History Channel - Original Air Date: 2006
A serious survey of the great Tunguska explosion, its history, and what probably caused it. Particularly interesting is the footage of Russian scientists and expeditions dating back from the present to the time of the explosion. My favorite bit is the Russian scientist who replicates the blast pattern of the explosion using a room filled with what looks like matchsticks standing on end. This experiment reveals the angle of impact and amount of force needed to create the devastation seen in the Siberian forest. A good show with good science. The most likely culprit for the explosion: a stony asteroid exploding before it hit the tundra. (Sorry UFO buffs!) The show ends with a call to find and intercept future near-earth-objects (NEOs) like the one that flattened Tunguska.