Death By Dust, What Killed The Dinosaurs?

Publication Info:

Transcript:

Brandon C. Johnson et al. 2026. Heat and Wildfires during the K-Pg Mass Extinction Enhanced by Fine Dust. Journal of Geophysical Research: Biogeosciences 131 (7): e2026JG009837; doi: 10.1029/2026JG009837

Some new reaserch is revisiting some old ideas about what wiped out the dinosaurs. The asteroid that hit our planet 66 million years ago eradicated the non avian dinosaurs, but exactly how it happened and how long it took has been a question for decades.

Episode 319

Notes:

So, there's new awful news for the last of the dinosaurs. 66 million years ago, our planet got Mount Everest dropped on it, or at least a ball of rock and ice roughly the size of Mount Everest. Falling at what's now the end of the Yucatán Peninsula. Now, obviously, anything right near the impact was going to experience different effects than the animals on the rest of the planet, and it's been thought that they got wiped out relatively quickly with various other effects taking care of the remaining animals that went extinct. Tons of horrible, awful things happened to the animals that had survived. And tons of great research has been done about those horrible, awful things, and a bunch of great papers have been written about that research. I'm not going to talk about any of it today because, thanks to some new research, it looks like a lot of the animals that went extinct never even saw those later effects. And for most of the life on our planet, within hours, it was death by dust. Because the actual impact ejected 1.6 * 10^15 kg of dust into the atmosphere. That's 1.6 quadrillion kg of material. That's 16 followed by 14 zeros. Then, as that material reentered the atmosphere, glass spherules decoupled from the rest of the vapor. With that vapor becoming an extremely fine dust that literally enveloped our entire planet, blocking out radiation, leaving our planet with no way to get light or to cool off. Then, as those glass spherules fell through the atmosphere, they're large enough that they generated extreme heat, basically igniting what it could hit, or cooking the rest of the surface of our planet. Like I said, awful news for anything that was alive, and it's probably not a fun fact, but it is really cool research. As usual, if you want more information, here's the source.