The Chicxulub Asteroid Impact - The Day the Dinosaurs Died One of the deepest scars on our planet is hidden beneath the Yucatán Peninsula and the Gulf of Mexico. The buried crater, over 90 miles in diameter, was created when a massive asteroid struck the planet 66 million years ago and brought a calamitous end to the reign of dinosaurs. Though dinosaur extinction probably took weeks or months, in just one day, 425 feet of material accumulated where the asteroid hit with the power of 10 billion a