[Music] our planet has been struck by a series of disasters that wiped out 99% of all species that ever lived but if it hadn't been for these catastrophes none of us would be here at all 65 million years ago an asteroid the size of Everest smashed into the Earth at 60 times the speed of sound it triggered one of the greatest mass extinctions the planet had ever seen and the death of the dinosaurs this is the story of that great [Music] [Applause] impact our planet is around 4 and 1/2 billion years old and a lot has happened in that time it's tough getting a handle on such an enormous period so to put it in perspective imagine the whole of Earth's violent history compressed into a single day represented by a clock at midnight the planet formed at 11:38 in the evening the Earth suffered a catastrophic Cosmic impact a strike so large it blasted billions of tons of debris into space and set the whole planet on fire it triggered a chain of events that wiped out 70% of all life on Earth including the dinosaurs it was event that changed the course of evolution and led directly to the emergence of mammals and eventually humans but how do we know what happened over many years scientists pieced together a series of Clues from around the world to build a detailed picture of the day the dinosaurs died this is the Red Deer River Valley valy in the Canadian [Music] Badlands here paleontologist Phil Curry hunts for Clues to one of the most violent chapters in Earth's history the last great mass extinction Curry searches for the fossilized remains of the last of the dinosaurs buried within the valley rocks the wonderful thing about these bad lands is you can go almost anywhere and at specific levels you can actually find bone in great abundance this was picked up in less than 10 minutes and we have things like whole claws sometimes whole teeth basically along the Red Deer River we have 10 million years of dinosaur and history represented and at each level there are different dinosaurs these layers of rock represent millions of years of evolution the deeper the layer the further back it is in time well as you can see the uh um rock here is actually in layers so we have layer of sandstone here layer of mudstone below it layers of coal uh layers of silt Stone layers of different things but they're all laid down horizontally one on top of the other in a way it's kind of like looking at a book from the back forwards each one of these pages of course um represents a different uh page in the history of the earth somewhere in these layers lie Clues to the death of the dinosaurs several feet below the surface is a layer that's intrigued scientists for Generations the Cretaceous tertiary or KT boundary this is exact what I was looking for this is where we have the Cretaceous tertiary boundary and this is the area that for long time we suspected uh would tell us something about the extinction of dinosaurs because below the layer we have dinosaurs and above the layer we have no evidence of dinosaurs at all the layer dates to the same time period as the mass extinction that wiped out 70% of all life on Earth so this appear appears to be the Smoking Gun this may be the layer that indicated that there was a catastrophe 65 million years ago the KT boundary extends far beyond the Canadian Badlands scientists have found the same layer all over the world below it fossils from countless species above it 70% of them are gone including the dinosaurs nobody knew what caused the Mass extermination until Clues emerged 5,000 m away in southern Europe zumaya Beach Northern Spain hidden Within These spectacular Cliffs is evidence of what scientists believe wiped the dinosaurs off the face of the Earth almost 30 years ago biologist Yan Schmidt came to these very Cliffs he was investigating what wiped out the dinosaurs and was one of the first to think the KT boundary layer might hold the answer I started to analyze the Rocks chemically approaching the KT boundary right there cuz I thought there must be something hidden in the rocks to tell the story how they got extinct why they disappear what he discovered shock the scientific world the samples contained an extremely rare metal iridium that is it's rare in rocks on Earth most of the Earth's idium is trapped 4,000 Mi below ground in the planet's core but it is found in meteorites and asteroids and when you find a high abundance of orid we know you have a clue to extraterrestrial mat material it has to come from outer space rather than from the surface of the Earth there was only one conclusion a very big object must have hit the earth the idium suggested that 65 million years ago a massive asteroid hit the planet at the exact same time as the death of the dinosaurs many scientists were now convinced they had have the murder weapon a catastrophic asteroid strike but to prove it they needed toine the crime scene the sight of the impact so scientists began a global search for an impact crater by measuring the worldwide spread of aridium they estimated that the crater must have been enormous around 125 miles in diameter the problem with the ridim is it's it's it's within the meteorite but the meteorite is totally vaporized and the ridium is thrown out over the whole world it doesn't matter where you're here or there on the surface of the planet you find the same amount of idium so it doesn't tell you where to look for the scientists knew there had been an impact and they knew it was big but finding it was tough because millions of years of erosion had wiped away the evidence of the impact site it would take a combination of luck and sheer perseverance to find the dino [Music] killer 11:38 p.m. on our clock of the Earth's history 65 million years ago 70% of all life on the planet has been wiped out in including the dinosaurs scientists thought this could have been the result of a cataclysmic asteroid impact but they had no real evidence of an impact big enough to cause such Mayhem to prove it and to build a picture of how the dinosaurs died they needed to find the impact crater Dan Dera is a NASA planetary scientist he specializes in the aftermath of massive Cosmic impacts and and where better to come than here one of the world's most spectacular asteroid [Music] craters meteor crater Arizona the impact that created it happened just 50,000 years ago the asteroid that struck here was only 150 ft across yet it created a crater 3/4 of a mile wide and devastated an area the size of Los Angeles meteor crater is many times smaller than the crater that would have been left by the KT asteroid but it demonstrates the enormous power of even a relatively small asteroid strike if a meteorite the size of a large house could make a crater of this size imagine the devastation rought by the impact of an asteroid the size of Mount Everest that's the scale of the KT impact meteor crater is a key clue in the search for the KT strike because buried in its walls is evidence of how Cosmic impacts transform stone that immense impact released in energy our modern estimates are something on the order of 1 to 10 megatons that's that's the scale of the largest nuclear devices we've ever detonated uh that immense impact excavated millions of tons of rock it it peeled open the desert like the Petals of an immense flower and sprayed blocks of of of ejecta huge masses of rock the size of a small house for for miles in every direction out into the desert the Heat and Trauma of the impact was enough to transform Rock itself shocking and pulverizing individual mineral grains one sign of the violence of an impact event like this can be found in the uh in the Rocks themselves uh this is Coconino Sandstone it's a pretty solid Sandstone it's made out of quartz grains that have been cemented together um when this rock was shocked uh in the impact itself it was pulverized and broke those sand grains down into a much finer material almost the consistency of flower uh you can see here what what the impact has done to that material which has now been cemented back together in the walls of the crater very violent event that can turn rock into flower this dramatic transformation was a vital clue in the search for the location of the asteroid strike it pointed the scientists in the right direction following the trail Dan Dura flies North to Trinidad [Music] Colorado he examines levels of minerals in the KT boundary line the layer contains tiny mineral crystals similar to the ones at meteor crater as small as grains of salt it's quartz but that's not why it's interesting it's interesting because something smashed it to Pieces so here in the uh in the in the uh the KT boundary layer this this thin white clay layer deposited um we uh we we find evidence not only of the of the idium which was the original signature that something funny something extraterrestrial was going on here this is that layer where we also find the shocked quartz shocked quartz is created when quartz is smashed by an extreme force at speeds exceeding thousands of miles an [Music] hour only one natural phenomenon packs enough punch to shock quartz an asteroid impact these tiny grains seem to confirm that the asteroid that hit the earth was colossal and the impact took place around the time of the dinosaur extinction but the quartz grains also took scientists a step closer to the impact site while the idium was spread evenly around the boundary layer the shocked quartz was not as we look at the thickness of this layer um here in Colorado it's about a half an inch thick or so as we move to the southeast however that layer gets thicker and thicker it it grows into meters thick as we move toward the southeast toward the Caribbean and so the increasing amount of shocked quartz and the thickening of that layer as we move to the southeast toward the Caribbean is a probably a pretty good indication that uh that the impact occurred in that region of the world the shocked cords pointed to an packed somewhere in the Caribbean still the scientist couldn't find the crater then researchers got a lucky break in 1978 PMX the Mexican oil company was surveying the Yucatan Peninsula geophysical data from the survey and gravity field maps revealed a giant horse Sho shaped structure buried 3/4 of a mile underground Beneath the Sea off the Mexican Coast it was huge 112 M across 12 M deep with outer impact Rings stretching to 125 m in diameter you see circles around each other like a bullseye and the Rings Define the size of a crater and it turns out that the largest ring was around 200 km in size and that was exactly the size of the crater which was predicted 10 years before it was massive it was old and it had all the signs of an impact crater they took samples during Drilling and later on the microscope we found shock quartz by analysis of the Rocks we found High abundance of idium the aridium and shocked quartz in the crater match samples from the KT boundary layer scientists were convinced they had found the impact crater but to be sure they wanted physical evidence at the surface they got their break inside a Mayan human sacrificial pit in tropical Mexico 11:38 p.m. on our clock of Earth's history 65 million years ago go 70% of all species on Earth including the dinosaurs were wiped out scientists believe the cause was a catastrophic asteroid impact they Unearthed evidence of a massive crater in Mexico's Yucatan Peninsula buried off the coast deep under ground what the scientists wanted was real physical evidence at the surface to prove that this really was the site of the KT impact chichin nah in Mexico the Mayans worshiped here a thousand years ago but the land they built on was shaped by an event 65 million years [Music] earlier the area is famous for its Mayan temples and and also for its cenotes or sink [Music] holes they form when limestone rocks get hollowed out by water forming caves as the cave gets bigger its roof weakens finally it collapses leaving an open Cote to the Mayans they were sacrificial pools to us they're pointers to a species killing impact crater in 1996 NASA scientist Adriana OKO made the connection between the cenotes and the impact she realized that the pattern of the cenotes across the region was physical evidence of the crater the discovery really was like a detective story and the cot ring was the last piece of the puzzle that gave Credence to to the theory cenotes normally occur along lines of weakness or faults in the Bedrock Oka realized that the Yucatan Cotes may not be on natural fault lines The Faults could have come from an impact she studied satellite images of the Yucatan Peninsula and compared them with the oil company's Maps the cenotes were arranged in a semicircular ring exactly matching that of the impact crater here we are at the rim of the Cretaceous tertiary impact [Music] crater dinot is one of um many hundreds Cotes that form a semicircle that is the surface evidence of the Cretaceous the tertiary impact crater if we were a satellite looking down on Earth um then we would be able to see the Ring of the Cotes the Ring of cenotes confirmed the impact's immense size you truly need to have that satellite perspective to be able to really get a the dimension it really truly is one of the largest impact graters on our planet the pattern of cenotes was the final clue in the hunt for the KT impact event finally scientists had the exact location of the impact they could begin to build up a detailed picture of the day the asteroids struck 65 million years ago a giant lump of rock hurdled through the solar system at 45,000 mph it was 6 Mi wide and weighed about a trillion tons the size of Mount Everest and it was on a collision course with Earth it smashed through the atmosphere and crashed into shallow Sees at 20 times the speed of a bullet the impact released 6 million times more energy than the 1980 eruption of Mount St [Music] Helens it set off a trail of Destruction that would end with the death of the Dinosaurs and you realize that at that size when that asteroid uh impacted the Earth at the moment it started to contact the surface of the Earth uh its trailing Edge was still up there at 35,000 ft that's that's you know the altitude that jetliners are flying so we were really talking a massive object slamming into the [Music] Earth in the history of the earth only one other impact was larger the collision with the protoplanet Thea 4.3 billion years before this Collision created our moon the KT impact was not nearly as large but its effects wiped out roughly 70% of life on the planet the initial plume of superheated gases and debris incinerated virtually all life in the Impact Zone nothing within a thousand mile radius stood a chance it literally would have been hell on Earth this mountain of rock would have immediately the contact point would have started glowing with a Brilliance like like the surface of the Sun um You probably just from the heat of the of the fireball itself coming in uh the the flesh would have been burned off your body just from just from the the intensity of that of that fireball itself to understand what happened on the day of annihilation scientists recreated in the lab NASA's Ames Research Center just outside San Francisco NASA scientist and asteroid strike expert Peter Schulz recreates the moment of impact when an asteroid hits shallow Seas just as it did 65 million years ago first he builds a layer of sand to represent the land then he covers it with water to simulate the ancient ocean what we're trying to do is to put an ocean in here we're trying to cover up the land with a shallow ocean so this is kind of like something comparable to the impact on Yucatan 65 million years ago to simulate the asteroid impact he uses the A's vertical gun it can fire a projectile at 18,000 M an hour we should probably be able to see everything coming in exploding and then moving down range so that that should be [Music] good okay Lo Schultz raises the barrel of the gun to recreate the most probable angle of impact he then loads the projectile a steel ball to represent the [Music] asteroid oh sweet okay get her saved come on get her saved it's vital to examine the impact in detail but the scaled down event happens too fast for the naked eye so Schulz records the impact using Ultra high-speed [Music] photography that is simply extraordinary look at [Music] that okay let's see let's see what really happened um Step through this slowly oh let me go back look at this oh this is gorgeous kapow here now it came in this direction slammed in this is now Vapor that's expanding heating up the atmosphere just turning it into fiery hot almost as hot as the surface of the sun it's really intense this is the part that would have been lasting seconds and then would have translated all the way down range and then the crater began to form the effect of the impact amazes even Schultz if we imagine this being the Earth our atmosphere or if we're imagining ourselves in a Jet Plane 65 million years ago we'd be flying along and we would be only about less than my fingernail height [Music] the simulation shows the pattern of debris ejected from the sand and water the bullet throws up pounds of debris 65 million years ago the asteroid would have kicked up billions of tons we're talking about 500 billion tons of debris that was tossed out we saw in the experiment that this was just a these were small splatters but imagine this being the size of building larger than buildings the size of a small City the material thrown up from the crater reached speeds of up to 25,000 M an hour some of the debris would have actually achieved Escape speed it would have gone faster than the earth could hold it together to hold it in its orbit that material could have made it to the moon there may be some material sent from the Earth to the Moon the immediate effects of the impact were devastating at the point of impact the temperature hit 16,000 de f it melted surrounding rocks and sent molten bullets flying out at supersonic speeds then came a violent and Powerful shock wave superheated 2,000 mph winds curdled out from the impact site incinerating everything in their path hell came to earth and its creatures had no place to run this is not this is worse than a horror movie this is worse than your worst dream it is very difficult to contain our imagination when it comes to thinking about something the scale the initial impact was over but the aftermath was just beginning the asteroid landed in water triggering a gigantic tidal wave one of the largest the Earth has ever seen 65 million years ago a gigantic asteroid smashed into the planet the impact shot out a superheated blast wave that reduced anything in the Kill Zone to ashes but this was just the beginning the asteroid landed in the sea generating a huge tsunami Peter Schultz's Recreation shows in miniature what he things happen next the shock wave from the impact itself actually causes the water to Splash out so we've already created a shock that is the beginning of a tsunami that would have traveled all the way across the Gulf of Mexico it would have been speeding along and then crashing on the shores in Alabama Georgia that whole region and over on the western side of of Mexico the tsunami of 2004 was around 30 ft High the tsunami 65 million years ago would have been 10 times higher and thousands of times more [Music] destructive a 300t wall of water hurdled out from the Impact Zone and at hundreds of miles an hour first a superheated [Music] fireball then a blast wave then a mega tsunami nothing within the Kill Zone could have survived the onslaught yet far from the impact radius literally on the other side of the earth dinosaurs were wiped out out something didn't add up unless the aftermath of the impact was even greater than thought back at the KT boundary in Colorado planetary scientist Dan Durda has Unearthed a microscopic clue that could explain how the impact triggered a global catastrophe in addition to the idium that we see in this layer and the shocked quartz grains we find uh small particles of soot in some cases actual charcoal but the soot we certainly see all across the layer and in all parts of the world and in fact if you add up the total amount of soot in that boundary layer uh it adds up to something spread globally it's something on the order of 70 billion tons of of soot and that's roughly equivalent to you know all the Earth's vegetation Going Up in Flames at once this layer of soot found in the KT boundary throughout the world can mean only one thing a global Inferno but just how does a whole planet Catch [Music] Fire Los Alamos New [Music] Mexico it's the birthplace of the atomic bomb but today losal scientist Cathy plco studies a much larger explosion here at the Applied Physics Division plusco and the team used supercomputers to study how a cosmic impact could incinerate an entire planet the simulation also reveals for the first time just how the planet burst into flames the impact was so powerful it hurled over 500 billion tons of debris into the air a lot of it makes it up into the upper atmosphere and some of it even makes it out of the atmosphere and it orbits in space for a little bit and then re impacts into the surface of the Earth somewhere else so this debris actually went all over the surface of the Earth and as it was coming back in just like when you see in a meteor shower things heat up as they come back in to Earth's atmosphere this debris would have heated up too but there was so much of it that it would have heated up the entire atmosphere and started forest fires just from SP anous combustion on the opposite side of the globe for hours after the impact billions of tons of superheated debris rained down on Earth it buried the planet in burning Rock and set the Earth on [Music] fire soon most of the world was Ablaze many animals far from the Impact Zone survived the initial blast only to die in the Raging wild fires for the dinosaurs anywhere on the planet would have been lethal at that point anything standing anywhere on the surface of the planet even in Antarctica or Siberia on the other side of the world would have been in real trouble it was a very very bad day for the dinosaurs incredibly against all the odds a few dinosaurs did find shelter and survived the tsunami and the global fires but even their days were numbered of all the places on the planet the asteroid could have struck it hit the worst possible spot 11:38 p.m. on the clock of Earth's history 65 million years ago a massive asteroid struck off the Mexican Coast the impact the tsunami and Global wildfires that followed wiped out almost every living thing on the planet a few hearty creatures still survived but they faced an even greater threat sudden and dramatic climate [Music] change the impact lofted all of this Ash and debris and dust into the atmosphere blanketing the entire atmosphere with an thick opaque layer that made it night for about two to six months you couldn't see anything you couldn't have seen your hand in front of your face on the other side of the world for 6 months if you were sitting on the moon watching this it it it would have been your worst science fiction movie it would have been a very very different place not the Blue Planet it would have probably been more of the great Planet dust and Ash blocked out the sun temperatures dropped like a stone and kept on dropping thanks to the impact's location if there was one place on Earth that would have been a bad place to be hit it was yukatan Peninsula the fact is that that area had a lot of sulfur bearing minerals and that has longer term effects on the global climate as well as immediate poisoning in the area around it the blast generated incredible heat it vaporized The Rock and blasted tons of sulfur dioxide into the air the gas mixed with water in the atmosphere to form droplets of sulfuric acid and that was a disaster the droplets were highly reflective they bounced the sun's heat energy away from the earth and sent temperatures plummeting so at first you have the dust lofted into the atmosphere which blocks out the Sun that eventually falls back as the atmosphere conve and cleans itself out but then you've still got these sulfur oxides up in the upper atmosphere which reflect sunlight and cool the planet so this prolonged the impact winter for probably another couple of [Music] years temperatures dropped by about 10° F Forest destroyed by the global fires struggled to regenerate eventually the sulfur dioxide fell to Earth and temperatures returned to normal but there was a sting in the tail the sulfur dioxide o side fell as acid rain first you have this 6mon long winter where there's no sunlight at all and then finally you get a little bit of sunlight and the plants think oh good finally I can Sprout my seeds and grow again and then the sulfur dioxide Falls as acid rain and burns all the leaves off your plants the food chain collapsed the few animals that had survived the blast the tsunami the Raging fires and the plummeting temperatures now began to starve and the asteroids After Effects just kept on coming now global cooling made way for global warming the Rocks the asteroid hit didn't just contain sulfur they also contained carbon dioxide vaporized by the impact the Rocks released billions of tons of greenhouse gases the equivalent of 3,000 years of modern fossil fuel burning the carbon dioxide was the last effect of the impact and it hung on for centuries now warming the planet instead of cooling it so the climate is then artificially warm and not returning to normal values for several centuries after the impact the effects of excess carbon dioxide were devastating temperatures increased by about 20° over the next 100 years it was global warming on a fast track it was a true ecosystem collapse something that we can't even imagine at any scale today and there was no recovery it wasn't a bad summer it was a devastating hundreds of years temperature soared much of the land turned to parched deserts vegetation died Plante eating dinosaurs starved to death now the carnivores had nothing to eat they died too after 150 million years years of Supremacy the reign of the dinosaurs came to an end they were goners they were great to live on the earth at that time they ruled the Earth but they couldn't defend themselves against the big one and now here we are the Supreme species on the planet could we survive and impact the size of the KT strike if if something as big as a k impact occurred now only a portion of the world would survive most of North America would be wiped out and the debris coming back through the atmosphere still would have affected them and then the longer term effects of the sudden change in climate maybe oscillating from something that would be incredibly warm to incredibly cold would have been very difficult to adjust it it it would have been a long time of survival but could it happen again or was it a oneoff of course it will happen again and this is nature this is what happens we get hit now and then and something that's as big as the KT impact should happen every 100 million years or so the bigger the impact the rarer it is so we could be waiting another 35 million years for another dinosaur killer but smaller impacts are much more frequent 50,000 years ago a 150 ft asteroid created the meteor crater in Arizona that one devastated an area the size of Los Angeles as recently as 1908 the tunguska asteroid destroyed an area of 830 Square mil impacts this big happen around every 100 years or so so we're do another one very soon the KT impact wiped out 70% of all species on Earth but despite the death and destruction life persisted somehow a few species not only survived they thrived and eventually evolved into US 65 million years ago a giant asteroid hit the earth it set off a chain of events that wiped out 70% of life on Earth including the [Music] dinosaurs but with the Dinosaurs gone a new species of animal the mammal took Center Stage these highly adaptive creatures were small in size but eventually they would dominate the planet one branch would evolve into humans the extinction of the dinosaurs clearly uh cleared the way if you will emptied the world of that particular ecological niche and gave the mammals a uh a chance to to rise to prominence and so the extinction of the dinosaurs was sort of the The Crucible of human evolution ultimately if you will we're we're here because they're not but why did these primitive mammals survive when so many other species didn't the answer lies in Golden Colorado here Jaylen Eberly hunts for the remains of our direct ancestors in a layer just above the KT boundary she's found the fossilized bones of animals that survived the impact the Fireball and extreme climate change they were small mammals the size of rodents they seem unlikely airs to the dinosaur's Crown but the qualities that had once kept them near the bottom of the food chain now took them to the top starting with their small size if we compare the KT meteorite impact to say something we can Envision today such as a nuclear war the organisms that would be most likely to survive something like that are going to be the small ones the ones that can escape the surface in some way through burrowing living underground they had a much higher chance of surviving than anything that would be on the surface such as these large dinosaurs and these Subterranean survivalists had another thing in their favor they were omnivores they would eat just about anything the mammals that you have right after the KT impact such as the spell right here by aidon these guys are generalists meaning they could probably eat a variety of different things for mammals being a generalist would be very helpful after the KT boundary because there are um there going to be a variety of foods on the scene and I think if you were um too specialized uh the KT boundary might have been might have been where you met your and mammals had another significant survival Advantage unlike the dinosaurs they didn't lay their eggs on the ground or raise their young out in the open where the Predators [Music] lurked dinosaurs lay eggs and their young developing eggs and then hatch mammals on the other hand they lay their eggs on the inside if you will and they young develop on the inside with that added protection of the mother the mother's body that probably was advantageous right after the KT boundary because those young just had further protection from the environments the elements Predator scavengers a few egg layers did make it some were the flying dinosaurs who laid their eggs in trees they evolved into Birds and the Primitive reptiles survived like crocodiles that buried their eggs underground along with the mammals these survivors of the catastrophe flourished it was the meek the burrowers and scavengers who inherited the Earth and eventually they evolved into us it's extraordinary that in part we owe our very existence to one freak event a cataclysmic impact that turned our planet into a fireball and Unleashed deadly Global chaos but if it hadn't we might might not be here at all
