The Fate of the Dinosaur-Killing Asteroid
The asteroid that caused the dinosaurs' extinction 66 million years ago was about 7 miles wide, leaving behind a massive crater in Mexico and a layer of iridium-rich rock, but little of its physical remains have been found. Its impact triggered global fires, tsunamis, and a 'nuclear winter' effect, leading to the extinction of about 75% of Earth's species.
