In 1908, something exploded above the remote Siberian forest of Tunguska with enough force to flatten roughly 2,000 square kilometres of trees — and more than a century later, no impact crater has eve

The 1908 Tunguska event flattened ~2,000 sq km of Siberian forest and left no crater. The reason is an airburst: a stony asteroid that disintegrated several kilometres up. What the evidence shows, what is still argued, and why a century-old blast still drives planetary defence. On the morning of 30 June 1908, something detonated in the sky over the Podkamennaya Tunguska River in remote Siberia and flattened roughly 2,000 square kilometres of forest. An estimated 80 million trees were knocked down, splayed outward from a cen... [3360 chars]