A really cool piece from IFLS featuring a video of, well, what the night sky could look like if we could see every asteroid.
Cool. Like a planetarium. It is humbling to think about the reality of impact events. The Tunguska impact in Siberia 1908 was from an asteroid estimated between 60 m (200 ft) to 190 m (620 ft) in diameter. Wiki: "It is estimated that the Tunguska explosion knocked down some 80 million trees over an area of 2,150 square kilometres (830 sq mi), and that the shock wave from the blast would have measured 5.0 on the Richter scale. An explosion of this magnitude would be capable of destroying a large metropolitan area" Even larger impact events have shaped the direction of life. Can we stop/deflect large bodies on short notice?
If we could see them, possibly. But since we can't see them we wouldn't find out about a potential catastrophic impact until it was far too late to do anything other than watch.