0:00 On June thirtieth, 1908, an explosion equivalent to one thousand Hiroshima bombs flattened eighty million trees across two thousand square kilometers of Siberian forest.0:11 The blast was heard hundreds of kilometers away and registered on seismic stations across Europe.0:18 And here's the part that scientists are still arguing about more than a century later: it left NO impact crater.0:26 Last time, we talked about London's Great Stink of 1858, a disaster you could literally smell coming.0:33 This was the opposite—a cataclysm almost no one saw, that happened in an instant, and shook the entire planet.0:41 So what actually happened that morning over the Podkamennaya Tunguska River?0:47 It’s a place so remote that even today it’s brutally difficult to get to.0:52 For the few indigenous Evenki people and Russian settlers living nearby, it was the end of the world.0:59 Eyewitnesses dozens of kilometers from the epicenter reported seeing a column of bluish light, nearly as bright as the sun, moving across the sky.1:09 Then came a flash, a pillar of fire, and a sound that people compared to artillery fire or rocks falling from the sky.1:18 One farmer sitting on his porch sixty-five kilometers away was thrown several meters by the shockwave and knocked unconscious.1:26 His shirt felt like it was on fire.1:29 For several nights afterward, the sky over Europe and Asia was so bright you could reportedly read a newspaper outside at midnight.1:38 Something massive had happened.1:40 But what?1:41 Here’s where the story gets strange.1:44 Because of the region’s isolation, and because Russia was about to be consumed by World War One and then a revolution, nobody went to investigate.1:54 Not for years.1:55 The first scientific expedition, led by a mineralogist named Leonid Kulik, didn’t reach the site until 1927.2:03 That’s NINETEEN years later.2:04 Kulik was funded by the Soviet government because he was hoping to find a gigantic iron meteorite he could salvage for Soviet industry.2:14 He was expecting to find a crater.2:16 He found a forest of dead trees.2:19 For kilometers in every direction, the trees were scorched and knocked over, all pointing away from a central point, like spokes on a wheel.2:29 But at the very center, at ground zero, a few trees were still standing, stripped of their branches and bark.2:36 Ghost trees.2:37 It was eerie.2:38 It was definitive proof of a massive, top-down explosion.2:42 But Kulik searched for years, over multiple expeditions, and he never found the crater.2:48 Or the meteorite.2:49 He found microscopic silicate and magnetite spheres in the soil, but the big prize, the object itself, was simply...2:58 gone.2:58 So where have we seen this before?3:00 The answer came on February fifteenth, 2013, over the Russian city of Chelyabinsk.3:06 You’ve seen the dashcam videos.3:08 A meteor, about twenty meters across, screamed into the atmosphere and exploded.3:14 It was an AIRBURST.3:15 It didn’t hit the ground.3:17 It disintegrated from the sheer pressure and heat about thirty kilometers up, releasing the energy of roughly thirty Hiroshima bombs.3:27 The shockwave blew out windows in thousands of buildings and injured over a thousand people, mostly from flying glass.3:35 Chelyabinsk was our modern Rosetta Stone for Tunguska.3:39 It proved that a space rock doesn’t need to hit the ground to cause immense damage.3:45 Now, apply that model to Tunguska.3:47 The leading theory is that a much larger object, maybe a stony asteroid or an icy comet nucleus somewhere between fifty and one hundred meters across, entered the atmosphere and detonated five to ten kilometers up.4:02 The explosion vaporized the object completely.4:05 That explains the blast wave, the felled trees, the thermal radiation that scorched everything, and the complete lack of a crater.4:15 The Chelyabinsk event was a city-shaker.4:17 Tunguska was a city-ERASER.4:19 If it had happened over Moscow or Paris, it would have been the single deadliest event in human history.4:27 And that’s the real takeaway.4:29 We have a very good theory, but without a single fragment of the original object, we don’t know for sure what it was.4:37 An asteroid?4:38 A comet?4:38 We can’t analyze its chemistry.4:41 So the mystery endures, not because we have no idea what happened, but because we can’t find the celestial bullet that was fired at our planet.4:51 The Tunguska event isn’t just a historical curiosity.4:55 It’s the Earth’s biggest near-miss in recorded history, a silent, eighty-million-tree monument to the fact that the sky is not nearly as empty as it looks.
