The Tunguska bolide: the brutal 12-megaton explosion in 1908 that brought us face to face with the horrors of space

The 1908 Tunguska explosion flattened a vast Siberian forest, likely after an asteroid or comet fragment exploded in the atmosphere.

It released about 12 megatons of energy, left no crater, and showed how devastating an airburst can be.

Similar impact events have happened before and since, so the risk is low but real.

Asteroid Day uses Tunguska to raise awareness about asteroid threats and planetary defense.