On the morning of June 30, 1908, a massive explosion rocked the remote region near the Podkamennaya Tunguska River in Siberia. The blast generated heat and shockwaves so powerful that it flattened roughly 80 million trees across an area twice the size of modern-day New York City. Eyewitnesses hundreds of miles away reported seeing a bright blue light followed by a pillar of fire and seismic waves that registered on barometers across Europe.
Despite the staggering destruction, when Soviet mineralogist Leonid Kulik led the first scientific expedition to the site in 1927, he made a baffling discovery: there was no impact crater anywhere to be found. Instead, he discovered a central ring of scorched, standing trees with their branches stripped away—resembling giant telephone poles—surrounded by millions of felled trees pointing radially outward. Modern consensus among astrophysicists is that the Tunguska event was caused by an airburst.
A stony meteoroid or small comet, measuring roughly 100 to 200 feet in diameter, entered Earth's atmosphere traveling at speeds around 33,000 miles per hour. As the space rock plunged through the thick lower atmosphere, extreme aerodynamic pressure and heat caused it to rapidly fragment and vaporize approximately 3 to 6 miles above the ground. The sudden energy release—estimated between 10 to 15 megatons of TNT, or roughly 1,000 times more powerful than the Hiroshima atomic bomb—created a high-altitude shockwave that flattened the forest below while leaving the ground surface intact from direct mechanical impact.