1 00:00:06,966 --> 00:00:09,969 [crickets chirping] 2 00:00:10,011 --> 00:00:12,889 [enchanting orchestral music] 3 00:00:12,930 --> 00:00:17,143 * * 4 00:00:17,185 --> 00:00:19,062 - Greetings. Bill Nye here. 5 00:00:19,103 --> 00:00:20,730 Beautiful night, isn't it? 6 00:00:20,772 --> 00:00:24,609 Hard to believe that charming, twinkly sky above us 7 00:00:24,650 --> 00:00:27,403 is filled with celestial shrapnel-- 8 00:00:27,445 --> 00:00:29,781 ancient rocks and debris left over 9 00:00:29,822 --> 00:00:31,616 from the birth of our solar system 10 00:00:31,657 --> 00:00:33,910 that can, with very little prompting, 11 00:00:33,951 --> 00:00:39,082 come hurtling toward Earth with devastating consequences. 12 00:00:39,123 --> 00:00:41,918 [comet whooshing] 13 00:00:41,959 --> 00:00:44,712 [tires screeching] 14 00:00:44,754 --> 00:00:47,673 [explosion] 15 00:00:51,010 --> 00:00:52,303 [gasps softly] 16 00:00:52,345 --> 00:00:55,306 [dramatic music] 17 00:00:55,348 --> 00:01:02,438 * * 18 00:01:16,285 --> 00:01:19,414 [cow mooing] 19 00:01:25,962 --> 00:01:29,716 Here we are again, my friends, in the Disaster Institute, 20 00:01:29,757 --> 00:01:32,427 a conservatory of catastrophic events 21 00:01:32,468 --> 00:01:35,513 that have happened in the past, are happening now, 22 00:01:35,555 --> 00:01:38,808 or could happen at any moment. 23 00:01:38,850 --> 00:01:42,061 We're here to witness the end of the world as we know it. 24 00:01:42,103 --> 00:01:43,646 It will be instructive. 25 00:01:43,688 --> 00:01:45,398 We'll learn how science can provide 26 00:01:45,440 --> 00:01:48,401 a blueprint for our survival. 27 00:01:48,443 --> 00:01:51,988 Tonight's disaster comes from beyond the sky. 28 00:01:52,029 --> 00:01:53,448 The last time this happened, 29 00:01:53,489 --> 00:01:57,493 nine out of ten living things on Earth disappeared. 30 00:01:57,535 --> 00:01:59,787 It's about to happen again. 31 00:01:59,829 --> 00:02:01,873 Our beautiful, blue Earth was formed 32 00:02:01,914 --> 00:02:05,251 about 4.6 billion years ago, 33 00:02:05,293 --> 00:02:07,128 but honestly, madam, you don't look 34 00:02:07,170 --> 00:02:08,671 a day over three billion. 35 00:02:10,715 --> 00:02:12,717 Many of the ingredients of life, 36 00:02:12,759 --> 00:02:15,094 including almost all of Earth's water, 37 00:02:15,136 --> 00:02:17,055 were carried here by flying boulders 38 00:02:17,096 --> 00:02:18,681 and ice blocks. 39 00:02:18,723 --> 00:02:21,476 We call them asteroids and comets. 40 00:02:21,517 --> 00:02:23,770 Some of those icy rocks are still out there, 41 00:02:23,811 --> 00:02:27,356 but along with bringing us the building blocks of life, 42 00:02:27,398 --> 00:02:31,694 those objects can also be building blocks of death. 43 00:02:32,945 --> 00:02:34,572 Brace for impact. 44 00:02:34,614 --> 00:02:38,034 [soft dramatic music] 45 00:02:38,076 --> 00:02:39,744 Any advice? 46 00:02:39,786 --> 00:02:42,747 * * 47 00:02:42,789 --> 00:02:44,957 - [growls] 48 00:02:44,999 --> 00:02:48,544 - Our planet is under constant assault. 49 00:02:48,586 --> 00:02:52,048 About 50 tons of cosmic dust, rock, and debris 50 00:02:52,090 --> 00:02:55,551 fall to Earth every single day. 51 00:02:55,593 --> 00:02:57,011 If you live out in the country 52 00:02:57,053 --> 00:02:59,972 away from factories and other urban pollution, 53 00:03:00,014 --> 00:03:02,058 the film that accumulates on your car 54 00:03:02,100 --> 00:03:04,352 or your windshield, a lot of that 55 00:03:04,394 --> 00:03:06,896 is asteroid and comet dust. 56 00:03:06,938 --> 00:03:10,066 You can pull out tiny bits of metal asteroids 57 00:03:10,108 --> 00:03:11,984 using a magnet. 58 00:03:15,279 --> 00:03:17,698 This dust came from deep space. 59 00:03:19,617 --> 00:03:21,953 Most of the celestial objects are so small, 60 00:03:21,994 --> 00:03:23,746 they never even reach the ground. 61 00:03:23,788 --> 00:03:25,790 They vaporize on the way down, 62 00:03:25,832 --> 00:03:28,668 or they just blow away in the wind. 63 00:03:28,710 --> 00:03:31,587 Every once in a while, though, a space rock will land 64 00:03:31,629 --> 00:03:35,591 in your backyard or, blam, right on top of your car, 65 00:03:35,633 --> 00:03:38,594 like back in 1992 in Peekskill, New York, 66 00:03:38,636 --> 00:03:40,555 when a bowling-ball-sized meteorite 67 00:03:40,596 --> 00:03:43,474 put a hole through a totally innocent Chevy Malibu. 68 00:03:43,516 --> 00:03:47,812 * * 69 00:03:47,854 --> 00:03:49,772 [explosion] 70 00:03:49,814 --> 00:03:52,233 Your living room isn't safe either, 71 00:03:52,275 --> 00:03:55,069 as Ann Hodges discovered in 1954 72 00:03:55,111 --> 00:03:57,947 when a space rock cruising through the cosmos 73 00:03:57,989 --> 00:04:00,074 for four and a half billion years 74 00:04:00,116 --> 00:04:02,910 crashed through the roof of her Alabama home 75 00:04:02,952 --> 00:04:05,204 and walloped her while she napped. 76 00:04:05,246 --> 00:04:06,748 Ouch. 77 00:04:06,789 --> 00:04:09,709 That object was only a foot in diameter. 78 00:04:09,751 --> 00:04:11,627 Imagine something that's 100, 79 00:04:11,669 --> 00:04:15,131 1,000, 10,000 times that big. 80 00:04:15,173 --> 00:04:17,800 Most scientists agree that an impact event 81 00:04:17,842 --> 00:04:20,136 caused the most recent mass extinction 82 00:04:20,178 --> 00:04:21,888 66 million years ago. 83 00:04:21,929 --> 00:04:25,141 It struck around what today is known as the Yucatan Peninsula 84 00:04:25,183 --> 00:04:26,517 off the Gulf of Mexico. 85 00:04:26,559 --> 00:04:29,937 75% of all life on Earth went extinct. 86 00:04:29,979 --> 00:04:32,565 Think about it, three quarters of us. 87 00:04:32,607 --> 00:04:35,151 That's like if a comet struck "Sex and the City" 88 00:04:35,193 --> 00:04:36,944 and only Carrie survived. 89 00:04:36,986 --> 00:04:39,989 I mean, who's she gonna talk to? 90 00:04:40,031 --> 00:04:42,200 The dinosaur-killing space rock 91 00:04:42,241 --> 00:04:43,701 was nine miles wide 92 00:04:43,743 --> 00:04:46,245 and slammed into Earth so hard... 93 00:04:46,287 --> 00:04:47,997 [explosion] 94 00:04:48,039 --> 00:04:51,042 That it created a crater ten times that big. 95 00:04:51,084 --> 00:04:54,337 The crash threw huge amounts of debris into the air, 96 00:04:54,379 --> 00:04:56,506 blocking out the sun. 97 00:04:56,547 --> 00:04:59,175 Plant growth slowed so drastically 98 00:04:59,217 --> 00:05:02,220 that the entire ecosystem collapsed. 99 00:05:02,261 --> 00:05:04,430 Only one kind of dinosaur survived, 100 00:05:04,472 --> 00:05:08,267 the ones that could fly, birds. 101 00:05:08,309 --> 00:05:10,561 That's right, folks, that cheerful chirping 102 00:05:10,603 --> 00:05:13,272 you hear every morning are the shrieks 103 00:05:13,314 --> 00:05:16,150 of modern-day descendants of dinosaurs. 104 00:05:18,111 --> 00:05:20,363 [explosion] 105 00:05:20,405 --> 00:05:23,241 Get ready for the next big extinction event. 106 00:05:23,282 --> 00:05:26,035 It is coming. 107 00:05:26,077 --> 00:05:30,540 We're about to take a ride on our disaster simulator. 108 00:05:30,581 --> 00:05:34,252 I want you to experience this disaster firsthand 109 00:05:34,293 --> 00:05:37,213 from different points of view-- 110 00:05:37,255 --> 00:05:39,257 an astronomer-turned-detective 111 00:05:39,298 --> 00:05:42,051 trying to prevent the death of our planet, 112 00:05:42,093 --> 00:05:44,804 a fanatic searching for meaning 113 00:05:44,846 --> 00:05:46,472 in the end of the world... 114 00:05:46,514 --> 00:05:48,015 [comet whooshing] 115 00:05:48,057 --> 00:05:50,560 And a condescending Congressman 116 00:05:50,601 --> 00:05:51,936 who foolishly believes 117 00:05:51,978 --> 00:05:54,522 that lightning never strikes twice. 118 00:05:54,564 --> 00:05:56,065 - Now, who are you gonna believe? 119 00:05:56,107 --> 00:05:57,525 * * 120 00:05:57,567 --> 00:06:00,069 - But, Bill, 66 million years ago 121 00:06:00,111 --> 00:06:01,904 is so yesterday. 122 00:06:01,946 --> 00:06:05,783 Things that happened back then don't happen now. 123 00:06:05,825 --> 00:06:07,910 That, my friends, is where you're wrong. 124 00:06:07,952 --> 00:06:08,995 * * 125 00:06:09,036 --> 00:06:10,079 Dead wrong. 126 00:06:10,121 --> 00:06:14,709 * * 127 00:06:14,751 --> 00:06:19,505 Our story begins here in a farm field in Ohio 128 00:06:19,547 --> 00:06:22,300 in the not-so-distant future. 129 00:06:22,341 --> 00:06:24,927 This crater was created by a shock wave-- 130 00:06:24,969 --> 00:06:27,889 that fireball seen lighting up the sky last night. 131 00:06:27,930 --> 00:06:30,224 [explosion] 132 00:06:35,563 --> 00:06:38,691 Our esteemed colleague is an astronomer 133 00:06:38,733 --> 00:06:41,110 who hurried here to study the impact site. 134 00:06:41,152 --> 00:06:42,695 * * 135 00:06:42,737 --> 00:06:44,864 She spent the last few years in Chile 136 00:06:44,906 --> 00:06:47,200 helping to build a new telescope. 137 00:06:47,241 --> 00:06:50,369 * * 138 00:06:50,411 --> 00:06:53,581 She concludes that the debris in this crater 139 00:06:53,623 --> 00:06:56,959 came from an icy comet. 140 00:06:57,001 --> 00:07:00,630 Now, comet impacts are rare and usually create something 141 00:07:00,671 --> 00:07:03,007 much larger than this. 142 00:07:03,049 --> 00:07:05,760 She suspects it was a cometary fragment, 143 00:07:05,802 --> 00:07:08,137 which leads to a mystery. 144 00:07:08,179 --> 00:07:10,223 What happened to the rest of the comet? 145 00:07:10,264 --> 00:07:11,974 * * 146 00:07:12,016 --> 00:07:15,686 The next clue comes from 250 miles above. 147 00:07:15,728 --> 00:07:21,067 * * 148 00:07:21,109 --> 00:07:23,277 Up here on the International Space Station, 149 00:07:23,319 --> 00:07:25,405 things seem pretty normal. 150 00:07:25,446 --> 00:07:27,698 Could use a little sugar though. 151 00:07:32,328 --> 00:07:33,663 [crashing and beeping] 152 00:07:33,704 --> 00:07:35,415 What's that? 153 00:07:35,456 --> 00:07:38,334 Micrometeorites, tiny space rocks 154 00:07:38,376 --> 00:07:41,671 no bigger than a grain of rice hitting at 20 times 155 00:07:41,713 --> 00:07:43,464 the speed of a rifle bullet. 156 00:07:43,506 --> 00:07:44,882 The International Space Station's 157 00:07:44,924 --> 00:07:46,759 designed to handle small impacts, 158 00:07:46,801 --> 00:07:48,052 but this is like nothing 159 00:07:48,094 --> 00:07:50,221 they've ever encountered before. 160 00:07:50,263 --> 00:07:53,683 [crashing and beeping] 161 00:07:53,725 --> 00:07:55,435 [glass shattering] 162 00:07:55,476 --> 00:07:57,854 Air leaks, power losses. 163 00:07:57,895 --> 00:08:00,523 Not great. Really not great. 164 00:08:00,565 --> 00:08:05,319 * * 165 00:08:05,361 --> 00:08:09,198 A comet fragment crashes in a farm field in Ohio. 166 00:08:09,240 --> 00:08:13,661 Within hours, a swarm of space pebbles pummels the ISS. 167 00:08:13,703 --> 00:08:15,371 What's going on? 168 00:08:15,413 --> 00:08:18,458 * * 169 00:08:18,499 --> 00:08:21,586 This is the brand new Vera C. Rubin Observatory 170 00:08:21,627 --> 00:08:24,547 on a mountaintop in North Central Chile. 171 00:08:24,589 --> 00:08:27,300 It's named after Vera Rubin. 172 00:08:27,341 --> 00:08:29,844 She was an amazing American astronomer 173 00:08:29,886 --> 00:08:33,056 who studied how galaxies spin and was the first person 174 00:08:33,097 --> 00:08:35,892 to discover hard evidence of the existence 175 00:08:35,933 --> 00:08:38,770 of dark matter, all the while advocating 176 00:08:38,811 --> 00:08:40,688 for women in science. 177 00:08:40,730 --> 00:08:42,732 Back then, women were denied access 178 00:08:42,774 --> 00:08:45,234 to most major observatories. 179 00:08:45,276 --> 00:08:50,031 She's what many experts might call a total badass. 180 00:08:50,073 --> 00:08:53,367 Speaking of badass, behold this wide field 181 00:08:53,409 --> 00:08:54,911 reflecting telescope. 182 00:08:54,952 --> 00:08:57,747 It has an 8.4-meter primary mirror. 183 00:08:57,789 --> 00:09:00,833 That's as wide as a tennis court. 184 00:09:00,875 --> 00:09:03,378 It will photograph the entire visible sky 185 00:09:03,419 --> 00:09:06,756 every few nights as part of a 10-year survey 186 00:09:06,798 --> 00:09:10,093 of, you know, all of space and time. 187 00:09:10,134 --> 00:09:12,804 It will provide the deepest, widest images 188 00:09:12,845 --> 00:09:15,264 of the universe captured so far. 189 00:09:15,306 --> 00:09:18,017 Imagine what it could do looking for a comet. 190 00:09:19,727 --> 00:09:21,479 To check out our hunch 191 00:09:21,521 --> 00:09:23,231 that the small farm field impact 192 00:09:23,272 --> 00:09:25,775 and the micrometeoroid incident in space 193 00:09:25,817 --> 00:09:28,611 are connected, our astronomer has returned 194 00:09:28,653 --> 00:09:30,613 to her home base in Chile. 195 00:09:30,655 --> 00:09:34,242 She studies the orbit of the ISS. 196 00:09:34,283 --> 00:09:36,285 Turns out it passed over the impact site 197 00:09:36,327 --> 00:09:39,205 just hours before the meteoroid swarm. 198 00:09:39,247 --> 00:09:42,625 That almost certainly means the station got smacked 199 00:09:42,667 --> 00:09:44,460 by the comet's tail. 200 00:09:44,502 --> 00:09:48,589 The two events are connected, but there's still a question-- 201 00:09:48,631 --> 00:09:49,882 a big one. 202 00:09:49,924 --> 00:09:51,968 Where is the rest of the comet? 203 00:09:52,009 --> 00:09:54,262 And could it still pose a threat in the future? 204 00:09:54,303 --> 00:09:56,222 [computers beeping] 205 00:09:56,264 --> 00:09:59,100 * * 206 00:09:59,142 --> 00:10:00,810 To answer those questions, 207 00:10:00,852 --> 00:10:03,104 she needs to find the parent comet, 208 00:10:03,146 --> 00:10:05,606 and to do that, our astronomer needs 209 00:10:05,648 --> 00:10:07,984 to do a little time traveling. 210 00:10:08,025 --> 00:10:09,485 Now, astronomers use something 211 00:10:09,527 --> 00:10:11,779 called precovery observations. 212 00:10:11,821 --> 00:10:14,657 That's short for pre-discovery recovery, 213 00:10:14,699 --> 00:10:16,159 obviously. 214 00:10:16,200 --> 00:10:19,120 She scans through images taken a few nights earlier. 215 00:10:20,788 --> 00:10:24,041 Using computer modeling, she retraces the path 216 00:10:24,083 --> 00:10:27,587 of the comet fragment all the way back to Jupiter, 217 00:10:27,628 --> 00:10:29,047 half a billion miles away 218 00:10:29,088 --> 00:10:31,632 and nearly two years in the past, 219 00:10:31,674 --> 00:10:33,760 and what she finds is startling. 220 00:10:33,801 --> 00:10:35,553 * * 221 00:10:35,595 --> 00:10:39,140 Our astronomer confirms that the farm field impact 222 00:10:39,182 --> 00:10:41,684 and the space station pebble storm 223 00:10:41,726 --> 00:10:43,061 were both caused by objects 224 00:10:43,102 --> 00:10:45,688 that came here by way of Jupiter. 225 00:10:45,730 --> 00:10:47,607 Now, she wonders, could there be 226 00:10:47,648 --> 00:10:48,983 more objects that were disturbed 227 00:10:49,025 --> 00:10:51,360 from the very same path? 228 00:10:51,402 --> 00:10:53,696 The answer is yes. 229 00:10:53,738 --> 00:10:57,700 [comet whooshing] 230 00:10:57,742 --> 00:11:00,078 Two years ago, a massive comet 231 00:11:00,119 --> 00:11:02,497 passed by Jupiter where it got torn apart 232 00:11:02,538 --> 00:11:05,792 by the giant planet's powerful gravity. 233 00:11:05,833 --> 00:11:09,379 Two fragments plunged into Jupiter's atmosphere, 234 00:11:09,420 --> 00:11:12,965 creating a pair of dark spots when they exploded. 235 00:11:13,007 --> 00:11:15,426 At the time, astronomers assumed 236 00:11:15,468 --> 00:11:19,597 they were giant storm systems not uncommon on Jupiter, 237 00:11:19,639 --> 00:11:23,684 but they were wrong. Those were comet impacts. 238 00:11:23,726 --> 00:11:28,106 * * 239 00:11:28,147 --> 00:11:29,982 The surviving cometary fragments 240 00:11:30,024 --> 00:11:31,234 whipped around Jupiter, 241 00:11:31,275 --> 00:11:34,237 spreading out like a string of pearls, 242 00:11:34,278 --> 00:11:36,406 and I'm not talking about what Grandma Nye wears 243 00:11:36,447 --> 00:11:38,199 with a sweater set. 244 00:11:38,241 --> 00:11:41,119 It's a string of smaller but still deadly 245 00:11:41,160 --> 00:11:44,247 comet fragments ranging from a few hundred meters 246 00:11:44,288 --> 00:11:46,958 to a couple of kilometers wide. 247 00:11:46,999 --> 00:11:48,584 And here's the really bad news, 248 00:11:48,626 --> 00:11:52,088 the other comet fragments in this string of pearls 249 00:11:52,130 --> 00:11:54,924 are headed our way, meaning that they could 250 00:11:54,966 --> 00:11:56,718 smash land right here on Earth, 251 00:11:56,759 --> 00:12:00,471 and it's impossible to predict exactly how close 252 00:12:00,513 --> 00:12:02,056 they'll get to Earth. 253 00:12:02,098 --> 00:12:04,267 Maybe we'll get lucky, and they'll all miss. 254 00:12:04,308 --> 00:12:07,437 Maybe there'll be no disaster today. 255 00:12:07,478 --> 00:12:08,938 * * 256 00:12:08,980 --> 00:12:11,482 What do you think? 257 00:12:11,524 --> 00:12:16,821 * * 258 00:12:20,283 --> 00:12:23,745 [dramatic music] 259 00:12:23,786 --> 00:12:27,415 - Our astronomer has gone from watching the stars 260 00:12:27,457 --> 00:12:29,375 to warning the world. 261 00:12:29,417 --> 00:12:31,169 She has joined forces with others 262 00:12:31,210 --> 00:12:33,838 in the scientific community to raise the alarm 263 00:12:33,880 --> 00:12:35,840 about the deadly string of comets 264 00:12:35,882 --> 00:12:37,633 threatening our planet. 265 00:12:37,675 --> 00:12:40,053 They contact a powerful, ambitious Congressman 266 00:12:40,094 --> 00:12:42,472 to request emergency funding for a plan 267 00:12:42,513 --> 00:12:44,265 to deflect the comet. - Sounds like an overreact. 268 00:12:44,307 --> 00:12:46,976 - But to get those projects off the ground quickly 269 00:12:47,018 --> 00:12:48,603 will be a monumental undertaking 270 00:12:48,644 --> 00:12:50,104 and cost billions. 271 00:12:50,146 --> 00:12:53,983 Unfortunately, he's spoken to his own experts. 272 00:12:54,025 --> 00:12:55,693 They've assured him that nobody 273 00:12:55,735 --> 00:12:58,154 can predict the exact path of these things. 274 00:12:58,196 --> 00:12:59,447 We don't have enough data, 275 00:12:59,489 --> 00:13:01,949 and there are too many variables to consider. 276 00:13:01,991 --> 00:13:04,577 He accuses her of getting too emotional 277 00:13:04,619 --> 00:13:06,829 and blames it on her lack of experience. 278 00:13:06,871 --> 00:13:07,955 - These things fly past the Earth 279 00:13:07,997 --> 00:13:09,457 all the time, am I right? 280 00:13:09,499 --> 00:13:11,959 - Our astronomer now knows how Vera Rubin must have felt. 281 00:13:12,001 --> 00:13:13,878 She argues that, no matter how small 282 00:13:13,920 --> 00:13:17,048 the possibility of an impact, we can't risk doing nothing. 283 00:13:17,090 --> 00:13:19,967 The time to get prepared was yesterday. 284 00:13:20,009 --> 00:13:22,011 - If we don't act now, we don't have a chance. 285 00:13:22,053 --> 00:13:23,137 [computer beeps] 286 00:13:23,179 --> 00:13:25,473 - Here it is, folks, our act of cow. 287 00:13:25,515 --> 00:13:27,308 [cow moos] 288 00:13:27,350 --> 00:13:29,977 Act of cow symbolizes the human negligence 289 00:13:30,019 --> 00:13:33,106 that can trigger a disaster or make one worse. 290 00:13:33,147 --> 00:13:36,150 It's inspired by a bovine named Daisy who, 291 00:13:36,192 --> 00:13:38,694 as legend has it, kicked over a lantern 292 00:13:38,736 --> 00:13:41,280 and started the Great Chicago Fire. 293 00:13:41,322 --> 00:13:42,824 [cow mooing] 294 00:13:42,865 --> 00:13:45,034 Kind of unfair to Daisy, if you ask me. 295 00:13:45,076 --> 00:13:47,662 I mean, who leaves a lantern behind a cow? 296 00:13:47,703 --> 00:13:49,205 Yeah, no one you know. 297 00:13:49,247 --> 00:13:51,332 Well, in this case, the congressman 298 00:13:51,374 --> 00:13:54,460 has spoken with the president and his advisors. 299 00:13:54,502 --> 00:13:57,213 Everyone agrees that the science isn't settled, 300 00:13:57,255 --> 00:14:00,007 so why waste billions of taxpayer dollars 301 00:14:00,049 --> 00:14:02,677 on something that only might happen? 302 00:14:02,719 --> 00:14:06,139 The congressman also calls it highly suspicious 303 00:14:06,180 --> 00:14:08,641 that just a few weeks after astronomers switched 304 00:14:08,683 --> 00:14:11,686 on their half-billion-dollar Rubin telescope, 305 00:14:11,728 --> 00:14:12,979 they happened to discover 306 00:14:13,020 --> 00:14:15,022 an existential threat to humanity, 307 00:14:15,064 --> 00:14:18,526 and now, those greedy, bloodsucking scientists 308 00:14:18,568 --> 00:14:21,028 are asking for more, more, and more-- 309 00:14:21,070 --> 00:14:25,074 more instruments, more missions, more money. 310 00:14:25,116 --> 00:14:26,534 - Now, who are you gonna believe, 311 00:14:26,576 --> 00:14:29,912 some rat-faced science twerp 312 00:14:29,954 --> 00:14:32,707 or a straight shooter who tells it like it is? 313 00:14:32,749 --> 00:14:35,585 And what it is is a hoax. 314 00:14:36,753 --> 00:14:38,004 - A hoax. A hoax. 315 00:14:38,046 --> 00:14:39,505 The H word. Really? 316 00:14:39,547 --> 00:14:41,049 Come on. 317 00:14:41,090 --> 00:14:43,718 Over the next few weeks, the world is in a state 318 00:14:43,760 --> 00:14:45,678 of chaotic uncertainty. 319 00:14:45,720 --> 00:14:47,055 [indistinct chatter] 320 00:14:47,096 --> 00:14:49,390 Professional and citizen scientists 321 00:14:49,432 --> 00:14:51,851 across the globe get louder and louder 322 00:14:51,893 --> 00:14:53,019 with their warnings. 323 00:14:53,061 --> 00:14:55,730 Some politicians and naysayers 324 00:14:55,772 --> 00:14:57,690 get more vehement in their denials. 325 00:14:57,732 --> 00:15:00,777 [people chanting indistinctly] 326 00:15:00,818 --> 00:15:03,404 Even as nations compete for emergency supplies 327 00:15:03,446 --> 00:15:06,324 and accuse each other of hoarding, 328 00:15:06,365 --> 00:15:08,242 preppers build bunkers. 329 00:15:08,284 --> 00:15:10,661 Deniers and conspiracy theorists 330 00:15:10,703 --> 00:15:13,331 battle each other on social media. 331 00:15:13,372 --> 00:15:16,334 [phones beeping] 332 00:15:16,375 --> 00:15:20,129 * * 333 00:15:20,171 --> 00:15:22,090 [people cheering] 334 00:15:22,131 --> 00:15:25,093 News of the possible comet strike is spreading. 335 00:15:25,134 --> 00:15:27,804 Folks are naturally freaked out, 336 00:15:27,845 --> 00:15:30,390 so comet cults like this one are springing up 337 00:15:30,431 --> 00:15:31,891 all over the world. 338 00:15:31,933 --> 00:15:33,935 People join for various reasons-- 339 00:15:33,976 --> 00:15:37,647 fear, superstition, human connection-- 340 00:15:37,688 --> 00:15:40,108 like my good buddy over there. 341 00:15:40,149 --> 00:15:42,819 We've been through some crazy disasters together. 342 00:15:42,860 --> 00:15:45,738 He must have nerves of steel by now. 343 00:15:45,780 --> 00:15:46,948 - Honk if you love comets! 344 00:15:46,989 --> 00:15:49,909 [cheering and honking] 345 00:15:49,951 --> 00:15:52,286 - I guess he figures he can't beat what's coming, 346 00:15:52,328 --> 00:15:54,997 so I might as well make friends with him. 347 00:15:55,039 --> 00:15:57,125 Hey, man. It's Bill. 348 00:16:02,672 --> 00:16:05,133 - No, no, no, no, no! 349 00:16:05,174 --> 00:16:06,968 - We are born of sin and this is why-- 350 00:16:07,009 --> 00:16:10,221 - Doomsday enthusiasts are nothing new. 351 00:16:10,263 --> 00:16:13,808 You might say we are obsessed with how the world will end. 352 00:16:13,850 --> 00:16:16,728 [explosion] 353 00:16:16,769 --> 00:16:20,273 Every major religion features a vision of the apocalypse, 354 00:16:20,314 --> 00:16:22,400 and so-called doomsday prophets 355 00:16:22,442 --> 00:16:25,319 make a good living by predicting Armageddon. 356 00:16:25,361 --> 00:16:28,156 Nostradamus claimed that Earth would be struck 357 00:16:28,197 --> 00:16:30,533 by a giant comet, and that the world would end 358 00:16:30,575 --> 00:16:34,036 in the year 2004... 359 00:16:34,078 --> 00:16:35,955 which it didn't, unless you count 360 00:16:35,997 --> 00:16:37,331 the cancellation of "Friends." 361 00:16:37,373 --> 00:16:39,584 [laughter] 362 00:16:39,625 --> 00:16:42,336 People are obsessed with the end of the world. 363 00:16:42,378 --> 00:16:43,713 Don't believe me? 364 00:16:43,755 --> 00:16:45,840 Well, why are you watching this show? 365 00:16:45,882 --> 00:16:49,010 [explosion] 366 00:16:51,763 --> 00:16:53,222 It's a different episode. 367 00:16:55,058 --> 00:16:58,519 As the days turn into weeks, the news cycle moves on. 368 00:16:58,561 --> 00:17:02,065 Most people are tired of even hearing the word comet. 369 00:17:02,106 --> 00:17:04,817 The media thrives on the here and now, 370 00:17:04,859 --> 00:17:06,944 not the later and maybe. 371 00:17:06,986 --> 00:17:08,696 People have more immediate problems 372 00:17:08,738 --> 00:17:12,200 to face like going to work, paying their bills on time, 373 00:17:12,241 --> 00:17:15,453 and other more earthly matters, 374 00:17:15,495 --> 00:17:17,371 until one fateful night, 375 00:17:17,413 --> 00:17:21,667 the threat becomes impossible to ignore. 376 00:17:21,709 --> 00:17:24,837 [explosion] 377 00:17:26,923 --> 00:17:28,758 [people screaming] 378 00:17:28,800 --> 00:17:30,885 - [gasps] 379 00:17:30,927 --> 00:17:34,764 [car alarms blaring] 380 00:17:34,806 --> 00:17:38,643 - Look, it is hard to believe what we're seeing. 381 00:17:38,684 --> 00:17:40,353 For those of you just tuning in, 382 00:17:40,395 --> 00:17:43,231 have you looked up at the night sky lately? 383 00:17:43,272 --> 00:17:46,067 * * 384 00:17:46,109 --> 00:17:49,237 [animals chirping and calling] 385 00:17:49,278 --> 00:17:54,075 * * 386 00:17:54,117 --> 00:17:55,743 [car horns blaring] 387 00:17:55,785 --> 00:17:57,161 - The sight of the moon impact 388 00:17:57,203 --> 00:18:00,123 is a serious wake-up call for humanity. 389 00:18:00,164 --> 00:18:03,751 People of Earth, you are in danger. 390 00:18:03,793 --> 00:18:05,253 * * 391 00:18:08,631 --> 00:18:11,551 [dramatic music] 392 00:18:11,592 --> 00:18:18,641 * * 393 00:18:18,683 --> 00:18:21,227 - After the comet impact on the Moon, 394 00:18:21,269 --> 00:18:22,478 there is no denying 395 00:18:22,520 --> 00:18:24,772 the threat to Earth any longer. 396 00:18:24,814 --> 00:18:27,692 More comets are heading our way. 397 00:18:27,734 --> 00:18:30,611 Astronomers are now the most important people 398 00:18:30,653 --> 00:18:32,780 in the world because they're the only ones 399 00:18:32,822 --> 00:18:36,284 who can predict where the comets might hit next. 400 00:18:36,325 --> 00:18:37,744 They are updating their simulations 401 00:18:37,785 --> 00:18:41,122 minute by minute to account for the erratic motions 402 00:18:41,164 --> 00:18:42,498 of the comet fragments. 403 00:18:42,540 --> 00:18:44,417 It's too late to deflect them. 404 00:18:44,459 --> 00:18:46,669 That opportunity was lost months ago 405 00:18:46,711 --> 00:18:48,755 when the congressmen blocked funding efforts 406 00:18:48,796 --> 00:18:50,131 and downplayed the threat. 407 00:18:50,173 --> 00:18:51,549 - Tells it like it is. 408 00:18:51,591 --> 00:18:54,010 And what it is is a hoax. 409 00:18:54,052 --> 00:18:56,679 - Damage control is all we can hope for, 410 00:18:56,721 --> 00:18:58,431 and it doesn't look good. 411 00:18:58,473 --> 00:19:01,434 The latest projections show a 90% chance 412 00:19:01,476 --> 00:19:05,605 of at least one impact, a 50% chance of three or more, 413 00:19:05,646 --> 00:19:08,066 and you don't have to be a statistician to know 414 00:19:08,107 --> 00:19:10,985 there's a 100% chance we're screwed. 415 00:19:13,988 --> 00:19:16,741 They can now estimate the approximate impact times. 416 00:19:16,783 --> 00:19:18,159 [bell chimes] 417 00:19:18,201 --> 00:19:19,619 The countdown has begun. 418 00:19:19,660 --> 00:19:21,329 [clock ticking] 419 00:19:21,370 --> 00:19:24,791 The world has about 11 days, or a million seconds, 420 00:19:24,832 --> 00:19:26,667 before the first fragment arrives 421 00:19:26,709 --> 00:19:29,420 and we find out how bad it's going to be. 422 00:19:29,462 --> 00:19:31,172 I'll give you a hint. 423 00:19:31,214 --> 00:19:33,007 It's going to be bad. 424 00:19:33,049 --> 00:19:34,967 * * 425 00:19:35,009 --> 00:19:37,303 Earth's surface is mostly water, 426 00:19:37,345 --> 00:19:39,972 so an ocean strike is likely. 427 00:19:40,014 --> 00:19:42,183 Bad news for beach-goers. 428 00:19:42,225 --> 00:19:47,230 * * 429 00:19:47,271 --> 00:19:48,898 But this obnoxious Congressman 430 00:19:48,940 --> 00:19:52,193 decides it's a great time to take a vacation. 431 00:19:52,235 --> 00:19:54,987 * * 432 00:19:55,029 --> 00:19:58,324 Most official agencies are recommending the evacuation 433 00:19:58,366 --> 00:20:01,244 of coastal cities, but it's virtually impossible 434 00:20:01,285 --> 00:20:02,870 to predict with any accuracy 435 00:20:02,912 --> 00:20:05,998 which areas will truly be safe, 436 00:20:06,040 --> 00:20:09,127 so our Congressman is heading to the Yucatan Peninsula, 437 00:20:09,168 --> 00:20:10,837 where the dinosaur-killing asteroid 438 00:20:10,878 --> 00:20:12,338 landed back in the day. 439 00:20:12,380 --> 00:20:15,091 He figures there's no way lightning will strike 440 00:20:15,133 --> 00:20:17,343 twice in the same place. 441 00:20:17,385 --> 00:20:20,263 By the way, lightning does strike twice in the same place 442 00:20:20,304 --> 00:20:21,723 all the time. 443 00:20:21,764 --> 00:20:24,058 The Empire State Building gets struck dozens of times 444 00:20:24,100 --> 00:20:27,145 every year, an example off the top of my head. 445 00:20:29,731 --> 00:20:31,607 [phone chimes] - [snoring] 446 00:20:31,649 --> 00:20:38,740 * * 447 00:21:35,296 --> 00:21:38,216 [upbeat tropical music] 448 00:21:38,257 --> 00:21:39,759 * * 449 00:21:39,801 --> 00:21:42,637 - Thanks, babe. One more. 450 00:21:45,139 --> 00:21:46,766 [exhales deeply] 451 00:21:50,311 --> 00:21:53,231 [comet whooshing] 452 00:21:57,026 --> 00:21:58,653 No way! 453 00:22:02,949 --> 00:22:04,742 - After the impact off the coast 454 00:22:04,784 --> 00:22:07,870 of the Yucatan Peninsula, astronomers do everything 455 00:22:07,912 --> 00:22:10,123 they can to pinpoint where the next one 456 00:22:10,164 --> 00:22:12,250 will hit so they can evacuate 457 00:22:12,291 --> 00:22:14,877 as many people as possible and so governments 458 00:22:14,919 --> 00:22:16,879 can brace for the worst. 459 00:22:16,921 --> 00:22:18,506 - If there is an imminent impact, we need to alert-- 460 00:22:18,548 --> 00:22:20,800 - It looks like the largest comet in the swarm 461 00:22:20,842 --> 00:22:23,052 is on course to graze Antarctica, 462 00:22:23,094 --> 00:22:25,471 and another is just hours behind. 463 00:22:25,513 --> 00:22:28,474 [dramatic music] 464 00:22:28,516 --> 00:22:35,398 * * 465 00:22:39,360 --> 00:22:41,320 [explosion] 466 00:23:08,389 --> 00:23:11,309 [sirens blaring] 467 00:23:17,315 --> 00:23:20,318 Remember the effects of global climate change 468 00:23:20,359 --> 00:23:23,988 I've been whining about for 30 years? 469 00:23:24,030 --> 00:23:26,783 Well, all of that just happened in about 30 seconds. 470 00:23:26,824 --> 00:23:28,159 - One more thing-- - Yeah. 471 00:23:28,201 --> 00:23:29,702 - Take the-- 472 00:23:29,744 --> 00:23:31,996 [panicked chatter] 473 00:23:32,038 --> 00:23:34,040 - And here at the Rubin Observatory, 474 00:23:34,082 --> 00:23:36,417 the telescope has been blinded by impact debris 475 00:23:36,459 --> 00:23:38,378 spreading through the atmosphere. 476 00:23:38,419 --> 00:23:42,673 No one on Earth can track anything anymore, 477 00:23:42,715 --> 00:23:44,926 and there's one more impact on the way. 478 00:23:44,967 --> 00:23:52,183 * * 479 00:23:52,475 --> 00:23:55,436 [people cheering] 480 00:24:01,734 --> 00:24:08,825 * * 481 00:24:11,869 --> 00:24:15,164 - [screaming] 482 00:24:18,042 --> 00:24:25,174 * * 483 00:24:29,262 --> 00:24:31,556 It's been an hour since Canada got hit, 484 00:24:31,597 --> 00:24:34,892 and it looks like the impacts have finally stopped, 485 00:24:34,934 --> 00:24:36,436 but the entire world will suffer 486 00:24:36,477 --> 00:24:38,521 the effects for decades. 487 00:24:38,563 --> 00:24:41,149 In a few weeks, Earth will be a gray ball 488 00:24:41,190 --> 00:24:43,526 and shrouded in debris, smoke, and ash. 489 00:24:43,568 --> 00:24:45,445 If humans survive this, 490 00:24:45,486 --> 00:24:47,739 we'll have to learn to live and grow food 491 00:24:47,780 --> 00:24:48,990 in sub-zero temperatures. 492 00:24:49,031 --> 00:24:52,493 [impacts thudding] 493 00:24:52,535 --> 00:24:53,828 It's not over yet. 494 00:24:53,870 --> 00:24:56,122 These are tektites from the Canadian impact 495 00:24:56,164 --> 00:24:59,876 falling back to Earth like hot bullets. 496 00:24:59,917 --> 00:25:02,045 Whoa! 497 00:25:02,086 --> 00:25:03,880 [tires squealing] 498 00:25:09,844 --> 00:25:12,513 [tires screech] 499 00:25:14,599 --> 00:25:16,642 [screaming] 500 00:25:16,684 --> 00:25:20,438 [explosion] 501 00:25:24,358 --> 00:25:29,947 - Our disaster simulation has come to an impactful end. 502 00:25:29,989 --> 00:25:31,741 Well, that sucked. 503 00:25:31,783 --> 00:25:34,077 Maybe the suckiest part is that sooty layer 504 00:25:34,118 --> 00:25:36,245 in our stratosphere which is going to block 505 00:25:36,287 --> 00:25:38,247 the sunlight for decades. 506 00:25:38,289 --> 00:25:42,460 Most of the remaining humans on Earth will freeze or starve. 507 00:25:42,502 --> 00:25:44,295 How bad will it get? 508 00:25:44,337 --> 00:25:47,757 Just ask any old ancient dinosaur. 509 00:25:47,799 --> 00:25:50,885 Of course, you can't ask them because they're dead, 510 00:25:50,927 --> 00:25:52,261 all of them. 511 00:25:52,303 --> 00:25:53,679 Get it? 512 00:25:53,721 --> 00:25:56,182 [dramatic music] 513 00:25:56,224 --> 00:25:58,434 So how do we stop more space rocks 514 00:25:58,476 --> 00:26:00,478 from killing us all? 515 00:26:00,520 --> 00:26:01,813 First, we'll need to know 516 00:26:01,854 --> 00:26:03,773 where those rocks are coming from. 517 00:26:03,815 --> 00:26:07,193 Let's hit the lab and suit up. 518 00:26:07,235 --> 00:26:10,405 Major cometary impacts have happened a few times 519 00:26:10,446 --> 00:26:11,989 in Earth's history, 520 00:26:12,031 --> 00:26:15,159 and each time one of them hit, it turned life on this planet 521 00:26:15,201 --> 00:26:19,789 upside-down, but the story of these icy messengers of death 522 00:26:19,831 --> 00:26:23,042 goes back even further, before life, 523 00:26:23,084 --> 00:26:26,838 before Earth, out beyond any of the Sun's planets. 524 00:26:33,845 --> 00:26:36,556 I'm about to take you to the outermost reaches 525 00:26:36,597 --> 00:26:38,182 of our solar system, 526 00:26:38,224 --> 00:26:40,893 a place very few people even know about, 527 00:26:40,935 --> 00:26:43,146 so pee now if you have to. 528 00:26:43,187 --> 00:26:47,191 * * 529 00:26:47,233 --> 00:26:50,153 [tranquil music] 530 00:26:50,194 --> 00:26:55,241 * * 531 00:26:55,283 --> 00:26:57,618 Welcome to the Oort cloud, 532 00:26:57,660 --> 00:27:00,496 named for Jan Oort, the astronomer 533 00:27:00,538 --> 00:27:02,749 who realized it must exist. 534 00:27:02,790 --> 00:27:07,628 The Oort cloud is a vast, spherical shell of icy debris 535 00:27:07,670 --> 00:27:10,173 that surrounds the entire solar system. 536 00:27:10,214 --> 00:27:12,967 It's made up of the same ancient stardust 537 00:27:13,009 --> 00:27:16,137 and star gas that became our Sun and Earth 538 00:27:16,179 --> 00:27:17,972 and the other planets, 539 00:27:18,014 --> 00:27:20,892 but it never got sucked in by any of them. 540 00:27:20,933 --> 00:27:24,687 Instead, it got scattered to the dim reaches, 541 00:27:24,729 --> 00:27:28,024 trapped out here in this twilight zone. 542 00:27:28,066 --> 00:27:30,568 If you could zoom out to see our solar system 543 00:27:30,610 --> 00:27:32,987 from a light year away, the Oort cloud 544 00:27:33,029 --> 00:27:36,532 might look something like this. 545 00:27:36,574 --> 00:27:43,748 * * 546 00:27:53,132 --> 00:27:54,300 That's right. 547 00:27:54,342 --> 00:27:56,844 Our entire solar system is surrounded 548 00:27:56,886 --> 00:28:01,808 by a shell of icy rocks. 549 00:28:01,849 --> 00:28:05,728 There are trillions of comets out here. 550 00:28:05,770 --> 00:28:07,772 Unlike asteroids, which, simply put, 551 00:28:07,814 --> 00:28:10,400 are big space rocks, and meteoroids, 552 00:28:10,441 --> 00:28:13,069 which are small space rocks, 553 00:28:13,111 --> 00:28:15,113 comets are cosmic snowballs 554 00:28:15,154 --> 00:28:19,367 full of water ice, and frozen carbon compounds. 555 00:28:19,409 --> 00:28:22,370 As a comet moves closer to the Sun, 556 00:28:22,412 --> 00:28:25,415 the snowball starts to vaporize 557 00:28:25,456 --> 00:28:29,377 and spew dust and gases, forming a pair of tails 558 00:28:29,419 --> 00:28:32,296 that can stretch for millions of miles. 559 00:28:32,338 --> 00:28:34,090 * * 560 00:28:34,132 --> 00:28:36,843 Comets typically pass far away from Earth, 561 00:28:36,884 --> 00:28:39,095 but occasionally, they come close enough 562 00:28:39,137 --> 00:28:43,266 to produce a dazzling spectacle in our skies. 563 00:28:43,307 --> 00:28:48,730 Now, all these objects orbit the Sun, but very slowly. 564 00:28:48,771 --> 00:28:51,399 The Sun's pull is so weak out here 565 00:28:51,441 --> 00:28:54,736 that it takes only the tiniest random tug, 566 00:28:54,777 --> 00:28:57,905 like the gravity from a distant passing star, 567 00:28:57,947 --> 00:28:59,615 to nudge one of these comets 568 00:28:59,657 --> 00:29:01,451 out of the Oort cloud. 569 00:29:01,492 --> 00:29:03,745 When its orbit is disturbed, 570 00:29:03,786 --> 00:29:06,122 a comet will start falling toward the Sun 571 00:29:06,164 --> 00:29:08,541 and begin its long, long journey 572 00:29:08,583 --> 00:29:10,460 across our solar system. 573 00:29:10,501 --> 00:29:13,463 [dramatic music] 574 00:29:13,504 --> 00:29:20,386 * * 575 00:29:38,321 --> 00:29:42,283 Jupiter's gravity is so strong, it can easily rip a comet 576 00:29:42,325 --> 00:29:44,410 like this one to pieces. 577 00:29:44,452 --> 00:29:46,370 Happens all the time. 578 00:29:46,412 --> 00:29:53,378 * * 579 00:29:57,673 --> 00:30:01,386 String of pearl impacts leave telltale signatures behind. 580 00:30:01,427 --> 00:30:04,847 They're called crater chains, and they are everywhere 581 00:30:04,889 --> 00:30:06,808 in our solar system. 582 00:30:06,849 --> 00:30:08,601 Some of you may remember when NASA's 583 00:30:08,643 --> 00:30:11,521 Voyager 1 spacecraft flew past Jupiter's moon, 584 00:30:11,562 --> 00:30:14,524 Callisto, in 1979. 585 00:30:14,565 --> 00:30:17,276 It spotted curious chains of craters. 586 00:30:17,318 --> 00:30:21,030 * * 587 00:30:21,072 --> 00:30:24,325 Eight more chains were later found on Callisto, 588 00:30:24,367 --> 00:30:27,412 along with three similar chains on Ganymede, 589 00:30:27,453 --> 00:30:29,122 Jupiter's biggest moon. 590 00:30:32,417 --> 00:30:37,046 At first, the crater chains were a mystery 591 00:30:37,088 --> 00:30:40,258 until the discovery of comet Shoemaker-Levy 9. 592 00:30:40,299 --> 00:30:44,220 Not a law firm, Shoemaker-Levy was a string of pearls, 593 00:30:44,262 --> 00:30:46,556 a chain of comet fragments 594 00:30:46,597 --> 00:30:48,349 created when Jupiter's gravity 595 00:30:48,391 --> 00:30:51,352 ripped the original comet apart. 596 00:30:51,394 --> 00:30:54,897 Shoemaker-Levy got its revenge in 1994, 597 00:30:54,939 --> 00:30:56,733 crashing into Jupiter. 598 00:30:56,774 --> 00:30:59,610 Astronomers watched in awe as the broken bits 599 00:30:59,652 --> 00:31:02,697 hit like machine gunfire. 600 00:31:02,739 --> 00:31:05,575 In fact, everywhere we look in the solar system, 601 00:31:05,616 --> 00:31:07,577 it's all craters-- 602 00:31:07,618 --> 00:31:09,912 craters, craters, and more craters. 603 00:31:09,954 --> 00:31:16,586 * * 604 00:31:16,627 --> 00:31:20,173 The only reason we don't see craters everywhere on Earth 605 00:31:20,214 --> 00:31:24,260 is because our planet is good at hiding its scars. 606 00:31:24,302 --> 00:31:26,763 If we drained away Earth's ocean 607 00:31:26,804 --> 00:31:30,975 and stripped off its forests and all the other concealers, 608 00:31:31,017 --> 00:31:33,352 it might look something like this. 609 00:31:33,394 --> 00:31:34,604 * * 610 00:31:34,645 --> 00:31:38,107 Behold the Earth naked. 611 00:31:38,149 --> 00:31:40,943 What? Not what you imagined? 612 00:31:40,985 --> 00:31:43,654 That's enough. This is a family show. 613 00:31:43,696 --> 00:31:46,324 [enchanting orchestral music] 614 00:31:46,365 --> 00:31:48,451 Earth's taken quite a few shots 615 00:31:48,493 --> 00:31:50,995 over the last four and a half billion years, 616 00:31:51,037 --> 00:31:53,122 and we're still in the line of fire, 617 00:31:53,164 --> 00:31:54,916 but here's the great news. 618 00:31:54,957 --> 00:31:57,543 Of all the natural disasters showcased 619 00:31:57,585 --> 00:32:01,255 in this institute of ours, this is the only one 620 00:32:01,297 --> 00:32:03,549 that's entirely preventable. 621 00:32:03,591 --> 00:32:06,052 How? With science. 622 00:32:10,640 --> 00:32:13,518 [tranquil music] 623 00:32:13,559 --> 00:32:14,560 * * 624 00:32:14,602 --> 00:32:16,020 - To prevent an impact, 625 00:32:16,062 --> 00:32:18,398 we first have to find the impactors, 626 00:32:18,439 --> 00:32:20,566 see what's coming at us. 627 00:32:20,608 --> 00:32:23,653 That's what the Asteroid Terrestrial-impact 628 00:32:23,694 --> 00:32:25,571 Last Alert System is trying to do. 629 00:32:25,613 --> 00:32:27,949 We call it ATLAS. 630 00:32:27,990 --> 00:32:31,119 It's in Maui, Hawaii. You know Atlas. 631 00:32:31,160 --> 00:32:32,787 In Greek mythology, he was the guy holding up 632 00:32:32,829 --> 00:32:35,331 the Earth on his shoulders. 633 00:32:35,373 --> 00:32:39,127 Well, this ATLAS is trying to hold up life on Earth, 634 00:32:39,168 --> 00:32:42,130 and it's a full-time job with no benefits. 635 00:32:42,171 --> 00:32:43,965 * * 636 00:32:44,006 --> 00:32:46,509 The robotic telescopes in ATLAS 637 00:32:46,551 --> 00:32:49,011 are part of a critical early warning system 638 00:32:49,053 --> 00:32:51,848 that scientists use to detect near-Earth objects 639 00:32:51,889 --> 00:32:56,519 a few days or sometimes only a few hours before they hit. 640 00:32:56,561 --> 00:32:59,021 * * 641 00:32:59,063 --> 00:33:02,316 The most important thing we need is advance notice. 642 00:33:02,358 --> 00:33:03,901 There's an old saying-- 643 00:33:03,943 --> 00:33:06,154 I mean, an old saying among comet hunters-- 644 00:33:06,195 --> 00:33:08,698 that finding a distant comet is like looking 645 00:33:08,740 --> 00:33:11,242 for a charcoal briquette in the dark 646 00:33:11,284 --> 00:33:12,952 or trying to find a flattering pair 647 00:33:12,994 --> 00:33:15,413 of cargo pants. It's almost impossible. 648 00:33:15,455 --> 00:33:18,708 * * 649 00:33:18,750 --> 00:33:21,461 Near-Earth objects fly past us all the time. 650 00:33:21,502 --> 00:33:23,796 * * 651 00:33:23,838 --> 00:33:27,133 Scientists estimate that several dozen large asteroids 652 00:33:27,175 --> 00:33:30,053 fly past Earth at a distance closer than the orbit 653 00:33:30,094 --> 00:33:32,930 of the Moon every year, 654 00:33:32,972 --> 00:33:35,600 but only a fraction of these are actually detected. 655 00:33:35,641 --> 00:33:38,978 * * 656 00:33:39,020 --> 00:33:43,024 The ones we do see are usually spotted after they pass by, 657 00:33:43,066 --> 00:33:45,234 and only one or two are detected with more 658 00:33:45,276 --> 00:33:47,028 than 24 hours' notice. 659 00:33:47,070 --> 00:33:49,155 * * 660 00:33:49,197 --> 00:33:51,074 Not trying to freak you out here, 661 00:33:51,115 --> 00:33:53,534 but we might want to find a better way to detect 662 00:33:53,576 --> 00:33:56,287 these unexpected guests. 663 00:33:56,329 --> 00:33:58,790 That's why we need this. 664 00:33:58,831 --> 00:34:01,626 It's the Near-Earth Object Surveyor spacecraft, 665 00:34:01,667 --> 00:34:03,503 the NEO Surveyor. 666 00:34:03,544 --> 00:34:05,421 It's a new kind of space telescope 667 00:34:05,463 --> 00:34:06,589 designed to hunt down 668 00:34:06,631 --> 00:34:09,217 potentially hazardous space rocks. 669 00:34:09,258 --> 00:34:12,804 Now, they get warmed ever so slightly by the Sun, 670 00:34:12,845 --> 00:34:15,556 and it's fantastically cold out there in space, 671 00:34:15,598 --> 00:34:18,059 so if you have a detector sensitive enough, 672 00:34:18,101 --> 00:34:20,603 you can sense their reflected heat. 673 00:34:20,645 --> 00:34:23,856 It's like night vision for space rocks. 674 00:34:23,898 --> 00:34:26,859 By making this opening wide and dark, 675 00:34:26,901 --> 00:34:29,612 it stays as cold as possible in here. 676 00:34:29,654 --> 00:34:32,490 Then down inside are the most advanced 677 00:34:32,532 --> 00:34:35,535 heat-detecting sensors ever built. 678 00:34:35,576 --> 00:34:37,745 So let's get it flying, 679 00:34:37,787 --> 00:34:39,497 then we can go looking for that thing. 680 00:34:39,539 --> 00:34:41,833 * * 681 00:34:41,874 --> 00:34:43,167 Oh, yeah. 682 00:34:43,209 --> 00:34:50,133 * * 683 00:34:56,764 --> 00:35:00,017 Seriously, let's say we find a comet or an asteroid 684 00:35:00,059 --> 00:35:02,228 and we know that it's got our name on it. 685 00:35:02,270 --> 00:35:05,690 Well people, you might think we could just blow that baby up 686 00:35:05,732 --> 00:35:07,608 in Bruce Willis fashion-- 687 00:35:07,650 --> 00:35:09,986 throw a nuke at it and Bob's your uncle. 688 00:35:10,027 --> 00:35:14,198 Actually, a nuke is a pretty good idea... 689 00:35:14,240 --> 00:35:16,325 if scientists and engineers figure out 690 00:35:16,367 --> 00:35:17,910 the right way to use it. 691 00:35:17,952 --> 00:35:19,829 Space agencies have been studying ways 692 00:35:19,871 --> 00:35:21,748 to make this work without having to rely 693 00:35:21,789 --> 00:35:24,709 on a bunch of yoked up and bronzed oil drillers. 694 00:35:24,751 --> 00:35:26,127 Here's one way. 695 00:35:26,169 --> 00:35:28,129 You could use the nuclear weapon 696 00:35:28,171 --> 00:35:31,674 to blast a crater in the surface of the comet. 697 00:35:31,716 --> 00:35:34,469 The explosion, along with the spewed out stuff-- 698 00:35:34,510 --> 00:35:37,263 the ejecta-- would nudge the comet 699 00:35:37,305 --> 00:35:38,723 in a different direction. 700 00:35:38,765 --> 00:35:42,602 Or you could set off your standoff burst 701 00:35:42,643 --> 00:35:45,480 some distance away that uses radiation 702 00:35:45,521 --> 00:35:47,106 to heat the comet. 703 00:35:47,148 --> 00:35:49,150 Some of the surface would vaporize, 704 00:35:49,192 --> 00:35:53,237 and that umph would push the object into another orbit. 705 00:35:53,279 --> 00:35:55,990 We'd go like this. 706 00:35:56,032 --> 00:35:58,993 [explosion] 707 00:36:01,204 --> 00:36:04,165 [coughing] 708 00:36:06,751 --> 00:36:08,836 It's a tricky operation. 709 00:36:08,878 --> 00:36:11,881 Set off your bomb too far away, and you might not change 710 00:36:11,923 --> 00:36:13,424 the object's course enough. 711 00:36:13,466 --> 00:36:16,969 Too close, and instead of a single object coming in, 712 00:36:17,011 --> 00:36:19,639 you might end up with a string of jagged pearls 713 00:36:19,680 --> 00:36:20,848 headed our way. 714 00:36:20,890 --> 00:36:24,018 That's why we, planetary defense types, 715 00:36:24,060 --> 00:36:27,105 want to have a whole menu of designs ready to go, 716 00:36:27,146 --> 00:36:29,899 including ones that are a lot more subtle. 717 00:36:29,941 --> 00:36:32,902 We still don't know exactly how much force 718 00:36:32,944 --> 00:36:34,570 any of this will take, 719 00:36:34,612 --> 00:36:38,533 so consider NASA's DART mission-- 720 00:36:38,574 --> 00:36:42,412 the Double Asteroid Redirection Test. 721 00:36:42,453 --> 00:36:45,456 The DART spacecraft was launched in 2021, 722 00:36:45,498 --> 00:36:48,751 and it's on course to slam into a small asteroid 723 00:36:48,793 --> 00:36:51,796 named Dimorphos in the fall of 2022. 724 00:36:51,838 --> 00:36:54,799 [dramatic music] 725 00:36:54,841 --> 00:36:57,802 * * 726 00:36:57,844 --> 00:37:00,388 If DART works, we could use this method 727 00:37:00,430 --> 00:37:03,641 to deflect a future space rock that might be headed our way. 728 00:37:03,683 --> 00:37:10,773 * * 729 00:37:13,276 --> 00:37:16,779 DART will shift things around as the force of its impact 730 00:37:16,821 --> 00:37:19,407 will change the orbit just a tiny bit-- 731 00:37:19,449 --> 00:37:21,868 the kind of nudge needed to prevent an asteroid 732 00:37:21,909 --> 00:37:23,578 from getting too close to us. 733 00:37:23,619 --> 00:37:25,913 But wait, there's more. 734 00:37:25,955 --> 00:37:28,666 Now, it's laser time. 735 00:37:28,708 --> 00:37:31,294 What if we could combine the heat of a nuke 736 00:37:31,335 --> 00:37:34,047 with the kind of control you get with light? 737 00:37:34,088 --> 00:37:37,717 What if you blasted a comet with lasers? 738 00:37:37,759 --> 00:37:39,927 Well, how do we deliver lasers 739 00:37:39,969 --> 00:37:41,220 to a near-Earth object, you ask? 740 00:37:41,262 --> 00:37:44,182 Oh, keep your pants on. I'll show you. 741 00:37:49,604 --> 00:37:53,649 Ha ha! Behold the Laser Bees. 742 00:37:54,567 --> 00:37:57,528 It's an idea my colleagues at the Planetary Society 743 00:37:57,570 --> 00:37:58,946 have been cooking up. 744 00:37:58,988 --> 00:38:00,698 We'd send a swarm of them-- 745 00:38:00,740 --> 00:38:02,116 dozens, maybe. 746 00:38:02,158 --> 00:38:03,993 The laser beams from the bees 747 00:38:04,035 --> 00:38:06,954 would burn or oblate a bit of comet ice 748 00:38:06,996 --> 00:38:09,457 and cause it to out-gas into space. 749 00:38:09,499 --> 00:38:12,502 [buzzing] 750 00:38:12,543 --> 00:38:13,961 [clears throat] 751 00:38:14,003 --> 00:38:16,047 Except in space, there's no sound, 752 00:38:16,089 --> 00:38:18,091 so it would just be like this. 753 00:38:21,344 --> 00:38:24,639 It's an idea so crazy, it just might work. 754 00:38:24,680 --> 00:38:26,140 [sighs] 755 00:38:26,182 --> 00:38:27,975 OK, let's all take a deep breath 756 00:38:28,017 --> 00:38:29,977 and replay our story, 757 00:38:30,019 --> 00:38:32,980 this time with systems in place. 758 00:38:33,022 --> 00:38:35,650 Our astronomer and her colleagues 759 00:38:35,691 --> 00:38:38,903 along with folks just like you and me have put pressure 760 00:38:38,945 --> 00:38:41,906 on our legislators to take the threat more seriously 761 00:38:41,948 --> 00:38:43,699 no matter what the cost 762 00:38:43,741 --> 00:38:45,159 or how long the odds 763 00:38:45,201 --> 00:38:47,787 because the safety of our planet isn't theirs 764 00:38:47,829 --> 00:38:48,996 to gamble with. 765 00:38:49,038 --> 00:38:50,623 - Thank you for choosing to listen to us. 766 00:38:50,665 --> 00:38:53,418 - Our Congressman listens to the science and leads the way 767 00:38:53,459 --> 00:38:56,337 in green-lighting a full-fledged global effort 768 00:38:56,379 --> 00:38:58,131 to save our planet. 769 00:38:58,172 --> 00:39:00,258 More than 100 countries invest 770 00:39:00,299 --> 00:39:02,218 in the most urgent and ambitious 771 00:39:02,260 --> 00:39:05,179 technological undertaking since the Moon landings. 772 00:39:05,221 --> 00:39:08,516 But the question is, will it work? 773 00:39:08,558 --> 00:39:12,186 * * 774 00:39:12,228 --> 00:39:15,231 [lasers humming] 775 00:39:15,273 --> 00:39:22,238 * * 776 00:39:22,280 --> 00:39:25,241 [comet whooshing] 777 00:39:25,283 --> 00:39:32,206 * * 778 00:39:41,883 --> 00:39:45,595 [tranquil music] 779 00:39:45,636 --> 00:39:47,597 The mission was a success. 780 00:39:47,638 --> 00:39:51,059 Now the string of pearls will safely pass the Earth 781 00:39:51,100 --> 00:39:53,436 in an event as beautiful as it sounds, 782 00:39:53,478 --> 00:39:55,813 and we have nothing to fear. 783 00:39:55,855 --> 00:39:59,734 Instead, the light show is spectacular. 784 00:39:59,776 --> 00:40:02,695 [triumphant music] 785 00:40:02,737 --> 00:40:06,199 * * 786 00:40:11,204 --> 00:40:13,498 - Our ancient dino friends are goners, 787 00:40:13,539 --> 00:40:17,085 and we could be too, but it's not too late for us. 788 00:40:17,126 --> 00:40:21,339 Asteroid and comet impacts are preventable natural disasters 789 00:40:21,381 --> 00:40:23,424 if we set our minds to it. 790 00:40:23,466 --> 00:40:25,551 As far as we know, the dinosaurs 791 00:40:25,593 --> 00:40:29,097 had no space program, but we do. 792 00:40:29,138 --> 00:40:30,848 And we--you and me-- 793 00:40:30,890 --> 00:40:33,434 have the power to make sure our representatives 794 00:40:33,476 --> 00:40:35,895 represent us when it comes to investing 795 00:40:35,937 --> 00:40:39,524 in the technology that could save our world. 796 00:40:39,565 --> 00:40:42,902 We have an opportunity to prevent our own extinction 797 00:40:42,944 --> 00:40:45,905 while at the same time learning extraordinary things 798 00:40:45,947 --> 00:40:49,033 about our universe and our place within it. 799 00:40:49,075 --> 00:40:52,787 With a robust infrastructure of telescopes and spacecraft, 800 00:40:52,829 --> 00:40:55,915 we'll learn more about how the solar system was formed, 801 00:40:55,957 --> 00:40:59,544 about the origins of life here, and the prospects for life 802 00:40:59,585 --> 00:41:01,629 elsewhere in the universe. 803 00:41:01,671 --> 00:41:04,465 Even if you set aside the practical benefits, 804 00:41:04,507 --> 00:41:07,844 face it, people, space exploration is cool. 805 00:41:07,885 --> 00:41:10,179 Averting a potential mass extinction 806 00:41:10,221 --> 00:41:12,432 has never been so easy or come with 807 00:41:12,473 --> 00:41:15,184 so many fun and fabulous rewards. 808 00:41:15,226 --> 00:41:19,188 The more we invest in exploring the possibilities up there, 809 00:41:19,230 --> 00:41:21,774 the better our lives will be down here.