1 00:00:00,600 --> 00:00:03,401 Dazzling, legendary 2 00:00:03,402 --> 00:00:06,870 It's the most beautiful planet in the night sky. 3 00:00:06,871 --> 00:00:10,342 But secretive saturn has been holding out on us. 4 00:00:10,343 --> 00:00:12,676 We learned a vast amount about it, 5 00:00:12,677 --> 00:00:15,913 And most of this has been very surprising. 6 00:00:15,914 --> 00:00:18,883 We thought we knew those bodies. We had no idea. 7 00:00:18,884 --> 00:00:22,586 Saturn boils with extreme weather 8 00:00:22,587 --> 00:00:24,156 And weird lights. 9 00:00:24,157 --> 00:00:26,557 The rings ripple and twist, 10 00:00:26,558 --> 00:00:29,694 Bullied by over 60 remarkable moons. 11 00:00:29,695 --> 00:00:34,399 They are individual worlds. They each have a story to tell. 12 00:00:34,400 --> 00:00:36,201 This is a planetary explorer's dream. 13 00:00:36,202 --> 00:00:38,170 Today, saturn's moons 14 00:00:38,171 --> 00:00:41,305 Are the hottest property in the search for alien life. 15 00:00:41,306 --> 00:00:43,708 If there's one place in the solar system 16 00:00:43,709 --> 00:00:46,412 I would put a bet that life exists there right now, 17 00:00:46,413 --> 00:00:47,579 I would choose saturn. 18 00:00:47,580 --> 00:00:49,613 And on saturn's largest moon, 19 00:00:49,614 --> 00:00:52,616 We may have already found it. 20 00:00:52,617 --> 00:00:54,152 We've found some curious things on titan, 21 00:00:54,153 --> 00:00:56,321 And it might just be evidence of life. 22 00:01:11,905 --> 00:01:14,740 Saturn, the jewel of the night sky, 23 00:01:14,741 --> 00:01:18,411 Dazzles us with its beauty and scale. 24 00:01:20,013 --> 00:01:21,714 It's huge so big, 25 00:01:21,715 --> 00:01:26,619 You could fit more than 700 earths inside it. 26 00:01:26,620 --> 00:01:29,957 But don't let size fool you. 27 00:01:29,958 --> 00:01:31,791 One of the most interesting things about saturn 28 00:01:31,792 --> 00:01:35,694 Is that it is so big compared to how much stuff is in it, 29 00:01:35,695 --> 00:01:38,297 That it's actually lower density than water. 30 00:01:38,298 --> 00:01:41,667 The old joke is that if you could find a bathtub big enough 31 00:01:41,668 --> 00:01:43,035 And fill it with water, 32 00:01:43,036 --> 00:01:45,771 Saturn would float, but it would leave a ring. 33 00:01:45,772 --> 00:01:47,908 Other planets have rings, 34 00:01:47,909 --> 00:01:51,913 But none so vast and glorious as saturn's. 35 00:01:51,914 --> 00:01:54,048 The journey from the outside of the main rings 36 00:01:54,049 --> 00:01:57,884 To the inside edge is 66,000 miles 37 00:01:57,885 --> 00:02:01,188 Over 2 1/2 times the distance around the earth. 38 00:02:01,189 --> 00:02:04,859 Yet this vast collection of dust and ice particles 39 00:02:04,860 --> 00:02:09,496 Is whisper-Thin in places just tens of feet. 40 00:02:09,497 --> 00:02:11,298 Saturn's rings are made up 41 00:02:11,299 --> 00:02:13,301 Of mostly very small particles, of ice and rock. 42 00:02:13,302 --> 00:02:15,269 Some of the particles are larger, 43 00:02:15,270 --> 00:02:17,773 But for the most part, no bigger than grains of dust. 44 00:02:19,707 --> 00:02:21,041 Racing within the rings 45 00:02:21,042 --> 00:02:23,745 And orbiting far outside them are over 60 moons 46 00:02:23,746 --> 00:02:28,248 Made from rock and water ice. 47 00:02:28,249 --> 00:02:31,352 They range in size from tiny snowballs 48 00:02:31,353 --> 00:02:35,156 To worlds with active geology, 49 00:02:35,157 --> 00:02:38,560 Liquid water... 50 00:02:38,561 --> 00:02:42,062 weather systems, and possibly even life, 51 00:02:42,063 --> 00:02:45,566 A billion miles from the warmth of the sun. 52 00:02:45,567 --> 00:02:47,068 It's so cold out there, 53 00:02:47,069 --> 00:02:48,437 We just thought there'd be nothing there, 54 00:02:48,438 --> 00:02:51,375 And we were so wrong. We were so wrong. 55 00:02:55,745 --> 00:02:57,880 Saturn's first shocker 56 00:02:57,881 --> 00:02:59,448 Its wild weather. 57 00:03:03,419 --> 00:03:06,789 The storms on saturn are extremely violent, 58 00:03:06,790 --> 00:03:08,656 Unlike anything we see on the planet earth. 59 00:03:08,657 --> 00:03:12,327 In fact, saturn has the second fastest winds 60 00:03:12,328 --> 00:03:15,263 In the entire solar system. 61 00:03:16,032 --> 00:03:19,268 These winds race through saturn's cloud tops 62 00:03:19,269 --> 00:03:21,105 At over a thousand miles an hour, 63 00:03:21,106 --> 00:03:24,073 Four times faster than earth's strongest cyclones. 64 00:03:26,509 --> 00:03:31,147 And lightning bolts flash up to 10,000 times more powerfully 65 00:03:31,148 --> 00:03:32,883 Than those on earth. 66 00:03:34,418 --> 00:03:36,886 Everything on saturn is just so very, very much bigger. 67 00:03:36,887 --> 00:03:38,354 I mean, there are weather systems 68 00:03:38,355 --> 00:03:40,823 That are as big or bigger than the earth. 69 00:03:40,824 --> 00:03:44,526 Saturn's ferocious weather is surprising, 70 00:03:44,527 --> 00:03:47,262 Because on earth, weather is driven 71 00:03:47,263 --> 00:03:49,933 By the heat energy of the sun. 72 00:03:49,934 --> 00:03:53,502 The sun warms the land, generating wind. 73 00:03:53,503 --> 00:03:58,775 It causes the seas to evaporate, creating clouds and rain. 74 00:04:00,078 --> 00:04:03,915 Saturn lies too far from the sun to feel the same warmth, 75 00:04:03,916 --> 00:04:06,018 So the heat that drives its weather 76 00:04:06,019 --> 00:04:10,020 Must be coming from somewhere else. 77 00:04:10,021 --> 00:04:12,589 To understand this mysterious heat source, 78 00:04:12,590 --> 00:04:16,028 We need to go back 4 1/2 billion years... 79 00:04:17,328 --> 00:04:20,131 to the birth of the ringed planet. 80 00:04:24,735 --> 00:04:27,037 The planets in our solar system 81 00:04:27,038 --> 00:04:29,839 Emerged from a vast, swirling cloud 82 00:04:29,840 --> 00:04:32,944 Of ice, dust, and gas. 83 00:04:34,879 --> 00:04:38,548 The same ingredients can still be found on earth today 84 00:04:38,549 --> 00:04:40,318 In places like iceland, 85 00:04:40,319 --> 00:04:44,354 Where volcanic ash mixes with icy glaciers. 86 00:04:44,355 --> 00:04:47,524 If you wanna build a giant planet like saturn, 87 00:04:47,525 --> 00:04:51,796 This pile of raw material here is a great visual analog. 88 00:04:51,797 --> 00:04:54,065 There's a lot of oxygen and hydrogen in the universe. 89 00:04:54,066 --> 00:04:56,334 That makes water, and that makes water ice, 90 00:04:56,335 --> 00:04:58,469 And the stuff initially that made the solar system 91 00:04:58,470 --> 00:04:59,971 Is basically this stuff here. 92 00:04:59,972 --> 00:05:02,541 It's dirty ice, water ice, with a little bit of 93 00:05:02,542 --> 00:05:05,008 Little bit of rocky and metallic minerals left in there 94 00:05:05,009 --> 00:05:06,879 Out there in the cold of space. 95 00:05:08,816 --> 00:05:10,815 4 1/2 billion years ago, 96 00:05:10,816 --> 00:05:13,519 A vast cloud of dirty ice particles 97 00:05:13,520 --> 00:05:18,524 Shrouded in hydrogen and helium collapses under its own gravity, 98 00:05:18,525 --> 00:05:22,495 And at the center, a new star our sun 99 00:05:22,496 --> 00:05:24,698 Sparks into life. 100 00:05:25,965 --> 00:05:29,402 The heat of the new star melts the ice closest to it 101 00:05:29,403 --> 00:05:33,772 And blows away the gas, leaving only rocky debris behind. 102 00:05:33,773 --> 00:05:38,644 But farther out, icy material and gas survive. 103 00:05:38,645 --> 00:05:41,948 A boundary forms a frost line 104 00:05:41,949 --> 00:05:46,987 Between the rocky inner cloud and the icy gas beyond. 105 00:05:47,422 --> 00:05:50,055 Once you fire up that campfire, if you will, 106 00:05:50,056 --> 00:05:51,557 What would be left behind in the inner solar system 107 00:05:51,558 --> 00:05:52,959 Is gonna be this stuff 108 00:05:52,960 --> 00:05:55,060 Silicate minerals you make a planet like the earth from. 109 00:05:55,061 --> 00:05:58,298 But far away from the sun, where it's colder, 110 00:05:58,299 --> 00:06:01,567 You cross the frost line, and what's out there 111 00:06:01,568 --> 00:06:05,437 Is still cold enough to maintain the ice behind, 112 00:06:05,438 --> 00:06:07,807 And there's a lot of it there. 113 00:06:07,808 --> 00:06:10,810 At first you make sort of a solid core of this material, 114 00:06:10,811 --> 00:06:11,978 But when you reach a critical mass, 115 00:06:11,979 --> 00:06:14,014 You've got enough gravitational influence 116 00:06:14,015 --> 00:06:16,683 To start to directly draw in some of the hydrogen and helium 117 00:06:16,684 --> 00:06:18,986 In the interplanetary cloud. 118 00:06:20,287 --> 00:06:23,122 Saturn's huge solid core, 119 00:06:23,123 --> 00:06:26,325 Now 10 to 20 times the size of the earth, 120 00:06:26,326 --> 00:06:30,863 Generates relentless gravity and draws in gas. 121 00:06:30,864 --> 00:06:35,970 The bigger this gas ball gets, the more material it sucks in. 122 00:06:36,371 --> 00:06:39,007 Saturn's massive gravity then gets to work 123 00:06:39,008 --> 00:06:43,010 On its fledgling atmosphere, compressing it. 124 00:06:43,011 --> 00:06:47,046 And like any gas under pressure, it gets hot 125 00:06:47,047 --> 00:06:49,184 Seriously hot. 126 00:06:50,417 --> 00:06:53,486 Even today, saturn's high pressure atmosphere 127 00:06:53,487 --> 00:06:56,923 Heats its core to 21,000 degrees 128 00:06:56,924 --> 00:07:00,728 Twice the temperature of the surface of the sun. 129 00:07:01,931 --> 00:07:03,998 And it's this heat rising up 130 00:07:03,999 --> 00:07:06,767 Which forms saturn's distinct bands 131 00:07:06,768 --> 00:07:10,706 And drives its extreme weather. 132 00:07:10,707 --> 00:07:13,009 Saturn's actually rotating very quickly. 133 00:07:13,010 --> 00:07:14,308 It's a large planet. 134 00:07:14,309 --> 00:07:16,911 It rotates once on its axis about every 10 hours. 135 00:07:16,912 --> 00:07:19,481 So as the weather comes up from the interior, 136 00:07:19,482 --> 00:07:21,650 It gets smeared out into bands. 137 00:07:24,419 --> 00:07:26,454 That's saturn's north pole. 138 00:07:26,455 --> 00:07:30,026 The bands do something that at first glance, seems impossible. 139 00:07:30,427 --> 00:07:33,495 There is a gigantic vortex 140 00:07:33,496 --> 00:07:35,264 A spinning region of air 141 00:07:35,265 --> 00:07:37,834 That's shaped like a perfect hexagon. 142 00:07:37,835 --> 00:07:39,435 You have waves 143 00:07:39,436 --> 00:07:40,937 Of pressure, density, and temperature 144 00:07:40,938 --> 00:07:43,204 That start to interact with each other. 145 00:07:43,205 --> 00:07:45,408 And these waves can actually interfere 146 00:07:45,409 --> 00:07:46,709 And become one big wave 147 00:07:46,710 --> 00:07:48,978 That goes all the way around the planet. 148 00:07:48,979 --> 00:07:50,714 This giant wave settles 149 00:07:50,715 --> 00:07:54,317 Into a long-Lasting pattern, because below, 150 00:07:54,318 --> 00:07:55,952 There's no rocky surface 151 00:07:55,953 --> 00:07:58,421 To disrupt the winds that form it. 152 00:07:58,422 --> 00:08:01,591 They form a beautifully defined regular hexagon. 153 00:08:01,592 --> 00:08:03,928 It's one of the most spectacular things about saturn. 154 00:08:06,696 --> 00:08:08,899 It took robotic probes 155 00:08:08,900 --> 00:08:11,500 To reveal the weird weather on saturn, 156 00:08:11,501 --> 00:08:14,337 But if these close-Up shots of storms and lightning 157 00:08:14,338 --> 00:08:16,673 Took scientists by surprise, 158 00:08:16,674 --> 00:08:21,344 They were nothing compared to the shock of what came next, 159 00:08:21,345 --> 00:08:24,414 Because the rings are alive. 160 00:08:36,194 --> 00:08:38,896 Imagine saturn without its rings 161 00:08:38,897 --> 00:08:44,169 Just a pale globe floating in the darkness of space. 162 00:08:46,571 --> 00:08:49,774 With rings, it's magical. 163 00:08:53,177 --> 00:08:54,445 Undoubtedly, the one thing 164 00:08:54,446 --> 00:08:56,814 That captures everyone about saturn is the rings. 165 00:08:56,815 --> 00:08:59,885 It's inspired fiction stories, and it's inspired everyone 166 00:08:59,886 --> 00:09:01,953 Who's looked at it in the night sky. 167 00:09:01,954 --> 00:09:04,689 When i was 4 or 5 years old, 168 00:09:04,690 --> 00:09:07,224 My parents bought a small department store telescope, 169 00:09:07,225 --> 00:09:09,895 And i remember looking down into that eyepiece 170 00:09:09,896 --> 00:09:13,998 And seeing this perfect jewel of a planet. 171 00:09:13,999 --> 00:09:16,000 There's just nothing better than this, 172 00:09:16,001 --> 00:09:17,167 And you can just see the rings 173 00:09:17,168 --> 00:09:19,037 Going around the planet just perfectly. 174 00:09:19,038 --> 00:09:22,641 They're just a gorgeous elliptical race track. 175 00:09:22,642 --> 00:09:26,211 From the eyepiece of a small telescope, 176 00:09:26,212 --> 00:09:30,047 The rings seem quiet and serene. 177 00:09:30,048 --> 00:09:33,819 But up close, it's a very different picture. 178 00:09:33,820 --> 00:09:38,123 We know this thanks to a space probe called cassini, 179 00:09:38,124 --> 00:09:41,495 And over 10 years of images like these. 180 00:09:43,164 --> 00:09:46,999 Ice particles jostle for position like stock cars, 181 00:09:47,000 --> 00:09:48,467 Traveling inside the rings 182 00:09:48,468 --> 00:09:52,605 At hundreds of thousands of miles an hour. 183 00:09:52,606 --> 00:09:55,341 These particles range in size from chunks of ice 184 00:09:55,342 --> 00:10:00,779 As big as houses to the finest powder snow. 185 00:10:00,780 --> 00:10:02,615 It wasn't until we went to saturn 186 00:10:02,616 --> 00:10:04,851 And stayed there with cassini that we learned 187 00:10:04,852 --> 00:10:07,519 Just how fiercely complex it is. 188 00:10:07,520 --> 00:10:09,556 You have the gravity of the planet itself 189 00:10:09,557 --> 00:10:10,956 And all of these moons 190 00:10:10,957 --> 00:10:13,860 Interacting with the rings and the moons and the planet. 191 00:10:13,861 --> 00:10:17,496 All of these things are sculpting that entire system 192 00:10:17,497 --> 00:10:20,433 On scales that are both subtle and gross, 193 00:10:20,434 --> 00:10:25,173 And it makes this magnificent crown jewel of the solar system. 194 00:10:25,774 --> 00:10:27,975 As small moons go around and side, 195 00:10:27,976 --> 00:10:30,945 The ring particles dance around them in response. 196 00:10:30,946 --> 00:10:33,480 We see areas of the rings that get raised up 197 00:10:33,481 --> 00:10:34,682 As the moon goes by. 198 00:10:34,683 --> 00:10:37,351 Moons will even switch orbits with each other, 199 00:10:37,352 --> 00:10:38,720 So there's a lot of dynamic stuff 200 00:10:38,721 --> 00:10:40,988 Going on inside the rings. 201 00:10:41,390 --> 00:10:43,391 Scientists believe that from time to time, 202 00:10:43,392 --> 00:10:46,727 Saturn's icy moons break up, 203 00:10:46,728 --> 00:10:49,097 Adding new material to the rings. 204 00:10:50,900 --> 00:10:53,702 This means that the structure of the rings 205 00:10:53,703 --> 00:10:57,203 Is constantly evolving. 206 00:10:57,204 --> 00:11:00,007 With cassini, scientists can deconstruct the physics 207 00:11:00,008 --> 00:11:03,511 Of this evolution, and it's teaching us the rules 208 00:11:03,512 --> 00:11:06,516 That make the whole universe tick. 209 00:11:10,386 --> 00:11:12,319 All the planets in our solar system 210 00:11:12,320 --> 00:11:16,156 Evolve from the same flat disc of dust and gas 211 00:11:16,157 --> 00:11:19,028 4 1/2 billion years ago. 212 00:11:19,229 --> 00:11:23,866 Astronomers see similar discs around young distant stars. 213 00:11:23,867 --> 00:11:26,267 But even with our most powerful telescopes, 214 00:11:26,268 --> 00:11:30,204 We can't see planets forming. They're too far away. 215 00:11:30,205 --> 00:11:33,508 But saturn's rings are right on our doorstep, 216 00:11:33,509 --> 00:11:37,112 A veritable snapshot of a mini solar system 217 00:11:37,113 --> 00:11:40,550 Caught in the process of formation. 218 00:11:40,551 --> 00:11:41,852 Looking at the rings, 219 00:11:41,853 --> 00:11:46,022 We're looking at the formation of planets or bodies 220 00:11:46,023 --> 00:11:48,456 In an arrested state of development. 221 00:11:48,457 --> 00:11:50,426 It's like you took the beginning stages 222 00:11:50,427 --> 00:11:53,295 Of the formation of the planets but stopped it. 223 00:11:56,066 --> 00:11:59,835 Cassini shows structures forming spontaneously 224 00:11:59,836 --> 00:12:01,938 Inside the rings. 225 00:12:01,939 --> 00:12:03,772 They don't even need to be tickled. 226 00:12:03,773 --> 00:12:07,743 They don't need to be disturbed into forming structures. 227 00:12:07,744 --> 00:12:10,113 They form them on their own. 228 00:12:10,114 --> 00:12:11,414 Does this tiny moon, 229 00:12:11,415 --> 00:12:14,017 Captured in the process of formation, 230 00:12:14,018 --> 00:12:16,618 Show us how the earth started its life? 231 00:12:16,619 --> 00:12:21,557 You get something that just happens to form 232 00:12:21,558 --> 00:12:25,161 Out of random processes, and that mimics what astronomers 233 00:12:25,162 --> 00:12:28,664 Think they're seeing in protoplanetary discs 234 00:12:28,665 --> 00:12:32,102 Surrounding other stars in the cosmos around us. 235 00:12:32,103 --> 00:12:36,773 Cassini sees curious propeller-Like structures 236 00:12:36,774 --> 00:12:39,910 Inside saturn's broad a ring. 237 00:12:39,911 --> 00:12:45,083 They're caused by ring particles washing over tiny hidden moons. 238 00:12:47,018 --> 00:12:49,420 The particles collide with the moons, 239 00:12:49,421 --> 00:12:52,690 Sending them into random, ever-Changing orbits, 240 00:12:52,691 --> 00:12:56,228 Sometimes closer to saturn and sometimes farther away. 241 00:12:59,998 --> 00:13:03,132 Perhaps similar forces influenced the earth's formation 242 00:13:03,133 --> 00:13:04,702 Around the sun, 243 00:13:04,703 --> 00:13:08,507 Pushing it into closer or wider orbits. 244 00:13:12,611 --> 00:13:14,912 Saturn's rings also help us understand 245 00:13:14,913 --> 00:13:18,382 Why planets stop growing. 246 00:13:18,383 --> 00:13:20,617 A walnut-Shaped moon called "pan" 247 00:13:20,618 --> 00:13:24,654 Sits near the middle of saturn's a ring. 248 00:13:24,655 --> 00:13:28,391 With so much ice around it to gobble up, 249 00:13:28,392 --> 00:13:31,728 Pan should be huge, but it's tiny, 250 00:13:31,729 --> 00:13:34,198 Only 20 miles in diameter. 251 00:13:34,199 --> 00:13:37,134 If you have a moon embedded in a disc of ring particles, 252 00:13:37,135 --> 00:13:40,138 You might naively think it just secretes ring particles 253 00:13:40,139 --> 00:13:43,540 Until it grows into a, you know, a bigger moon. 254 00:13:43,541 --> 00:13:46,877 But actually we find moons create gaps 255 00:13:46,878 --> 00:13:48,246 In the ring around them. 256 00:13:48,247 --> 00:13:50,215 So pan has created the inky gap. 257 00:13:50,216 --> 00:13:52,518 Daphnis has created the keeler gap. 258 00:13:52,786 --> 00:13:55,887 Rather than pulling ring material in, 259 00:13:55,888 --> 00:13:58,891 Pan appears to push it away. 260 00:13:58,892 --> 00:14:00,225 As the moon passes 261 00:14:00,226 --> 00:14:02,695 The slower moving material outside it, 262 00:14:02,696 --> 00:14:05,598 Pan's gravity flings the particles out 263 00:14:05,599 --> 00:14:08,133 Into wider orbits. 264 00:14:08,134 --> 00:14:11,671 The faster material inside pan's orbit is slow. 265 00:14:11,672 --> 00:14:14,605 As it passes, the little moon, causing it to fall away 266 00:14:14,606 --> 00:14:16,275 Towards saturn. 267 00:14:16,276 --> 00:14:21,313 This natural cutoff and growth might explain why 268 00:14:21,314 --> 00:14:23,782 Multiple planets form around stars, 269 00:14:23,783 --> 00:14:28,621 Instead of single giant planets that eat the whole buffet. 270 00:14:28,622 --> 00:14:32,257 Of all cassini's discoveries, 271 00:14:32,258 --> 00:14:36,628 The most important is also the most surprising 272 00:14:36,629 --> 00:14:42,201 A tiny ice moon that may be home to life. 273 00:14:53,582 --> 00:14:54,816 For most of history, 274 00:14:54,817 --> 00:14:57,851 The only moon we've been able to study up close 275 00:14:57,852 --> 00:15:00,254 Is our own. 276 00:15:00,255 --> 00:15:05,925 Multiple deep craters tell a powerful story. 277 00:15:05,926 --> 00:15:07,794 Our moon is dead. 278 00:15:07,795 --> 00:15:09,697 There's no active geology or weather 279 00:15:09,698 --> 00:15:12,467 To wipe away these ancient scars. 280 00:15:12,468 --> 00:15:17,004 But what about the moons around other planets like saturn? 281 00:15:17,005 --> 00:15:18,040 Are they dead, too? 282 00:15:18,841 --> 00:15:20,274 Our first assumption about saturn 283 00:15:20,275 --> 00:15:21,843 Was that the moons would be like that 284 00:15:21,844 --> 00:15:25,348 Cold, dead, lifeless relics from the early solar system. 285 00:15:25,349 --> 00:15:27,648 It wasn't until we invented spacecraft 286 00:15:27,649 --> 00:15:30,951 That could go to these moons that we discovered 287 00:15:30,952 --> 00:15:34,823 How incredibly diverse our solar system truly is. 288 00:15:40,096 --> 00:15:41,962 Take enceladus 289 00:15:41,963 --> 00:15:46,869 An ice moon barely 300 miles across. 290 00:15:46,870 --> 00:15:51,940 Nobody paid it any attention a decade ago. 291 00:15:51,941 --> 00:15:56,345 But today, it's a geological rock star. 292 00:15:56,346 --> 00:15:57,445 And this is why. 293 00:15:57,846 --> 00:16:01,950 Enceladus orbits inside saturn's outer most ring 294 00:16:01,951 --> 00:16:04,454 The e ring. 295 00:16:04,455 --> 00:16:08,023 The e ring puzzled scientists because they couldn't figure out 296 00:16:08,024 --> 00:16:10,627 How a ring so broad and so diffuse 297 00:16:10,628 --> 00:16:12,897 Could hold itself together. 298 00:16:14,665 --> 00:16:19,134 The cassini team decided to take a close fly by of enceladus 299 00:16:19,135 --> 00:16:22,805 To solve the mystery. 300 00:16:22,806 --> 00:16:23,940 Did it have something to do 301 00:16:23,941 --> 00:16:26,142 With keeping the particles together? 302 00:16:26,143 --> 00:16:30,179 What was the connection between the e ring and enceladus? 303 00:16:30,180 --> 00:16:33,315 Well, now we know that enceladus is actually responsible 304 00:16:33,316 --> 00:16:35,485 For the e ring being there in the first place. 305 00:16:37,489 --> 00:16:42,925 2005, cassini captures an astonishing sight 306 00:16:42,926 --> 00:16:47,598 A hundred geysers shooting ice particles miles into space 307 00:16:47,599 --> 00:16:50,367 From cracks in the south pole. 308 00:16:50,368 --> 00:16:55,673 Enceladus is hurdling its guts into space at a colossal rate. 309 00:16:55,674 --> 00:16:57,607 As enceladus orbits saturn, 310 00:16:57,608 --> 00:17:01,377 These icy plumes feed a vast shimmering halo 311 00:17:01,378 --> 00:17:02,945 Around the planet 312 00:17:02,946 --> 00:17:07,485 The mysterious e ring. 313 00:17:09,121 --> 00:17:12,925 This icy plume also interacts with saturn's magnetic field, 314 00:17:12,926 --> 00:17:16,729 Causing a plasma cloud of charged particles. 315 00:17:19,931 --> 00:17:23,501 The particles race along saturn's magnetic field lines 316 00:17:23,502 --> 00:17:26,269 And slam into saturn's polar atmosphere, 317 00:17:26,270 --> 00:17:31,309 Raising huge ultraviolet auroras. 318 00:17:31,310 --> 00:17:35,446 Geysers explain the e ring, 319 00:17:35,447 --> 00:17:38,717 But how can they exist on a frozen moon 320 00:17:38,718 --> 00:17:41,754 A billion miles from the sun? 321 00:17:44,624 --> 00:17:48,559 On earth, geysers form in highly volcanic places 322 00:17:48,560 --> 00:17:52,597 Where water comes into contact with hot rocks. 323 00:17:52,598 --> 00:17:56,768 Enceladus, so small, and so far from the sun, 324 00:17:56,769 --> 00:17:59,437 Should be cold and dead. 325 00:17:59,438 --> 00:18:03,475 But thanks to saturn's gravity, it's not. 326 00:18:06,446 --> 00:18:08,581 The source of the heating on enceladus 327 00:18:08,582 --> 00:18:11,717 Is the eccentric orbit of that moon. 328 00:18:11,718 --> 00:18:13,718 Sometimes it's a little closer to saturn, 329 00:18:13,719 --> 00:18:15,688 Sometimes it's a little further away. 330 00:18:15,689 --> 00:18:18,357 And that heating on enceladus from that kneading 331 00:18:18,358 --> 00:18:21,960 Gravitationally making the moon stretch and pull 332 00:18:21,961 --> 00:18:23,394 Is what warms the interior, 333 00:18:23,395 --> 00:18:26,332 Causing the activity on enceladus that we see today. 334 00:18:29,670 --> 00:18:31,906 The gravitational pull of saturn 335 00:18:31,907 --> 00:18:36,575 Reaches deep into enceladus beyond its water-Ice exterior 336 00:18:36,576 --> 00:18:39,180 Gripping its rocky core. 337 00:18:41,847 --> 00:18:44,983 As saturn's grasp strengthens and weakens, 338 00:18:44,984 --> 00:18:47,885 It massages this cold, rocky heart, 339 00:18:47,886 --> 00:18:52,091 Bringing it to geological life with frictional heat. 340 00:18:52,592 --> 00:18:54,894 The heat melts the ice around it, 341 00:18:54,895 --> 00:18:56,730 Creating a vast subsurface lake 342 00:18:56,731 --> 00:18:59,198 At the southern pole of enceladus. 343 00:18:59,199 --> 00:19:03,903 This water jets out through huge cracks in the surface ice. 344 00:19:04,904 --> 00:19:07,239 On earth, where there's liquid water, 345 00:19:07,240 --> 00:19:08,741 There's life. 346 00:19:08,742 --> 00:19:11,311 Could enceladus have what it takes 347 00:19:11,312 --> 00:19:15,081 For simple organisms to exist? 348 00:19:15,082 --> 00:19:17,885 Once cassini saw these geysers, the scientists knew 349 00:19:17,886 --> 00:19:20,687 They had found something extremely wonderful. 350 00:19:20,688 --> 00:19:23,690 They actually changed the mission of cassini itself, 351 00:19:23,691 --> 00:19:25,292 Changed its trajectory. 352 00:19:25,293 --> 00:19:28,495 We sent the cassini spacecraft to fly very, very close 353 00:19:28,496 --> 00:19:32,998 Over these cracks where the water was rushing out. 354 00:19:32,999 --> 00:19:35,301 Scientists clung to the faint hope 355 00:19:35,302 --> 00:19:39,072 That the water would contain salts and organic molecules 356 00:19:39,073 --> 00:19:40,373 Like ammonia, 357 00:19:40,374 --> 00:19:44,210 The building blocks of life here on earth. 358 00:19:44,211 --> 00:19:49,984 Stunningly, cassini's censors tasted all of them in abundance. 359 00:19:49,985 --> 00:19:52,821 In that plume, there's organic material. 360 00:19:52,822 --> 00:19:55,890 It's not water. It's a soup. 361 00:19:55,891 --> 00:19:57,391 That's incredible. 362 00:19:57,392 --> 00:19:59,660 All the main requirements for habitability, 363 00:19:59,661 --> 00:20:03,564 Energy source, liquid water, source of biological nitrogen 364 00:20:03,565 --> 00:20:05,934 And ammonia, organic material, 365 00:20:05,935 --> 00:20:08,270 And the samples are coming up into space. 366 00:20:08,271 --> 00:20:10,572 There's a big sign free samples, take one. 367 00:20:10,573 --> 00:20:12,841 There could be life that could've evolved there. 368 00:20:12,842 --> 00:20:15,075 Now we don't know. We haven't seen it. 369 00:20:15,076 --> 00:20:19,514 But the conditions there are as good there now 370 00:20:19,515 --> 00:20:21,849 As they were on earth 3 billion years ago 371 00:20:21,850 --> 00:20:23,517 When life arose here. 372 00:20:23,518 --> 00:20:26,888 The sensational realization that enceladus 373 00:20:26,889 --> 00:20:30,057 May harbor life has sparked intense debate 374 00:20:30,058 --> 00:20:32,493 About future missions to find it, 375 00:20:32,494 --> 00:20:37,132 Because it has a rival for those precious research dollars. 376 00:20:37,133 --> 00:20:41,936 Saturn's largest moon, titan, could also be home to life 377 00:20:41,937 --> 00:20:44,137 Bizarre life. 378 00:20:44,138 --> 00:20:46,575 And we may have already found it. 379 00:20:56,522 --> 00:20:59,924 More than 60 moons orbit the planet saturn, 380 00:20:59,925 --> 00:21:03,694 But one dwarfs them all. 381 00:21:03,695 --> 00:21:08,264 Titan is a colossus, bigger than the planet mercury. 382 00:21:08,265 --> 00:21:13,104 A thick orange haze hides its surface from our telescopes, 383 00:21:13,105 --> 00:21:16,240 And when the cassini mission first appeared beneath 384 00:21:16,241 --> 00:21:20,144 Titan's orange cloak, it revealed a world weirder 385 00:21:20,145 --> 00:21:22,680 Than we could ever have imagined. 386 00:21:22,681 --> 00:21:25,182 Titan is an amazing place. 387 00:21:25,183 --> 00:21:27,318 And of all the things going on around saturn, 388 00:21:27,319 --> 00:21:30,923 Titan might be the most exciting of all. 389 00:21:33,090 --> 00:21:36,926 Titan has mountains and deserts, rivers and lakes. 390 00:21:36,927 --> 00:21:42,265 Only the earth can match it for geological diversity. 391 00:21:42,266 --> 00:21:46,136 But here, water ice takes the place of bedrock, 392 00:21:46,137 --> 00:21:49,205 Frozen at 300 degrees below zero. 393 00:21:49,206 --> 00:21:51,274 And instead of water, 394 00:21:51,275 --> 00:21:54,944 The rivers on titan flow with methane. 395 00:21:54,945 --> 00:21:58,817 This is a place where it actually rains liquid methane, 396 00:21:58,818 --> 00:22:00,418 Liquid natural gas. 397 00:22:00,419 --> 00:22:04,356 This liquid is filling up rivers and lakes. 398 00:22:04,357 --> 00:22:06,759 This makes titan incredibly special. 399 00:22:06,760 --> 00:22:09,194 It's only the second world in the solar system 400 00:22:09,195 --> 00:22:12,499 Where we know there's liquid on the surface. 401 00:22:15,467 --> 00:22:17,034 And like earth, 402 00:22:17,035 --> 00:22:20,672 Titan has a thick nitrogen-Rich atmosphere. 403 00:22:20,673 --> 00:22:22,808 But instead of the oxygen we breathe, 404 00:22:22,809 --> 00:22:26,412 Titan's air is spiked with carbon-Rich molecules 405 00:22:26,413 --> 00:22:30,514 That stain it a dull orange. 406 00:22:30,515 --> 00:22:33,719 It's a soup of methane and ethane and propane 407 00:22:33,720 --> 00:22:35,220 And acetylene. 408 00:22:35,221 --> 00:22:37,289 Uh, the list of organic molecules is literally 409 00:22:37,290 --> 00:22:39,593 Hundreds, hundreds long that we've detected there. 410 00:22:41,694 --> 00:22:43,194 Titan's complex cocktail 411 00:22:43,195 --> 00:22:48,165 Of atmospheric chemicals intrigue scientists. 412 00:22:48,166 --> 00:22:50,836 But it also puzzles them, 413 00:22:50,837 --> 00:22:55,875 Especially methane gas, which rapidly decays in sunlight. 414 00:22:55,876 --> 00:22:58,311 So even a billion miles from the sun, 415 00:22:58,312 --> 00:23:02,782 Titan's thick haze should've lifted long ago. 416 00:23:02,783 --> 00:23:06,786 A vast source of methane must be replenishing 417 00:23:06,787 --> 00:23:08,921 The orange smog. 418 00:23:08,922 --> 00:23:10,190 Before cassini, 419 00:23:10,191 --> 00:23:11,691 Scientists assumed the whole of titan 420 00:23:11,692 --> 00:23:14,360 Was covered in massive impact craters. 421 00:23:14,361 --> 00:23:17,599 Perhaps crater lakes filled with liquid methane 422 00:23:17,600 --> 00:23:20,132 Were evaporating into the atmosphere, 423 00:23:20,133 --> 00:23:23,902 Supplying the missing gas. 424 00:23:23,903 --> 00:23:26,038 To help prove this theory, 425 00:23:26,039 --> 00:23:30,043 Cassini carried a hitchhiker all the way to saturn. 426 00:23:30,044 --> 00:23:34,280 The huygens lander released high above titan's equator 427 00:23:34,281 --> 00:23:39,653 Parachuted through the clouds, snapping photographs as it fell. 428 00:23:41,856 --> 00:23:43,391 As it went through the atmosphere, 429 00:23:43,392 --> 00:23:44,725 It took a huge amount of data 430 00:23:44,726 --> 00:23:48,629 And then landed on the moon itself and took pictures. 431 00:23:48,630 --> 00:23:50,898 When we first saw those pictures, 432 00:23:50,899 --> 00:23:53,100 It was life-Changing. 433 00:23:53,101 --> 00:23:56,938 There were no craters. 434 00:23:56,939 --> 00:24:01,042 It looked like flowing liquid had once shaped the landscape, 435 00:24:01,043 --> 00:24:05,246 But at the landing site and as far as huygens could see, 436 00:24:05,247 --> 00:24:09,449 That liquid was long gone. 437 00:24:09,450 --> 00:24:12,253 Huygens landed in a spot almost identical 438 00:24:12,254 --> 00:24:13,921 To what we're standing on right now. 439 00:24:13,922 --> 00:24:16,157 If we look all around, 440 00:24:16,158 --> 00:24:19,392 We can see this bleak, barren landscape. 441 00:24:19,393 --> 00:24:21,194 We see pebbles and cobbles 442 00:24:21,195 --> 00:24:22,796 That have been rounded and smoothed 443 00:24:22,797 --> 00:24:24,699 Because they've come through river channels. 444 00:24:24,700 --> 00:24:27,067 We see plenty of those at the huygens landing site. 445 00:24:27,068 --> 00:24:30,038 Uh, in addition to that, we see lots of sand. 446 00:24:30,039 --> 00:24:34,911 The desert huygens landed in is huge. 447 00:24:34,912 --> 00:24:38,248 It stretches all the way around titan's equator... 448 00:24:41,483 --> 00:24:45,053 with 300-Foot tall dunes sculpted by the wind 449 00:24:45,054 --> 00:24:48,624 Just as they are on earth. 450 00:24:48,625 --> 00:24:51,894 If the vast crater lakes weren't at the equator, 451 00:24:51,895 --> 00:24:55,297 They had to be at titan's poles. 452 00:24:55,298 --> 00:24:58,334 Cassini scheduled a number of additional flybys 453 00:24:58,335 --> 00:25:00,705 To look for any signs of liquid. 454 00:25:01,506 --> 00:25:03,772 One of the instruments onboard cassini 455 00:25:03,773 --> 00:25:05,941 Is basically a radar gun. 456 00:25:05,942 --> 00:25:09,378 It shoots radar waves at titan, and they get reflected back. 457 00:25:09,379 --> 00:25:12,515 After two years of hunting with this instrument, 458 00:25:12,516 --> 00:25:14,984 Scientists finally got the signal 459 00:25:14,985 --> 00:25:16,686 They were waiting for. 460 00:25:16,687 --> 00:25:18,121 One of the things it found 461 00:25:18,122 --> 00:25:19,855 Is that near the north pole of titan 462 00:25:19,856 --> 00:25:22,624 Were regions that were not reflecting radar, 463 00:25:22,625 --> 00:25:24,694 And that sounds a lot like liquid. 464 00:25:24,695 --> 00:25:27,630 Liquid absorbs that energy and doesn't reflect it back. 465 00:25:27,631 --> 00:25:30,800 Later observations clinched it. 466 00:25:30,801 --> 00:25:32,367 When cassini finally imaged 467 00:25:32,368 --> 00:25:34,871 The north polar regions of titan, 468 00:25:34,872 --> 00:25:37,040 It it finally saw these lakes and seas of methane 469 00:25:37,041 --> 00:25:38,642 That we'd been looking for, 470 00:25:38,643 --> 00:25:41,877 Only they weren't contained in impact craters like we thought. 471 00:25:41,878 --> 00:25:44,079 Instead they're contained in big lake basins 472 00:25:44,080 --> 00:25:45,916 That look just like they do on earth. 473 00:25:51,290 --> 00:25:54,223 Basin lakes like this one in mono county, california, 474 00:25:54,224 --> 00:25:58,629 Form in the depressions leftover from tectonic activity. 475 00:25:58,630 --> 00:26:01,031 These geological features on titan 476 00:26:01,032 --> 00:26:03,934 Could only mean one shocking thing 477 00:26:03,935 --> 00:26:08,839 The moon was alive with geological activity. 478 00:26:08,840 --> 00:26:11,341 If we were sitting on the margins of kraken mare, 479 00:26:11,342 --> 00:26:14,779 Which is the largest sea that we see on titan, 480 00:26:14,780 --> 00:26:18,383 Then we would probably see something very similar to this landscape. 481 00:26:18,384 --> 00:26:21,053 We would look out across a fairly calm surface, 482 00:26:21,054 --> 00:26:23,687 We think the winds are not very strong on titan. 483 00:26:23,688 --> 00:26:27,224 And so we'd have this calm lake of methane and ethane. 484 00:26:27,225 --> 00:26:29,926 And in the distance we would see hills and mountains 485 00:26:29,927 --> 00:26:31,462 That have formed on titan 486 00:26:31,463 --> 00:26:33,196 Probably through tectonic processes 487 00:26:33,197 --> 00:26:35,532 In much the same way that mountains are built on earth. 488 00:26:35,533 --> 00:26:38,969 Except on titan, it's so cold, 489 00:26:38,970 --> 00:26:43,006 The volcanoes spew water, not lava. 490 00:26:43,007 --> 00:26:47,880 And the mountains and lake basins are solid ice. 491 00:26:48,981 --> 00:26:53,084 At first, scientists thought that methane evaporating 492 00:26:53,085 --> 00:26:57,255 From these lakes generated titan's smog. 493 00:26:57,256 --> 00:27:00,926 But when cassini flew by to measure the lakes again, 494 00:27:00,927 --> 00:27:03,195 The levels appear to be the same. 495 00:27:03,196 --> 00:27:07,166 The lakes didn't look like they were evaporating at all. 496 00:27:07,167 --> 00:27:09,034 Scientists were stumped. 497 00:27:09,035 --> 00:27:11,136 Either the lakes weren't the source 498 00:27:11,137 --> 00:27:13,072 Of atmospheric methane 499 00:27:13,073 --> 00:27:16,775 Or they were somehow being refilled. 500 00:27:16,776 --> 00:27:19,811 Planetary geologist, jani radebaugh, 501 00:27:19,812 --> 00:27:22,615 Believes a crucial clue to the missing methane 502 00:27:22,616 --> 00:27:26,217 Lies in the formation of rocky deposits called tufa. 503 00:27:27,688 --> 00:27:29,988 They're found here at mono lake, 504 00:27:29,989 --> 00:27:33,325 Where clean spring water rises up from the ground 505 00:27:33,326 --> 00:27:38,165 Into the mineral-Rich lake where the two water types react. 506 00:27:42,003 --> 00:27:45,605 This is very exciting because this could be a clue 507 00:27:45,606 --> 00:27:47,140 To the missing methane on titan. 508 00:27:47,141 --> 00:27:51,276 So it's rock that has been formed from the chemicals 509 00:27:51,277 --> 00:27:52,879 Contained in two fluids. 510 00:27:52,880 --> 00:27:56,416 There is water that's emerging at the margin of the lake. 511 00:27:56,417 --> 00:27:57,819 It's interacting with the lake water 512 00:27:57,820 --> 00:27:59,919 Which has a very different chemistry 513 00:27:59,920 --> 00:28:02,421 And all of the chemicals that are dissolved 514 00:28:02,422 --> 00:28:05,524 Combine with each other and create this rock. 515 00:28:05,525 --> 00:28:08,861 Radar images of titan's largest lake 516 00:28:08,862 --> 00:28:11,630 Reveal rocky structures around the margins 517 00:28:11,631 --> 00:28:15,702 That look just like mono lake's tufa. 518 00:28:15,703 --> 00:28:18,504 Titan's tufa, if that's what they are, 519 00:28:18,505 --> 00:28:21,875 Could be evidence of a layer of liquid methane 520 00:28:21,876 --> 00:28:24,578 That sits above titan's frozen core 521 00:28:24,579 --> 00:28:28,249 And rises and springs to feed its lakes 522 00:28:28,250 --> 00:28:31,519 Just like spring water rises to feed mono lake. 523 00:28:31,520 --> 00:28:33,586 So when those methane springs come in, 524 00:28:33,587 --> 00:28:37,958 They interact with the lakes and a rock precipitates out. 525 00:28:37,959 --> 00:28:40,426 So we see these organic rocks 526 00:28:40,427 --> 00:28:42,730 Dotting the margins of the lakes. 527 00:28:42,731 --> 00:28:44,464 And almost certainly there's also methane 528 00:28:44,465 --> 00:28:46,499 Just bubbling up and emerging 529 00:28:46,500 --> 00:28:48,170 At the margins of the lake as well. 530 00:28:49,939 --> 00:28:51,372 If jani is right, 531 00:28:51,373 --> 00:28:55,944 Titan's lakes do evaporate, feeding the atmospheric smog, 532 00:28:55,945 --> 00:28:57,779 But they're constantly replenished 533 00:28:57,780 --> 00:29:02,818 By underground methane springs replacing the lost fluid. 534 00:29:05,721 --> 00:29:08,657 Titan is no dead world. 535 00:29:08,658 --> 00:29:14,196 It's alive with active geology and complex chemistry. 536 00:29:14,197 --> 00:29:16,898 And it might be alive with something else 537 00:29:16,899 --> 00:29:19,136 Something really big. 538 00:29:32,281 --> 00:29:34,616 We used to think that saturn was too far 539 00:29:34,617 --> 00:29:38,756 From the sun and too cold to play host to anything dramatic. 540 00:29:40,957 --> 00:29:44,894 We could not have been more wrong. 541 00:29:44,895 --> 00:29:48,431 The planet boils and bangs with active weather 542 00:29:48,432 --> 00:29:51,934 Storms, lightning, and auroras. 543 00:29:51,935 --> 00:29:55,540 The rings constantly evolve. 544 00:29:58,475 --> 00:30:03,078 And the moons aren't the frozen snowballs we expected. 545 00:30:03,079 --> 00:30:08,652 They're shaped by active geology with warm water geysers 546 00:30:08,653 --> 00:30:10,922 And lakes of liquid methane. 547 00:30:11,123 --> 00:30:15,626 And now on saturn's largest moon, titan, 548 00:30:15,627 --> 00:30:21,465 Scientists may have uncovered the first tangible evidence... 549 00:30:21,466 --> 00:30:25,603 of extraterrestrial life. 550 00:30:25,604 --> 00:30:27,404 Our search for life has been 551 00:30:27,405 --> 00:30:30,007 Focused on liquid water follow the water. 552 00:30:30,008 --> 00:30:31,843 I think it's a good strategy. 553 00:30:31,844 --> 00:30:34,245 But i think we are limiting ourselves if we think that 554 00:30:34,246 --> 00:30:36,514 That's the only place to look. 555 00:30:36,515 --> 00:30:39,382 I think liquids may be interesting 556 00:30:39,383 --> 00:30:41,554 Even if they're not water. 557 00:30:42,722 --> 00:30:44,758 Astrobiologist, chris mckay, 558 00:30:44,759 --> 00:30:46,792 Believes that life on titan 559 00:30:46,793 --> 00:30:49,660 May have evolved to live in liquid methane, 560 00:30:49,661 --> 00:30:52,530 Not liquid water. 561 00:30:52,531 --> 00:30:54,165 But titan is so cold, 562 00:30:54,166 --> 00:30:58,436 Simple life would play by a very different set of rules 563 00:30:58,437 --> 00:31:01,740 Where bigger is better. 564 00:31:01,741 --> 00:31:02,940 When we go to other worlds, 565 00:31:02,941 --> 00:31:04,341 We're gonna be looking for bacteria, 566 00:31:04,342 --> 00:31:06,645 And we assume that they're gonna be very small. 567 00:31:06,646 --> 00:31:10,281 But you could ask the question, why are bacteria so small? 568 00:31:10,282 --> 00:31:14,886 Well, i think the answer is because they live in water. 569 00:31:14,887 --> 00:31:18,990 On earth, bacteria don't need to grow big 570 00:31:18,991 --> 00:31:21,693 In order to thrive. 571 00:31:21,694 --> 00:31:23,797 Water dissolves almost everything, 572 00:31:23,798 --> 00:31:26,532 So it provides a nutrient-Rich environment 573 00:31:26,533 --> 00:31:31,168 Where small and simple bring success. 574 00:31:31,169 --> 00:31:34,205 You go to titan where the liquid is liquid methane, 575 00:31:34,206 --> 00:31:36,340 Liquid ethane, very different from water. 576 00:31:36,341 --> 00:31:38,576 There's no reason an organism should be small. 577 00:31:38,577 --> 00:31:40,980 In fact, quite the opposite. It should be huge. 578 00:31:40,981 --> 00:31:45,683 Mckay envisions enormous single-Celled organisms 579 00:31:45,684 --> 00:31:50,054 Around titan's shores, looking like sheets of paper. 580 00:31:50,055 --> 00:31:52,624 Their huge surface area would maximize 581 00:31:52,625 --> 00:31:56,296 The uptake of food from the nutrient-Poor liquid methane. 582 00:31:56,597 --> 00:31:58,263 I predict if there's life on titan 583 00:31:58,264 --> 00:32:00,933 Living in liquid methane, you won't need a microscope to see it. 584 00:32:00,934 --> 00:32:02,536 You'll need a yardstick. 585 00:32:05,838 --> 00:32:09,409 When cassini released the huygens probe 586 00:32:09,410 --> 00:32:11,979 High above the cloud tops of titan, 587 00:32:11,980 --> 00:32:14,914 Mckay realized he had an opportunity 588 00:32:14,915 --> 00:32:18,718 To bolster his theories of life on the surface. 589 00:32:18,719 --> 00:32:23,221 His methane-Loving life-Forms must be eating to survive. 590 00:32:23,222 --> 00:32:25,659 Perhaps huygens' delicate sensors 591 00:32:25,660 --> 00:32:29,697 Would pick up evidence of ground level feasting. 592 00:32:30,098 --> 00:32:32,733 As huygens was on its way to titan, 593 00:32:32,734 --> 00:32:35,936 I'm sitting in a hotel room writing up a paper saying, 594 00:32:35,937 --> 00:32:37,937 Hey, what if there's life on titan? 595 00:32:37,938 --> 00:32:40,307 What would it eat? And how would we detect it? 596 00:32:40,308 --> 00:32:42,542 How would this probe flying through the atmosphere 597 00:32:42,543 --> 00:32:44,043 Detect it? 598 00:32:44,044 --> 00:32:46,513 Literally the day huygens landed, 599 00:32:46,514 --> 00:32:49,116 I submitted this paper to the journal, 600 00:32:49,117 --> 00:32:51,787 Predicting that if there was life on titan, 601 00:32:51,788 --> 00:32:53,987 It would eat hydrogen and the probe 602 00:32:53,988 --> 00:32:56,423 Would be able to measure this depletion of hydrogen. 603 00:32:56,424 --> 00:32:58,926 So let's look for hydrogen. 604 00:32:59,727 --> 00:33:02,830 Huygens parachutes through titan's atmosphere, 605 00:33:02,831 --> 00:33:05,399 Sampling the gases as it goes. 606 00:33:05,400 --> 00:33:08,002 The upper atmosphere has plenty of hydrogen, 607 00:33:08,003 --> 00:33:09,571 So do the middle layers, 608 00:33:09,572 --> 00:33:14,975 But at ground level, there's a surprise result 609 00:33:14,976 --> 00:33:17,512 An apparently drop-Off in the concentration 610 00:33:17,513 --> 00:33:19,814 Of hydrogen in the air. 611 00:33:19,815 --> 00:33:25,054 Something or perhaps someone was using it up. 612 00:33:25,488 --> 00:33:29,824 When i heard a report that there was a depletion of hydrogen, 613 00:33:29,825 --> 00:33:32,895 I my heart raced 'cause i thought, 614 00:33:32,896 --> 00:33:34,496 If this is if this is hard data 615 00:33:34,497 --> 00:33:36,232 For depletion of hydrogen, 616 00:33:36,233 --> 00:33:39,370 I can't imagine any other way besides biology to explain that. 617 00:33:41,305 --> 00:33:43,172 It's exciting in that it's consistent 618 00:33:43,173 --> 00:33:45,308 With what we predicted, 619 00:33:45,309 --> 00:33:47,243 But we have to wait for this to be confirmed 620 00:33:47,244 --> 00:33:50,079 By other calculations, by direct measurements, 621 00:33:50,080 --> 00:33:53,049 And so on. 622 00:33:53,050 --> 00:33:57,018 If future missions can confirm methane-Based life 623 00:33:57,019 --> 00:34:00,723 On titan, it will surely be the greatest discovery 624 00:34:00,724 --> 00:34:02,291 In the history of science. 625 00:34:02,292 --> 00:34:07,429 Because this low temperature biology must have arisen 626 00:34:07,430 --> 00:34:11,568 Independently of life on earth. 627 00:34:12,069 --> 00:34:15,671 If we discover life, let's say on mars, 628 00:34:15,672 --> 00:34:17,840 There will always be the possibility 629 00:34:17,841 --> 00:34:20,008 That rocks and ice and bits of material 630 00:34:20,009 --> 00:34:21,677 Could've been exchanged. 631 00:34:21,678 --> 00:34:23,612 But the chances of that happening from earth 632 00:34:23,613 --> 00:34:27,016 All the way to saturn are next to nothing. 633 00:34:27,017 --> 00:34:30,119 If we find a second example of life in our solar system 634 00:34:30,120 --> 00:34:32,054 Especially in a place like titan 635 00:34:32,055 --> 00:34:35,825 Which is so alien to the earth, so cold and so different, 636 00:34:35,826 --> 00:34:39,262 That tells us something excruciatingly important. 637 00:34:39,263 --> 00:34:43,067 And that is that life must be everywhere in the universe. 638 00:34:49,707 --> 00:34:52,742 Robotic missions offer tantalizing hints 639 00:34:52,743 --> 00:34:56,280 Of simple life on enceladus and titan. 640 00:34:56,281 --> 00:35:01,150 But is saturn's realm only fit for giant bacteria 641 00:35:01,151 --> 00:35:06,758 Or is it a place we humans could one day call home? 642 00:35:19,705 --> 00:35:24,242 Saturn orbits a billion miles from the sun. 643 00:35:24,243 --> 00:35:27,778 So far out it takes an hour for its reflected light 644 00:35:27,779 --> 00:35:31,682 To reach our eyes. 645 00:35:31,683 --> 00:35:33,450 Yet the future of our civilization 646 00:35:33,451 --> 00:35:37,655 May rest on humans one day colonizing the moons 647 00:35:37,656 --> 00:35:41,358 Surrounding this gas giant planet. 648 00:35:41,359 --> 00:35:44,362 It won't be easy, but saturn has something 649 00:35:44,363 --> 00:35:46,764 Worth the trouble 650 00:35:46,765 --> 00:35:50,901 A magical source of fuel called helium-3 651 00:35:50,902 --> 00:35:54,037 That can satisfy our increasing hunger for energy 652 00:35:54,038 --> 00:35:56,842 For millions of years. 653 00:35:56,843 --> 00:35:59,311 Some futurists believe that we have to have 654 00:35:59,312 --> 00:36:01,914 A commercial incentive to going to saturn. 655 00:36:01,915 --> 00:36:06,084 Not just to mine the minerals of the moons of saturn, 656 00:36:06,085 --> 00:36:11,456 But also to harvest fuel in the form of helium-3. 657 00:36:11,457 --> 00:36:13,925 Helium-3 is a rare substance that we can use 658 00:36:13,926 --> 00:36:18,796 In fusion engines to provide perhaps unlimited energy. 659 00:36:18,797 --> 00:36:23,469 Helium-3 may very well replace oil as the fuel 660 00:36:23,470 --> 00:36:26,606 To take us into the centuries to come. 661 00:36:26,607 --> 00:36:29,409 With its single neutron and twin protons, 662 00:36:29,410 --> 00:36:33,612 Helium-3 is uniquely suited to a form of energy production 663 00:36:33,613 --> 00:36:35,447 Called fusion 664 00:36:35,448 --> 00:36:40,186 The same process that burns in the heart of a star. 665 00:36:40,187 --> 00:36:42,021 When two nuclei are crushed together 666 00:36:42,022 --> 00:36:44,789 Under enormous pressure, they fuse, 667 00:36:44,790 --> 00:36:49,862 Creating a new heavier atom and a burst of pure energy. 668 00:36:49,863 --> 00:36:54,134 Best of all, helium-3 doesn't release 669 00:36:54,135 --> 00:36:56,134 Any of the harmful radiation 670 00:36:56,135 --> 00:36:59,772 Associated with other fusion fuels. 671 00:36:59,773 --> 00:37:02,375 The only trouble with helium-3 672 00:37:02,376 --> 00:37:06,346 There's precious little to be found on earth. 673 00:37:06,347 --> 00:37:08,882 Now you could find some helium-3 on the moon, 674 00:37:08,883 --> 00:37:12,252 But the major supplies of helium-3 in our solar system 675 00:37:12,253 --> 00:37:14,888 Are located in the atmospheres of the giant planets. 676 00:37:14,889 --> 00:37:16,991 I call the gas giants 677 00:37:16,992 --> 00:37:18,794 "The persian gulf of the solar system" 678 00:37:18,795 --> 00:37:22,529 Because they are the location of its primary energy resources 679 00:37:22,530 --> 00:37:25,600 Outside of the sun. 680 00:37:25,601 --> 00:37:26,766 The gas giants provide 681 00:37:26,767 --> 00:37:30,904 A near inexhaustible supply of helium-3. 682 00:37:30,905 --> 00:37:34,475 But how could we extract it? 683 00:37:34,476 --> 00:37:36,277 Jupiter has the most. 684 00:37:36,278 --> 00:37:39,582 But the planet's immense gravity and dangerous radiation belts 685 00:37:39,583 --> 00:37:44,250 Make it a no-Go for mining. 686 00:37:44,251 --> 00:37:48,755 Neptune and uranus are way too far away to be practical. 687 00:37:48,756 --> 00:37:52,393 That leaves saturn with relatively low gravity 688 00:37:52,394 --> 00:37:54,362 For such a big planet. 689 00:37:54,363 --> 00:38:00,134 And far lower levels of deadly radiation than around jupiter. 690 00:38:00,135 --> 00:38:03,372 If we're gonna have a future human economy based on 691 00:38:03,373 --> 00:38:05,973 Using controlled fusion and helium-3, 692 00:38:05,974 --> 00:38:08,676 Saturn is the destination of choice. 693 00:38:08,677 --> 00:38:13,047 Futurists envision winged drones flying through 694 00:38:13,048 --> 00:38:19,321 The upper atmosphere of saturn, scooping up gases. 695 00:38:19,322 --> 00:38:23,091 But where to process this super fuel? 696 00:38:23,092 --> 00:38:28,231 The ideal base of operations would clearly be titan. 697 00:38:29,432 --> 00:38:31,900 With gravity as gentle as our moons 698 00:38:31,901 --> 00:38:34,002 And a thick earth-Like atmosphere, 699 00:38:34,003 --> 00:38:39,341 Titan is surprisingly suitable for a human outpost. 700 00:38:39,342 --> 00:38:41,710 We could have huge dome settlements on titan. 701 00:38:41,711 --> 00:38:44,147 They would not have to be strong enough to hold pressure. 702 00:38:44,148 --> 00:38:46,350 They could just be thin, inflatable membranes. 703 00:38:46,351 --> 00:38:49,319 You could have dome cities like you see in science fiction 704 00:38:49,320 --> 00:38:52,654 Which are really not possible in places like the moon. 705 00:38:52,655 --> 00:38:55,491 Walking out onto the surface of titan 706 00:38:55,492 --> 00:38:58,960 Would be much easier than on the moon or on mars. 707 00:38:58,961 --> 00:39:00,897 The pressure on titan is kind of nice. 708 00:39:00,898 --> 00:39:03,799 It's 1 1/2 times earth pressure. 709 00:39:03,800 --> 00:39:05,801 You would need a source of oxygen. 710 00:39:05,802 --> 00:39:07,703 And you need a very warm coat. 711 00:39:07,704 --> 00:39:11,574 But it wouldn't feel as cold as you might think 712 00:39:11,575 --> 00:39:17,112 Because the atmosphere is calm and there's not strong wind. 713 00:39:17,113 --> 00:39:19,082 I think a coat like you might wear in antarctica 714 00:39:19,083 --> 00:39:20,516 Might be adequate. 715 00:39:20,517 --> 00:39:23,252 So you can imagine somebody stepping out of the spaceship, 716 00:39:23,253 --> 00:39:26,489 Having a parka on, a mask, like a s.C.U.B.A. Mask 717 00:39:26,490 --> 00:39:28,190 To provide oxygen, 718 00:39:28,191 --> 00:39:30,292 And literally walking out on the surface. 719 00:39:30,293 --> 00:39:33,830 Titan's low gravity and dense atmosphere 720 00:39:33,831 --> 00:39:38,101 Could even send us soaring from place to place. 721 00:39:38,102 --> 00:39:39,603 Let's say you had, you know, 722 00:39:39,604 --> 00:39:41,337 It's a little bit of a wing on your arm, 723 00:39:41,338 --> 00:39:42,806 And you started to flap your arms. 724 00:39:42,807 --> 00:39:44,843 Remember it's almost like you're you're on the moon, 725 00:39:44,844 --> 00:39:46,409 But with a thick atmosphere. 726 00:39:46,410 --> 00:39:48,145 And you'd really be able to lift yourself 727 00:39:48,146 --> 00:39:50,381 Off the surface, maybe fly, just a little bit. 728 00:39:55,320 --> 00:39:57,621 When the helium-3 trade route has opened 729 00:39:57,622 --> 00:40:00,790 And the earth becomes a fusion economy, 730 00:40:00,791 --> 00:40:02,592 A new generation of rockets 731 00:40:02,593 --> 00:40:05,728 Will open up interplanetary travel to everyone, 732 00:40:05,729 --> 00:40:09,868 Taking humans to mars and jupiter, 733 00:40:09,869 --> 00:40:12,771 Not in years, but in months. 734 00:40:14,740 --> 00:40:18,909 And helium-3 might even power adventure tourism 735 00:40:18,910 --> 00:40:21,245 To saturn itself. 736 00:40:21,246 --> 00:40:22,679 You can imagine in a hundred years 737 00:40:22,680 --> 00:40:24,715 When space travel is easy and there will 738 00:40:24,741 --> 00:40:26,551 Be hotels orbiting the moon and mars 739 00:40:26,552 --> 00:40:28,652 And everything, what would be the one? 740 00:40:28,653 --> 00:40:31,455 What would be the place, right, to go? 741 00:40:31,456 --> 00:40:32,891 It would be saturn. 742 00:40:37,195 --> 00:40:40,665 I would hope one day that there is such a thing 743 00:40:40,666 --> 00:40:44,969 As space tourism and people can visit places like enceladus. 744 00:40:44,970 --> 00:40:46,105 It should be called 745 00:40:46,106 --> 00:40:47,904 The enceladus interplanetary geyser park 746 00:40:47,905 --> 00:40:51,009 Because it would be a phenomenal place to just go visit. 747 00:40:54,579 --> 00:40:57,147 Standing on enceladus would be an amazing sight. 748 00:40:57,148 --> 00:40:59,850 All of this frost condensing back out on the surface 749 00:40:59,851 --> 00:41:02,020 Makes an incredibly brilliant white. 750 00:41:02,021 --> 00:41:03,883 It's got some of the best powder snow for 751 00:41:03,909 --> 00:41:05,549 Skiing anywhere in the solar system. 752 00:41:09,928 --> 00:41:11,929 You could get close enough to actually 753 00:41:11,930 --> 00:41:14,400 See the individual rings, 754 00:41:14,401 --> 00:41:17,136 Maybe even see the little moons in the gaps sculpting 755 00:41:17,137 --> 00:41:19,070 And pulling and pushing and prodding, 756 00:41:19,071 --> 00:41:22,641 Shepherding those ring particles around. 757 00:41:22,642 --> 00:41:24,277 You could go back over and over again, 758 00:41:24,278 --> 00:41:27,647 And it would always be alien and exotic and exciting. 759 00:41:31,383 --> 00:41:35,853 From a cold, dead jewel in our telescopes 760 00:41:35,854 --> 00:41:40,092 To a place alive with magic and mayhem 761 00:41:40,093 --> 00:41:43,661 Saturn and its worlds have come alive 762 00:41:43,662 --> 00:41:47,099 And may harbor life itself. 763 00:41:47,100 --> 00:41:51,770 Someday soon, this planet could remake our universe, 764 00:41:51,771 --> 00:41:56,075 And nothing will ever be the same.