ASTEROID IMPACT MAY HAVE KILLED DINOSAURS THROUGH GLOBAL FIRESTORM

A new study published in the Journal of Geophysical Research: Biogeosciences proposes that dinosaurs may have died in a global firestorm following the asteroid impact that created the Chicxulub crater on the Yucatan Peninsula. According to research from Purdue University, when the asteroid struck, it ejected a massive plume of vaporised rock, soil and organic matter into the upper atmosphere. This material condensed into tiny spherules that fell back to Earth and heated as they descended. The fine dust that resulted from the impact became trapped in the atmosphere and prevented this thermal radiation from escaping into space.

The study's modelling suggests that fine dust acted like a lid on a pot, trapping heat from the falling spherules. Brandon C. Johnson, one of the study authors, stated that animals in the Cretaceous period received 17 times the dose of thermal radiation that is 100 percent lethal to humans. Spherules from the impact have been found across the world, including in the gills of fossilised fish believed to have died shortly after the event. Without the fine dust layer, Johnson added, the falling debris would have caused some extinctions but likely would not have been sufficient to ignite widespread wildfires.

The firestorm hypothesis challenges the prevailing "impact winter" theory, which proposes that dust and ash blocked sunlight and caused global temperatures to drop. Both explanations account for the extinction event 66 million years ago, though the rapid thermal pulse suggested by the new research would have compressed the extinction process into hours rather than years. The study represents a renewed focus on the fire scenario in scientific debate over how the dinosaurs died.