A cosmic object, likely a stony asteroid roughly 60 meters wide, detonated several miles above the Podkamennaya Tunguska River with a force estimated at 10-15 megatons. The blast flattened an estimated 80 million trees over 2,150 square kilometers. Because the region was so remote, no confirmed deaths were recorded, though eyewitnesses reported the sky burning and being knocked off their feet hundreds of kilometers away.
Herders of the Evenki people near the Podkamennaya Tunguska River watched the sky split apart. A column of blue-white light, they said, brighter than the sun, moved across the heavens, followed by a flash and a sound like artillery fire that rolled on for minutes. Reindeer scattered, tents collapsed, and one man was reportedly thrown from his porch and knocked unconscious.
The Russian Empire, distracted by revolution and war, sent no scientific expedition for nearly two decades. When the mineralogist Leonid Kulik finally trekked into the taiga in 1927, he found no crater at all, just a vast, eerie fan of scorched trees lying flat with their tops pointed away from a central zone, like matchsticks blown by a giant's breath. At the very center, trees remained standing, stripped of branches and bark, a signature of an airburst rather than a ground impact.
Modern estimates put the energy release at 1,000 times that of the Hiroshima bomb. Had the object arrived four hours later, Earth's rotation would have positioned St. Petersburg beneath it. The event remains the benchmark by which scientists measure the danger of near-Earth asteroids, and every June 30 is now marked as International Asteroid Day in its honor.
Key people: Leonid Kulik