Meteor shower. Artwork of the meteor shower that may have occurred hours before the Chicxulub met- eorite impact that allegedly caused the extinction of the dinosaurs and 70% of all Earth's species. It happened 65 million years ago. The meteorite was an asteroid or comet, and dust grains accompanying it may have entered the atmosphere before it. As they fell, friction with the atmosphere made them heat up, glow and vaporise. The asteroid or comet was too big to burn up, hitting the ground at Chicxulub on the Yucatan peninsula, Mexico. The impact threw large amounts of debris into the atmopshere, blocking the sunlight and causing global climate changes.