Glossary

The Chicxulub crater is a buried impact structure approximately 180 km in diameter located beneath the Yucatán Peninsula, Mexico, with its centre near the coastal town of Chicxulub Puerto. It was formed approximately 66 million years ago when an asteroid estimated at 10–15 km in diameter struck the Earth at a speed of roughly 20 km/s, releasing kinetic energy on the order of 72 teratonnes of TNT equivalent (approximately 300 zettajoules). The impact generated a transient cavity roughly 100 km wide and 30 km deep, which subsequently collapsed to form the final crater structure, including a prominent peak ring approximately 90 km in diameter. The impact is widely accepted as the primary cause of the Cretaceous–Paleogene (K–Pg) mass extinction, which eliminated approximately 75–80% of all species on Earth, including all non-avian dinosaurs. The collision injected vast quantities of dust, sulfate aerosols, and soot into the atmosphere, triggering a global impact winter that suppressed photosynthesis, disrupted food chains, and caused severe temperature fluctuations lasting years to decades. This event marks the boundary between the Mesozoic and Cenozoic eras, fundamentally reshaping the trajectory of life on Earth and enabling the subsequent radiation of mammals, birds, and flowering plants into ecological niches formerly occupied by dinosaurs and other Mesozoic fauna.