117K views · 1.6K reactions | The Tunguska Event of 1908 - A Meteorite Impact or an Exploding Alien Spacecraft | Strange Mysteries | Facebook

Tunguska wiped out 80 million trees in 1908—but 100 years later, you’d barely know it happened. So how do we really detect ancient impact events? Scientists use techniques like Optically Stimulated Luminescence (OSL) to date when soil and rock layers were last exposed to light—unlocking the hidden timeline of cataclysms past. The Earth bears the scars of countless impacts. Most are invisible… unless you know where—and how—to look. | The Randall Carlson