Most of us learned the demise of the dinosaurs went something like this: monster asteroid head-butted Earth, everything exploded with fire, and whatever was alive perished and ended up a fossil to be unearthed millions of years later.
The phenomenon sort of went like that, but the impact of this asteroid was infinitely more monstrous. Like, global thermonuclear war monstrous.
Think of an object from space about the size of San Francisco (about 6 miles wide) slamming into Mexico’s Yucatan peninsula during the late Cretaceous period—and spreading its influence far beyond the point of impact. It wasn’t just the dinosaurs that descended into extinction, either. Try 75% of anything that breathed. Besides the massive volcanic eruptions that are pictured in so many dinosaur-mageddon visions, the asteroid Chicxulub also rocked the planet with massive earthquakes and tsunamis. It vaporized rock that shot miles above the earth and rained down as searing dust hot enough to send wildfires blazing across the surface.
The only living thing that could possibly survive breathing fire is a dragon, and dragons don’t exist outside fantasy epics like Game of Thrones.
That was just the opening act. So much soot blasted back into the sky from the wildfires that it blacked out the sun. Total darkness lasted two years, and in the absence of sunlight, plants wither when photosynthesis cannot occur. These plants were the main food source of many species of dinosaurs and the last edible thing around for any that weren’t obliterated by the initial blast. But even if an extended dust eclipse hadn’t meant the end of most plant life, average land temperatures of 50° Fahrenheit that plummeted to 20° over the oceans would have. The effect of hundred Hiroshima-sized nuclear weapons wouldn’t come remotely close to that.
“Fires created by an asteroid impact and fires created by a nuclear war can put large amounts of soot high up above where the rain happens, so they can exist for a longer period of time and have these global consequences,” said Charles Bardeen of the National Center of Atmospheric Research, whose team’s research was recently published in Proceedings of the National Academy of Sciences. “As long as that soot gets injected above where the rain would happen, it can stay in the atmosphere for a long time.”
It took seven years for temperatures on land to have some semblance of normality again. With colleagues from NASA and the University of Colorado Boulder, Bradeen simulated the post-collision climate using advanced technology. He believes that the plunge in temperature and the impact on Earth’s climate was so extreme that next to this kind of destruction, nuclear war would be nothing.
This also explains why prehistoric creatures like the coelacanth have been found to exist in the depths of the ocean. So long as you could survive in depths past 1,600 feet, you were pretty much protected from extinction-level chaos.
At least we won’t have to worry about another such apocalypse for at least 200 million years.