It was just after seven in the morning on June 30, 1908, when something extraordinary happened above the remote wilds of Siberia. A colossal explosion ripped through the atmosphere five miles above the earth, unleashing chaos below. The explosion scorched and flattened the forest, toppling trees like matchsticks across a 20-mile stretch. Fifty miles away, the force shattered windows and knocked people off their feet. Even a hundred miles from the blast, folks watched in awe as a towering black cloud of ash rose into the sky, accompanied by a thunderous roar that echoed as far as 300 miles. Across the globe, scientists scratched their heads as their instruments picked up strange disturbances from northern Russia. Even now, over a century later, the plants and animals in that area grow in odd, unnatural ways. So, what on earth—or beyond it—happened in Tunguska that day?
The closest people to the explosion were a group of reindeer herders, camped out 25 miles from ground zero. They were fast asleep in their tents when the blast hit, hurling them into the air like ragdolls. One unfortunate individual lost their life, while the others were rendered unconscious. When they finally regained consciousness, the surrounding forest was reduced to a smoking ruin. Further south, at a trading post in Vanavara, 50 miles from the epicentre, witnesses saw the sky tear open, the northern half ablaze with fire. A scorching wave of heat swept over them, so intense it felt like their clothes might burst into flames. The blast tossed them 20 feet through the air, and as they struggled to regain their senses, a deafening crash rang out, followed by a sound like a hailstorm of pebbles raining down.
Those farther off saw the spectacle unfold in the sky beforehand. In scattered towns, people spotted a brilliant “ball of fire” streaking across the morning, trailing a shimmering, iridescent tail. To many, it looked like the end of days had begun. A local paper, the Sibir, captured the scene from Nizhne-Karelinsk, 200 miles away: villagers saw a glowing object, radiating a bluish-white light, descending straight down for ten long minutes. It looked like a “pipe,” they said. The sky was clear that hot, dry day, save for a small, dark cloud low on the horizon where the object appeared. As it neared the ground, it seemed to shatter, replaced by a massive plume of black smoke and a sound like falling boulders or cannon fire. Houses trembled, and a forked flame pierced the cloud. Old women cried, convinced the world was ending.
It wasn’t until March 1927 that the Russians sent someone to investigate. Leonid Kulik, tapped by the Soviet Academy of Sciences, trekked to the site and found an eerie sight: rows of fallen trees fanning out from a central point. He snapped photos and poked around but found no chunks of rock or meteorite—just empty, blasted land. Whatever had caused this cosmic commotion seemed to have burned itself out completely. The lack of debris baffled the Russians. They figured only a giant space rock could wreak such havoc.
Then came World War II, and the atomic bombs dropped on Hiroshima and Nagasaki. Photos of those ruined cities looked eerily similar to Tunguska’s devastation. Witnesses’ stories started sounding more like a nuclear blast, too. But in 1908, no one had nukes—so what gave? Some started whispering about a crashed alien spaceship. Today, people mostly dismiss that theory, replacing it with ideas such as antimatter or a tiny black hole exploding over Siberia. With improved scientific understanding, we now estimate that the blast had a 40-megaton impact, similar to the power of a nuke, but with a larger impact. However, determining the cause of Tunguska remains a challenge, as we grapple with unsolved mysteries.