid from the extinction level event which killed the dinosaurs was about 5 kilometers in diameter.

• roc 13y ago
  And the object that exploded over Chelyabinsk last year was estimated at 20m in diameter. So 270m, while a long way off "catastrophic", is well into "serious".
  • greenyoda 13y ago
    It could still be catastrophic. If it hit a large city, it could immediately wipe out millions of people. If it hit the ocean near the shore, it could create massive tsunamis. If it fragmented into tiny particles on impact or caused a huge firestorm, it could block out enough sunlight to cause a "nuclear winter" scenario: "Similar climatic effects are believed to have followed large comet and asteroid impacts in the past, due to sulfate bearing rock being pulverized and lofted high into the air combined with the ignition of multiple forest firestorms, which is sometimes termed an impact winter..."[1] [1] https://en.wikipedia.org/wiki/Nuclear_winter https://en.wikipedia.org/wiki/Nuclear_winter
    • justin66 13y ago
      Not to mention if it came down in a politically tense time and the ensuing confusion triggered us to deploy the instruments of our civilization's destruction, which we like to keep ready at hand.
      • aaronem 13y ago
        I think I remember reading that one. Lucifer's Hammer, right?
    • mbell 13y ago
      > If it hit a large city, it could immediately wipe out millions of people. I'd bet that an ocean impact would be worse, the resulting Tsunami could level dozens of cities.