The Tunguska event
At 7.17 am on the morning of June 30, 1908, an explosion erupted in remote Siberia, ripping two thousand square kilometres of trees from their roots. Called the Tunguska event, it felled over eighty million trees, killed hundreds of reindeer, registered on barometers as far away as England, and made the night skies glow as far away as China.
The region is so remote that the first scientific expedition to the impact sight wasn’t for 19 years, led by Leonid Kulik, and they found no crater like you might expect, just mineral traces and endless felled trees. Even after 100 years, scientists aren’t 100% certain about what happened.
People have come up with all sorts of fabulously impossible explanations—a UFO crash, the annihilation of a chunk of antimatter, a mini black hole, Nikola Tesla’s “death ray”, a visitation by the god Ogdy—but the generally accepted theory is that the Tunguska event was, in fact, a large asteroid. It’s thought that during its plunge down through the atmosphere, the combination of speed, pressure and accumulated heat caused it to detonate 5–10 kilometres up, burning itself up and producing an immense shockwave.
The size of the asteroid is still debated, but it’s the largest impact event on or near Earth in recorded history. On average, an asteroid this size will plunge through Earth’s atmosphere every 300 years.
(Image Credit: Leonid Kulik)