The Why Files: Operation Podcast - 8: Chicxulub Asteroid Impact - The Day the Dinosaurs Died

Episode Date: June 26, 2022

The Chicxulub Asteroid Impact - The Day the Dinosaurs Died  One of the deepest scars on our planet is hidden beneath the Yucatán Peninsula and the Gulf of Mexico. The buried crater, over 90 miles in diameter, was created when a massive asteroid struck the planet 66 million years ago and brought a calamitous end to the reign of dinosaurs.   Though dinosaur extinction probably took weeks or months, in just one day, 425 feet of material accumulated where the asteroid hit with the power of 10 billion atomic bombs. The blast ignited trees and plants for thousands of miles -- which were quickly extinguished by mega tsunamis with waves that may have reached as far inland as Illinois.   And at the low-end estimate of 10.1 on the Richter scale, the subsequent earthquake would have been more powerful than anything ever measured or experienced by humans.  And then things got worse.    Let's find out why. --- Support this podcast: https://podcasters.spotify.com/pod/show/thewhyfiles/support

If it's a flat or a squeal, a wobble or peel, your tread's worn down or you need a new wheel, wherever you go, you can get it from our Tread Experts. Until May 30th, purchase four new Michelin passenger or light truck tires and receive up to $70 by prepaid MasterCard. Conditions apply. Details at Michelin.ca. Find a Michelin Tread Experts dealer near you at TreadExperts.ca slash locations. From tires to auto repair, we're always there at Treadexperts.ca slash locations. From tires to auto repair, we're always there, treadexperts.ca. Okay, kids, story time. Ooh, I love story time.

66 million years ago, it was a perfect day. Dinosaurs roamed the earth, tending to their young, feeding, enjoying the warmth of the sun. Fish and sea creatures weave through tangled algae in the deep waters of the ocean. Tiny mammals burrowed in holes deep in the ground, snug and safe from the predators lurking above. And then, in one second, the world ended. Let's find out why welcome to the y files where smart folks like us come to laugh and learn 66 million years ago the

entire course of history on our planet changed in an instant a giant asteroid almost 20 kilometers wide or about twice the size of Mount Everest smashed into the earth at 12 miles per second per second. That's over 50000 kph or 40 times the speed of sound. Whoa, whoa, whoa, whoa. What happened? Well, chaos happened. Chaos that would cause mile high tsunamis across entire oceans and walls of fire across entire continents.

Chaos that would wipe out 70 percent of life on Earth. Chaos that would kill the dinosaurs and chaos that would change our planet forever. The asteroid smacked into the Yucatan Peninsula, resulting in a massive explosion that created one of the largest known impact craters on Earth at ninety three miles in diameter. This happened just outside the little town of modern day Chicxulub, Mexico. This catastrophic event is known as the Chicxulub impact. What kind of lube? Chicxulub. Got it.

The estimated energy of the impact was somewhere between two and over 50 yadajules. Is a yadajules a lot of jewels? Oh, yes. Let's keep it conservative and say the impact was two yadajules. That's the same as 40 billion times the energy delivered by the atomic bomb in Hiroshima. 40 billion times. And all of that energy occurred in less than one second. All at once. The Cretaceous period, which lasted about 80 million years,

ended the very second this asteroid hit the Earth. This gave way to a new era, an era of calamitous death and destruction, of massive craters and flaming forests of the extinction of the dinosaurs. This moment, the moment of the Chicxulub impact marked the beginning of the Cenozoic era. The blast was so extreme that in the sky above it, where there should have been air, the rock had punched a hole of outer space vacuum.

And as the atmosphere rushed in to close the hole, enormous volumes of earth were expelled into orbit and beyond, all within a second or two of impact. Now, this material, which included pieces of the asteroid itself, were set aflame and rained back down on the earth as fiery rock, each chunk the size of a skyscraper. The impact had other disastrous consequences. A mega tsunami over 330 feet tall erupted from the sea and stretched all the way from Mexico to Texas and Florida. And that was lucky. Lucky? Yep. The water in the Gulf of Mexico is relatively shallow. If the asteroid had struck in the deep Pacific Ocean, it would have unleashed tsunamis five kilometers high. That sounds higher than a mountain. It's higher

than most aircraft fly. Oh boy. Is it over yet? Oh, no, it's just getting started. Across land for thousands of miles, death was instant, and this is shown by fossils discovered in soil samples from New Jersey, which is thirty one hundred miles away. Now, while some life survived the impact, there was an immediate mass extinction of millions of species. As for the dinosaurs, no one knows whether their species died out all at once or if it took weeks to fully eliminate them. But either way, this was the day the dinosaurs died. When the asteroid hit, it plunged deep underground. Less than one second later, superheated dust, ash and steam exploded from the depths of the crater and were thrown high into the Earth's atmosphere.

Now, rocks at the impact site contained large amounts of sulfur that, when vaporized, led to a sulfate haze that spread across the entire surface of the Earth and led to years of environmental conditions that would suffocate even more life on the planet. Known as an impact winter, the dust, ash, and haze blocked out the sun, creating a decade long winter across the entire planet. Winter is here. Well, father always promised me plants just couldn't grow in these conditions and the food chain was demolished. It was impossible for dinosaurs to survive if they didn't die immediately after impact. They were definitely wiped out by the end of the impact winter.

How does winter kill animals? We have with this all the time, at least once a year. Well, this winter was different. It lasted years and there was no sun. It was darkness without sun photosynthesis stops without photosynthesis. Plants die without plants. Animals die without animals. Bigger animals die across the entire planet, food wasn't just scarce.

It was gone. Did things get better yet? No, they get worse. Don't cry it out loud. Particles and gases released by the many, perhaps thousands of volcanic eruptions decimated the Earth's climate. Poisonous snow fell around the world for years. Seas turned acidic. Air was barely breathable.

Plants and animals that didn't freeze suffocated or starved. The animals that died on the day of the impact were the lucky ones. Does winter finally end? I mean, did they kill the Night King or whatever? Yeah, eventually things get warmer. Oh, happy ending, at least. Sorta. The volcanoes were also releasing carbon dioxide. So once the impact particles had evaporated from the atmosphere, the CO2 remained creating a runaway greenhouse effect. So the planet began to warm again.

Now, surviving life forms, most likely species that live beneath the surface, were protected from the blast and its aftermath by deep dens. And they had a chance to prosper at the end of the winter. Cold blooded reptiles who could not generate their own body heat, had a far smaller chance of survival. This period of warming led to the creation of new fertile habitats across the globe, and any life that had survived so far thrived once again. This new version of the earth looked completely different from the days of the dinosaurs. Predatory birds and reptiles no longer dominated the food chain. Mammals were prospering. The version of the Earth that we know today had finally begun.

You searched for your informant, who disappeared without a trace. You knew there were witnesses, but lips were sealed. You swept the city, driving closer to the truth, while curled up on the couch with your cat. There's more to imagine when you listen. Discover heart-pounding thrillers on Audible. You sailed beyond the horizon in search of an island

scrubbed from every map. You battled krakens and navigated through storms. Your spade struck the lid of a long-lost treasure chest. While you cooked a lasagna. There's more to imagine when you listen. Discover best-selling adventure stories on Audible. You searched for your informant, who disappeared without a trace.

You knew there were witnesses, but lips were sealed. You swept the city, driving closer to the truth, while curled up on the couch with your cat. There's more to imagine when you listen. Discover heart-pounding thrillers on Audible. The Chicxulub impact, which has been theorized for decades, was only recently discovered. In 1978, geophysicists Glenn Penfield and Antonio Carmago were working for the Mexican oil company Pemex as part of an airborne magnetic survey of the Gulf of Mexico, scouting possible locations for oil drilling.

Their data showed a large concentric set of onshore gravity anomalies that looked an awful lot like an impact crater. About the same time, Nobel Prize winning geologist Luis Alvarez and his son Walter were studying chemicals in the soil when they discovered large amounts of iridium dating back to 65 million years. No, that's what Captain America's shield is made of. No, no, no, no. That's vibranium. Iridium is an element that's rare on Earth, but it's commonly found in meteors. Superheroes are commonly found in meteorites. Okay, okay, you're excited about MCU phase four, but let's stay focused.

Sorry, sorry, sorry, go ahead. It was then that Luis Alvarez theorized that a massive asteroid might have hit the Earth at the beginning of the Cenozoic era. The same Iridium was found in soil all around the globe, and it contained large amounts of soot, which would indicate forest fires across the planet during the same time. Also, grains of quartz were found within the soil that had been deformed by high shock waves common during explosions. Now, in 1990, scientists finally confirmed the massive crater now buried under deep layers of limestone. They did this by

drilling and mapping gravity fields over the Gulf of Mexico. Still, there is no complete certainty about dinosaur extinction. Nobody knows if they were killed in an instant or in a month or over the course of years. Most of them probably died during the impact winter. It's crazy to think that a nice day can turn catastrophic in an instant, but it can. One geophysicist said it would have been a pleasant day one second and the world was already over by the next. Now, the worst disaster movie Hollywood could ever create, Shrek, would not even come close to the destruction, the nightmare, the absolute horror that was unleashed that day, literally out of the blue. If there's a lesson to be learned, it's live today like tomorrow's going to suck. Amen, brother. Our existence is fragile.

There are millions of asteroids in the solar system, and they range in size from small pebbles up to 600 miles across, much larger than the Chicxulub asteroid. In fact, there are almost 2 million asteroids in our solar system that are one kilometer wide or larger, and many asteroid orbits intersect with the Earth's meteor showers like the Leonids and the Perseids and others occur when the Earth flies through debris fields in space. So you're saying this could happen again?

Oh, there's no doubt about it. There have been other mass extinctions that remain mysteries to this day. About 250 million years ago, it's believed that around 90 percent of species were eliminated during a period called the Great Dying. Meteors impact the Earth every day. They've been doing so since the beginning of time. So it's not a question of if another large impact is going to occur on Earth. It's just a question of when NASA tracks the orbits of thousands of celestial objects.

There's been some pretty close calls over the years. And I don't mean 40 years ago or 60. I mean, last July, asteroid twenty nineteen, OK, missed the Earth by forty five thousand miles. That's much closer to us than the moon. And this thing was moving at almost ninety thousand kph. Now, even though it was relatively small, it had the energy of 30 times the atomic blast at Hiroshima. It was called a city killer. In August of 2020, an asteroid the size of a truck passed only 1,800 miles above the Indian Ocean.

That's closer to us than a lot of orbiting satellites. That's a close shave. It was. There are some scientists, many scientists, who believe that the greatest threat to our civilization is not war or plague or climate change, but another meteor impact. Now, fortunately, we have the technology to venture to asteroids and potentially even change their trajectory. We don't get this job done. Everybody's gone. But these projects are expensive and spectacular impacts are so rare

that there's not a lot of support for this type of initiative. But there probably should be. Now, if we could take a break from fighting with each other for just a minute and turn our eyes skyward, we might see that every human being, every form of life on this planet has a common enemy. And it's just a matter of time before that enemy comes knocking. Thanks for hanging out with us today.

My name is AJ. That's hecklefish. This has been the Y files. We covered a lot today. They got me thinking about potential new videos and let me know in the comments if you'd like to learn about how we visit asteroids, the potential for mining them, and how we can avoid the type of impact that threatens all life on the planet. We're working hard for you.

So do us a favor. give us a thumbs up. And if we haven't earned your subscription today, I promise we'll keep making fun, brainy content until we do earn it. Until next time, be safe, be kind and know that you are appreciated.