1 00:00:24,440 --> 00:00:28,960 The Earth, home to millions of species. 2 00:00:33,520 --> 00:00:36,800 But what might live... beyond? 3 00:00:42,240 --> 00:00:45,680 Astronomers have discovered thousands of planets 4 00:00:45,760 --> 00:00:47,880 outside our solar system. 5 00:00:50,680 --> 00:00:53,640 They believe there are trillions more. 6 00:00:56,840 --> 00:01:00,280 If life exists on only a fraction of them, 7 00:01:01,440 --> 00:01:06,200 then the universe must be... alive. 8 00:01:15,880 --> 00:01:19,560 All living things have the same needs. 9 00:01:22,320 --> 00:01:23,280 To feed... 10 00:01:30,320 --> 00:01:31,480 reproduce... 11 00:01:35,920 --> 00:01:37,480 and evolve. 12 00:01:41,040 --> 00:01:43,680 By applying the laws of life on Earth 13 00:01:44,240 --> 00:01:46,280 to the rest of the universe... 14 00:01:48,040 --> 00:01:49,840 it's possible to imagine 15 00:01:50,400 --> 00:01:51,800 what could live... 16 00:01:53,120 --> 00:01:55,320 on alien worlds. 17 00:02:28,640 --> 00:02:32,240 Being an astronomer, it's sort of like being a human conversation piece. 18 00:02:33,840 --> 00:02:37,280 There's two questions you always get. The first is "What's inside a black hole?" 19 00:02:37,360 --> 00:02:40,000 And the second, which is the one people are really interested in, 20 00:02:40,080 --> 00:02:42,400 is "What about life elsewhere in the universe?" 21 00:02:46,160 --> 00:02:49,440 And then, you know, almost always, we come down to this place. 22 00:03:07,760 --> 00:03:11,680 Area 51 is a secret U.S. Air Force base. 23 00:03:13,320 --> 00:03:19,120 Its existence was only officially recognized in 2013. 24 00:03:24,760 --> 00:03:26,840 So, what really goes on back there? 25 00:03:26,920 --> 00:03:29,640 Well... nobody knows. 26 00:03:29,720 --> 00:03:32,040 Of course, some people think they know. 27 00:03:32,120 --> 00:03:35,440 The believers, the... the conspiracy theorists, 28 00:03:35,520 --> 00:03:38,840 they think that that's where all the alien bodies are. 29 00:03:38,920 --> 00:03:43,280 All the dead aliens in the crashed spaceships are taken somewhere back there 30 00:03:43,360 --> 00:03:46,400 and they're held in refrigerators or "defructinators," 31 00:03:46,480 --> 00:03:49,240 or whatever technology you need for an alien body. 32 00:03:49,760 --> 00:03:52,680 And, you know, that's essentially where all the secrets 33 00:03:52,760 --> 00:03:55,480 that we're not allowed to know about are being kept. 34 00:04:04,520 --> 00:04:08,200 This is footage supposedly showing an alien body 35 00:04:08,920 --> 00:04:11,200 being examined at Area 51. 36 00:04:17,040 --> 00:04:18,720 But the video is a hoax... 37 00:04:21,640 --> 00:04:25,440 perpetuating the idea that aliens are among us. 38 00:04:35,040 --> 00:04:39,320 The reason why most ufology sounds like a science-fiction story is, 39 00:04:39,400 --> 00:04:41,280 it is a science fiction story. 40 00:04:53,880 --> 00:04:57,560 But, you know, in spite of the silliness of ufology, 41 00:04:57,640 --> 00:05:02,000 I do believe that there is other life in the universe. 42 00:05:02,080 --> 00:05:05,480 And, as a scientist, um, I... I... I'm taken to that belief, 43 00:05:05,560 --> 00:05:09,080 because I really believe that's where the numbers now are leading us. 44 00:05:18,560 --> 00:05:21,000 A couple of years ago, a colleague and I 45 00:05:21,400 --> 00:05:24,520 tried to take all the amazing data that we now have, 46 00:05:24,600 --> 00:05:26,280 and we wrote down an equation 47 00:05:26,360 --> 00:05:29,080 that allowed us to calculate 48 00:05:29,160 --> 00:05:34,640 the total number of planets out there that might have civilizations on them. 49 00:05:35,160 --> 00:05:40,160 Essentially, what we found was that there were ten billion... 50 00:05:40,880 --> 00:05:42,080 trillion... 51 00:05:43,000 --> 00:05:44,120 planets out there... 52 00:05:45,440 --> 00:05:50,040 in the right place where life, and possibly, civilizations could form. 53 00:05:57,520 --> 00:06:00,600 Every one of those planets is essentially an experiment. 54 00:06:00,680 --> 00:06:04,480 And for none of them, other than ours, to turn out with a civilization... 55 00:06:05,160 --> 00:06:07,120 that's pushing it quite a bit. 56 00:06:14,120 --> 00:06:18,000 If alien civilizations are statistically so likely, 57 00:06:18,720 --> 00:06:21,280 why haven't astronomers found any sign of them? 58 00:06:25,120 --> 00:06:26,440 Where is everyone? 59 00:06:29,240 --> 00:06:30,360 Think about it this way. 60 00:06:30,480 --> 00:06:35,880 Out there in the Pacific Ocean, there's 187 million billion gallons of water. 61 00:06:35,960 --> 00:06:40,080 Now, if I take this bucket here and throw it over... 62 00:06:43,400 --> 00:06:44,680 and then haul up, 63 00:06:45,800 --> 00:06:46,920 see what's in it... 64 00:06:49,240 --> 00:06:51,400 All righty. What do we see? 65 00:06:53,240 --> 00:06:54,200 Nothing. 66 00:06:55,720 --> 00:06:58,240 Should I take the fact that I don't see any life in my bucket 67 00:06:58,320 --> 00:07:00,520 to tell me that there's no life in the Pacific Ocean? 68 00:07:00,640 --> 00:07:03,880 Well, that would be crazy, right? There's all kinds of life out there. 69 00:07:03,960 --> 00:07:07,360 There are sea otters, and whales, and octopuses, and jellyfishes, 70 00:07:07,440 --> 00:07:09,240 and God only knows what's out there. 71 00:07:10,000 --> 00:07:11,640 They're just not in this bucket. 72 00:07:14,240 --> 00:07:16,720 That's why this is a perfect metaphor 73 00:07:16,800 --> 00:07:19,280 for the search for extraterrestrial intelligence. 74 00:07:21,280 --> 00:07:24,240 Every time we look at an individual star, 75 00:07:24,320 --> 00:07:26,240 that's like dropping a bucket in the ocean. 76 00:07:28,840 --> 00:07:31,280 We're going to have to look at a lot of stars, 77 00:07:31,360 --> 00:07:34,160 and we're gonna have to search through a lot of data... 78 00:07:35,080 --> 00:07:39,040 until we find the clue that leads us to another civilization. 79 00:07:53,400 --> 00:07:59,520 What sort of alien civilizations might exist in the vastness of space? 80 00:08:05,800 --> 00:08:10,520 Imagine a planet nine billion years old, 81 00:08:10,960 --> 00:08:13,040 twice as old as Earth. 82 00:08:14,120 --> 00:08:18,600 Old enough that a truly advanced intelligence could evolve. 83 00:08:22,440 --> 00:08:24,600 This is Terra. 84 00:08:31,720 --> 00:08:34,280 It was once a fertile world. 85 00:08:36,320 --> 00:08:38,080 Now, it is barren. 86 00:08:39,640 --> 00:08:42,640 But life can still thrive here... 87 00:08:45,040 --> 00:08:47,280 in artificial domes. 88 00:08:57,480 --> 00:09:01,080 Plants convert sunlight into glucose energy... 89 00:09:03,320 --> 00:09:06,000 which feeds the inhabitants of Terra. 90 00:09:16,520 --> 00:09:22,040 Each box contains the brain matter of a super-intelligent being. 91 00:09:24,320 --> 00:09:28,000 Over time, they've evolved not to need their bodies. 92 00:09:30,440 --> 00:09:33,200 They exist only as neural tissue. 93 00:09:38,880 --> 00:09:41,680 They never age. They never die. 94 00:09:42,440 --> 00:09:45,640 They're monitored and maintained by robots. 95 00:09:49,680 --> 00:09:51,440 Each is an individual. 96 00:09:53,240 --> 00:09:56,280 But they're connected to think as one. 97 00:09:57,120 --> 00:09:58,760 A hive mind. 98 00:10:02,240 --> 00:10:06,120 This is a hyper-advanced civilization. 99 00:10:14,280 --> 00:10:21,080 On Earth, humans are the only species to have created any form of civilization. 100 00:10:25,320 --> 00:10:29,200 Why haven't other intelligent creatures done the same thing? 101 00:10:38,440 --> 00:10:42,080 The octopus is as close to an alien intelligence 102 00:10:42,160 --> 00:10:44,200 as exists on our planet. 103 00:10:51,960 --> 00:10:54,800 Octopuses belong to a group called cephalopods. 104 00:10:57,040 --> 00:10:59,960 And they have evolved down a completely different pathway. 105 00:11:04,440 --> 00:11:08,520 The octopus has separate nervous systems in each of its arms. 106 00:11:09,720 --> 00:11:12,640 So, each arm contains about 14 million neurons. 107 00:11:13,320 --> 00:11:16,120 And each arm can make independent decisions. 108 00:11:17,040 --> 00:11:21,320 So the octopus can be said to have, essentially, nine separate brains. 109 00:11:25,480 --> 00:11:27,640 I kind of wanna reach out and touch him. 110 00:11:33,480 --> 00:11:35,880 Lego toys are quite hard to get apart. 111 00:11:37,040 --> 00:11:40,160 But we're curious to see if he's gonna be able to open them. 112 00:12:07,760 --> 00:12:10,200 Octopuses are clearly smart. 113 00:12:13,440 --> 00:12:17,360 But being smart isn't enough to form a civilization. 114 00:12:28,040 --> 00:12:30,360 The key is cooperation... 115 00:12:32,200 --> 00:12:34,080 sharing ideas... 116 00:12:35,760 --> 00:12:41,040 passing down knowledge from one generation to the next. 117 00:12:45,120 --> 00:12:47,640 Our culture is constantly improving. 118 00:12:48,600 --> 00:12:51,680 We keep building on each other's inventions. 119 00:12:55,840 --> 00:12:56,880 All right. 120 00:13:00,320 --> 00:13:02,160 Take this taxi, for example. 121 00:13:03,040 --> 00:13:06,400 Wheels were invented more than five-and-a-half thousand years ago. 122 00:13:07,080 --> 00:13:10,560 Iron has been smelted more than four-and-a-half thousand years ago. 123 00:13:12,440 --> 00:13:16,800 Vulcanized rubber has been used for tires since about 180 years. 124 00:13:19,360 --> 00:13:21,360 So, all of these inventions were necessary 125 00:13:21,440 --> 00:13:24,200 to actually build something as complicated as this car. 126 00:13:27,520 --> 00:13:31,760 An octopus, by comparison, has to pretty much figure out everything for himself. 127 00:13:33,800 --> 00:13:37,280 There is no improving and building on previous solutions. 128 00:13:37,840 --> 00:13:40,680 And that's pretty limiting, even if you have nine brains. 129 00:13:44,720 --> 00:13:48,400 Civilizations are like living organisms... 130 00:13:50,240 --> 00:13:52,480 with millions of connected parts. 131 00:13:55,920 --> 00:13:57,560 It's this connectivity 132 00:13:58,120 --> 00:14:00,240 that allows them to grow. 133 00:14:12,120 --> 00:14:16,080 But the civilization on Terra is in peril. 134 00:14:19,520 --> 00:14:22,800 Its star is double the age of our own sun. 135 00:14:28,080 --> 00:14:32,760 And as stars get older, they burn bigger and brighter. 136 00:14:37,680 --> 00:14:42,040 Eventually, the planet Terra will be incinerated. 137 00:14:48,920 --> 00:14:51,680 So an escape plan is underway... 138 00:14:56,440 --> 00:15:00,200 to colonize another planet in the same solar system... 139 00:15:03,160 --> 00:15:05,440 further from the star than Terra. 140 00:15:12,920 --> 00:15:16,600 There's ice on this world, but no atmosphere. 141 00:15:19,640 --> 00:15:22,280 It needs to be manufactured. 142 00:15:33,840 --> 00:15:37,800 This is engineering on a planetary scale. 143 00:15:42,320 --> 00:15:45,280 Giant machines melt the ice caps 144 00:15:46,040 --> 00:15:48,360 to release vapor and gas... 145 00:15:52,920 --> 00:15:56,600 generating enough atmosphere to warm the planet. 146 00:16:00,920 --> 00:16:06,120 Such a massive project requires a massive amount of energy... 147 00:16:08,480 --> 00:16:12,160 delivered directly from the aging star. 148 00:16:24,120 --> 00:16:30,080 The ability to harness energy is the bedrock of civilization itself. 149 00:16:45,120 --> 00:16:47,960 Part of what I do is to try and predict the future. 150 00:16:48,640 --> 00:16:52,960 And you can look back in history and get a lot of ideas from there, 151 00:16:54,240 --> 00:16:59,280 but there are underlying trends we can use to some extent to see what's to come, 152 00:17:00,440 --> 00:17:03,600 like life expectancy, wealth, population size. 153 00:17:04,000 --> 00:17:08,840 And one of the most revealing is the amount of energy that civilizations use. 154 00:17:11,280 --> 00:17:14,880 The more energy a civilization can access, 155 00:17:15,440 --> 00:17:17,600 the more powerful it becomes. 156 00:17:20,040 --> 00:17:22,480 That's the secret of progress... 157 00:17:24,040 --> 00:17:26,720 from the Stone Age until today. 158 00:17:39,400 --> 00:17:42,400 So, unleashing the heat and energy in charcoal 159 00:17:42,480 --> 00:17:46,080 allowed us to get temperatures hot enough to smelt metals 160 00:17:46,160 --> 00:17:48,040 to make tools and weapons. 161 00:17:52,040 --> 00:17:56,680 Later on, of course, we harnessed fossil fuels like coal and gas, 162 00:17:57,200 --> 00:18:00,600 allowing the creation of vehicles that could hurtle us across the world 163 00:18:00,680 --> 00:18:03,640 at much higher speed than we ever had before. 164 00:18:11,160 --> 00:18:16,080 But the greatest source of energy is, of course, our star. 165 00:18:36,640 --> 00:18:42,880 The Noor Power Station is the largest solar complex of its kind in the world. 166 00:18:48,080 --> 00:18:52,400 Half a million mirrors at the edge of the Sahara Desert. 167 00:19:00,880 --> 00:19:04,120 The ones over here are heliostats, 168 00:19:04,200 --> 00:19:07,040 and they track the sun as it moves through the sky 169 00:19:07,120 --> 00:19:11,000 and focus all its energy down on that tower. 170 00:19:16,320 --> 00:19:18,920 And that energy goes out into the world 171 00:19:19,000 --> 00:19:21,000 and powers modern civilization. 172 00:19:24,440 --> 00:19:26,240 More and more of our transport, 173 00:19:26,680 --> 00:19:28,840 our lighting, our agriculture. 174 00:19:28,920 --> 00:19:31,760 Very relevant for here, air conditioning. 175 00:19:32,360 --> 00:19:34,480 Basically, everything that keeps us safe, 176 00:19:34,560 --> 00:19:38,480 working and entertained comes from electricity. 177 00:19:38,560 --> 00:19:40,840 And more and more of that electricity 178 00:19:40,920 --> 00:19:44,000 is coming from solar power plants like this. 179 00:19:49,640 --> 00:19:56,080 But humans use only a tiny fraction of all the energy available from the sun. 180 00:19:58,080 --> 00:20:04,840 So, 430 quintillion joules of the sun's energy fall on the Earth every hour. 181 00:20:04,920 --> 00:20:10,040 For comparison, that's very roughly 2,000 Hiroshima bombs every second. 182 00:20:10,800 --> 00:20:12,840 A lot of energy. How much do we use? 183 00:20:12,920 --> 00:20:19,040 Well, humanity uses 410 quintillion joules... in a year. 184 00:20:20,840 --> 00:20:23,000 So, in a year, we fail to use 185 00:20:23,080 --> 00:20:26,920 all the energy that the sun sends us in a single hour. 186 00:20:28,440 --> 00:20:31,160 Imagine if we could capture all that energy 187 00:20:31,240 --> 00:20:33,480 and use it to power our civilization. 188 00:20:34,920 --> 00:20:37,400 What miracles could we accomplish? 189 00:20:37,920 --> 00:20:40,200 What places could we explore with all that? 190 00:20:44,160 --> 00:20:46,440 According to astrophysicists, 191 00:20:46,520 --> 00:20:51,800 any truly advanced civilization will be able to harness all its energy... 192 00:20:53,280 --> 00:20:55,080 directly from the stars. 193 00:21:03,440 --> 00:21:09,120 By this measure, the civilization on Terra is supremely advanced. 194 00:21:14,680 --> 00:21:17,400 It has built solar panels in space, 195 00:21:18,000 --> 00:21:19,400 near to its star... 196 00:21:22,720 --> 00:21:24,280 for maximum effect. 197 00:21:38,120 --> 00:21:40,880 But as the star becomes bigger and brighter... 198 00:21:43,840 --> 00:21:46,800 it also becomes more volatile. 199 00:21:52,960 --> 00:21:54,320 A solar flare. 200 00:22:10,840 --> 00:22:15,560 Sooner or later, this will be the destiny of Terra itself... 201 00:22:18,280 --> 00:22:21,720 to be swept away by the power of its sun. 202 00:22:27,920 --> 00:22:33,680 The solution is to colonize the new planet as quickly as possible. 203 00:22:39,040 --> 00:22:40,880 There are no life forms here. 204 00:22:42,560 --> 00:22:45,040 All the work is done by machines. 205 00:22:51,120 --> 00:22:55,920 They're able to think for themselves and make their own decisions. 206 00:22:59,840 --> 00:23:02,200 They are artificially intelligent. 207 00:23:11,320 --> 00:23:14,320 If humans are to form colonies in space, 208 00:23:14,400 --> 00:23:17,440 the groundwork will be done in the same way... 209 00:23:20,160 --> 00:23:22,000 using robots. 210 00:23:26,120 --> 00:23:28,360 And those robots will be designed 211 00:23:29,240 --> 00:23:31,280 by people like Philip Metzger. 212 00:23:33,840 --> 00:23:37,680 He has spent his whole life in and around the space program. 213 00:23:40,480 --> 00:23:42,640 My father used to work in this building, 214 00:23:42,720 --> 00:23:45,000 and he helped build the Saturn V rockets 215 00:23:45,080 --> 00:23:48,040 that were large enough to take humans to the moon. 216 00:23:48,680 --> 00:23:51,520 Apollo 11, this is the launch operations manager. 217 00:23:51,600 --> 00:23:54,080 The launch team wishes you good luck and Godspeed. 218 00:23:54,840 --> 00:23:57,400 Ah, thank you very much. Know it will be a good one. 219 00:24:03,440 --> 00:24:06,160 I'll never forget the Apollo 11 flight. 220 00:24:09,320 --> 00:24:11,160 I was seven years old. 221 00:24:11,720 --> 00:24:14,720 I was across the river during the launch, watching it. 222 00:24:16,040 --> 00:24:17,960 There were helicopters flying around. 223 00:24:19,120 --> 00:24:20,880 People had come from all over the world, 224 00:24:21,280 --> 00:24:24,320 coming to watch the moon launch. 225 00:24:24,400 --> 00:24:25,800 It was electric. 226 00:24:25,880 --> 00:24:29,920 Astronauts report it feels good. 20 seconds and counting. 227 00:24:31,280 --> 00:24:34,080 T minus 15 seconds, guidance is internal. 228 00:24:34,840 --> 00:24:36,640 Twelve, eleven, 229 00:24:36,720 --> 00:24:38,840 ten, nine... 230 00:24:38,920 --> 00:24:40,720 Ignition sequence starts. 231 00:24:40,800 --> 00:24:43,320 six... five... four... 232 00:24:43,400 --> 00:24:46,160 three... two... one... 233 00:24:46,800 --> 00:24:47,760 zero. 234 00:24:51,000 --> 00:24:51,960 Liftoff! 235 00:24:52,040 --> 00:24:53,520 We have a liftoff. 236 00:25:01,640 --> 00:25:06,280 As it climbed into the sky, you could see that long, beautiful flame 237 00:25:06,360 --> 00:25:08,800 shimmering across the water. 238 00:25:11,320 --> 00:25:12,920 We got skirts-up? 239 00:25:13,680 --> 00:25:15,320 Roger, we confirm skirts-up. 240 00:25:17,840 --> 00:25:22,280 So, I grew up wanting to be a rocket scientist, my entire life. 241 00:25:36,720 --> 00:25:39,240 Philip became a NASA scientist. 242 00:25:40,720 --> 00:25:42,920 But rather than sticking at rocket design, 243 00:25:44,240 --> 00:25:46,320 he moved into robotics. 244 00:25:52,040 --> 00:25:55,280 If we ever really want to do anything fabulous in space, 245 00:25:55,360 --> 00:25:56,880 we need robots. 246 00:26:05,760 --> 00:26:09,360 RASSOR is designed to work in tough planetary environments. 247 00:26:12,200 --> 00:26:14,160 It can climb over rocks. 248 00:26:14,240 --> 00:26:17,480 If it gets stuck, it can get itself unstuck. 249 00:26:19,840 --> 00:26:23,240 If it flips upside down, it can flip itself over. 250 00:26:24,240 --> 00:26:26,920 In any situation, it can get itself out of trouble. 251 00:26:29,520 --> 00:26:33,240 The simplest thing that we could mine on a planet is the regolith, 252 00:26:33,840 --> 00:26:36,680 the dirt that covers the planetary surface. 253 00:26:38,640 --> 00:26:40,960 You can extract metal from the regolith. 254 00:26:42,720 --> 00:26:47,480 You can also make ceramics that are used for insulating electrical systems. 255 00:26:48,480 --> 00:26:50,480 And you can make rocket fuel. 256 00:26:53,520 --> 00:26:56,280 But mining does take intelligence. 257 00:26:58,120 --> 00:27:00,800 You have to know where to drive, where to cut. 258 00:27:01,400 --> 00:27:04,360 You've gotta keep from getting lost, get yourself unstuck. 259 00:27:04,440 --> 00:27:07,360 So it's going to take a clever machine like RASSOR 260 00:27:07,440 --> 00:27:09,960 to be able to start industry in space. 261 00:27:12,240 --> 00:27:15,880 The Holy Grail of robotics is self-replication... 262 00:27:17,680 --> 00:27:20,280 a machine that can make copies of itself. 263 00:27:23,480 --> 00:27:26,480 This is a spare wheel for RASSOR. 264 00:27:27,200 --> 00:27:33,600 A robot part made by a robot for another robot, using space materials. 265 00:27:34,680 --> 00:27:37,600 But this is an early example of how we're evolving the robots 266 00:27:37,680 --> 00:27:44,400 toward a fully closed ecology of robots that can self-reproduce in space. 267 00:27:50,520 --> 00:27:54,840 Once you've got self-reproducing robots, everywhere is a place you can go. 268 00:27:55,920 --> 00:27:58,000 I don't think there are any limits. 269 00:28:11,920 --> 00:28:14,600 Without input from any life form, 270 00:28:15,840 --> 00:28:18,560 the robots are re-engineering a planet... 271 00:28:21,520 --> 00:28:23,720 making it ready for colonization. 272 00:28:34,840 --> 00:28:37,400 Now, it's time to abandon Terra. 273 00:28:41,240 --> 00:28:44,240 Each of the domes has been designed for this moment... 274 00:28:47,040 --> 00:28:49,080 to get into orbit. 275 00:28:53,840 --> 00:28:57,080 From here, they will travel to their new home. 276 00:29:12,040 --> 00:29:15,720 The domes have their own life-support systems. 277 00:29:17,720 --> 00:29:19,520 But they're helpless 278 00:29:20,120 --> 00:29:23,400 against a high-energy burst of solar radiation. 279 00:29:48,960 --> 00:29:53,400 Nothing is evolved to survive in the vacuum of space. 280 00:29:59,040 --> 00:30:03,080 This is as true for aliens as it is for humans. 281 00:30:11,320 --> 00:30:15,520 Michael Foale knows all about the dangers of space travel. 282 00:30:20,040 --> 00:30:26,640 In 1997, he was a guest American astronaut on the Russian Mir space station... 283 00:30:29,760 --> 00:30:32,680 during the first collision in space. 284 00:30:37,840 --> 00:30:40,960 There was, uh, an attempt by the Russian commander, Vasily, 285 00:30:41,040 --> 00:30:44,760 and his crewmate to control a cargo ship that weighed seven tons, 286 00:30:44,840 --> 00:30:46,760 and dock it without the radar, 287 00:30:46,840 --> 00:30:49,840 without speed, without distance measurements... 288 00:30:49,920 --> 00:30:51,760 Dock it to our space station. 289 00:31:06,920 --> 00:31:08,200 I felt the station... 290 00:31:08,680 --> 00:31:12,840 I didn't "felt" it, I saw the station move all around me and I heard a thud. 291 00:31:19,880 --> 00:31:23,920 And at that point I thought, "Mm... This could be it, you know, where I die." 292 00:31:24,000 --> 00:31:26,280 Uh, 'cause I'm looking at all these bolts 293 00:31:26,360 --> 00:31:28,560 and I was just waiting for those bolts to part, 294 00:31:28,640 --> 00:31:31,440 and to, kind of, rip open and just see the vacuum of space. 295 00:31:38,600 --> 00:31:41,840 And then, all the fans, all the lights, 296 00:31:42,360 --> 00:31:45,240 all the computers failed and went silent. 297 00:31:49,720 --> 00:31:52,480 And now we're in a completely silent station 298 00:31:53,120 --> 00:31:54,600 that's getting cold. 299 00:31:59,400 --> 00:32:02,080 We've lost power. 300 00:32:03,160 --> 00:32:06,880 Pressure is at 602. 301 00:32:09,520 --> 00:32:11,680 And then my ears started to pop. 302 00:32:13,480 --> 00:32:15,120 I knew we were depressurizing, 303 00:32:16,520 --> 00:32:19,240 and that basically, air was leaving the space station, 304 00:32:20,800 --> 00:32:22,920 and we only had 23 minutes left to live, 305 00:32:23,000 --> 00:32:25,520 if we stayed there and we didn't stop the leak. 306 00:32:26,880 --> 00:32:29,480 I started helping Sasha pull these cables out. 307 00:32:30,840 --> 00:32:33,640 Huge cables I thought would have taken us hours to undo, 308 00:32:33,720 --> 00:32:35,080 we did them in six minutes. 309 00:32:35,720 --> 00:32:39,960 And we'd take this cap and we'd put it in and it sucks in, and it goes... "pew." 310 00:32:40,040 --> 00:32:41,960 And at that point, we've stopped the leak. 311 00:32:47,240 --> 00:32:50,320 And it was there in front of the window, looking at the galaxy... 312 00:32:51,680 --> 00:32:52,680 I said... 313 00:32:53,320 --> 00:32:58,360 "Well, I know it's been a really bad day, but this is an amazingly beautiful view." 314 00:33:01,120 --> 00:33:04,200 You're kind of sensing, trying to sense all of the, uh... 315 00:33:04,280 --> 00:33:06,360 The presence in the... in the universe. 316 00:33:14,360 --> 00:33:19,200 In total, Michael Foale went into space on six missions. 317 00:33:19,680 --> 00:33:21,440 Oops, more hair going away. 318 00:33:24,040 --> 00:33:26,480 But every second spent off-world 319 00:33:27,520 --> 00:33:30,000 increased his dose of radiation. 320 00:33:33,440 --> 00:33:35,520 We're exposed to radiation on Earth, 321 00:33:36,520 --> 00:33:38,400 but once you go into orbit, 322 00:33:38,480 --> 00:33:41,480 now you're exposed to thousands of times more radiation. 323 00:33:44,000 --> 00:33:47,880 And that radiation now is damaging our DNA much faster, 324 00:33:48,720 --> 00:33:52,320 and the repair mechanisms that we evolved to have 325 00:33:52,400 --> 00:33:54,280 are not able to cope with it. 326 00:34:14,600 --> 00:34:16,920 When I came back from my space flights, 327 00:34:17,480 --> 00:34:22,720 they found I had, like, four percent of my white blood cells had DNA mutations. 328 00:34:28,080 --> 00:34:32,320 Most of those mutated cells get killed by other white blood cells in your body, 329 00:34:34,280 --> 00:34:36,440 but, some of them, unfortunately, don't die. 330 00:34:37,800 --> 00:34:41,320 They reproduce and mutate and become cancers. 331 00:34:42,600 --> 00:34:45,600 That is a fundamental risk for astronauts. 332 00:34:52,920 --> 00:34:55,880 And if we imagine going out to stars, 333 00:34:55,960 --> 00:35:00,000 it could be that, out of a hundred ships, only one of them makes it. 334 00:35:12,480 --> 00:35:15,880 Long-distance space travel will always be risky... 335 00:35:18,080 --> 00:35:20,080 even for intelligent aliens. 336 00:35:22,520 --> 00:35:26,360 There's no protection against a sudden blast of stellar radiation. 337 00:35:35,560 --> 00:35:38,280 But for those that make it to the end of the journey, 338 00:35:39,440 --> 00:35:41,320 this is their reward... 339 00:35:43,800 --> 00:35:45,520 a new Terra. 340 00:35:56,520 --> 00:35:59,320 Rather than adapting to a different world, 341 00:36:00,640 --> 00:36:03,800 they have created a copy of their old world. 342 00:36:08,000 --> 00:36:11,560 Such are the benefits of an advanced civilization. 343 00:36:21,960 --> 00:36:24,640 But how long will the good times last? 344 00:36:28,720 --> 00:36:33,000 The star keeps growing, bigger and brighter... 345 00:36:34,280 --> 00:36:36,280 spitting out more radiation. 346 00:36:42,400 --> 00:36:47,200 Eventually, it will render the new planet as lifeless as Terra. 347 00:36:57,320 --> 00:36:59,840 And then they'll need to relocate again, 348 00:37:01,080 --> 00:37:04,000 to another planet, further from the star. 349 00:37:15,240 --> 00:37:18,200 This is the advantage of being mobile. 350 00:37:20,520 --> 00:37:23,880 It's possible to transit from world to world, 351 00:37:24,400 --> 00:37:27,200 making and remaking home. 352 00:37:39,480 --> 00:37:44,640 Perhaps there's an alien civilization already headed for Earth. 353 00:37:48,120 --> 00:37:50,600 If so, should we hide from them, 354 00:37:51,440 --> 00:37:53,240 or make ourselves known? 355 00:37:57,560 --> 00:37:58,840 Okay. Um... 356 00:37:59,720 --> 00:38:01,880 Let me... Let me end by saying... 357 00:38:03,120 --> 00:38:07,200 Let me close by telling you why we should begin transmitting 358 00:38:07,280 --> 00:38:09,920 and why we should begin right now. 359 00:38:16,920 --> 00:38:21,800 Doug Vakoch wants to open up a dialogue with potential aliens 360 00:38:22,480 --> 00:38:25,000 by sending them radio messages. 361 00:38:37,520 --> 00:38:40,720 But first, he needs to persuade astronomers on Earth 362 00:38:41,920 --> 00:38:43,480 that it's a good idea. 363 00:38:51,680 --> 00:38:53,480 This is where it all started. 364 00:38:55,640 --> 00:38:59,400 The biggest radio telescope Earth had ever seen. 365 00:39:13,240 --> 00:39:15,280 There's something about being here, 366 00:39:16,480 --> 00:39:18,920 the awesomeness, the scale of the place. 367 00:39:27,040 --> 00:39:32,080 This is where, in 1974, we sent humanity's first message into space. 368 00:39:40,800 --> 00:39:45,880 It starts by these pulses that count out the numbers from one through ten. 369 00:39:48,920 --> 00:39:51,280 Then after we've shown extraterrestrials how we count, 370 00:39:51,360 --> 00:39:53,280 we use those numbers to describe 371 00:39:53,360 --> 00:39:56,280 some of the chemical elements essential to life on Earth. 372 00:39:58,520 --> 00:40:00,080 And then after that... 373 00:40:01,040 --> 00:40:02,720 what we look like, 374 00:40:03,640 --> 00:40:05,480 how many humans there are, 375 00:40:06,040 --> 00:40:07,240 how tall we are. 376 00:40:09,040 --> 00:40:12,000 Then after that, a representation of our solar system. 377 00:40:13,120 --> 00:40:17,000 And then it ends with a representation of this telescope itself, 378 00:40:17,080 --> 00:40:18,600 where the message came from. 379 00:40:21,600 --> 00:40:24,040 The pulses of the Arecibo message 380 00:40:24,120 --> 00:40:26,400 could be arranged into a pictogram 381 00:40:27,000 --> 00:40:31,240 to inform intelligent aliens about life on Earth. 382 00:40:38,520 --> 00:40:40,080 But it was a one-time event, 383 00:40:40,920 --> 00:40:45,880 aimed at a star cluster 25,000 light-years away. 384 00:40:50,120 --> 00:40:52,600 If we'd been sending messages to nearby stars 385 00:40:52,680 --> 00:40:54,840 at the same time we sent out the Arecibo message, 386 00:40:54,920 --> 00:40:59,400 we could be getting responses today from any of thousands of stars. 387 00:41:00,760 --> 00:41:03,480 But we haven't, and so we're in the dark. 388 00:41:06,320 --> 00:41:10,560 The biggest reason we haven't sent more messages is because we're afraid. 389 00:41:11,760 --> 00:41:15,040 Because the blockbuster science-fiction films 390 00:41:15,120 --> 00:41:17,880 show aliens coming to Earth and annihilating us... 391 00:41:20,920 --> 00:41:23,280 and so that's what we think would really happen. 392 00:41:27,240 --> 00:41:31,960 I think the... the most prominent challenge is the concern that some people have 393 00:41:32,040 --> 00:41:37,520 that transmitting intentional messages, uh, will lead to an alien invasion. 394 00:41:37,920 --> 00:41:40,000 And I think the easiest response to that is, 395 00:41:40,080 --> 00:41:44,280 our planet has been giving off evidence of life for two billion years. 396 00:41:44,800 --> 00:41:47,240 So, if there are any really paranoid aliens out there 397 00:41:47,320 --> 00:41:49,560 who want to annihilate any competition, 398 00:41:49,640 --> 00:41:52,200 they've had a long time to come here, and I haven't seen 'em. 399 00:41:56,440 --> 00:41:59,280 Rather than sending an occasional message into space, 400 00:42:00,440 --> 00:42:03,400 Doug's plan is to transmit thousands of them... 401 00:42:05,800 --> 00:42:08,600 when the Arecibo telescope is on downtime. 402 00:42:12,640 --> 00:42:15,600 With radio astronomy, you can do it any time of the day. 403 00:42:16,320 --> 00:42:18,600 But... I like to do it at night. 404 00:42:21,560 --> 00:42:23,920 Caffeine is essential for astronomers. Um... 405 00:42:24,760 --> 00:42:28,120 A lot of late nights in the observations and we have to stay sharp. 406 00:42:36,440 --> 00:42:41,440 Once a month, Arecibo does a survey of recently discovered asteroids. 407 00:42:44,040 --> 00:42:46,800 Quite often there's a gap, maybe an hour, 408 00:42:46,880 --> 00:42:50,640 where the transmitter is transmitting off into space at no particular place. 409 00:42:56,640 --> 00:43:01,560 What I'm proposing is that Arecibo should use those gaps in the schedule 410 00:43:02,040 --> 00:43:05,320 to target nearby stars with a message, 411 00:43:05,400 --> 00:43:08,880 in case there are any extraterrestrials in orbit around that star. 412 00:43:13,120 --> 00:43:17,240 Each month, we could be targeting about 50 stars 413 00:43:17,680 --> 00:43:20,080 that may support intelligent life. 414 00:43:20,160 --> 00:43:23,040 And for me, it's a no-brainer. I think we should be doing it. 415 00:43:26,160 --> 00:43:29,320 I think of this in terms of what's sometimes called 416 00:43:29,400 --> 00:43:31,040 "joining the galactic club." 417 00:43:31,720 --> 00:43:36,760 And what I find so strange about that analogy is that no one ever talks about, 418 00:43:36,840 --> 00:43:40,280 um, paying our dues or even submitting an application. 419 00:43:40,360 --> 00:43:43,680 And that's what messaging extraterrestrial intelligence does. 420 00:43:43,760 --> 00:43:46,520 It may just be our way of making first contact. 421 00:43:46,960 --> 00:43:47,800 Thanks. 422 00:43:47,880 --> 00:43:51,040 Thank you very much to Doug for this interesting presentation. 423 00:44:00,120 --> 00:44:04,080 When we reach out to other stars, when we send them our messages, 424 00:44:05,520 --> 00:44:10,600 in the best-case scenario, we get a reply back in 10 or 20 years. 425 00:44:12,720 --> 00:44:16,560 But realistically, it could take thousands of years. 426 00:44:21,040 --> 00:44:23,360 So this is something that we're doing, 427 00:44:23,800 --> 00:44:28,480 not for ourselves, but for our children, for our grandchildren. 428 00:44:29,560 --> 00:44:31,080 And even for the aliens. 429 00:44:34,280 --> 00:44:37,160 Eight, seven, six, 430 00:44:37,240 --> 00:44:40,200 five, four, three, 431 00:44:40,720 --> 00:44:42,360 two, one. 432 00:44:43,680 --> 00:44:45,320 Mission liftoff. 433 00:44:50,760 --> 00:44:52,440 Switching down range. 434 00:44:52,520 --> 00:44:58,760 In 2018, the latest planet-hunting telescope went into orbit. 435 00:45:07,840 --> 00:45:10,680 It is finding evidence of new worlds 436 00:45:11,960 --> 00:45:13,760 across the night sky. 437 00:45:23,520 --> 00:45:26,520 Astronomers think it's only a matter of time 438 00:45:26,920 --> 00:45:30,000 before some alien life forms are discovered. 439 00:45:35,520 --> 00:45:39,360 Among them, perhaps, intelligent beings. 440 00:45:45,120 --> 00:45:47,680 One day, we will know for sure. 441 00:45:51,920 --> 00:45:57,800 Until then, we can only guess at who or what is out there.