At 7:17 AM on June 30, 1908, the sky over the remote Tunguska River in Siberia split in two. Sixty-five kilometers away, at the Vanavara trading post, a farmer named Semyon Semyonov was on his porch. He saw a brilliant flash and felt a wave of heat so intense he thought his shirt was on fire. Moments later, a "mighty crash" threw him several feet and knocked him unconscious. The explosion, equivalent to 15 megatons of TNT, was a thousand times more powerful than the atomic bomb later dropped on Hiroshima. It was the largest impact-related event in recorded history, yet it happened in a vast, empty wilderness, far from the world's attention. What could have caused such a cataclysm?
Tunguska
The 1908 explosion over Siberia that flattened 80 million trees and left no crater, inspiring modern planetary defense.
Chapter 1
The Sky Splits in Two
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Frequently Asked Questions
What was the Tunguska event?
The Tunguska event was a massive explosion that occurred over a remote part of Siberia on June 30, 1908. It is believed to have been caused by a stony asteroid or comet fragment, about 50 to 100 meters wide, exploding in mid-air. The blast released energy equivalent to 10-15 megatons of TNT.
Why did it take so long to investigate the Tunguska site?
It took 19 years for a scientific expedition to reach the epicenter due to the site's extreme remoteness and major political upheavals. While Leonid Kulik conducted a preliminary investigation in 1921, World War I and the Russian Revolution had previously diverted resources, making a full expedition to the impact site impossible until 1927.
Is there a crater at the Tunguska site?
No, there is no impact crater. Despite extensive searches, none was ever found because the object disintegrated in a massive airburst 5 to 10 kilometers above the ground. The lack of a crater is the key piece of evidence that the object vaporized before it could strike the Earth.
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