The blast that flattened 80 million trees with no crater

On the morning of 30 June 1908, a massive airburst over Siberia felled roughly 80 million trees across 2,150 square kilometres — with no impact crater ever found. Decades of speculation followed, but scientists now largely agree it was a stony asteroid, 50–60 metres wide, exploding 5–10 km above the ground with the force of a large nuclear weapon.

— Standard astronomical and geological accounts, Tunguska event — 30 June 1908, Krasnoyarsk Krai, Russia