Widespread wildfires, a red sky, and upper atmospheric temperatures reaching 2,700 degrees? That was Earth around 66 million years ago following an ancient asteroid impact, a new paper suggests.
The paper's authors looked at the meteorological and geological consequences of the massive space rock strike that carved out the Chicxulub crater in Mexico. The asteroid, which likely caused the mass extinction of the dinosaurs and other life at the end of the Cretaceous period, would have been about the size of Manhattan.
Previous research has challenged the idea that the 'dino-killing' asteroid caused global fires, arguing that charcoal deposits in ancient sedimentary rocks were not sufficient to support the wildfire hypothesis. But the new paper actually found more than enough charcoal to do the job.
“Our data show the conditions back then are consistent with widespread fires across the planet,” co-author Douglas Robertson, a research scientist at the Cooperative Institute for Research in Environmental Sciences, said in a written statement. “Those conditions resulted in 100 percent extinction rates for about 80 percent of all life on Earth.”
The researchers noted that the asteroid strike would have vaporized huge amounts of rock high above Earth's atmosphere. When that material then re-entered the atmosphere, infrared radiation scoured the Earth and everything heated up.
“It’s likely that the total amount of infrared heat was equal to a 1 megaton bomb exploding every four miles over the entire Earth," Robertson said.
The research conducted by Robertson and his co-authors was published online this week in the Journal of Geophysical Research-Biogeosciences.