0 00:00:11,000 --> 00:00:20,000 INDOXXI Support dengan like & share :) 1 00:00:03,280 --> 00:00:07,119 Once upon a time, dinosaurs ruled the world. 2 00:00:07,120 --> 00:00:09,200 But 66 million years ago... 3 00:00:11,200 --> 00:00:14,000 they vanished, virtually overnight. 4 00:00:15,560 --> 00:00:21,119 So what precisely happened in the minutes, the days, the weeks 5 00:00:21,120 --> 00:00:25,559 that wiped out three-quarters of the animal species on the planet? 6 00:00:25,560 --> 00:00:30,679 Many scientists now believe it was the impact of an asteroid 7 00:00:30,680 --> 00:00:32,559 that caused their extinction. 8 00:00:32,560 --> 00:00:37,480 But nobody has been able to prove it... until now. 9 00:00:39,840 --> 00:00:43,399 Evolutionary biologist Ben Garrod and I have been granted 10 00:00:43,400 --> 00:00:46,959 exclusive access to a multi-million-pound drilling mission 11 00:00:46,960 --> 00:00:50,399 into the exact point where the asteroid hit. 12 00:00:50,400 --> 00:00:53,359 This really is one of the most impressive science laboratories 13 00:00:53,360 --> 00:00:54,679 I've ever seen. 14 00:00:54,680 --> 00:00:57,519 Could the team's findings about the asteroid 15 00:00:57,520 --> 00:01:00,880 finally solve the ultimate dinosaur mystery? 16 00:01:02,600 --> 00:01:05,079 This is an absolutely amazing event - 17 00:01:05,080 --> 00:01:09,240 mountains the size of the Himalayas were formed in seconds. 18 00:01:11,360 --> 00:01:13,679 With Ben at the impact site, 19 00:01:13,680 --> 00:01:16,279 I will be traveling across the world 20 00:01:16,280 --> 00:01:19,399 to look for evidence of the events that followed. 21 00:01:19,400 --> 00:01:23,159 That is a bit of fossilized bone, 22 00:01:23,160 --> 00:01:25,759 and they're everywhere, scattered across this hillside. 23 00:01:25,760 --> 00:01:27,079 It's just extraordinary. 24 00:01:27,080 --> 00:01:29,879 Armed with astonishing new revelations... 25 00:01:29,880 --> 00:01:33,959 Right here, we have the smoking gun, and here, we have the bodies. 26 00:01:33,960 --> 00:01:37,119 We may finally be able to paint a picture 27 00:01:37,120 --> 00:01:40,680 of the demise of the dinosaurs. 28 00:02:03,200 --> 00:02:05,239 I'm off the coast of Mexico right now 29 00:02:05,240 --> 00:02:07,039 and this thing you can see behind me 30 00:02:07,040 --> 00:02:09,479 is a specially adapted drilling platform. 31 00:02:09,480 --> 00:02:12,519 Now, there's an international team of scientists on board 32 00:02:12,520 --> 00:02:15,919 who are drilling far beneath the seabed where we are now 33 00:02:15,920 --> 00:02:19,600 to look for evidence to see why and how the dinosaurs died. 34 00:02:21,160 --> 00:02:23,839 This is the exact spot of a huge asteroid strike 35 00:02:23,840 --> 00:02:29,479 that happened at precisely the same time the dinosaurs were wiped out. 36 00:02:29,480 --> 00:02:33,479 This is Earth, 66 million years ago. 37 00:02:33,480 --> 00:02:35,119 Here's the asteroid. 38 00:02:35,120 --> 00:02:39,039 It's nine miles across the size of a city. 39 00:02:39,040 --> 00:02:41,199 And here's the first surprising thing - 40 00:02:41,200 --> 00:02:42,679 the speed of it. 41 00:02:42,680 --> 00:02:45,359 It may not look that fast at this scale, 42 00:02:45,360 --> 00:02:50,360 but it was traveling an unbelievable 40,000 miles an hour. 43 00:02:52,680 --> 00:02:54,239 Seen from the ground, 44 00:02:54,240 --> 00:02:58,279 it would have gone from a mere dot in the sky to impact 45 00:02:58,280 --> 00:02:59,840 in a matter of seconds. 46 00:03:04,560 --> 00:03:07,159 The asteroid smashed into a shallow sea 47 00:03:07,160 --> 00:03:08,959 north of modern-day Mexico, 48 00:03:08,960 --> 00:03:11,480 exactly where the team is starting to drill. 49 00:03:13,320 --> 00:03:18,719 The theory goes that this impact set off a chain reaction of events 50 00:03:18,720 --> 00:03:20,120 that killed the dinosaurs. 51 00:03:22,160 --> 00:03:24,360 But here's the heart of the mystery... 52 00:03:27,400 --> 00:03:31,159 When you compare the size of the asteroid and the Earth, 53 00:03:31,160 --> 00:03:33,919 well, the asteroid is comparatively small. 54 00:03:33,920 --> 00:03:37,639 It's like a grain of sand hitting a bowling ball. 55 00:03:37,640 --> 00:03:41,479 So how did this asteroid cause a mass extinction 56 00:03:41,480 --> 00:03:43,120 all around the globe? 57 00:03:44,920 --> 00:03:47,999 By extracting rock from the impact crater, 58 00:03:48,000 --> 00:03:50,480 the team hopes to find out. 59 00:03:54,520 --> 00:03:57,719 So, I'm not even strapped in, and I don't especially like heights! 60 00:03:57,720 --> 00:03:59,560 But this is great, this is great. 61 00:04:02,600 --> 00:04:06,919 This multi-million-pound operation has been decades in the planning 62 00:04:06,920 --> 00:04:09,880 and we're the only film crew to have access. 63 00:04:12,360 --> 00:04:16,279 Professor Joanna Morgan first proposed the operation. 64 00:04:16,280 --> 00:04:17,439 It's been a long wait. 65 00:04:17,440 --> 00:04:19,119 I've been excited for, you know, 66 00:04:19,120 --> 00:04:22,839 16 years, so to actually... For it to be happening 67 00:04:22,840 --> 00:04:24,479 is quite scary. 68 00:04:24,480 --> 00:04:29,239 We've had so much effort between us to get us to this point 69 00:04:29,240 --> 00:04:32,039 that... that you really want some lovely results. 70 00:04:32,040 --> 00:04:35,399 Joining her on board to co-direct operations 71 00:04:35,400 --> 00:04:37,319 is Professor Sean Gulick. 72 00:04:37,320 --> 00:04:41,199 So, this is the ultimate test of some ideas, right? 73 00:04:41,200 --> 00:04:43,759 We have all these models about how the extinction happened, 74 00:04:43,760 --> 00:04:46,399 but without some samples from ground zero, 75 00:04:46,400 --> 00:04:48,080 we can't really test them. 76 00:04:51,640 --> 00:04:54,759 This really is one of the most impressive science laboratories 77 00:04:54,760 --> 00:04:57,119 I've ever seen, and it's an amazing place - 78 00:04:57,120 --> 00:04:59,000 we're going to have a quick look around. 79 00:05:02,320 --> 00:05:05,559 This central area here is incredibly important. 80 00:05:05,560 --> 00:05:09,319 This is known as Main Street by the crew and scientists. 81 00:05:09,320 --> 00:05:12,439 Now, these shipping containers are actually science labs 82 00:05:12,440 --> 00:05:14,160 and, in each one... 83 00:05:15,560 --> 00:05:17,720 is a whole, entire laboratory. 84 00:05:20,800 --> 00:05:23,399 You can see in here huge amounts of equipment. 85 00:05:23,400 --> 00:05:25,280 This is one of the scanning labs. 86 00:05:28,040 --> 00:05:30,039 But there are still lots of personal touches. 87 00:05:30,040 --> 00:05:32,039 You can see where all the different scientists 88 00:05:32,040 --> 00:05:33,639 and the rest of the crew are from. 89 00:05:33,640 --> 00:05:35,000 But my hometown's not on here! 90 00:05:39,560 --> 00:05:41,160 But this is the star of the show. 91 00:05:42,720 --> 00:05:48,159 This huge drill will bore through 1.5km of solid rock, 92 00:05:48,160 --> 00:05:50,440 taking us back to the time of the dinosaurs. 93 00:05:51,640 --> 00:05:52,959 This is the drill bit. 94 00:05:52,960 --> 00:05:56,399 Each one of these little nodules is an industrial diamond. 95 00:05:56,400 --> 00:05:58,919 We've had this one modified with a higher-speed head 96 00:05:58,920 --> 00:06:00,560 that allows us to core. 97 00:06:02,040 --> 00:06:06,279 Literally collecting a column of rock three metres at a time 98 00:06:06,280 --> 00:06:09,199 and, as we go further down the borehole, 99 00:06:09,200 --> 00:06:11,599 we go further back in time, 100 00:06:11,600 --> 00:06:13,919 until we actually get to the moment of the impact, 101 00:06:13,920 --> 00:06:15,560 about 66 million years ago. 102 00:06:17,000 --> 00:06:19,959 As Ben joins the team drilling down into the rock 103 00:06:19,960 --> 00:06:22,279 for evidence of the asteroid's effects, 104 00:06:22,280 --> 00:06:26,320 I'm traveling the world to look for clues from fossils. 105 00:06:28,520 --> 00:06:33,399 My first stop, 1,700 miles from the crater, 106 00:06:33,400 --> 00:06:34,879 is New Jersey. 107 00:06:34,880 --> 00:06:37,879 I'm here to see a mass prehistoric graveyard 108 00:06:37,880 --> 00:06:41,080 unlike anything that's been unearthed before. 109 00:06:43,240 --> 00:06:44,719 This disused quarry 110 00:06:44,720 --> 00:06:49,679 may be one of the most important paleontological sites in the world. 111 00:06:49,680 --> 00:06:52,879 I'm here to view an intriguing discovery 112 00:06:52,880 --> 00:06:55,279 that may directly link the mass extinction 113 00:06:55,280 --> 00:06:58,839 to the asteroid impact. 114 00:06:58,840 --> 00:07:02,519 There's something very strange about this mass extinction. 115 00:07:02,520 --> 00:07:07,879 So many animals died on that day, and yet, it's virtually impossible 116 00:07:07,880 --> 00:07:11,559 to find casualties of this devastating event. 117 00:07:11,560 --> 00:07:14,799 But palaeontologists here in New Jersey 118 00:07:14,800 --> 00:07:17,359 think they might have found just that - 119 00:07:17,360 --> 00:07:21,519 evidence of the day the dinosaurs died. 120 00:07:21,520 --> 00:07:23,839 It's such an extraordinary claim, 121 00:07:23,840 --> 00:07:27,120 I want to see exactly what they've discovered. 122 00:07:30,280 --> 00:07:34,039 'I've arranged to meet palaeontologist Kenneth Lacovara, 123 00:07:34,040 --> 00:07:35,999 'one of the most experienced - 124 00:07:36,000 --> 00:07:39,319 'and luckiest - fossil hunters in the world. 125 00:07:39,320 --> 00:07:42,079 'He's going to show me where the discovery was made, 126 00:07:42,080 --> 00:07:44,239 'in what used to be the seabed.' 127 00:07:44,240 --> 00:07:45,959 We're going back through time. 128 00:07:45,960 --> 00:07:49,039 We are. Now, if you take one more step, Alice, 129 00:07:49,040 --> 00:07:50,519 you will be in the Cretaceous. 130 00:07:50,520 --> 00:07:51,919 Excellent. 131 00:07:51,920 --> 00:07:55,759 'As we descend into the quarry, we arrive at layers of sediment 132 00:07:55,760 --> 00:07:58,519 'that were deposited during the Cretaceous period, 133 00:07:58,520 --> 00:08:01,119 'when dinosaurs ruled the Earth.' 134 00:08:01,120 --> 00:08:03,479 So, down here, we're in the Cretaceous period. 135 00:08:03,480 --> 00:08:08,279 Here, we're in the Paleogene period, after the Cretaceous. 136 00:08:08,280 --> 00:08:11,639 'The boundary between the two periods marks the moment 137 00:08:11,640 --> 00:08:15,679 'that the dinosaurs went extinct, 66 million years ago.' 138 00:08:15,680 --> 00:08:18,639 So, this is the boundary right here. 139 00:08:18,640 --> 00:08:22,479 No-one in the world has found an in-place dinosaur fossil 140 00:08:22,480 --> 00:08:24,680 one centimetre above that line. 141 00:08:28,680 --> 00:08:33,439 The team uncovered a dense layer of fossils right at this boundary line. 142 00:08:33,440 --> 00:08:36,879 It's potentially a unique discovery. 143 00:08:36,880 --> 00:08:38,399 Dinosaurs. 144 00:08:38,400 --> 00:08:39,799 No dinosaurs. 145 00:08:39,800 --> 00:08:42,199 Gosh, that's extraordinary. 146 00:08:42,200 --> 00:08:48,079 'The animals found here are typical of the late Cretaceous.' 147 00:08:48,080 --> 00:08:52,079 - That's a formidable-looking tooth. - It is, isn't it? - Yeah. 148 00:08:52,080 --> 00:08:53,919 What's that from? 149 00:08:53,920 --> 00:08:56,000 This is from a mosasaur. 150 00:08:58,360 --> 00:09:02,159 Mosasaur's a giant marine reptile, an apex predator. 151 00:09:02,160 --> 00:09:04,799 Think of a Komodo dragon that's as long as a bus, 152 00:09:04,800 --> 00:09:06,439 with paddles for limbs, 153 00:09:06,440 --> 00:09:09,639 a two-meter jaw packed full of these teeth. 154 00:09:09,640 --> 00:09:14,199 We find mosasaurs here below our bone bed and in the bone bed. 155 00:09:14,200 --> 00:09:17,319 We never find mosasaurs above the bone bed 156 00:09:17,320 --> 00:09:19,920 because they go extinct along with the dinosaurs. 157 00:09:21,680 --> 00:09:24,679 Ken believes that the mosasaurs he's found here 158 00:09:24,680 --> 00:09:27,480 may be some of the last that ever lived... 159 00:09:28,800 --> 00:09:32,480 and that they died as part of the great extinction event. 160 00:09:34,240 --> 00:09:36,599 To understand why, 161 00:09:36,600 --> 00:09:40,520 we have to look at the other fossils that Ken has found in the quarry. 162 00:09:45,440 --> 00:09:48,200 - This is incredible, Ken! - HE LAUGHS 163 00:09:50,000 --> 00:09:51,879 Look at all those fossils. 164 00:09:51,880 --> 00:09:53,839 - 25,000 of them. - SHE GASPS 165 00:09:53,840 --> 00:09:57,439 The way you've laid them out in this grid, is this as you found them? 166 00:09:57,440 --> 00:09:59,839 These are the places in which we've found them, yep. 167 00:09:59,840 --> 00:10:01,959 - 170 square metres of them. - SHE GASPS 168 00:10:01,960 --> 00:10:05,479 It's an astonishing amount of work. 169 00:10:05,480 --> 00:10:07,519 All these fossils occur in a layer 170 00:10:07,520 --> 00:10:10,399 that's no more than ten centimetres thick. 171 00:10:10,400 --> 00:10:13,079 'For Ken, the first clue that these animals all died 172 00:10:13,080 --> 00:10:15,479 'in a single catastrophic event 173 00:10:15,480 --> 00:10:20,439 'is that the skeletons are largely intact with no teeth marks on them.' 174 00:10:20,440 --> 00:10:22,839 They weren't transported, they weren't scavenged, 175 00:10:22,840 --> 00:10:25,839 they died suddenly and they were buried quickly. 176 00:10:25,840 --> 00:10:29,479 That tells us that this is a moment in geological time 177 00:10:29,480 --> 00:10:33,799 that's days, weeks, maybe months, but this is not thousands of years, 178 00:10:33,800 --> 00:10:35,999 this is not hundreds of thousands of years. 179 00:10:36,000 --> 00:10:38,240 This is, essentially, an instantaneous event. 180 00:10:39,960 --> 00:10:44,759 'A second clue comes from the surprising mix of species 181 00:10:44,760 --> 00:10:47,759 'that had lived in many different environments.' 182 00:10:47,760 --> 00:10:51,239 I mean, I can pick out large vertebrates. 183 00:10:51,240 --> 00:10:53,559 Sure. We see the occasional bird here. 184 00:10:53,560 --> 00:10:55,599 There's a tibia from a crocodile. 185 00:10:55,600 --> 00:10:58,799 And that's laying next to a piece of the outer shell 186 00:10:58,800 --> 00:10:59,999 of a huge sea turtle, 187 00:11:00,000 --> 00:11:03,680 something that would be maybe a meter-and-a-half across. 188 00:11:04,760 --> 00:11:06,679 'And just a few feet away, 189 00:11:06,680 --> 00:11:10,279 'Ken found another turtle from a different part of the ocean.' 190 00:11:10,280 --> 00:11:13,959 This is a coastal-living turtle. 191 00:11:13,960 --> 00:11:16,839 You can see how tightly articulated it is. 192 00:11:16,840 --> 00:11:19,639 The shell doesn't flex, so we know that this turtle 193 00:11:19,640 --> 00:11:21,719 didn't dive deeply in the ocean. 194 00:11:21,720 --> 00:11:24,319 This animal was living around the coast, in the shallow water. 195 00:11:24,320 --> 00:11:26,359 So, what do you think you've got here? 196 00:11:26,360 --> 00:11:28,239 All this stuff died suddenly, 197 00:11:28,240 --> 00:11:30,199 and was buried all at about the same time, 198 00:11:30,200 --> 00:11:32,639 so that means all the stuff that comes in from the coast 199 00:11:32,640 --> 00:11:34,559 has to come in suddenly. 200 00:11:34,560 --> 00:11:39,239 And that tells us that there is an environmental disturbance going on 201 00:11:39,240 --> 00:11:41,520 on the coastline, up-shore from here. 202 00:11:42,760 --> 00:11:44,079 Whatever was the cause, 203 00:11:44,080 --> 00:11:46,519 this calamity that wiped out these animals, 204 00:11:46,520 --> 00:11:48,719 it was happening in the deep water, 205 00:11:48,720 --> 00:11:50,559 it was happening along the coastline, 206 00:11:50,560 --> 00:11:51,920 and it's happening on land. 207 00:11:56,440 --> 00:12:00,559 Ken's theory is controversial, but if he's right, 208 00:12:00,560 --> 00:12:03,959 this could be the first fossil evidence 209 00:12:03,960 --> 00:12:08,840 of a sudden mass death event at the end of the Cretaceous... 210 00:12:11,000 --> 00:12:18,240 right at that point in time when 75% of life on Earth is wiped out. 211 00:12:20,040 --> 00:12:24,319 But what caused this mass death event? 212 00:12:24,320 --> 00:12:27,919 Could all these animals have been killed by the impact of an asteroid 213 00:12:27,920 --> 00:12:32,159 1,700 miles away in the Gulf of Mexico? 214 00:12:32,160 --> 00:12:35,999 Ben is with the scientists who have been drilling into the seabed 215 00:12:36,000 --> 00:12:38,399 above the asteroid crater. 216 00:12:38,400 --> 00:12:41,599 I'm here, right in the middle of the drilling platform, 217 00:12:41,600 --> 00:12:44,240 and there's a fresh core about to come out. 218 00:12:46,440 --> 00:12:50,160 We've already drilled through 500 metres of limestone sediment. 219 00:12:51,280 --> 00:12:54,119 Now, we're going to start to bring up rock core 220 00:12:54,120 --> 00:12:59,039 for the scientists to examine as we get closer to the impact crater. 221 00:12:59,040 --> 00:13:01,399 This is the first full core of the expedition, 222 00:13:01,400 --> 00:13:03,519 we're excited to say. 223 00:13:03,520 --> 00:13:06,719 The first full, three-meter-long core, 224 00:13:06,720 --> 00:13:07,919 some light layers. 225 00:13:07,920 --> 00:13:09,879 We're wondering if they're ashes or something. 226 00:13:09,880 --> 00:13:11,079 We're pretty excited. 227 00:13:11,080 --> 00:13:13,479 This, along with other core samples like it, 228 00:13:13,480 --> 00:13:15,559 can tell the team so much information 229 00:13:15,560 --> 00:13:18,280 about what was going on at the time of the impact. 230 00:13:20,520 --> 00:13:23,359 The first thing the team does with each new core 231 00:13:23,360 --> 00:13:25,600 is find out how old the rock is. 232 00:13:27,400 --> 00:13:31,439 Exactly what's living, exactly what fossils we find 233 00:13:31,440 --> 00:13:32,919 tell us what age we are. 234 00:13:32,920 --> 00:13:35,519 As soon as the core comes up on deck, 235 00:13:35,520 --> 00:13:37,959 we are given a small crumb of material, 236 00:13:37,960 --> 00:13:41,359 we take it back to the lab and give an age call 237 00:13:41,360 --> 00:13:44,520 within five minutes of the core appearing on the deck. 238 00:13:47,120 --> 00:13:49,519 I just got some sweet pictures. Look at this crystal - 239 00:13:49,520 --> 00:13:52,599 this is the same stuff from the core catcher under the microscope. 240 00:13:52,600 --> 00:13:53,840 Look at these crystals. 241 00:13:55,800 --> 00:13:57,999 Though it contains valuable information, 242 00:13:58,000 --> 00:14:01,519 this core isn't from the impact crater itself. 243 00:14:01,520 --> 00:14:05,279 Instead, it's from the layers of sediment above it. 244 00:14:05,280 --> 00:14:09,839 The team needs to drill a further 130 metres down into the sediment 245 00:14:09,840 --> 00:14:11,800 to get to the crater itself. 246 00:14:13,840 --> 00:14:17,239 The further down they go, the harder the rock is, 247 00:14:17,240 --> 00:14:20,920 so that means weeks of 24-hours-a-day drilling. 248 00:14:23,360 --> 00:14:26,719 They want to pull core from an area of the inner crater 249 00:14:26,720 --> 00:14:29,159 called the peak ring, 250 00:14:29,160 --> 00:14:32,080 found only in the largest of super craters. 251 00:14:35,400 --> 00:14:38,719 They're formed when the massive impact of an asteroid 252 00:14:38,720 --> 00:14:42,159 forces rock to erupt in a central uprising, 253 00:14:42,160 --> 00:14:46,200 which then collapses outwards to form the distinctive peak ring. 254 00:14:47,920 --> 00:14:51,079 It's these rocks that contain the clues to what happened 255 00:14:51,080 --> 00:14:53,160 in the moments after impact. 256 00:14:59,800 --> 00:15:04,079 It's been three weeks since the team started drilling into the seabed 257 00:15:04,080 --> 00:15:06,839 and time and money are running short. 258 00:15:06,840 --> 00:15:09,239 We didn't sample that because it's in the middle of a core. 259 00:15:09,240 --> 00:15:12,999 The drill is nearly through the hundreds of metres of limestone 260 00:15:13,000 --> 00:15:15,559 that has built up since the asteroid struck, 261 00:15:15,560 --> 00:15:18,280 approaching rock layers from the day of impact. 262 00:15:20,080 --> 00:15:21,839 I mean, look at this on the microscope. 263 00:15:21,840 --> 00:15:27,919 I would say somewhere between about 64.5 million years ago 264 00:15:27,920 --> 00:15:31,079 and 63.5. 265 00:15:31,080 --> 00:15:32,119 Wow. 266 00:15:32,120 --> 00:15:36,479 - Wow, so this was E4... - Yup. - ..Which is 53 million. 267 00:15:36,480 --> 00:15:39,599 Now we are 63, so we have 10 million. 268 00:15:39,600 --> 00:15:41,639 Yeah, that sounds like a good estimate, 269 00:15:41,640 --> 00:15:44,679 - so 10 million years in three metres. - In three metres. 270 00:15:44,680 --> 00:15:46,519 We've been stuck in the same zone for a while, 271 00:15:46,520 --> 00:15:48,799 going forward very slowly, and then all of a sudden... 272 00:15:48,800 --> 00:15:51,359 - HE CLICKS HIS FINGERS - ..boom, big jump in time. 273 00:15:51,360 --> 00:15:55,279 The team are noticing clues in the latest cores - 274 00:15:55,280 --> 00:15:56,880 something extraordinary. 275 00:15:59,120 --> 00:16:02,079 But as you go down, it's just more and more and more of it. 276 00:16:02,080 --> 00:16:03,999 It's got this greenish tint. 277 00:16:04,000 --> 00:16:05,999 Yeah, there's one right there. 278 00:16:06,000 --> 00:16:12,479 We've now had four cores of ever-coarsening sands. 279 00:16:12,480 --> 00:16:15,080 I think the only process on Earth that can do that is a tsunami. 280 00:16:18,520 --> 00:16:23,479 Tsunamis are huge, turbulent waves that rip material from the seabed. 281 00:16:23,480 --> 00:16:24,959 When the wave passes, 282 00:16:24,960 --> 00:16:30,279 the material is deposited back on the ocean floor in size order. 283 00:16:30,280 --> 00:16:33,959 The heaviest, most coarse sand settles first, 284 00:16:33,960 --> 00:16:36,519 the finer sand on top. 285 00:16:36,520 --> 00:16:39,560 The thicker the deposit, the bigger the tsunami. 286 00:16:43,280 --> 00:16:46,039 And the fact it's already, like, 12 metres thick 287 00:16:46,040 --> 00:16:48,399 probably already makes it one of the largest, 288 00:16:48,400 --> 00:16:50,639 maybe the largest tsunami deposit ever discovered. 289 00:16:50,640 --> 00:16:53,959 And if it keeps getting thicker as we go, it will absolutely, 290 00:16:53,960 --> 00:16:57,799 unquestionably, be the largest tsunami deposit ever discovered. 291 00:16:57,800 --> 00:17:00,359 And, of course, it's right here in ground zero of the impact. 292 00:17:00,360 --> 00:17:04,999 It's the first major clue of how the impact of this asteroid 293 00:17:05,000 --> 00:17:07,759 could have caused a deadly chain of events, 294 00:17:07,760 --> 00:17:11,720 starting with the biggest tsunami in history. 295 00:17:13,200 --> 00:17:16,239 1,700 miles away in New Jersey, 296 00:17:16,240 --> 00:17:18,799 Ken Lacovara has also picked up evidence 297 00:17:18,800 --> 00:17:21,920 of what could have been a tsunami. 298 00:17:23,640 --> 00:17:27,399 After that asteroid hit, it's just chaos on the continent. 299 00:17:27,400 --> 00:17:30,599 There are tsunami waves lapping up against the continent. 300 00:17:30,600 --> 00:17:33,239 You're going to have trees floating down the estuaries. 301 00:17:33,240 --> 00:17:35,799 You're going to have sediment choking the rivers. 302 00:17:35,800 --> 00:17:38,239 And that's exactly what we see there. 303 00:17:38,240 --> 00:17:41,479 Here in our fossil bed, we get a mixture of marine organisms 304 00:17:41,480 --> 00:17:43,879 and organisms that came in from the land. 305 00:17:43,880 --> 00:17:46,880 One of our more common fossils is wood. 306 00:17:50,160 --> 00:17:52,559 In the Gulf of Mexico, the crew are on the verge 307 00:17:52,560 --> 00:17:55,799 of breaking into the asteroid impact crater, 308 00:17:55,800 --> 00:17:59,000 but, at the worst possible moment, they've hit a roadblock. 309 00:18:01,000 --> 00:18:02,919 So they just woke me up because there's 310 00:18:02,920 --> 00:18:04,719 a problem with the drilling. 311 00:18:04,720 --> 00:18:07,319 We don't know if it's snapped or if it just got stuck a little bit. 312 00:18:07,320 --> 00:18:09,199 We don't know, but they have to bring it back 313 00:18:09,200 --> 00:18:11,919 to the surface to take a look. 314 00:18:11,920 --> 00:18:13,479 As they get nearer the crater, 315 00:18:13,480 --> 00:18:15,839 the rock is getting tougher to penetrate, 316 00:18:15,840 --> 00:18:17,999 and that's causing problems with the drill. 317 00:18:18,000 --> 00:18:19,359 TOOL BUZZES 318 00:18:19,360 --> 00:18:21,919 Getting to the point where you start pushing the drill 319 00:18:21,920 --> 00:18:24,839 beyond its capacity, and right now, there's no... 320 00:18:24,840 --> 00:18:28,000 There's no drilling rods, no bit, no anything in the hole. 321 00:18:31,120 --> 00:18:33,079 While the engineers fix the rig, 322 00:18:33,080 --> 00:18:36,839 the scientists lose valuable drilling time. 323 00:18:36,840 --> 00:18:39,319 Behind me, you'll notice the rig is not moving. 324 00:18:39,320 --> 00:18:41,319 SPARKS CRACKLE 325 00:18:41,320 --> 00:18:44,320 The pump that allows it to turn is actually broken. 326 00:18:46,840 --> 00:18:49,479 RUMBLING 327 00:18:49,480 --> 00:18:51,320 We're in a bit of a race against time now. 328 00:18:54,280 --> 00:18:56,640 We're going to struggle to get to 1,500 metres. 329 00:18:58,880 --> 00:19:00,359 So we're all hopeful - 330 00:19:00,360 --> 00:19:02,879 fingers, toes and so on are crossed - 331 00:19:02,880 --> 00:19:04,480 and we'll see how this goes. 332 00:19:08,840 --> 00:19:11,239 Finally, after a month of drilling, 333 00:19:11,240 --> 00:19:14,320 the team are pulling rock from the asteroid crater itself. 334 00:19:16,160 --> 00:19:19,039 Already, they're seeing evidence of the incredible heat 335 00:19:19,040 --> 00:19:21,239 generated by the impact - 336 00:19:21,240 --> 00:19:23,079 rock that has melted. 337 00:19:23,080 --> 00:19:24,319 And look at... 338 00:19:24,320 --> 00:19:27,999 In this part, it is very clear that we have different kinds of colours, 339 00:19:28,000 --> 00:19:29,319 like this red color. 340 00:19:29,320 --> 00:19:32,319 It goes from green to red... 341 00:19:32,320 --> 00:19:34,479 - I think it's melting the material. - Melted... - Yeah. 342 00:19:34,480 --> 00:19:36,639 - What about this? - I think that is a big cluster melt. 343 00:19:36,640 --> 00:19:38,999 That does, too. Look at that. That looks like the suevite. 344 00:19:39,000 --> 00:19:41,879 And we are now fully into impact rocks directly, 345 00:19:41,880 --> 00:19:45,279 and it's really easy to see, because it's granite, 346 00:19:45,280 --> 00:19:51,159 and so you can see these spotted, leopard-looking big chunks. 347 00:19:51,160 --> 00:19:52,839 So, in effect, you know, 348 00:19:52,840 --> 00:19:55,880 these were formed, you know, on the days that the dinos died. 349 00:19:58,000 --> 00:19:59,999 Quite heavy, these, aren't they? 350 00:20:00,000 --> 00:20:03,679 Yeah, you really appreciate just... just how solid this rock is. 351 00:20:03,680 --> 00:20:05,599 How deep have you gone with this so far? 352 00:20:05,600 --> 00:20:09,159 We've got to just 1,330 metres, about that. 353 00:20:09,160 --> 00:20:11,959 So, we were hoping to get 1,500 metres, 354 00:20:11,960 --> 00:20:14,959 but we've got 700 metres of peak ring materials, 355 00:20:14,960 --> 00:20:16,639 so we're pretty happy. 356 00:20:16,640 --> 00:20:18,199 Why couldn't you get 1,500? 357 00:20:18,200 --> 00:20:19,679 SHE LAUGHS 358 00:20:19,680 --> 00:20:21,359 Cos... cos the budget ran out. 359 00:20:21,360 --> 00:20:22,759 Oh, no! 360 00:20:22,760 --> 00:20:25,639 I'm dying to ask the question that I wanted to know as a kid - 361 00:20:25,640 --> 00:20:26,959 where's the asteroid? 362 00:20:26,960 --> 00:20:30,039 - Yes, a lot of people think I'm going to find the asteroid... - Yeah. 363 00:20:30,040 --> 00:20:31,839 And ask me that question a lot. 364 00:20:31,840 --> 00:20:35,519 Something like 95 or more percent of the asteroid is vaporized. 365 00:20:35,520 --> 00:20:39,639 - Mm-hm. - So, in fact, there's hardly any asteroid here 366 00:20:39,640 --> 00:20:41,359 beneath the surface. 367 00:20:41,360 --> 00:20:43,119 The asteroid material has been, sort of, 368 00:20:43,120 --> 00:20:44,719 spread all around the globe, 369 00:20:44,720 --> 00:20:48,399 so it's been ejected way above the Earth's atmosphere, 370 00:20:48,400 --> 00:20:51,600 traveled round the globe, and landed around the Earth. 371 00:20:54,400 --> 00:20:56,880 After eight weeks, the work here is done. 372 00:20:58,920 --> 00:21:00,799 I don't think it could have gone much better. 373 00:21:00,800 --> 00:21:03,159 I'll not forget this place. 374 00:21:03,160 --> 00:21:05,999 It's been an amazing expedition, and I expect we'll have lots more 375 00:21:06,000 --> 00:21:08,039 discoveries to come. 376 00:21:08,040 --> 00:21:10,959 More than 300 rock cores have been extracted, 377 00:21:10,960 --> 00:21:15,320 which the team hopes will tell the story of how the dinosaurs died. 378 00:21:34,040 --> 00:21:37,479 Four months and over 5,000 miles later, 379 00:21:37,480 --> 00:21:39,119 the rock cores are now here 380 00:21:39,120 --> 00:21:42,239 at the University of Bremen in Germany, 381 00:21:42,240 --> 00:21:43,679 for the second phase 382 00:21:43,680 --> 00:21:47,679 of this colossal and unparalleled scientific journey. 383 00:21:47,680 --> 00:21:51,759 I'm inside a huge fridge that's now home to all the samples that 384 00:21:51,760 --> 00:21:54,479 were taken up from the Gulf of Mexico, 385 00:21:54,480 --> 00:21:57,359 and it's really cold in here, as you might expect. 386 00:21:57,360 --> 00:22:00,839 Now, this is to stop any organisms from growing 387 00:22:00,840 --> 00:22:02,880 and contaminating these samples. 388 00:22:05,520 --> 00:22:09,159 This is a test recording. Say something. 389 00:22:09,160 --> 00:22:11,039 Oh. Hello, hello. 390 00:22:11,040 --> 00:22:15,119 Here in Bremen, the research team is working to find out what happened, 391 00:22:15,120 --> 00:22:18,519 minute by minute, after the asteroid struck, 392 00:22:18,520 --> 00:22:20,880 and what that meant for the dinosaurs. 393 00:22:23,480 --> 00:22:26,879 OK, this is day two that we've had the samples, 394 00:22:26,880 --> 00:22:30,599 and I'm going to take you through the... around the labs 395 00:22:30,600 --> 00:22:32,879 where everybody's started their analysis. 396 00:22:32,880 --> 00:22:35,639 Over here we can see people looking through microscopes, 397 00:22:35,640 --> 00:22:38,239 looking at thin slides that have been collected from offshore. 398 00:22:38,240 --> 00:22:41,799 Hi, Philippe. I'm going to film you while you take a look at this core. 399 00:22:41,800 --> 00:22:43,440 Hey! 400 00:22:47,160 --> 00:22:50,839 Unraveling these cores is a mammoth task. 401 00:22:50,840 --> 00:22:55,079 Over 800 metres of rock has to be carefully split, 402 00:22:55,080 --> 00:22:56,840 tested and photographed. 403 00:23:00,240 --> 00:23:03,359 But what they're starting to reveal about the force of the impact 404 00:23:03,360 --> 00:23:05,200 is literally earth-shattering. 405 00:23:09,160 --> 00:23:13,919 This core, from above the crater, is what typical geology looks like - 406 00:23:13,920 --> 00:23:17,119 layer upon layer of similar-looking rock, 407 00:23:17,120 --> 00:23:20,200 laid down on the seabed very slowly. 408 00:23:21,800 --> 00:23:26,320 This three metres of limestone took millions of years to accumulate. 409 00:23:28,720 --> 00:23:30,560 But when the asteroid struck... 410 00:23:32,920 --> 00:23:34,960 it was geology at hyper-speed. 411 00:23:37,560 --> 00:23:43,639 The next 600 metres of rock were deposited in a single day, 412 00:23:43,640 --> 00:23:46,960 leaving a unique and chaotic jumble. 413 00:23:53,080 --> 00:23:55,999 Sean, I mean, how do you make sense of this incredible place 414 00:23:56,000 --> 00:23:57,479 - that you've got here? - It is amazing. 415 00:23:57,480 --> 00:24:00,039 This is 150km worth of core, 416 00:24:00,040 --> 00:24:02,519 collected by the International Ocean Discovery Program 417 00:24:02,520 --> 00:24:04,959 - and all its predecessors back to the late '60s. - Mm-hm. 418 00:24:04,960 --> 00:24:06,039 But from all these cores, 419 00:24:06,040 --> 00:24:08,319 - the most amazing is the one we just collected... - Yeah. 420 00:24:08,320 --> 00:24:10,439 - In the Chicxulub impact crater. - Of course, yeah. 421 00:24:10,440 --> 00:24:14,159 You can see this black, flowing texture of the rock. 422 00:24:14,160 --> 00:24:15,279 This is actually... 423 00:24:15,280 --> 00:24:18,039 - It looks like it flowed, right? - Mm. - You can see the textures in it. 424 00:24:18,040 --> 00:24:20,159 This is actually melted basement rock, 425 00:24:20,160 --> 00:24:24,519 melted granite, and it actually takes amazing pressures to do that, 426 00:24:24,520 --> 00:24:26,319 and amazing pressures to melt the rock. 427 00:24:26,320 --> 00:24:27,519 This is... 428 00:24:27,520 --> 00:24:29,839 So I've got a piece of what would be considered, sort of, 429 00:24:29,840 --> 00:24:31,199 normal granite, if you will - 430 00:24:31,200 --> 00:24:34,319 the kind that you might put on your counter-top, 431 00:24:34,320 --> 00:24:36,239 and that's why we use it, cos it's nice and hard. 432 00:24:36,240 --> 00:24:38,199 - I mean, it... Right? - Pretty solid. 433 00:24:38,200 --> 00:24:39,799 But this... Yeah, exactly. 434 00:24:39,800 --> 00:24:44,119 This stuff has actually seen shock of an incredible level, 435 00:24:44,120 --> 00:24:47,679 so think of it as pressure waves moving down through the granite, 436 00:24:47,680 --> 00:24:50,119 like lots and lots of little earthquakes. 437 00:24:50,120 --> 00:24:51,279 And what it's done to it is, 438 00:24:51,280 --> 00:24:53,399 all the way down at the scale of a crystal, 439 00:24:53,400 --> 00:24:55,359 - is it's actually deformed it... - Mm-hmm. 440 00:24:55,360 --> 00:24:56,960 So that the final granite... 441 00:24:59,000 --> 00:25:00,159 can be broken. 442 00:25:00,160 --> 00:25:02,399 - It just crumbled up. That's... that's amazing. - Yeah. 443 00:25:02,400 --> 00:25:07,559 Oh, wow. Just such incredible, amazing forces at work here. 444 00:25:07,560 --> 00:25:10,479 This whole event, it's... I'm still finding it difficult. 445 00:25:10,480 --> 00:25:13,159 Well, even as a geophysicist, where we study this for a living, 446 00:25:13,160 --> 00:25:15,999 it's really hard to wrap our brains around the enormity of 447 00:25:16,000 --> 00:25:18,519 the pressures involved, and the enormity of the destruction 448 00:25:18,520 --> 00:25:21,959 - that happens in the middle of an impact, and so quickly. - Mm-hm. 449 00:25:21,960 --> 00:25:24,000 This all happened in less than ten minutes. 450 00:25:25,760 --> 00:25:29,719 It's becoming clear just how mind-bogglingly huge 451 00:25:29,720 --> 00:25:31,400 the Yucatan impact really was. 452 00:25:33,640 --> 00:25:35,719 And to help grasp its scale, 453 00:25:35,720 --> 00:25:40,080 Sean is taking a trip to a more recent impact site in Arizona. 454 00:25:48,720 --> 00:25:53,719 This simple crater here was created by about a 50-meter, or 150-foot, 455 00:25:53,720 --> 00:25:56,480 asteroid impacting the Earth, about 50,000 years ago. 456 00:25:57,800 --> 00:26:00,839 It's about a mile across. It's actually quite small. 457 00:26:00,840 --> 00:26:03,159 It's basically, simply, a bowl-shaped crater. 458 00:26:03,160 --> 00:26:05,839 Everything above the red line that you see there is actually 459 00:26:05,840 --> 00:26:09,519 material that used to be buried that has been flipped up on end, 460 00:26:09,520 --> 00:26:11,559 and is now... or flipped upside-down, 461 00:26:11,560 --> 00:26:14,360 and is now laying as a pile of broken-up material. 462 00:26:16,200 --> 00:26:19,719 By studying the shape of the crater and the upheaval of the rock layers, 463 00:26:19,720 --> 00:26:22,879 Sean, Jo and the team can compare this site to 464 00:26:22,880 --> 00:26:25,519 the Yucatan impact zone, 465 00:26:25,520 --> 00:26:28,119 Even a small asteroid strike like this 466 00:26:28,120 --> 00:26:31,399 would have had dramatic consequences. 467 00:26:31,400 --> 00:26:35,839 So it comes in at something like 26,000mph. 468 00:26:35,840 --> 00:26:39,079 10km away from here, we would have a fireball reaching, 469 00:26:39,080 --> 00:26:42,079 maybe 20km away from here, a shock wave, 470 00:26:42,080 --> 00:26:45,399 and, say, 40km away from here are hurricane-force winds, 471 00:26:45,400 --> 00:26:47,599 but that would just have been a bad day 472 00:26:47,600 --> 00:26:49,480 in, today, northern Arizona. 473 00:26:52,200 --> 00:26:55,719 So this is what a 50m-wide asteroid can do - 474 00:26:55,720 --> 00:26:58,479 it's devastating, but localized. 475 00:26:58,480 --> 00:27:01,679 But what about an asteroid that is nine miles across 476 00:27:01,680 --> 00:27:04,960 and leaves a crater 120 miles wide? 477 00:27:09,440 --> 00:27:11,599 To understand the effects of that impact, 478 00:27:11,600 --> 00:27:15,240 the team needs to know exactly how much energy it released. 479 00:27:17,160 --> 00:27:20,919 To do that, they're comparing rock samples from Yucatan 480 00:27:20,920 --> 00:27:27,000 to data gathered from some of the largest ever man-made explosions. 481 00:27:33,840 --> 00:27:37,039 This is the Nevada Test Site, 482 00:27:37,040 --> 00:27:40,360 the most bombed place in the world. 483 00:27:42,800 --> 00:27:48,039 The US military have detonated 904 atomic bombs here. 484 00:27:48,040 --> 00:27:52,239 To help us understand how atomic bombs connect to asteroids, 485 00:27:52,240 --> 00:27:53,559 we've enlisted the help 486 00:27:53,560 --> 00:27:56,280 of physicists Mark Boslough and David Dearborn. 487 00:27:58,720 --> 00:28:00,719 The blast must have come all the way through, 488 00:28:00,720 --> 00:28:02,199 and I bet these windows blew out. 489 00:28:02,200 --> 00:28:05,919 Those shards of glass would be accelerated by 90mph wind. 490 00:28:05,920 --> 00:28:09,159 - Wind, the windows were gone. Yes. - And they're totally... boom. 491 00:28:09,160 --> 00:28:12,799 This house was part of a test village called Survival Town, 492 00:28:12,800 --> 00:28:15,760 built to study the effects of a nuclear blast. 493 00:28:17,680 --> 00:28:22,919 It actually survived a blast called Apple-2 in May 1965. 494 00:28:22,920 --> 00:28:24,959 EXPLOSION 495 00:28:24,960 --> 00:28:27,000 WIND HOWLS 496 00:28:28,600 --> 00:28:31,040 Most of the damage is done by the fireball... 497 00:28:34,200 --> 00:28:38,800 and the heat that is generated, or the blast wave as it goes by... 498 00:28:41,360 --> 00:28:43,600 and the houses that were in closer didn't survive. 499 00:28:52,040 --> 00:28:54,559 Those of us who work on asteroid impacts, 500 00:28:54,560 --> 00:28:57,279 we naturally started comparing them to nuclear explosions. 501 00:28:57,280 --> 00:28:59,040 It's a similar phenomenon. 502 00:29:00,800 --> 00:29:02,759 The experimenters had high-speed cameras, 503 00:29:02,760 --> 00:29:05,799 they had gauges that measured the intensity of the shock wave, 504 00:29:05,800 --> 00:29:08,160 the blast wave in the air. 505 00:29:09,400 --> 00:29:12,639 The tests found that nuclear explosions are devastating 506 00:29:12,640 --> 00:29:15,199 even at a microscopic level, 507 00:29:15,200 --> 00:29:19,760 causing catastrophic shock to minerals such as quartz. 508 00:29:22,040 --> 00:29:25,839 The pressure is so high in a shock wave from a nuclear explosion 509 00:29:25,840 --> 00:29:28,999 that it actually exceeds the strength of a crystal. 510 00:29:29,000 --> 00:29:32,839 Crystal is made up of a uniform array of atoms 511 00:29:32,840 --> 00:29:36,639 and that uniformity is completely disrupted by a strong shock wave, 512 00:29:36,640 --> 00:29:38,880 and that's what shocked quartz is. 513 00:29:41,240 --> 00:29:44,319 In Bremen, Professor Joanna Morgan is looking at quartz 514 00:29:44,320 --> 00:29:48,079 found in rock cores from the asteroid impact site. 515 00:29:48,080 --> 00:29:52,039 From nuclear test data, she knows exactly how much force 516 00:29:52,040 --> 00:29:55,039 it takes to shock quartz. 517 00:29:55,040 --> 00:29:58,599 From this, she can tell how much force the Yucatan rock 518 00:29:58,600 --> 00:30:01,999 has been subjected to and begin to calculate the exact amount of 519 00:30:02,000 --> 00:30:04,759 energy released when the asteroid struck. 520 00:30:04,760 --> 00:30:09,079 So this is a piece of shocked quartz that we recently drilled 521 00:30:09,080 --> 00:30:10,559 from the Chicxulub impact crater. 522 00:30:10,560 --> 00:30:12,719 There's lots of lines here. 523 00:30:12,720 --> 00:30:15,599 Essentially, the more lines we have on the screen, 524 00:30:15,600 --> 00:30:18,319 different directions, the more shocked this rock has been. 525 00:30:18,320 --> 00:30:20,399 These are caused by the impact, 526 00:30:20,400 --> 00:30:22,839 by the shock wave that travels through this piece of quartz. 527 00:30:22,840 --> 00:30:25,679 So we used exactly the same hydro-codes, they're called, 528 00:30:25,680 --> 00:30:30,239 to model nuclear explosions as we do to model the impact craters. 529 00:30:30,240 --> 00:30:34,119 We've actually stolen these codes and applied them to our simulations 530 00:30:34,120 --> 00:30:35,519 of impact crater formation. 531 00:30:35,520 --> 00:30:37,599 What sort of force were we actually talking about 532 00:30:37,600 --> 00:30:38,999 from the asteroid hitting it? 533 00:30:39,000 --> 00:30:42,359 This event was equivalent to about 10 billion Hiroshima’s, 534 00:30:42,360 --> 00:30:45,159 so, absolutely enormous. 535 00:30:45,160 --> 00:30:48,119 The most dramatic event in the last 100 million years. 536 00:30:48,120 --> 00:30:50,119 10 billion Hiroshima’s combined? 537 00:30:50,120 --> 00:30:52,479 - That's the amount of force going into this? - Absolutely. 538 00:30:52,480 --> 00:30:53,840 It's incredible, it really is. 539 00:30:59,360 --> 00:31:01,639 Finally, we have hard evidence 540 00:31:01,640 --> 00:31:05,999 of just how powerful the asteroid strike really was. 541 00:31:06,000 --> 00:31:08,039 10 billion Hiroshima’s. 542 00:31:08,040 --> 00:31:10,200 It's a major revelation. 543 00:31:12,400 --> 00:31:15,359 But the truly incredible thing about this asteroid strike 544 00:31:15,360 --> 00:31:18,679 was that it changed the face of our planet within seconds. 545 00:31:18,680 --> 00:31:21,039 And now we know that, 546 00:31:21,040 --> 00:31:24,000 we can do something that has never been done before. 547 00:31:25,840 --> 00:31:29,639 'Create a simulation of exactly how the impact affected Earth 548 00:31:29,640 --> 00:31:31,600 'and the dinosaurs.' 549 00:31:32,640 --> 00:31:36,559 Here's what the new results tell us about those crucial initial minutes 550 00:31:36,560 --> 00:31:38,440 after the asteroid struck. 551 00:31:41,960 --> 00:31:44,159 The asteroid, nine miles wide, 552 00:31:44,160 --> 00:31:48,680 smashes into the Yucatan at 40,000mph... 553 00:31:57,640 --> 00:31:59,440 vaporizing instantly. 554 00:32:01,640 --> 00:32:08,479 The impact makes a hole in the earth 20 miles deep and 120 miles across, 555 00:32:08,480 --> 00:32:13,840 turning the surrounding sea to steam and shattering the earth below. 556 00:32:14,840 --> 00:32:19,639 Rock from deep in the Earth's crust then rises miles into the air, 557 00:32:19,640 --> 00:32:23,639 forming a tower higher than the Himalayas 558 00:32:23,640 --> 00:32:28,720 that collapses to form a strange ring of peaks that exists today. 559 00:32:30,680 --> 00:32:33,480 All this in the first ten minutes. 560 00:32:35,800 --> 00:32:37,919 What did this mean for the dinosaurs? 561 00:32:37,920 --> 00:32:42,400 Well, it started an unstoppable and devastating chain of events. 562 00:32:44,560 --> 00:32:47,719 First, like an enormous nuclear explosion, 563 00:32:47,720 --> 00:32:51,639 a radiation fireball 10,000 degrees centigrade 564 00:32:51,640 --> 00:32:54,240 spreads out from the impact zone. 565 00:32:56,680 --> 00:33:00,359 This searing hot sphere fries everything within 566 00:33:00,360 --> 00:33:03,200 a 600-mile radius in an instant. 567 00:33:05,880 --> 00:33:10,359 The truly global devastation had its roots not in the blast, 568 00:33:10,360 --> 00:33:12,079 but in the huge vapor plume 569 00:33:12,080 --> 00:33:15,680 that rose out of the crater and through the atmosphere. 570 00:33:19,920 --> 00:33:24,279 A red-hot cloud of vaporized asteroid and rock, 571 00:33:24,280 --> 00:33:27,239 expanding upwards 600 miles, 572 00:33:27,240 --> 00:33:31,880 spreading rapidly outwards to fill the planet's atmosphere. 573 00:33:37,720 --> 00:33:41,400 Back then, faraway New Jersey was covered in ocean. 574 00:33:45,880 --> 00:33:50,560 And it too would soon feel the effects of the impact. 575 00:33:51,800 --> 00:33:55,439 1,700 miles from the site of the impact, 576 00:33:55,440 --> 00:33:58,079 the fireball wouldn't have been visible. 577 00:33:58,080 --> 00:34:01,479 That blazing, towering, swirling cloud 578 00:34:01,480 --> 00:34:03,799 would've been just over the horizon, 579 00:34:03,800 --> 00:34:06,399 but we might have seen a faint glow. 580 00:34:06,400 --> 00:34:10,840 The animals here were safe from the direct radiation. 581 00:34:13,040 --> 00:34:15,039 Two-and-a-half hours later, 582 00:34:15,040 --> 00:34:17,759 like the sound of heavy traffic in the distance, 583 00:34:17,760 --> 00:34:21,600 the shock wave, now a sound wave, arrived. 584 00:34:25,920 --> 00:34:29,439 Wind starts to whip up, growing stronger and stronger until 585 00:34:29,440 --> 00:34:32,480 we're facing into hurricane-force winds. 586 00:34:38,200 --> 00:34:39,999 The blast wave from the impact 587 00:34:40,000 --> 00:34:42,800 surged across the Earth at enormous speed. 588 00:34:44,160 --> 00:34:47,759 Its effects would have been short-lived, 589 00:34:47,760 --> 00:34:50,399 but those few traumatic hours 590 00:34:50,400 --> 00:34:54,840 left an indelible impression in the earth's geological record. 591 00:34:57,760 --> 00:35:02,959 These are beads of molten rock that rained down from the skies 592 00:35:02,960 --> 00:35:04,839 and as they cool, they become glass. 593 00:35:04,840 --> 00:35:06,879 And if you melt rock and you cool it fast, 594 00:35:06,880 --> 00:35:10,079 it doesn't have a chance to turn back into rock, it forms glass. 595 00:35:10,080 --> 00:35:11,319 Glass called spherules. 596 00:35:11,320 --> 00:35:14,439 And we find these little spherules right here 597 00:35:14,440 --> 00:35:16,600 in this mass death assemblage. 598 00:35:19,400 --> 00:35:23,599 What produces the kind of energy and heat needed 599 00:35:23,600 --> 00:35:26,039 to form these spherules, then? 600 00:35:26,040 --> 00:35:28,599 Well, when you have an asteroid impact, 601 00:35:28,600 --> 00:35:31,479 it melts the rock and it flies up through the atmosphere 602 00:35:31,480 --> 00:35:34,599 and these bits of molten rock rain down on the planet. 603 00:35:34,600 --> 00:35:39,039 'These 66-million-year-old droplets of molten rock show that 604 00:35:39,040 --> 00:35:40,759 'debris was falling on landscapes 605 00:35:40,760 --> 00:35:43,319 'far away from the impact zone itself.' 606 00:35:43,320 --> 00:35:48,119 Protected by the water, marine creatures like the mosasaurs 607 00:35:48,120 --> 00:35:51,679 may have been able to survive these immediate events. 608 00:35:51,680 --> 00:35:54,799 But for the dinosaurs on land, with nowhere to hide, 609 00:35:54,800 --> 00:35:57,320 this was the beginning of the end. 610 00:35:59,480 --> 00:36:01,999 To show how the effects might have played out 611 00:36:02,000 --> 00:36:03,679 for dinosaurs on the ground, 612 00:36:03,680 --> 00:36:08,039 we've enlisted palaeontologists Steve Brusatte and Tom Williamson 613 00:36:08,040 --> 00:36:09,479 to our international team. 614 00:36:09,480 --> 00:36:12,519 They've come to New Mexico, 615 00:36:12,520 --> 00:36:15,639 1,200 miles from the impact zone, 616 00:36:15,640 --> 00:36:19,599 hunting for remains in one of the richest dinosaur fossil sites 617 00:36:19,600 --> 00:36:20,799 in the world. 618 00:36:20,800 --> 00:36:23,079 - Yeah. OK. - Whoa. 619 00:36:23,080 --> 00:36:25,839 - Got a bone layer. - Look at this. Check this out. 620 00:36:25,840 --> 00:36:29,399 A lot of times, we'll just be walking around in the Badlands, 621 00:36:29,400 --> 00:36:32,279 looking for stuff that's sticking out of the rock. 622 00:36:32,280 --> 00:36:34,879 That's always the first clue. 623 00:36:34,880 --> 00:36:37,439 This one's really sticking out. We can tell from the shape of it 624 00:36:37,440 --> 00:36:39,320 that it's part of the backbone of a dinosaur. 625 00:36:41,480 --> 00:36:45,479 It's a bone from the backbone of a horned dinosaur. 626 00:36:45,480 --> 00:36:48,519 This is probably Pentaceratops, 627 00:36:48,520 --> 00:36:50,719 which means five-horned face, 628 00:36:50,720 --> 00:36:54,759 two brow horns, a nasal horn and then a cheek horn on each side. 629 00:36:54,760 --> 00:36:57,159 Triceratops has three horns on its face. 630 00:36:57,160 --> 00:37:00,439 This guy had two more horns, so five horns total, 631 00:37:00,440 --> 00:37:03,040 so an even gaudier dinosaur. 632 00:37:04,680 --> 00:37:08,319 The ceratopsians, like Pentaceratops and Triceratops, 633 00:37:08,320 --> 00:37:11,919 were a large group of plant-eating dinosaurs 634 00:37:11,920 --> 00:37:14,079 that roamed the American landscape 635 00:37:14,080 --> 00:37:17,680 for the 20 million years leading up to the asteroid impact. 636 00:37:21,520 --> 00:37:24,000 - There it is. - Pretty good. Look at that. - Not bad. 637 00:37:25,080 --> 00:37:26,719 This whole area here, 638 00:37:26,720 --> 00:37:29,479 honestly, it's littered with these kind of bones. 639 00:37:29,480 --> 00:37:31,599 These were the cows of the Cretaceous, 640 00:37:31,600 --> 00:37:33,879 they would've been everywhere on this landscape. 641 00:37:33,880 --> 00:37:38,959 66 million years ago, this area would've looked very different. 642 00:37:38,960 --> 00:37:42,679 Today, it's known as the San Juan Badlands. 643 00:37:42,680 --> 00:37:45,040 Back then, it wasn't so bad at all. 644 00:37:46,920 --> 00:37:49,720 This whole area was a lush jungle. 645 00:37:51,120 --> 00:37:53,200 Dense vegetation. 646 00:37:55,200 --> 00:37:58,400 Thick forests cut through by flowing rivers. 647 00:38:04,960 --> 00:38:09,799 When that day started, this whole area here would've been teeming 648 00:38:09,800 --> 00:38:15,119 with dinosaurs, and then, about 2,000km or so, 649 00:38:15,120 --> 00:38:19,240 1,200 miles in this direction to the south-east, the asteroid hit. 650 00:38:29,120 --> 00:38:32,159 And very quickly, the dinosaurs would've realised 651 00:38:32,160 --> 00:38:34,119 that something was wrong, 652 00:38:34,120 --> 00:38:38,519 because there would've been an enormous red glowing cloud 653 00:38:38,520 --> 00:38:41,240 that would've filled up much of the sky here. 654 00:38:42,920 --> 00:38:45,759 The glowing cloud would've looked dramatic, 655 00:38:45,760 --> 00:38:47,599 but this far from the impact zone, 656 00:38:47,600 --> 00:38:51,280 the dinosaurs here would've been safe... for now. 657 00:38:52,760 --> 00:38:54,679 Now, their cousins down in Texas, 658 00:38:54,680 --> 00:38:58,119 about 1,000 kilometers closer to the impact site, 659 00:38:58,120 --> 00:38:59,319 they were toast. 660 00:38:59,320 --> 00:39:01,279 They were incinerated, they were vaporized. 661 00:39:01,280 --> 00:39:04,519 By studying the Yucatan rock core, 662 00:39:04,520 --> 00:39:06,920 we know the exact timing of what happened next. 663 00:39:08,520 --> 00:39:10,879 11 minutes after the impact, 664 00:39:10,880 --> 00:39:14,159 the vapor cloud arrived in New Mexico. 665 00:39:14,160 --> 00:39:19,440 The skies darkened and the temperature started to rise. 666 00:39:23,320 --> 00:39:26,319 It wasn't really a case of fire and brimstone 667 00:39:26,320 --> 00:39:27,959 raining down from the heavens. 668 00:39:27,960 --> 00:39:31,359 It was more a case of all of that stuff heating up the atmosphere 669 00:39:31,360 --> 00:39:35,080 and turning the atmosphere into a giant radiator. 670 00:39:40,720 --> 00:39:42,799 The heat was so intense that, 671 00:39:42,800 --> 00:39:45,159 over 1,000 miles away from the impact, 672 00:39:45,160 --> 00:39:48,160 many animals would have been roasted alive. 673 00:39:50,440 --> 00:39:52,799 Climate specialist Dr Brian Toon 674 00:39:52,800 --> 00:39:56,599 is the first scientist ever to theories what happened next. 675 00:39:56,600 --> 00:40:03,439 A devastating global firestorm he's studied for more than 20 years. 676 00:40:03,440 --> 00:40:08,359 It wasn't falling on you, it was 60km above the ground or so, 677 00:40:08,360 --> 00:40:13,479 and the glowing hot lava was emitting an amount of energy 678 00:40:13,480 --> 00:40:16,320 that's a few times larger than the sun. 679 00:40:18,240 --> 00:40:20,359 This is not a normal fire. 680 00:40:20,360 --> 00:40:23,839 The fire was started everywhere, which causes what's called 681 00:40:23,840 --> 00:40:25,680 a mass fire. 682 00:40:27,280 --> 00:40:31,319 Mass fires can be much hotter than a normal fire. 683 00:40:31,320 --> 00:40:34,439 Well, the leaves on the ground caught fire, 684 00:40:34,440 --> 00:40:36,200 leaves in the trees caught fire... 685 00:40:38,120 --> 00:40:39,800 The underbrush caught fire. 686 00:40:42,280 --> 00:40:45,679 There's winds at hurricane speeds rushing into the fire, 687 00:40:45,680 --> 00:40:49,319 drawing upward into the rising flames 688 00:40:49,320 --> 00:40:51,320 and they consume everything. 689 00:40:55,280 --> 00:40:58,639 And this vapor quickly spread across the planet. 690 00:40:58,640 --> 00:41:00,279 Probably only took a few hours 691 00:41:00,280 --> 00:41:03,280 for it to reach the furthest reaches of the Earth. 692 00:41:10,280 --> 00:41:14,279 Thanks to our new model of what happened after the impact, 693 00:41:14,280 --> 00:41:19,319 we now know that fires spread right around the globe. 694 00:41:19,320 --> 00:41:23,639 But were these fires devastating enough to cause the extinction 695 00:41:23,640 --> 00:41:27,680 of all of the world's dinosaurs in a single day? 696 00:41:30,240 --> 00:41:33,599 'To find out, I'm traveling far from the impact site 697 00:41:33,600 --> 00:41:36,879 'to the very tip of South America 698 00:41:36,880 --> 00:41:40,120 'and the remote wilderness of Patagonia.' 699 00:41:41,920 --> 00:41:45,960 Over 4,000 miles away from where the asteroid hit. 700 00:41:54,160 --> 00:41:59,959 I am all the way down here in Chile. 701 00:41:59,960 --> 00:42:01,679 Now, we tend to think of this asteroid 702 00:42:01,680 --> 00:42:05,479 as being absolutely enormous, and it was - 14km in diameter - 703 00:42:05,480 --> 00:42:08,519 but in the context of the size of the Earth, 704 00:42:08,520 --> 00:42:11,639 that's like a grain of sand impacting on a bowling ball. 705 00:42:11,640 --> 00:42:15,759 And I want to understand what kind of impact 706 00:42:15,760 --> 00:42:19,999 the asteroid landing here had on the dinosaurs 707 00:42:20,000 --> 00:42:23,280 right down here at the toe of South America. 708 00:42:28,880 --> 00:42:33,359 Leading the hunt for clues is palaeontologist Marcelo Leppe. 709 00:42:33,360 --> 00:42:36,639 He's taking me to look for dinosaur remains 710 00:42:36,640 --> 00:42:40,080 in a mountain valley that's best accessed on four legs. 711 00:42:50,000 --> 00:42:54,879 Marcelo, can you explain to me how the geology of this valley works? 712 00:42:54,880 --> 00:42:58,279 Actually, we are passing through time 713 00:42:58,280 --> 00:43:01,919 and we are moving to the end of the Cretaceous, 714 00:43:01,920 --> 00:43:04,359 to the end of the age of the dinosaurs. 715 00:43:04,360 --> 00:43:07,079 We are, at the moment, in 80 million years ago, 716 00:43:07,080 --> 00:43:08,559 this is Campanian. 717 00:43:08,560 --> 00:43:09,599 So this is fantastic. 718 00:43:09,600 --> 00:43:12,279 As we ride along the valley, as we ride north, 719 00:43:12,280 --> 00:43:14,999 we're riding from 80 million to 66 million years. 720 00:43:15,000 --> 00:43:16,320 Through time. 721 00:43:17,520 --> 00:43:20,520 Getting closer to that extinction event. 722 00:43:23,320 --> 00:43:26,359 We've reached the Valley of the Dinosaurs. 723 00:43:26,360 --> 00:43:30,159 Now I want to see what sort of dinosaurs lived here and find out 724 00:43:30,160 --> 00:43:33,720 what happened to them in the hours after the impact. 725 00:43:36,280 --> 00:43:38,399 So, shall we get off and have a look? 726 00:43:38,400 --> 00:43:42,480 - Yeah, let's leave the horses and look. - Seems like a good idea. 727 00:43:45,360 --> 00:43:48,399 The place is literally full of bones. 728 00:43:48,400 --> 00:43:50,919 As you can see, this sunlight is the best 729 00:43:50,920 --> 00:43:54,279 because the angular light is reflecting the bones. 730 00:43:54,280 --> 00:43:57,120 - Let's see if we can find a dinosaur, then. - Yeah, let's... let's see. 731 00:43:58,720 --> 00:44:00,040 Oh, for example, there. 732 00:44:01,120 --> 00:44:03,359 Or here. 733 00:44:03,360 --> 00:44:05,559 Look, just beside you. 734 00:44:05,560 --> 00:44:08,639 - This, here? - Yes, this is a dinosaur bone. 735 00:44:08,640 --> 00:44:10,519 Oh. That's fantastic. 736 00:44:10,520 --> 00:44:12,839 They're different color. Greyish, or white. 737 00:44:12,840 --> 00:44:14,839 Yeah, so what's that, then? 738 00:44:14,840 --> 00:44:17,279 Oh, it looks like a vertebrae. 739 00:44:17,280 --> 00:44:18,679 Probably the first one. 740 00:44:18,680 --> 00:44:20,159 OK, so... yeah. 741 00:44:20,160 --> 00:44:22,919 That looks like a facet, it looks like the surface of a joint 742 00:44:22,920 --> 00:44:24,599 and that would be where the skull sits. 743 00:44:24,600 --> 00:44:26,959 Any ideas what species? 744 00:44:26,960 --> 00:44:30,279 - Yeah, probably a hadrosaur. 99%. - Really? - Yeah. 745 00:44:30,280 --> 00:44:33,440 - That's your first hadrosaur, yeah? - Yeah, it is. 746 00:44:34,520 --> 00:44:38,240 'This valley is now a bone bed, four miles long.' 747 00:44:39,400 --> 00:44:44,199 Yes, that is a bit of fossilized bone and they're everywhere. 748 00:44:44,200 --> 00:44:45,799 Scattered across this hillside. 749 00:44:45,800 --> 00:44:47,160 It's just extraordinary. 750 00:44:50,280 --> 00:44:52,640 Once, it was home to herds of hadrosaurs. 751 00:44:57,040 --> 00:45:02,120 Plant-eaters up to 30-feet long with a distinctive duck-billed face. 752 00:45:04,520 --> 00:45:07,719 But did the dinosaurs down in Patagonia 753 00:45:07,720 --> 00:45:10,520 die on the day the asteroid hit? 754 00:45:16,880 --> 00:45:18,999 Thanks to the team in Bremen, 755 00:45:19,000 --> 00:45:22,919 we now know that once the asteroid struck the Yucatan Peninsula 756 00:45:22,920 --> 00:45:25,279 over 4,000 miles away, 757 00:45:25,280 --> 00:45:29,439 it took 42 minutes for the superheated cloud of debris 758 00:45:29,440 --> 00:45:31,080 to reach Patagonia. 759 00:45:33,360 --> 00:45:34,599 For much of the planet, 760 00:45:34,600 --> 00:45:37,679 the fires triggered by the burning sky 761 00:45:37,680 --> 00:45:39,840 led to total destruction. 762 00:45:46,840 --> 00:45:49,199 But Marcelo has found evidence 763 00:45:49,200 --> 00:45:51,880 that that may not have been the story here. 764 00:45:53,240 --> 00:45:56,879 Plants that the hadrosaurs used to eat. 765 00:45:56,880 --> 00:45:59,759 This is Nothofagus, the southern beech. 766 00:45:59,760 --> 00:46:02,359 They're all around here, aren't they? 767 00:46:02,360 --> 00:46:07,439 And if you want to see it, look at that architecture. 768 00:46:07,440 --> 00:46:10,079 And I want to show you also this one. 769 00:46:10,080 --> 00:46:11,559 This is from Las Chinas, 770 00:46:11,560 --> 00:46:14,599 the same valley we were looking for the hadrosaurs. 771 00:46:14,600 --> 00:46:15,959 Oh, this is fantastic. 772 00:46:15,960 --> 00:46:18,439 - This is what the hadrosaurs were walking on. - Yeah. 773 00:46:18,440 --> 00:46:21,679 - And if you want to compare it... - Well, that looks incredibly similar. 774 00:46:21,680 --> 00:46:23,239 Is there actually a relationship 775 00:46:23,240 --> 00:46:25,319 between this fossil leaf and this living one? 776 00:46:25,320 --> 00:46:27,999 Oh, there is a direct line 777 00:46:28,000 --> 00:46:32,159 from this fossil and this one that is living today in Patagonia. 778 00:46:32,160 --> 00:46:35,279 So this is fantastic evidence that, down here in Patagonia, 779 00:46:35,280 --> 00:46:37,720 some spaces did actually make it through. 780 00:46:40,120 --> 00:46:43,639 66 million years ago, this region was warm, wet 781 00:46:43,640 --> 00:46:46,720 and dense with vegetation like the southern beech. 782 00:46:48,880 --> 00:46:52,320 A species of plant that survived the fires on impact day. 783 00:46:55,080 --> 00:46:56,559 And if plants survived, 784 00:46:56,560 --> 00:46:59,520 maybe the dinosaurs here could have done, too. 785 00:47:04,840 --> 00:47:08,639 Life down here should have been badly hit, 786 00:47:08,640 --> 00:47:12,479 but the fossil evidence, particularly of plant life, 787 00:47:12,480 --> 00:47:14,879 is telling us a different story - 788 00:47:14,880 --> 00:47:17,719 that the immediate fallout from Chicxulub 789 00:47:17,720 --> 00:47:21,559 in Patagonia was not as bad as predicted. 790 00:47:21,560 --> 00:47:25,439 So perhaps our hadrosaurs had a stay of execution, 791 00:47:25,440 --> 00:47:28,599 maybe they made it through that first day. 792 00:47:28,600 --> 00:47:30,599 But something... 793 00:47:30,600 --> 00:47:32,160 Something got them in the end. 794 00:47:36,840 --> 00:47:40,879 To determine exactly what did happen in the days, weeks and months 795 00:47:40,880 --> 00:47:44,159 after the asteroid struck, the Bremen team are still 796 00:47:44,160 --> 00:47:47,880 hard at work studying rock samples from the impact crater. 797 00:47:52,280 --> 00:47:57,760 Dr Philippe Claeys thinks he's found perhaps the most important clue yet. 798 00:48:02,800 --> 00:48:05,119 So, Philippe, when this asteroid struck Earth, 799 00:48:05,120 --> 00:48:07,239 it had a massive and devastating impact. 800 00:48:07,240 --> 00:48:09,799 But that didn't quite seal the fate of the dinosaurs, did it? 801 00:48:09,800 --> 00:48:13,239 Probably not. Remember, the dinosaurs were ideally adapted 802 00:48:13,240 --> 00:48:15,399 to the late Cretaceous environment. 803 00:48:15,400 --> 00:48:18,879 They were the ultimate animal for the Cretaceous. 804 00:48:18,880 --> 00:48:20,479 What happened here is that 805 00:48:20,480 --> 00:48:23,439 we have an incredible change in the Earth's system, 806 00:48:23,440 --> 00:48:27,719 basically kills the dinosaur everywhere on Earth - 807 00:48:27,720 --> 00:48:30,959 in Africa, Antarctica, in the forests, or in the savanna. 808 00:48:30,960 --> 00:48:32,119 But what made them extinct? 809 00:48:32,120 --> 00:48:33,839 You talk about a global scale, suddenly. 810 00:48:33,840 --> 00:48:36,839 - What went global? What happened? - What went global is really 811 00:48:36,840 --> 00:48:39,599 the ejection of material from the crater. 812 00:48:39,600 --> 00:48:42,439 - Look at what I have in my pocket - this is gypsum. - Right, OK. 813 00:48:42,440 --> 00:48:46,959 This was part of Yucatan at the time of impact. - Yeah. - OK? 814 00:48:46,960 --> 00:48:49,719 And this material here contains sulphate. 815 00:48:49,720 --> 00:48:54,759 And this gypsum affects the chemistry of the atmosphere. 816 00:48:54,760 --> 00:48:56,759 It changes it drastically. 817 00:48:56,760 --> 00:48:58,879 This area's meant to be rich in this sort of stuff. 818 00:48:58,880 --> 00:49:02,359 It's supposed to be full of it. But it's not. 819 00:49:02,360 --> 00:49:05,399 We can look for the remnants of it here. 820 00:49:05,400 --> 00:49:07,159 In the core, it's totally absent, 821 00:49:07,160 --> 00:49:10,759 which means that almost the entire sequence of gypsum 822 00:49:10,760 --> 00:49:13,519 that was present in the sedimentary target 823 00:49:13,520 --> 00:49:15,960 at the time of impact went into the atmosphere. 824 00:49:20,880 --> 00:49:23,159 This is a huge discovery. 825 00:49:23,160 --> 00:49:26,719 The presence of gypsum means the plume of vaporized rock 826 00:49:26,720 --> 00:49:31,399 that spread across the world was dense with sulphates 827 00:49:31,400 --> 00:49:32,640 that blocked sunlight. 828 00:49:38,240 --> 00:49:42,719 The same thing happened after the 1991 eruption of Mount Pinatubo 829 00:49:42,720 --> 00:49:44,000 in the Philippines. 830 00:49:45,520 --> 00:49:49,919 Sulphates reduced the amount of sunlight reaching land by 10%, 831 00:49:49,920 --> 00:49:52,480 which caused a drop in global temperatures. 832 00:49:55,080 --> 00:49:59,839 25 years ago, Pinatubo had an incredible effect on the atmosphere. 833 00:49:59,840 --> 00:50:04,079 It cooled it by very little, but it had an effect. 834 00:50:04,080 --> 00:50:05,999 - And it stayed for a couple of years. - Right. 835 00:50:06,000 --> 00:50:09,199 Here, we have an event which is orders of magnitude more important. 836 00:50:09,200 --> 00:50:12,399 Pinatubo is nothing compared to the Chicxulub impact. 837 00:50:12,400 --> 00:50:15,599 It is really going global, no place is protected, 838 00:50:15,600 --> 00:50:17,039 no dinosaur can escape 839 00:50:17,040 --> 00:50:19,639 the consequence of the Chicxulub impact. 840 00:50:19,640 --> 00:50:21,199 This is the gypsum. 841 00:50:21,200 --> 00:50:24,040 - This is what killed the dinosaurs. - Wow. 842 00:50:28,320 --> 00:50:31,840 This astonishing find is the final piece of the jigsaw... 843 00:50:33,520 --> 00:50:35,559 allowing us, for the first time, 844 00:50:35,560 --> 00:50:38,600 to model what finally killed the dinosaurs. 845 00:50:40,880 --> 00:50:43,679 It's what happened in the days after the impact 846 00:50:43,680 --> 00:50:46,000 that made it a global extinction. 847 00:50:48,640 --> 00:50:51,160 Our blue planet turned Grey. 848 00:50:54,680 --> 00:50:58,999 Long after the hot skies cooled, ash and dust in the atmosphere 849 00:50:59,000 --> 00:51:01,560 almost completely blocked out the sun. 850 00:51:02,760 --> 00:51:06,039 As the lights went out, global temperatures plunged 851 00:51:06,040 --> 00:51:08,960 more than ten degrees centigrade within days. 852 00:51:13,920 --> 00:51:16,760 This is where we get to the great irony of the story. 853 00:51:21,320 --> 00:51:24,080 Because in the end, it wasn't the size of the asteroid... 854 00:51:26,680 --> 00:51:29,279 the scale of the blast, 855 00:51:29,280 --> 00:51:33,200 or even its global reach that made dinosaurs extinct. 856 00:51:34,600 --> 00:51:36,440 It was where the impact happened. 857 00:51:39,240 --> 00:51:41,999 Had the asteroid struck a few moments earlier, 858 00:51:42,000 --> 00:51:44,079 or maybe even a couple of seconds later, 859 00:51:44,080 --> 00:51:47,479 then rather than hitting shallow coastal waters, 860 00:51:47,480 --> 00:51:50,160 it might have hit deep ocean. 861 00:51:52,080 --> 00:51:55,079 An impact in the nearby Atlantic or Pacific oceans 862 00:51:55,080 --> 00:51:57,839 would have meant much less vaporized rock, 863 00:51:57,840 --> 00:51:59,800 including the deadly gypsum. 864 00:52:02,040 --> 00:52:04,399 The cloud would have been less dense 865 00:52:04,400 --> 00:52:07,680 and sunlight could have still reached the planet's surface... 866 00:52:09,480 --> 00:52:12,720 meaning what happened next might have been avoided. 867 00:52:14,160 --> 00:52:16,519 In this cold, dark world, 868 00:52:16,520 --> 00:52:19,519 food ran out in the oceans within a week, 869 00:52:19,520 --> 00:52:22,759 and shortly after, on land also. 870 00:52:22,760 --> 00:52:25,679 With nothing to eat anywhere on the planet, 871 00:52:25,680 --> 00:52:28,920 the mighty dinosaurs stood little chance of survival. 872 00:52:36,960 --> 00:52:41,639 In Patagonia, 10% of plant species went extinct. 873 00:52:41,640 --> 00:52:44,359 The southern beeches would have shed their leaves, 874 00:52:44,360 --> 00:52:48,079 shutting down for the long winter that the asteroid set off. 875 00:52:48,080 --> 00:52:50,520 The hadrosaurs were left to starve. 876 00:52:55,880 --> 00:52:58,759 The demise of the dinosaurs down here in Patagonia 877 00:52:58,760 --> 00:53:03,319 was nowhere near as dramatic as being obliterated by a blast wave, 878 00:53:03,320 --> 00:53:05,279 or drowned in a tsunami, 879 00:53:05,280 --> 00:53:08,959 or even being caught up in a colossal forest fire. 880 00:53:08,960 --> 00:53:11,240 But they were doomed, nonetheless. 881 00:53:15,200 --> 00:53:19,039 The dinosaurs as a group were hugely successful and diverse, 882 00:53:19,040 --> 00:53:23,080 they'd been on the planet for more than 150 million years. 883 00:53:24,840 --> 00:53:28,560 But this Chicxulub event was more than just a local phenomenon. 884 00:53:29,920 --> 00:53:32,479 It changed the climate globally, 885 00:53:32,480 --> 00:53:35,759 plunging the world into a deep, deep winter. 886 00:53:35,760 --> 00:53:38,839 And there was no time to adapt. 887 00:53:38,840 --> 00:53:40,119 So, in some ways, 888 00:53:40,120 --> 00:53:43,920 the dinosaurs that died instantaneously were the lucky ones. 889 00:53:49,680 --> 00:53:53,359 This sudden climate change may finally solve the mystery of 890 00:53:53,360 --> 00:53:54,960 what happened in New Jersey. 891 00:53:57,280 --> 00:54:01,079 As the food supply in the oceans dwindled, 892 00:54:01,080 --> 00:54:03,960 shallow water creatures roamed ever deeper. 893 00:54:05,360 --> 00:54:07,840 But eventually, the food would run out. 894 00:54:10,680 --> 00:54:16,599 And all of those animals from different parts of the oceans died, 895 00:54:16,600 --> 00:54:18,720 coming to rest in a single layer. 896 00:54:29,680 --> 00:54:34,559 It's been an incredible adventure decades in the planning. 897 00:54:34,560 --> 00:54:38,639 A multi-million-pound scientific expedition, 898 00:54:38,640 --> 00:54:43,359 weeks of drilling rock samples from deep inside a super crater, 899 00:54:43,360 --> 00:54:48,279 and months of studying hundreds of metres of rock samples. 900 00:54:48,280 --> 00:54:53,799 - So, this was E4. - Yep. - Which is 53 million to 55. 901 00:54:53,800 --> 00:54:57,039 We were just jazzed about the science, all day long. 902 00:54:57,040 --> 00:54:58,999 Many people have been up for 20 hours 903 00:54:59,000 --> 00:55:01,879 and they were still just going with enthusiasm, 904 00:55:01,880 --> 00:55:04,399 describing the cores, looking at the micro-fossils. 905 00:55:04,400 --> 00:55:07,119 It was a heady experience. 906 00:55:07,120 --> 00:55:11,439 All that hard work has paid off in a big way. 907 00:55:11,440 --> 00:55:16,399 The team has been able to reveal extraordinary new details, 908 00:55:16,400 --> 00:55:19,759 evidence about how the dinosaurs died. 909 00:55:19,760 --> 00:55:23,720 But perhaps even astonishing than what killed the dinosaurs... 910 00:55:24,920 --> 00:55:27,400 is what happened after they were gone. 911 00:55:30,560 --> 00:55:34,760 The asteroid and its aftermath ended the age of the dinosaurs. 912 00:55:37,360 --> 00:55:42,439 But as the cloud started to clear, months or years later, 913 00:55:42,440 --> 00:55:45,360 the dormant plants came back to life. 914 00:55:46,560 --> 00:55:52,199 And a tiny group of animals came out of hiding to inherit the Earth. 915 00:55:52,200 --> 00:55:55,559 Creatures that would, over millions of years, 916 00:55:55,560 --> 00:55:58,919 evolve into a huge range of different species... 917 00:55:58,920 --> 00:56:00,799 Including us. 918 00:56:00,800 --> 00:56:02,559 On the tip of my finger right here 919 00:56:02,560 --> 00:56:08,159 is a lower tooth of something called mesodma. 920 00:56:08,160 --> 00:56:11,320 This was a little guy who was probably about the size of a mouse. 921 00:56:14,200 --> 00:56:17,039 This is one tough little mammal. 922 00:56:17,040 --> 00:56:19,959 One of the very few species known to survive 923 00:56:19,960 --> 00:56:22,239 through the global devastation. 924 00:56:22,240 --> 00:56:23,959 It's a blade-like tooth. 925 00:56:23,960 --> 00:56:27,359 It was able to feed on things like insects and seeds, 926 00:56:27,360 --> 00:56:30,360 so it didn't have to rely on photosynthesis. 927 00:56:32,960 --> 00:56:38,559 Mammals had lived in the shadow of the dinosaurs for 100 million years. 928 00:56:38,560 --> 00:56:41,239 But now it was their turn. 929 00:56:41,240 --> 00:56:44,399 This chance event that was the doom of the dinosaurs 930 00:56:44,400 --> 00:56:48,040 was a stroke of luck for the surviving mammals. 931 00:56:50,800 --> 00:56:52,319 With the dinosaurs gone, 932 00:56:52,320 --> 00:56:55,279 suddenly, the landscape was empty of competitors 933 00:56:55,280 --> 00:56:56,800 and ripe with possibilities. 934 00:57:09,920 --> 00:57:12,559 Just half a million years after the extinction of the dinosaurs, 935 00:57:12,560 --> 00:57:16,079 and landscapes around the globe had filled up with mammals 936 00:57:16,080 --> 00:57:17,920 of all shapes and sizes. 937 00:57:22,000 --> 00:57:25,119 Fast forward another 60 million years or so, 938 00:57:25,120 --> 00:57:28,439 and we have the evolution of an extraordinary upright walking ape 939 00:57:28,440 --> 00:57:31,399 that contemplates its own existence 940 00:57:31,400 --> 00:57:35,679 and the demise of ancient creatures they'd never even seen. 941 00:57:35,680 --> 00:57:38,239 Chances are, if it wasn't for that asteroid, 942 00:57:38,240 --> 00:57:41,400 we wouldn't be here to tell the story today.