The asteroid that killed the dinosaurs hit the Earth at a site known as the Chicxulub crater, which is located on the Yucatán Peninsula in Mexico. The asteroid was about 10 to 15 kilometers wide and struck with such velocity that it created a crater approximately 150 to 200 kilometers in diameter. This impact caused massive devastation, huge tidal waves, fires, and threw large amounts of debris into the atmosphere, leading to the mass extinction event that wiped out about 75% of Earth's species, including all non-avian dinosaurs. The impact occurred around 66 million years ago.