The Chicxulub impactor was a massive asteroid or comet that struck the Earth around 66 million years ago. This event is widely believed to have caused the extinction of the dinosaurs, marking the end of the Cretaceous period. The impact created the Chicxulub crater in what is now Mexico, which is over 150 kilometers wide. When the Chicxulub impactor collided with Earth, it released an enormous amount of energy, equivalent to billions of atomic bombs. This catastrophic event triggered wildfires, tsunamis, and a "nuclear winter" effect, drastically altering the planet's climate. As a result, many species, including the dinosaurs, could not survive the harsh conditions that followed.