The Tunguska Event was 100 years ago today, in 1908. A rock fell from the sky, exploded in midair, and devastated a huge swath of Siberia with a 5-megaton blast. Had it hit a populated area it could have been a catastrophe.
It could happen again, with little or no warning, at any time. Unfortunately, despite a century to prepare and a number of close calls, we are not ready to do anything about it.
And I can’t help but think it’s because many in the public and the government think the idea of asteroids from space are funny. I suspect that the earthquakes, firestorms, tsunamis, and general death on a massive scale are not going to be all that amusing after the fact.