# Chicxulub Crater (DD-693) > The Chicxulub crater is a buried impact structure about 180 to 200 km across, centered near the town of Chicxulub on Mexico's Yucatán coast and extending under the Gulf of Mexico. It formed about 66 million years ago when an object roughly 10 km wide struck Earth, and the impact is tied to the end-Cretaceous mass extinction. Nothing of the crater is visible at the surface. It lies under about 1 km of younger sediment, and a ring of sinkholes (cenotes) traces its outline. Pemex geophysicists Glen Penfield and Antonio Camargo found it while searching for oil. It was identified as the impact site in 1991. In 2016, IODP-ICDP Expedition 364 drilled its peak ring, and a 2024 ruthenium-isotope study concluded the impactor was a carbonaceous asteroid that formed beyond Jupiter, not a comet. - Department: Science (also Space, History) - First published: 2026-01-14 - Last updated: 2026-01-14 - Permalink: https://detailenjoyer.com/case/chicxulub-crater/ - Author: Marcus Easterling (DetailEnjoyer), The Detail Department ## On the timeline - **1980**: The Alvarez team proposes that an asteroid impact ended the Cretaceous - **1991**: Hildebrand and colleagues identify Chicxulub as the impact crater - **2016**: IODP-ICDP Expedition 364 drills Chicxulub's peak ring Full timeline: https://detailenjoyer.com/timeline/?case=chicxulub-crater ## Quick facts - **DD-693-F01**: The Chicxulub crater is buried under about 1 km of sediment. _(Write-up · Exhibit A (Hidden scar))_ - **DD-693-F02**: A 2024 study found the impactor was a carbonaceous asteroid, not a comet. _(Write-up · Exhibit E (What hit))_ ## Write-up A crater you can't see. The 66-million-year-old scar is buried under about 1 km of sediment. 1. **Hidden scar**: The crater is buried under about 1 km of younger sediment, half on land and half under the Gulf of Mexico. A ring of cenotes on the Yucatán marks its edge. 2. **How big**: Estimates put it at about 180 to 200 km across, larger than the Reel's 150 km. It's one of the largest confirmed impact structures on Earth. 3. **Found by oil explorers**: Pemex geophysicists Glen Penfield and Antonio Camargo noticed the structure in geophysical data in the late 1970s. In 1991, Alan Hildebrand and colleagues linked it to the end-Cretaceous impact, which Luis and Walter Alvarez's team had proposed in 1980. 4. **Drilling the peak ring**: In 2016, IODP-ICDP Expedition 364 drilled into the crater's peak ring offshore and recovered core down to about 1,335 m below the seafloor. It showed the ring was made of shocked, uplifted rock from deep down. 5. **What hit**: A 2024 ruthenium-isotope study found the impactor was a carbonaceous (C-type) asteroid that formed beyond Jupiter, which rules out a comet. ## Related case files - [Dead Pools (DD-049)](https://detailenjoyer.com/case/dead-pools/): Another case under the Gulf of Mexico - [Nuclear Fireball (DD-052)](https://detailenjoyer.com/case/nuclear-fireball/): Another case about an enormous release of energy - [Three-Horned-Face! (DD-201)](https://detailenjoyer.com/case/three-horned-face/): I linked the impact that ended the Cretaceous - [The Cretaceous King (DD-202)](https://detailenjoyer.com/case/the-cretaceous-king/): I linked the impact that ended the Cretaceous - [striking! (DD-393)](https://detailenjoyer.com/case/striking/): I linked more impact craters - [Second Impact (DD-578)](https://detailenjoyer.com/case/second-impact/): The dinosaur-killing impact this Reel compares against - [Snake Supreme (DD-694)](https://detailenjoyer.com/case/snake-supreme/): Another case from tens of millions of years ago ## Reel vs. record - **Size**: the crater is usually put at about 180 to 200 km across, not 150 km (93 mi). - **Note**: Asteroid, not comet: a 2024 ruthenium-isotope study in Science concluded the impactor was a carbonaceous asteroid that formed beyond Jupiter. - **Wording**: scientists call it an 'impact winter', caused mostly by sulfate aerosols and soot blocking sunlight. 'Nuclear winter' is an analogy. - **Missing context**: the crater can't be seen. It's buried under about 1 km of sediment, and a ring of cenotes traces its outline. The footage probably doesn't show the crater itself. - **Debated detail**: how widespread the 'global wildfires' were is still debated. Soot was clearly produced, but how much burned worldwide is uncertain. ## Video: Chicxulub Crater: A Crater You Can't See - Duration: 30.2 s · Published: 2026-01-14 - File: https://detailenjoyer.com/assets/videos/DTg5ChIEaOG.mp4 ### Transcript DID YOU KNOW? The Chicxulub crater located on the Yucatan Peninsula in Mexico, is a massive impact structure created around 66 million years ago by the collision of a large asteroid or comet with Earth. Measuring approximately 150 km, or 93 mi in diameter, it is linked to the mass extinction event that wiped out the non-avian dinosaurs and many other species at the end of the Cretaceous period. The impact released an immense amount of energy, triggering global wildfires, tsunamis, and a nuclear winter effect that drastically cooled the planet and disrupted ecosystems. NOW YOU KNOW! ## Questions & answers **Q: About how wide is the Chicxulub crater?** A: About 180 to 200 km across. _(Source: Write-up · Exhibit B (How big) · Wikipedia: Chicxulub crater; IODP Proceedings Volume 364: Chicxulub, Drilling the K-Pg Impact Crater)_ **Q: Can you see the crater from the ground?** A: It's buried under about 1 km of sediment. _(Source: Write-up · Exhibit A (Hidden scar) · Wikipedia: Chicxulub crater; IODP Proceedings Volume 364: Chicxulub, Drilling the K-Pg Impact Crater)_ **Q: What did the 2024 ruthenium study conclude about the impactor?** A: It was a C-type asteroid from beyond Jupiter. _(Source: Write-up · Exhibit E (What hit) · Fischer-Gödde et al. (2024), Ruthenium isotopes show the Chicxulub impactor was a carbonaceous-type asteroid, Science)_ **Q: Which group first spotted the structure?** A: Pemex geophysicists Glen Penfield and Antonio Camargo. _(Source: Write-up · Exhibit C (Found by oil explorers) · Wikipedia: Chicxulub crater)_ **Q: In what year did Expedition 364 drill the peak ring?** A: 2016. _(Source: Write-up · Exhibit D (Drilling the peak ring) · Morgan et al. (2016), The formation of peak rings in large impact craters, Science; IODP Proceedings Volume 364: Chicxulub, Drilling the K-Pg Impact Crater)_ ## Sources - [Wikipedia: Chicxulub crater](https://en.wikipedia.org/wiki/Chicxulub_crater) - [Fischer-Gödde et al. (2024), Ruthenium isotopes show the Chicxulub impactor was a carbonaceous-type asteroid, Science](https://www.science.org/doi/10.1126/science.adk4868) - [Morgan et al. (2016), The formation of peak rings in large impact craters, Science](https://www.science.org/doi/10.1126/science.aah6561) - [IODP Proceedings Volume 364: Chicxulub, Drilling the K-Pg Impact Crater](https://doi.org/10.14379/iodp.proc.364.2017) ## Cite this case file Easterling, Marcus. "Chicxulub Crater." The Detail Department (DetailEnjoyer), case file DD-693, last updated Jan 14, 2026. https://detailenjoyer.com/case/chicxulub-crater/