The Tunguska Event

"At around 7:15 AM, Tungus natives and Russian settlers in the hills northwest of Lake Baikal observed a huge fireball moving across the sky, nearly as bright as the Sun. A few minutes later, there was a flash that lit up half of the sky, followed by a shock wave that knocked people off their feet and broke windows up to 650 km (400 mi) away. The explosion registered on seismic stations across Eurasia, and produced fluctuations in atmospheric pressure strong enough to be detected by the recently invented barographs in Britain. Over the next few weeks, night skies over Europe and western Russia glowed brightly enough for people to read by. In the United States, the Smithsonian Astrophysical Observatory and the Mount Wilson Observatory observed a decrease in atmospheric transparency that lasted for several months.

Had the object responsible for the explosion hit the Earth a few hours later, it would have exploded over Europe (most probably Scandinavia) instead of the sparsely-populated Tunguska region, producing massive loss of human life and changing the course of human history..."