66 million years ago, a ~10-kilometer asteroid slammed into Mexico's Yucatan Peninsula at 20 km/s, ending the Mesozoic era and triggering the extinction of 75% of Earth's species, including all non-avian dinosaurs.
1. Astounding Energy Release
The impact unleashed ~100 teratons of TNT equivalent energy (1 billion Hiroshima bombs), excavating a crater 180 km wide and 20 km deep within minutes.
2. Cascading Global Megadisasters
- **Megatsunamis**: Generated waves exceeding 300 meters, scouring continental shorelines.
- **Global Firestorms**: Vaporized ejecta re-entering the atmosphere radiated intense infrared heat, igniting worldwide wildfires.
- **Impact Winter**: Billions of tons of sulfur aerosols and soot blocked sunlight for years, halting photosynthesis and collapsing global food webs.
3. Evolutionary Legacy
Burrowing mammals and avian dinosaurs survived the fallout, eventually radiating into the diverse fauna of the Cenozoic era.