When the asteroid slammed into Mexico 65 million years ago, there was only a 13 percent chance that it would trigger a mass extinction, argue Kunio Kaiho, a geoscientist at Tohoku University, and Naga Oshima, a senior researcher at the Japan Meterological Agency.
“The probability of significant global cooling, mass extinction, and the subsequent appearance of mammals was quite low after an asteroid impact on the Earth’s surface,” they write in their paper.
Odds were 87 percent that the asteroid wouldn’t have prompted the evolution of mammals. In other words, the odds were longer that mammals would triumph than that Donald Trump would, on the eve of the 2016 president election (at least according to >FiveThirtyEight).
What set these odds? The location of the asteroid’s impact with Earth—and the mechanism that actually killed the dinosaurs in the days after the impact.
Researchers once believed that the Chicxulub asteroid (so named because it struck the modern-day location of Chicxulub, Mexico) was so devastating because it prompted forest fires around the world. Those fires released soot and ash into the high atmosphere, blocking out the sun’s rays and cooling global temperatures. Indeed, all around the world, geologists find the remnants of soot and sulfur at the rock layer that signifies this moment in geological history.“It turns out the dinosaurs just happened to be very, very unlucky.”>
But geologists and climate scientists have questioned whether forest fires alone could have set off a mass global cooling. Two years ago, a team led by Kaiho looked at the molecular structure of the soot. They argued that all that soot came from one origin point, and that its ratio of elements suggested a higher-energy burn than would normally occur in a wildfire.