Chicxulub impact charbroiled dinosaurs with superheated dust cloud

The asteroid that struck Earth 66 million years ago superheated the upper atmosphere, charbroiling living organisms and igniting wildfires, according to a study published on 28 July 2026. That event triggered the Cretaceous-Paleogene mass extinction, which wiped out three-quarters of all plant and animal species, including the dinosaurs.

Scientists have fiercely debated the kill mechanisms, but the widely accepted Alvarez hypothesis, proposed in 1980, suggested an impact caused the extinction based on high iridium levels in sedimentary layers worldwide. Dutch geophysicist Jan Smit independently reached a similar conclusion that same year.

Geophysicists first discovered the Chicxulub crater in Mexico’s Yucatan Peninsula in the late 1970s. The asteroid, between 11 and 81 kilometres wide, released energy a billion times greater than the atomic bombs dropped on Hiroshima and Nagasaki in 1945. It melted, shocked, and ejected granite, likely causing a megatsunami and filling the atmosphere with vaporised rock and sulfates.

According to the study, the charbroiling effect from the superheated dust cloud had not been the primary focus of previous research, but the new findings clarify how the impact caused such devastation. Further research will examine how atmospheric heating and wildfires contributed to the selective survival of some species, and may prompt reevaluation of other mass extinction events where similar processes played a role.