On June 30, 1908, a comet fragment exploded in Earth's atmosphere in Russian Siberia. A great blue-white fireball, brighter than the Sun streaked through the sky, exploded six to eight kilometers in the atmosphere with a blinding flash and intense pulse of heat.
electromagnetic pulse like anomalies were reported. The magnetic
storm began a few minutes after the explosion. A compass was
useless in Irkutsk, 1,000 km away.
The explosion was heard 1,000 km away with trees were flattened 30 km from a central point in the Stony Tunguska River Valley. Sides of trees were burned 60 km away. The blast destroyed over 600 square kilometers of forest as the pillar of smoke and dust rose over the area. No crater was found.
Scientists have observed the destruction and concluded the explosion had the force of a 30 megaton hydrogen bomb.
Although there were no meteorite pieces, tiny green globules of melted dust called trinities were discovered in the area, similar to those produced at the site of the first atomic bomb test in New Mexico.