What 1908 event flattened a vast area of forest near the Podkamennaya Tunguska River?

The Tunguska event was the 1908 event that flattened a vast forest near the Podkamennaya Tunguska River.

On 30 June 1908, a powerful explosion occurred over a remote part of central Siberia, then within the Russian Empire. The blast knocked down trees across an estimated 2,000 square kilometres, but no confirmed impact crater was found. The leading scientific explanation is that a stony asteroid or comet fragment exploded in the atmosphere before reaching the ground.

Witnesses reported bright skies, shock waves and atmospheric disturbances across a wide region. Because the location was extremely remote, a major scientific expedition did not reach the blast area until 1927, led by Leonid Kulik.

The event is often described as an airburst. Its estimated energy varies by model, commonly reaching several megatons of TNT. The Tunguska explosion differs from the 2013 Chelyabinsk event, which injured people mainly through shattered glass over a populated area.