Asteroid that killed dinosaurs turned Earth into a deadly pressure cooker

Purdue researchers say the Chicxulub impact threw up a dust cloud that trapped heat across Earth. The finding suggests this global blanket, not the collision alone, sealed the dinosaurs' fate.Animals on Earth's surface received 17 times the thermal radiation considered 100% lethal to humans. (Photo: Generative AI by India Today)Scientists have uncovered a crucial reason why the asteroid that struck Earth 66 million years ago triggered one of the most devastating mass extinctions in the planet's history.The impact didn't just unleash a colossal explosion, it wrapped Earth in a giant dust blanket that trapped heat, effectively turning the planet into an oven and wiping out the dinosaurs along with nearly three-quarters of all species.The findings, published in the Journal of Geophysical Research: Biogeosciences, come from researchers at Purdue University, who studied the aftermath of the asteroid impact that created the Chicxulub crater near present-day Mexico's Yucatn Peninsula.According to the researchers, the asteroid, roughly the size of Mount Everest, vapourised more than 1,000 cubic kilometres of rock and debris on impact. As this material blasted high above the atmosphere, it cooled and condensed into tiny droplets of molten rock known as spherules, while much finer dust particles spread across the globe. The asteroid, roughly the size of Mount Everest, vapourised more than 1,000 cubic kilometres of rock and debris on impact. (Photo: Getty) Unlike the larger spherules that eventually rained back to Earth, the microscopic dust remained suspended in the atmosphere, acting like a giant insulating blanket."We found that the cloud layer was so impermeable that it trapped almost all of the heat near Earth's surface, the dust essentially acted like a lid on a pot," said Alexandria Johnson, assistant professor of Earth, Atmospheric and Planetary Sciences at Purdue. Lead author Brandon Johnson explained that the trapped heat transformed the asteroid strike from a regional disaster into a global catastrophe."Without the dust cloud, it would have been bad, but it wouldn't have been a planetary catastrophe," he said. "The surface and everything on it was essentially being charbroiled."The study estimates that animals on Earth's surface received 17 times the thermal radiation considered 100% lethal to humans, enough to ignite grasslands, pine needles, lichens and even wood, sparking worldwide wildfires.Researchers say the dust cloud blocked sunlight, leaving the planet in darkness illuminated only by the glow of raging fires. The only creatures likely to survive the intense heat were those that found shelter underground, underwater or in other protected environments.The dust particles, measuring just 2.5 micrometres, about 30 times smaller than a human hair, may also have posed long-term health risks similar to modern wildfire smoke, lingering in the atmosphere for years or even decades.The discovery sheds new light on how a single asteroid impact reshaped Earth's biosphere, demonstrating that it was not merely the collision itself but the planet-wide dust blanket trapping heat that sealed the fate of the dinosaurs.- EndsPublished By: Sibu Kumar TripathiPublished On: Aug 3, 2026 13:30 IST