The Tunguska Event

One collision on earth is commonly regarded as one of the loudest sounds ever made (in human history, that is...).

On June 30, 1908, an object from space careened into the earth. Likely a meteor 620ft in diameter, this massive fragment imploded 6 miles above the earth's surface, creating an air blast that equated to an explosion 1000 times greater than the Hiroshima bombing.

Larger than most nuclear weapons, this meteor smoked a total of 80 million trees, destroying 830 square miles of forest. The explosion broke windows more than 100km away, and send sounds over hundreds of miles.

A 5.0 on the Richter Scale, the explision produced fluctuations to the earth's atmospheric pressure that were even noticed in Great Britain.

Had this fragment his NYC, the whole metropolitan area would be gone; flattened.

The Tunguska Event has prompted scientists around the world to consider asteroid impact avoidance...which basically consists of breaking the asteroid up until the fragments are too small to cause massive damage.