On today’s date 113 years ago, the largest asteroid impact in recorded history struck on a warm summer morning in Siberia, Russia. We observe Asteroid Day each year on June 30, on the anniversary of what’s now known as the Tunguska explosion.
The explosion happened over the sparsely populated northern forestland above the Podkamennaya Tunguska River in what is present-day Krasnoyarsk Krai.
The blast released enough energy to kill reindeer and flatten an estimated 80 million trees, over an area of 830 square miles (2,150 square km). Witnesses reported seeing a fireball – a bluish light, nearly as bright as the sun – moving across the sky. A flash and a sound similar to artillery fire was said to follow it. A powerful shockwave broke windows hundreds of miles away and knocked people off their feet.
Yet decades passed before anyone could explain the event.
