What happened
On the morning of June 30, 1908, at about 7:15 a.m. local time, residents of central Siberia saw a fireball brighter than the Sun streak across the sky. Moments later, an explosion occurred over the taiga near the Podkamennaya Tunguska River, flattening trees over an area of about 2,150 km². At the Vanavara trading post, some 60 km from the epicenter, the shock wave shattered windows and threw a man off his porch, and its trace was recorded by barographs in Europe. For several nights afterward the sky over Europe and western Asia was so bright that in London one could read a newspaper at midnight. The first scientific expedition to the site was organized by Leonid Kulik only in 1927. Instead of a crater, he found trees felled in a radial pattern and dead trunks still standing at the center.
Witnesses
Evenks and settlers from the surrounding area, including residents of the Vanavara trading post; the wave was recorded by seismographs and barographs in Russia and Europe.
Explanations and hypotheses
According to the prevailing hypothesis, a meteoroid several tens of meters in diameter – a rocky asteroid or a fragment of a comet – exploded at an altitude of 5–10 km, releasing energy most often estimated at 10–15 megatons of TNT. The absence of a crater is explained by the object breaking up in the air. Microscopic silicate and magnetite spherules have been found in the soil, but no larger fragments. Hypotheses of a spacecraft crash or antimatter have no basis in evidence.
Explained The phenomenon has a widely accepted, down-to-earth explanation.
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