# Chicxulub CO‑chondrite impact drives dust firestorm > Live situation record from CLSTR: https://clstr.news/situations/chicxulub-impactor-identified-as-rare-carbonaceous-chondrite > Updated: 2026-07-31T08:56:02.000Z. Sources: 48. Developments: 5. Recent work continues to refine the picture of the Chicxulub event as a CO‑class carbonaceous chondrite impact that generated a planet‑wide firestorm followed by an impact winter. High‑precision nickel‑isotope analyses confirmed the impactor’s CO nature and its low volatile content, implying that the primary extinction driver was a massive plume of fine dust rather than sulfur‑driven cooling. Modeling studies described the plume as micrometre‑scale dust and sugar‑grain‑sized spherules that remained aloft for years, creating an insulating lid that raised surface temperatures to roughly 3.5 times baseline and delivering thermal doses about 17 times lethal for humans, sufficient to ignite global wildfires within hours. A new international study led by Purdue University planetary scientist Brandon C. Johnson (JGR Biogeosciences, 31 July 2026) reinforces this scenario, emphasizing a previously under‑appreciated silicate dust layer formed from vaporized rock. The authors argue that this dust blanket amplified the heat pulse, driving a rapid, planet‑wide firestorm that likely caused the abrupt loss of ~75 % of species, including most non‑avian dinosaurs, before the dust‑laden atmosphere produced a prolonged impact winter. ## Claims - The impact vaporized over a thousand cubic kilometres of rock and soil. (corroborated by 9 sources) - The impact generated a global dust cloud that trapped thermal radiation. (corroborated by 9 sources) - The study was led by Brandon Johnson of Purdue University. (corroborated by 9 sources) - The Chicxulub asteroid was about 10 km in diameter and struck near the Yucatán Peninsula 66 million years ago. (corroborated by 9 sources) - Thermal radiation exposure was about 17 times the lethal dose for humans. (corroborated by 9 sources) - The firestorm could have killed most dinosaurs within a few hours after the impact. (corroborated by 9 sources) - Fine dust particles remained suspended for years, blocking sunlight and causing a prolonged cooling period. (corroborated by 9 sources) - Spherules about half the size of a grain of sugar formed as the vapor plume cooled and added extra heat on re‑entry. (corroborated by 9 sources) - A ~10 km‑diameter asteroid struck the Yucatán Peninsula about 66 million years ago, forming the Chicxulub crater. (corroborated by 7 sources) - The impact vaporized large amounts of rock, producing spherules that fell back to Earth and generated intense heat through atmospheric friction. (corroborated by 7 sources) - A fine dust cloud formed after the impact, acting as an insulating blanket that trapped heat and amplified surface heating by about 3.5 times previous estimates. (corroborated by 7 sources) - The amplified heat could have ignited global wildfires, potentially killing large animals within the first one to two hours after impact. (corroborated by 7 sources) ## Timeline ### 2026-07-31: Chicxulub Impact Likely Caused Global Firestorm, New Study Finds New research by Purdue’s Brandon Johnson suggests the Chicxulub impact created a heat‑trapping dust layer and global firestorm, delivering lethal temperatures and rapid extinction of most dinosaurs. 11 sources. https://clstr.news/cluster/new-study-says-chicxulub-impact-ignited-global-firestorm-killing-dinosaurs ### 2026-07-31: Chicxulub asteroid identified as rare CO carbonaceous chondrite Studies reveal the Chicxulub impactor was a rare CO carbonaceous chondrite and that its fine dust both blocked sunlight and trapped heat, possibly killing most land life within hours. 3 sources. https://clstr.news/cluster/chicxulub-asteroid-identified-as-rare-co-carbonaceous-chondrite ### 2026-07-28: Purdue Study Links Dust Cloud to Rapid Dinosaur Extinction A new Purdue‑Colorado study says the Chicxulub impact vaporized >1,000 km³ of rock, creating a dust cloud that trapped heat, ignited worldwide fires and likely killed most dinosaurs within hours. 12 sources. https://clstr.news/cluster/chicxulub-asteroid-dust-cloud-trapped-heat-causing-rapid-dinosaur-extinction ### 2026-07-20: Rare CO‑chondrite identified as the meteorite that caused dinosaur extinction New isotope analysis shows the dinosaur‑killing Chicxulub impactor was a rare CO‑chondrite, suggesting fine dust, not sulfur, drove the mass extinction 66 million years ago. 11 sources. https://clstr.news/cluster/cochondrite-meteorite-identified-as-dinosaur-killer ### 2026-07-17: Chicxulub impactor identified as rare Ornans carbonaceous chondrite Scientists identified the Chicxulub impactor as a rare Ornans carbonaceous chondrite, a tiny fraction of meteorites, linking its composition to the dinosaur‑killing event 66 M years ago. 12 sources. https://clstr.news/cluster/chicxulub-impactor-identified-as-rare-co-carbonaceous-chondrite --- Cite as: Chicxulub CO‑chondrite impact drives dust firestorm. CLSTR, https://clstr.news/situations/chicxulub-impactor-identified-as-rare-carbonaceous-chondrite