1 00:00:26,633 --> 00:00:28,033 MAN (over radio): Systems this is prop. 2 00:00:28,166 --> 00:00:30,333 I read you 500, do you read me? 3 00:00:30,467 --> 00:00:33,867 TYSON: These people are watching their life's work come to an end. 4 00:00:34,000 --> 00:00:35,367 MAN (over radio): The team is on its way to point. 5 00:00:35,500 --> 00:00:37,033 TYSON: On another world. 6 00:00:37,166 --> 00:00:40,533 MAN (over radio): All right. Roger that. 7 00:00:47,667 --> 00:00:52,166 TYSON: They were all young when they sent her on her way. 8 00:00:54,066 --> 00:00:59,367 These men and women have been traveling vicariously with her for more than two decades. 9 00:01:06,834 --> 00:01:12,400 And now, her work is done, so she must die. 10 00:01:16,633 --> 00:01:19,433 But before she takes the fatal plunge, 11 00:01:19,567 --> 00:01:24,400 they've given her one final, epic challenge. 12 00:01:35,066 --> 00:01:40,500 (theme music plays) 13 00:02:00,767 --> 00:02:07,233 ♪ ♪ 14 00:02:27,266 --> 00:02:33,200 ♪ ♪ 15 00:02:46,934 --> 00:02:49,934 TYSON: Gravity has a big bag of tricks, 16 00:02:50,066 --> 00:02:53,700 none lovelier than the ring systems of worlds. 17 00:02:53,834 --> 00:02:58,333 Our own solar system, alone, has four ringed planets. 18 00:03:02,233 --> 00:03:07,133 This one, with the romantic name J-1407B, 19 00:03:07,266 --> 00:03:11,333 is the first we've found circling another sun. 20 00:03:11,467 --> 00:03:14,934 Why haven't we found more ringed planets in our galaxy? 21 00:03:18,967 --> 00:03:22,700 Is it that the rings are so unusual, 22 00:03:22,834 --> 00:03:25,667 or are the methods we use to find exoplanets not very 23 00:03:25,800 --> 00:03:29,900 good at seeing the ring systems that may surround them? 24 00:03:30,900 --> 00:03:34,166 J-1407B's ring system is so vast, 25 00:03:34,300 --> 00:03:37,333 that it eclipsed its star for days. 26 00:03:37,967 --> 00:03:42,400 These rings extend across an astonishing 112 million miles. 27 00:03:43,066 --> 00:03:47,667 They would more than fill the distance between Earth and the sun. 28 00:03:49,100 --> 00:03:53,100 But as enormous as they are, they're shockingly thin. 29 00:03:53,233 --> 00:03:57,767 If the ring system of J-1407B were the size of a dinner plate, 30 00:03:57,900 --> 00:04:00,800 it would have to be 100 times thinner, 31 00:04:00,934 --> 00:04:03,633 as thin as a human hair. 32 00:04:06,433 --> 00:04:09,433 This surprising contrast between the immense territory 33 00:04:09,567 --> 00:04:11,834 of a ring system, and its thinness, 34 00:04:11,967 --> 00:04:15,000 is just as striking in our own solar system. 35 00:04:16,000 --> 00:04:19,266 The outermost ring of Neptune is so dainty, 36 00:04:19,400 --> 00:04:22,200 that it was first thought to be the fragments of a ring. 37 00:04:22,333 --> 00:04:25,400 Not a ring, but a collection of arcs. 38 00:04:25,533 --> 00:04:28,500 That was, until NASA's Voyager 2 spacecraft revealed 39 00:04:28,633 --> 00:04:31,734 that the so-called arcs were clumps, 40 00:04:31,867 --> 00:04:34,967 the thicker parts of a fainter, complete ring. 41 00:04:39,533 --> 00:04:42,467 It's funny that the weirdest planet in the solar system has 42 00:04:42,600 --> 00:04:45,200 attracted the least attention. 43 00:04:45,333 --> 00:04:48,100 Voyager 2 is the only spacecraft that has ever been 44 00:04:48,233 --> 00:04:51,333 sent on a reconnaissance mission to Uranus, 45 00:04:51,467 --> 00:04:55,033 one of the two ice giant planets that circle the sun. 46 00:04:56,667 --> 00:04:58,934 During its 20-year-long summers, 47 00:04:59,066 --> 00:05:01,967 the sun never sets on Uranus. 48 00:05:02,100 --> 00:05:04,266 The winters are equally as long, 49 00:05:04,400 --> 00:05:07,967 20 years of unbroken night. 50 00:05:11,233 --> 00:05:15,200 Unlike its fellow gas planets, Uranus is cold-hearted. 51 00:05:15,333 --> 00:05:18,433 It doesn't generate any internal heat. 52 00:05:26,100 --> 00:05:29,734 Uranus is one crazy world. 53 00:05:29,867 --> 00:05:32,600 The outer edge of Uranus's atmosphere is so hot, 54 00:05:32,734 --> 00:05:36,967 it's hotter than 500 degrees Fahrenheit. 55 00:05:40,133 --> 00:05:43,734 But Uranus also has the coldest clouds in the solar system, 56 00:05:43,867 --> 00:05:47,233 I'm talking nearly 400 degrees below zero. 57 00:05:54,367 --> 00:05:57,400 What kind of ocean is this? 58 00:05:57,533 --> 00:05:59,400 Is it made of ammonia? 59 00:05:59,533 --> 00:06:02,033 Water? 60 00:06:02,166 --> 00:06:07,033 Some scientists think it may be an ocean of liquid diamonds. 61 00:06:07,166 --> 00:06:11,667 Note to space agencies, might be worth another visit. 62 00:06:17,300 --> 00:06:21,000 Then there's that thing about it being sideways. 63 00:06:21,133 --> 00:06:26,667 Uranus revolves around the sun at a roughly 90 degree angle to its own orbital plane. 64 00:06:26,800 --> 00:06:30,934 What could have happened to Uranus that it got knocked on its ass? 65 00:06:32,166 --> 00:06:36,734 Our best guess is that it went something like this. 66 00:06:42,200 --> 00:06:45,600 Uranus was in a terrible accident. 67 00:06:46,166 --> 00:06:49,533 (crashing) 68 00:06:49,867 --> 00:06:52,800 (crashing) 69 00:06:52,934 --> 00:06:59,066 After the second blow, the rotational axis of Uranus tipped 98 degrees. 70 00:07:02,667 --> 00:07:04,800 There's another world in our solar system that we don't 71 00:07:04,934 --> 00:07:08,166 think of as having a ring. 72 00:07:08,300 --> 00:07:11,266 The rings of Jupiter were so dim that no ground-based 73 00:07:11,400 --> 00:07:13,967 telescope ever saw them. 74 00:07:14,100 --> 00:07:17,867 They were discovered when Voyager 1 came flying by. 75 00:07:23,300 --> 00:07:27,367 Our Saturn is graced by the loveliest, largest, 76 00:07:27,500 --> 00:07:31,934 and brightest ring system of any around our sun. 77 00:07:32,400 --> 00:07:35,600 It's the most distant planet that can be seen with the naked eye, 78 00:07:35,734 --> 00:07:39,066 and it made quite an impression on our ancestors. 79 00:07:48,200 --> 00:07:52,233 When I think of the Babylonians of 3,500 years ago looking up 80 00:07:52,367 --> 00:07:54,734 at the planets and stars, 81 00:07:54,867 --> 00:07:57,467 I wonder how unlikely it would have seemed that one of their 82 00:07:57,600 --> 00:08:01,066 species would actually send an emissary to that 83 00:08:01,200 --> 00:08:04,333 distant point of light. 84 00:08:12,800 --> 00:08:17,300 We are in the Deep Space Network room at NASA's Jet Propulsion Laboratory. 85 00:08:18,133 --> 00:08:23,400 In this place, the most ambitious voyages of discovery are directed and monitored. 86 00:08:24,834 --> 00:08:27,200 Why are these people so emotional? 87 00:08:27,333 --> 00:08:29,533 They have committed their professional lives to 88 00:08:29,667 --> 00:08:33,800 a collaboration with this robot. 89 00:08:40,800 --> 00:08:44,066 And now that partnership of decades is about to end 90 00:08:44,200 --> 00:08:47,333 in a most violent way. 91 00:08:47,467 --> 00:08:49,967 The pathway from our Earthbound helplessness to 92 00:08:50,100 --> 00:08:54,333 our presence in Saturn's skies is about to unfold. 93 00:09:02,600 --> 00:09:06,567 TYSON: What is that shimmering, unsteady thing we're looking at? 94 00:09:06,700 --> 00:09:11,233 That's what Galileo Galilei asked himself in 1610 when he 95 00:09:11,367 --> 00:09:14,600 became the first human to see Saturn as more than 96 00:09:14,734 --> 00:09:17,967 just a point of light. 97 00:09:20,734 --> 00:09:23,433 So, this is the telescope that made the modern 98 00:09:23,567 --> 00:09:26,433 scientific revolution possible. 99 00:09:26,567 --> 00:09:29,633 You know, you really started something. 100 00:09:29,767 --> 00:09:33,734 You looked through that thing and found the cosmos. 101 00:09:34,767 --> 00:09:38,133 That's not to say you didn't make your share of mistakes. 102 00:09:38,266 --> 00:09:41,000 You guessed wrong at what you thought you saw, 103 00:09:41,133 --> 00:09:43,667 believing that Saturn sported two symmetrical moons 104 00:09:43,800 --> 00:09:46,300 on either side of it. 105 00:09:46,433 --> 00:09:49,266 Two years later, when you took a second look, 106 00:09:49,400 --> 00:09:53,734 you were shocked to find that your "moons" had vanished. 107 00:09:53,867 --> 00:09:56,800 This was because both worlds, Earth and Saturn, 108 00:09:56,934 --> 00:10:01,033 were in motion, and the two worlds had changed in position to each other. 109 00:10:01,166 --> 00:10:04,700 You were now looking at Saturn's rings, edge-on. 110 00:10:05,400 --> 00:10:08,934 The Saturn ring system is 175,000 miles across, 111 00:10:09,066 --> 00:10:13,300 but on average only a few hundred feet thick. 112 00:10:13,433 --> 00:10:17,767 They were too thin for your fledgling telescope to see. 113 00:10:21,266 --> 00:10:24,934 But two years after that, you took a third look. 114 00:10:25,066 --> 00:10:29,166 Now, you thought that the planet had arms. 115 00:10:44,300 --> 00:10:50,700 ♪ ♪ 116 00:10:55,133 --> 00:10:57,800 40 years passed, until a Dutch astronomer named 117 00:10:57,934 --> 00:11:00,667 Christiaan Huygens took another look at Saturn with 118 00:11:00,800 --> 00:11:04,166 his own greatly improved telescope. 119 00:11:17,767 --> 00:11:20,400 Huygens was the first to know that worlds could 120 00:11:20,533 --> 00:11:24,667 be circled by rings, and Saturn was one of them. 121 00:11:24,800 --> 00:11:27,400 He also discovered Saturn's largest moon, 122 00:11:27,533 --> 00:11:30,934 which would later be known as Titan. 123 00:11:31,600 --> 00:11:34,233 When it finally came time for us to visit that world, 124 00:11:34,367 --> 00:11:38,300 our spacecraft bore Huygens's name. 125 00:11:39,867 --> 00:11:42,500 In science, there are the Galileos, the Newtons, 126 00:11:42,633 --> 00:11:44,567 the Darwins, the Einsteins. 127 00:11:44,700 --> 00:11:47,900 And then there's another kind of great scientist. 128 00:11:48,033 --> 00:11:50,633 Not the kind that paints a whole new picture of nature, 129 00:11:50,767 --> 00:11:53,233 but, like Christiaan Huygens, 130 00:11:53,367 --> 00:11:55,567 someone who has much to contribute, 131 00:11:55,700 --> 00:11:58,900 filling in a blank or two on that vast canvas. 132 00:11:59,033 --> 00:12:03,266 Such a scientist was Giovanni Domenico Cassini. 133 00:12:05,834 --> 00:12:09,734 He was born early in the 17th century in the town of Perinaldo, 134 00:12:09,867 --> 00:12:12,600 in what is now Italy. 135 00:12:12,734 --> 00:12:15,300 Cassini didn't start out as a scientist. 136 00:12:15,433 --> 00:12:19,734 He began his career as a pseudo-scientist, an astrologer. 137 00:12:20,400 --> 00:12:23,533 Astrology is a collection of ideas based on the notion that 138 00:12:23,667 --> 00:12:26,967 worlds have certain human personality traits, 139 00:12:27,100 --> 00:12:29,700 and that the influence of these distant worlds, 140 00:12:29,834 --> 00:12:32,400 depending on which are rising and falling at the time 141 00:12:32,533 --> 00:12:35,600 of your birth, will determine who you are and 142 00:12:35,734 --> 00:12:38,100 what your fate will be. 143 00:12:38,233 --> 00:12:39,967 It's another form of prejudice, 144 00:12:40,100 --> 00:12:42,166 making unfounded assumptions about who a person 145 00:12:42,300 --> 00:12:45,767 is without bothering to get to know them. 146 00:12:46,734 --> 00:12:50,133 Astronomy and astrology used to be the same thing, 147 00:12:50,266 --> 00:12:52,266 until there was a great awakening to our 148 00:12:52,400 --> 00:12:56,100 actual circumstances in the cosmos. 149 00:12:56,800 --> 00:12:59,667 In 1543, Nicolaus Copernicus, 150 00:12:59,800 --> 00:13:02,200 a Polish cleric demonstrated that, 151 00:13:02,333 --> 00:13:04,033 contrary to popular belief, 152 00:13:04,166 --> 00:13:07,266 we were not the center of the universe... 153 00:13:07,400 --> 00:13:10,900 the Earth and the other planets travelled around the sun. 154 00:13:11,033 --> 00:13:14,233 Demoting the Earth from the center of the universe 155 00:13:14,367 --> 00:13:17,800 was a severe blow to human self-esteem. 156 00:13:17,934 --> 00:13:19,567 More than a century later, 157 00:13:19,700 --> 00:13:22,033 some people still hadn't gotten over it, 158 00:13:22,166 --> 00:13:25,000 and Giovanni Cassini was one of them. 159 00:13:25,133 --> 00:13:28,333 Cassini accepted a terrific job offer, 160 00:13:28,467 --> 00:13:30,633 an appointment by Louis the XIV, 161 00:13:30,767 --> 00:13:33,834 the legendary sun King of France, 162 00:13:33,967 --> 00:13:39,166 Louis believed himself to be an absolute ruler whose dominion was God's will. 163 00:13:39,300 --> 00:13:42,100 But he was also the first monarch in Europe to recognize 164 00:13:42,233 --> 00:13:44,400 the great power of science. 165 00:13:44,533 --> 00:13:48,600 He knew it was vital to national security. 166 00:13:49,967 --> 00:13:53,066 Louis the XIV was inventing the first modern, 167 00:13:53,200 --> 00:13:56,333 governmental, scientific research institute, 168 00:13:56,467 --> 00:13:59,633 The Paris Observatory. 169 00:14:08,700 --> 00:14:11,266 Cassini told the absolute ruler that he would not be 170 00:14:11,400 --> 00:14:15,633 staying long in Paris, a year or two, at most. 171 00:14:17,900 --> 00:14:21,800 But when the King placed his new observatory at Cassini's disposal, 172 00:14:21,934 --> 00:14:26,200 he lost all interest in returning home to Italy ever again. 173 00:14:26,333 --> 00:14:29,433 For the next 125 years, 174 00:14:29,567 --> 00:14:33,900 the Paris Observatory would be led by a Cassini. 175 00:14:36,667 --> 00:14:39,700 Cassini rewarded his patron with a map of the Moon 176 00:14:39,834 --> 00:14:43,233 that remained cutting-edge for a century. 177 00:14:43,367 --> 00:14:46,200 King Louis financed a research expedition to South America 178 00:14:46,333 --> 00:14:49,166 to obtain more accurate measurements of longitude, 179 00:14:49,300 --> 00:14:52,800 intel of enormous value to the captains of his far-flung 180 00:14:52,934 --> 00:14:56,533 fleet and to astronomers. 181 00:14:57,300 --> 00:15:00,100 Cassini took all these data and became the first person 182 00:15:00,233 --> 00:15:03,133 to calculate the scale of the Copernican solar system 183 00:15:03,266 --> 00:15:05,967 that he had once rejected. 184 00:15:06,100 --> 00:15:08,467 With his increasingly powerful telescopes, 185 00:15:08,600 --> 00:15:11,300 he discovered the length of a day on Jupiter 186 00:15:11,433 --> 00:15:15,133 and the bands and spots on that planet's surface. 187 00:15:15,266 --> 00:15:18,767 Cassini discovered Jupiter's Great Red Spot independently 188 00:15:18,900 --> 00:15:21,700 of Robert Hooke in England, and to this day, 189 00:15:21,834 --> 00:15:24,433 they share the credit. 190 00:15:24,567 --> 00:15:28,533 Cassini went on to determine the length of the day on Mars. 191 00:15:30,233 --> 00:15:34,100 He was only off by three minutes. 192 00:15:34,233 --> 00:15:37,066 When he returned to his observations of Jupiter, 193 00:15:37,200 --> 00:15:39,967 he was stumped by the contradictions in them. 194 00:15:40,100 --> 00:15:44,000 The eclipses by Jupiter's moons did not begin when they were supposed to, 195 00:15:44,133 --> 00:15:47,800 they varied from observation to observation. 196 00:15:47,934 --> 00:15:51,200 Could it be that it was due to changes in the distance 197 00:15:51,333 --> 00:15:55,633 of the Earth from Jupiter, as the two worlds moved through the solar system? 198 00:15:56,533 --> 00:15:59,533 If that were true, then light could not travel at 199 00:15:59,667 --> 00:16:04,033 an infinite speed because it was taking longer to reach Earth. 200 00:16:04,166 --> 00:16:07,667 Was the speed of light finite? 201 00:16:07,800 --> 00:16:12,033 This idea was just too crazy for Cassini, too revolutionary. 202 00:16:12,166 --> 00:16:14,500 He rejected it out of hand. 203 00:16:14,633 --> 00:16:17,133 If he had followed the evidence wherever it led, 204 00:16:17,266 --> 00:16:19,633 he would have given us the yardstick for the cosmos that 205 00:16:19,767 --> 00:16:23,233 we still use 350 years later. 206 00:16:23,367 --> 00:16:26,066 But Cassini, ever the conservative, 207 00:16:26,200 --> 00:16:30,066 dismissed the idea as being just too wacky. 208 00:16:31,667 --> 00:16:33,734 Several years later, a Danish astronomer, 209 00:16:33,867 --> 00:16:38,500 Ole Romer, became Cassini's assistant at the Paris Observatory. 210 00:16:38,633 --> 00:16:41,967 Romer made his own observations of the eclipses 211 00:16:42,100 --> 00:16:45,400 of some of Jupiter's moons and found the same discrepancies 212 00:16:45,533 --> 00:16:48,533 in the data that Cassini had dismissed. 213 00:16:48,667 --> 00:16:51,700 But Romer recognized them for what they were, 214 00:16:51,834 --> 00:16:55,233 Pieces of evidence for the finite speed of light. 215 00:16:57,433 --> 00:16:59,800 There was a time, however, when Cassini's faithfulness 216 00:16:59,934 --> 00:17:03,300 to the data was so extreme, that he was willing to risk the 217 00:17:03,433 --> 00:17:06,100 displeasure of King Louis. 218 00:17:06,233 --> 00:17:10,500 The monarch asked Cassini to calculate the exact area of his realm. 219 00:17:10,633 --> 00:17:13,867 No one had ever attempted to make an accurate map, 220 00:17:14,000 --> 00:17:16,533 much less a topographical one that would feature all 221 00:17:16,667 --> 00:17:19,033 the mountains and rivers and valleys of France, 222 00:17:19,166 --> 00:17:21,533 or of any other country for that matter. 223 00:17:21,667 --> 00:17:25,100 Cassini rose to the task, but discovered results that 224 00:17:25,233 --> 00:17:28,567 could not possibly please the King. 225 00:17:34,233 --> 00:17:35,667 (sighs) 226 00:17:38,900 --> 00:17:40,867 Cassini told the King, 227 00:17:41,000 --> 00:17:44,400 "I have some rather disappointing news for you, Your Highness. 228 00:17:46,100 --> 00:17:51,066 We all thought that France was a whole lot bigger than our studies, revealed. 229 00:17:51,734 --> 00:17:56,800 I'm afraid, Your Majesty, your kingdom is much smaller than heretofore thought." 230 00:17:57,900 --> 00:17:59,700 (grunts) 231 00:17:59,834 --> 00:18:01,300 (gasps) 232 00:18:01,433 --> 00:18:03,633 TYSON: The King surprised everyone with his great good humor, 233 00:18:03,767 --> 00:18:07,100 saying, "Why, Cassini, you've robbed me of more land 234 00:18:07,233 --> 00:18:10,700 than all the armies of my enemies combined." 235 00:18:11,300 --> 00:18:15,633 (laughing) 236 00:18:16,567 --> 00:18:19,700 TYSON: And then, there is his work on Saturn. 237 00:18:23,166 --> 00:18:27,567 He was the first person to know what the rings of Saturn really were. 238 00:18:27,700 --> 00:18:30,667 He proposed that they were not solid, 239 00:18:30,800 --> 00:18:33,400 but instead composed of countless satellites orbiting 240 00:18:33,533 --> 00:18:36,367 the planet, and he observed that there was 241 00:18:36,500 --> 00:18:39,767 a division between the rings. 242 00:18:40,266 --> 00:18:44,533 Cassini filled in some of the big blanks in our understanding of Saturn, 243 00:18:44,667 --> 00:18:49,133 but how could we possibly ever get there? 244 00:18:51,266 --> 00:18:54,266 Accomplishing that mythic quest was left to one whose 245 00:18:54,400 --> 00:18:57,734 tragic life would have been completely forgotten, 246 00:18:57,867 --> 00:19:01,100 if not for what you are about to see. 247 00:19:12,300 --> 00:19:15,834 TYSON: Weighing in at more than 12,000 pounds at launch, 248 00:19:15,967 --> 00:19:19,767 NASA's Cassini spacecraft is the size of a bus. 249 00:19:19,900 --> 00:19:24,200 That figure included 70 pounds of plutonium 238 fuel, 250 00:19:24,333 --> 00:19:27,767 enough to last her for more than 20 years. 251 00:19:28,333 --> 00:19:31,734 But that's not what powered her mythic odyssey. 252 00:19:31,867 --> 00:19:36,567 She rode gravity's rainbow all the way to the outer-solar system. 253 00:19:41,333 --> 00:19:44,333 The lineage of the greatest of human achievements stretches 254 00:19:44,467 --> 00:19:47,233 further back than we might assume. 255 00:19:47,367 --> 00:19:51,633 Some of their roots are buried deep inside the tomb of lost hope. 256 00:19:53,033 --> 00:19:56,000 But somehow, dreams rise. 257 00:19:56,133 --> 00:19:59,300 The epic missions of the first golden age of space exploration, 258 00:19:59,433 --> 00:20:00,867 and likely the next, 259 00:20:01,000 --> 00:20:03,867 were made possible by a man whose two names, 260 00:20:04,000 --> 00:20:07,667 one real, one fake, are equally forgotten. 261 00:20:12,934 --> 00:20:14,700 (knocking) 262 00:20:14,834 --> 00:20:15,667 (grunts) 263 00:20:15,800 --> 00:20:17,200 (knocking) 264 00:20:17,333 --> 00:20:21,300 Alexander Shargei's early years are not well-documented, 265 00:20:21,433 --> 00:20:24,867 but it is believed that his mother, a political activist, 266 00:20:25,000 --> 00:20:29,100 was taken from him when he was only five years old. 267 00:20:34,867 --> 00:20:39,533 He took refuge in his father's physics and mathematics textbooks. 268 00:20:39,667 --> 00:20:42,700 But by the time Alexander was 13, 269 00:20:42,834 --> 00:20:45,567 the boy had lost his father, too. 270 00:20:45,700 --> 00:20:49,066 He lived with his grandmother, and despite great hardship, 271 00:20:49,200 --> 00:20:52,333 he managed to be accepted at the most prestigious high school, 272 00:20:52,467 --> 00:20:54,567 and afterwards gained admission to the 273 00:20:54,700 --> 00:20:57,433 best engineering institute in the Ukraine. 274 00:20:57,567 --> 00:21:00,867 But only two months after he arrived there, in 1914, 275 00:21:01,000 --> 00:21:03,233 he was drafted into the Czar's army to fight 276 00:21:03,367 --> 00:21:05,100 in the First World War. 277 00:21:05,233 --> 00:21:10,967 (explosions, gunfire) 278 00:21:16,266 --> 00:21:22,767 (explosions, gunfire) 279 00:21:25,967 --> 00:21:28,233 In the hell of war at the front, 280 00:21:28,367 --> 00:21:31,400 Alexander Shargei conceived a scientific strategy 281 00:21:31,533 --> 00:21:35,166 for exploring the Moon, not intended as fiction, 282 00:21:35,300 --> 00:21:38,033 but as blueprint. 283 00:21:41,800 --> 00:21:43,500 (engine blast) 284 00:21:45,200 --> 00:21:48,066 (engine blast) 285 00:21:57,734 --> 00:21:59,967 (engine blast) 286 00:22:01,400 --> 00:22:04,433 But Shargei's hell didn't end with the war. 287 00:22:04,567 --> 00:22:07,467 Now, Shargei was forced to navigate the treacherous 288 00:22:07,600 --> 00:22:10,700 political mine fields of revolutionary Russia. 289 00:22:10,834 --> 00:22:13,934 He was much better at figuring out how to get to the Moon. 290 00:22:14,500 --> 00:22:16,934 Former officers in the Czar's army and those, 291 00:22:17,066 --> 00:22:18,967 such as Shargei, who were forced to join 292 00:22:19,100 --> 00:22:21,133 the counter-revolutionary White Army, 293 00:22:21,266 --> 00:22:24,266 were assumed to be "enemies of the people." 294 00:22:27,800 --> 00:22:30,633 (shouting in Russian) 295 00:22:30,767 --> 00:22:33,800 TYSON: Shargei could find no peace in the Soviet Union, 296 00:22:33,934 --> 00:22:37,934 so in desperation he tried to escape to Poland. 297 00:22:44,133 --> 00:22:47,266 Shargei, weakened by illness, was stopped by guards 298 00:22:47,400 --> 00:22:51,200 and turned back from the border. 299 00:23:07,934 --> 00:23:10,934 TYSON: These were dangerous times, 300 00:23:11,066 --> 00:23:15,033 and there was no telling what would get you into serious trouble. 301 00:23:20,500 --> 00:23:23,734 No one knows where Shargei spent the next three years. 302 00:23:23,867 --> 00:23:26,200 He simply vanished. 303 00:23:26,333 --> 00:23:30,967 When at last he emerged, Alexander Shargei was no more. 304 00:23:31,767 --> 00:23:34,233 In his desperation to be left alone, 305 00:23:34,367 --> 00:23:36,934 he took the name of a dead man. 306 00:23:37,066 --> 00:23:40,333 He was now Yuri Kondratyuk. 307 00:23:41,900 --> 00:23:43,900 He finally published the book he had been dreaming 308 00:23:44,033 --> 00:23:47,133 about since his time in the trenches. 309 00:23:47,266 --> 00:23:49,266 No publisher was interested, 310 00:23:49,400 --> 00:23:52,367 so he printed it at his own expense. 311 00:23:53,600 --> 00:23:58,867 It was Kondratyuk's letter to a future no one else could see. 312 00:23:59,567 --> 00:24:03,633 He wrote it "To Whoever Will Read This Paper in Order to 313 00:24:03,767 --> 00:24:07,700 Build an Interplanetary Rocket." 314 00:24:09,834 --> 00:24:11,367 In the late 1920s, 315 00:24:11,500 --> 00:24:15,467 Kondratyuk was enlisted to design a grain elevator. 316 00:24:15,600 --> 00:24:18,133 The Soviet Union was going through a metal shortage, 317 00:24:18,266 --> 00:24:21,567 so Kondratyuk's challenge was to build the largest grain 318 00:24:21,700 --> 00:24:25,834 elevator possible without using more than a single nail. 319 00:24:27,266 --> 00:24:31,266 It ended up being so big, they named it "the Mastodon." 320 00:24:34,533 --> 00:24:38,333 Such was the nightmare logic of Stalin's Soviet Union. 321 00:24:38,467 --> 00:24:41,033 You could do the heroic in service to the state, 322 00:24:41,166 --> 00:24:44,000 successfully execute the seemingly impossible order 323 00:24:44,133 --> 00:24:47,467 to build a colossus with but a single nail. 324 00:24:47,600 --> 00:24:49,367 And when it was done, 325 00:24:49,500 --> 00:24:52,467 you could be imprisoned for sabotage. 326 00:24:52,600 --> 00:24:56,200 Who but an enemy of the state would do such a reckless thing 327 00:24:56,333 --> 00:25:01,000 as building a colossal grain elevator with only a single nail. 328 00:25:02,100 --> 00:25:04,567 It made no difference to Kondratyuk's fate that the 329 00:25:04,700 --> 00:25:07,567 grain elevator functioned for another 60 years, 330 00:25:07,700 --> 00:25:10,967 until it burned down. 331 00:25:11,467 --> 00:25:15,333 Kondratyuk was sentenced to three years in a special prison camp, 332 00:25:15,467 --> 00:25:18,000 something new, called a sharashka, 333 00:25:18,133 --> 00:25:23,266 where scientists and engineers slaved away on the nation's most ambitious projects. 334 00:25:24,266 --> 00:25:27,967 Kondratyuk threw himself into a wind power project, 335 00:25:28,100 --> 00:25:33,000 but still he dreamed of exploring the solar system. 336 00:25:35,934 --> 00:25:39,100 Soon after that, he met Sergei Korolev, 337 00:25:39,233 --> 00:25:43,700 who also dreamed of leaving Earth to explore the cosmos. 338 00:25:43,834 --> 00:25:48,600 Korolev would later become the father of the Soviet rocket program. 339 00:25:49,467 --> 00:25:52,333 Korolev wanted to enlist Kondratyuk in his fledgling 340 00:25:52,467 --> 00:25:56,066 rocket program, but Kondratyuk was so terrified 341 00:25:56,200 --> 00:25:59,734 that any change in his status might result in closer scrutiny by 342 00:25:59,867 --> 00:26:03,467 the secret police, he declined. 343 00:26:03,600 --> 00:26:08,033 If the authorities discovered that Kondratyuk was really Shargei, 344 00:26:08,166 --> 00:26:11,867 there was no telling what they would do to him. 345 00:26:13,000 --> 00:26:14,967 When Germany attacked Russia, 346 00:26:15,100 --> 00:26:18,433 Kondratyuk volunteered for armed service at the front, 347 00:26:18,567 --> 00:26:21,333 where he led a communications outfit. 348 00:26:21,467 --> 00:26:25,033 His precise fate is unknown, but he is believed to have 349 00:26:25,166 --> 00:26:29,633 died in battle on a February night in 1942. 350 00:26:31,033 --> 00:26:36,834 Alexander Shargei, aka Yuri Kondratyuk, was only 44. 351 00:26:37,600 --> 00:26:40,133 That was the end of his story, 352 00:26:40,266 --> 00:26:43,266 but not his dream. 353 00:26:43,400 --> 00:26:46,433 In the early days of the Apollo program, 354 00:26:46,567 --> 00:26:49,734 the scientists and engineers struggled to figure out how 355 00:26:49,867 --> 00:26:54,500 a rocket could leave the Earth and land directly on the Moon. 356 00:26:54,633 --> 00:26:56,633 They were stymied. 357 00:26:56,767 --> 00:26:58,867 They couldn't figure it out. 358 00:26:59,000 --> 00:27:02,533 You need a big powerful rocket to reach the Moon. 359 00:27:02,667 --> 00:27:04,433 How could you land such a thing on the surface 360 00:27:04,567 --> 00:27:07,567 of another world without crashing it? 361 00:27:10,600 --> 00:27:13,333 Being able to guarantee that it could take off again and 362 00:27:13,467 --> 00:27:18,066 bring your crew safely home, was even more of a longshot. 363 00:27:18,200 --> 00:27:20,734 This approach, known as "Direct Ascent," 364 00:27:20,867 --> 00:27:26,066 seemed like a dead-end to a NASA engineer named John Houbolt and his colleagues. 365 00:27:27,300 --> 00:27:31,066 One version of the story goes, two space scientists had kept 366 00:27:31,200 --> 00:27:34,967 the spark of Kondratyuk's dream alive. 367 00:27:35,100 --> 00:27:38,967 They delivered his 40 year-old manuscript to Houbolt. 368 00:27:51,266 --> 00:27:54,200 KONDRATYUK: First of all, to the question of the work, 369 00:27:54,333 --> 00:27:56,900 let it not frighten you... 370 00:28:01,567 --> 00:28:04,567 Speaking about the possibility of flight implementation, 371 00:28:04,700 --> 00:28:08,400 just only remember that there is nothing improbable on the 372 00:28:08,533 --> 00:28:11,433 theoretical side of the flight of a rocket into space... 373 00:28:11,567 --> 00:28:13,600 MAN (over radio): One, zero. 374 00:28:13,734 --> 00:28:20,233 (engine blast) 375 00:28:41,033 --> 00:28:47,300 (engine blast) 376 00:28:56,400 --> 00:28:58,734 ASTRONAUT (over radio): 37 degrees. 377 00:28:58,867 --> 00:29:00,367 MAN (over radio): It's still looking very good. 378 00:29:00,500 --> 00:29:02,266 You're go. 379 00:29:02,400 --> 00:29:06,166 ASTRONAUT (over radio): We got an alarm. Bravo One. 380 00:29:06,667 --> 00:29:08,600 MAN 2 (over radio): Bravo One. Rocket 1201 alarm. 381 00:29:08,734 --> 00:29:09,834 MAN (over radio): 1201 alarm. 382 00:29:09,967 --> 00:29:11,033 MAN 3 (over radio): Standby for go, Flight. 383 00:29:11,166 --> 00:29:12,567 MAN (over radio): Okay, we're go. 384 00:29:12,700 --> 00:29:14,500 MAN 2 (over radio): We're go. Sync tight. We're go. 385 00:29:14,633 --> 00:29:16,100 MAN 3 (over radio): Altitude 1600. 386 00:29:16,233 --> 00:29:18,100 MAN 2 (over radio): Eagle looking great. 387 00:29:18,233 --> 00:29:19,934 ASTRONAUT (over radio): Tranquility base here. 388 00:29:20,066 --> 00:29:23,767 The eagle has landed. 389 00:29:23,900 --> 00:29:26,333 The surface appears to be very fine grained 390 00:29:26,467 --> 00:29:27,633 as you get close to it. 391 00:29:27,767 --> 00:29:29,900 It's almost like a powder. 392 00:29:33,900 --> 00:29:36,266 TYSON: NASA picked up Kondratyuk's vision of a 393 00:29:36,400 --> 00:29:40,600 Lunar Orbiter Rendezvous and took it all the way to the Moon. 394 00:29:41,300 --> 00:29:45,066 But Kondratyuk's horizon extended far beyond. 395 00:29:47,066 --> 00:29:50,000 Kondratyuk envisioned the first reconnaissance of 396 00:29:50,133 --> 00:29:53,467 the solar system by swinging round the planets, 397 00:29:53,600 --> 00:29:56,433 and using the force of their gravity to slingshot 398 00:29:56,567 --> 00:29:59,367 the craft farther out into space. 399 00:29:59,900 --> 00:30:03,600 He dreamt that we would swing from world to world as 400 00:30:03,734 --> 00:30:07,000 our ancestors had done from tree to tree, 401 00:30:09,433 --> 00:30:14,266 bending gravity to human needs on a slightly grander scale. 402 00:30:14,400 --> 00:30:18,700 But what gravity giveth, it can also taketh away. 403 00:30:27,967 --> 00:30:32,266 TYSON: Why do some worlds have rings, and others don't? 404 00:30:34,800 --> 00:30:37,300 Why no rings for Earth? 405 00:30:37,433 --> 00:30:39,667 Or Mars? 406 00:30:39,800 --> 00:30:42,800 We wouldn't recognize Saturn without them. 407 00:30:42,934 --> 00:30:45,333 He looks naked without his rings, 408 00:30:45,467 --> 00:30:48,333 but how did he get them in the first place? 409 00:30:48,467 --> 00:30:52,066 This is exactly what the French astronomer Édouard Roche asked 410 00:30:52,200 --> 00:30:56,834 himself when he looked at Saturn through his telescope in 1848. 411 00:31:01,400 --> 00:31:04,900 Roche speculated that Saturn's rings were the debris of a moon, 412 00:31:05,033 --> 00:31:07,533 or moons, that had ventured too close, 413 00:31:07,667 --> 00:31:11,133 and were pulled apart by the massive planet. 414 00:31:17,266 --> 00:31:24,033 ♪ ♪ 415 00:31:26,400 --> 00:31:30,900 Roche was able to devise an equation that applies to all worlds. 416 00:31:31,033 --> 00:31:33,700 It tells you how closely a body can come to a planet 417 00:31:33,834 --> 00:31:37,400 before it's pulled apart by the planet's tidal forces of gravity, 418 00:31:37,533 --> 00:31:41,133 and is turned into a ring. 419 00:31:42,967 --> 00:31:46,333 That's the Roche limit. 420 00:31:46,467 --> 00:31:49,166 But until NASA's Cassini spacecraft executed a series 421 00:31:49,300 --> 00:31:51,967 of daredevil maneuvers in the Saturn system, 422 00:31:52,100 --> 00:31:54,100 there was a vigorous scientific debate about 423 00:31:54,233 --> 00:31:56,467 when his rings formed. 424 00:31:56,600 --> 00:31:58,333 Some astronomers suggested they were nearly 425 00:31:58,467 --> 00:32:00,767 as old as the planet itself. 426 00:32:00,900 --> 00:32:03,867 More than 4 billion years ago, when the planet coalesced out 427 00:32:04,000 --> 00:32:07,934 of the disc of gas and dust that surrounded the newborn sun, 428 00:32:08,066 --> 00:32:12,867 a moon, or moons, likely violated Saturn's Roche limit... 429 00:32:14,433 --> 00:32:17,367 Others thought the rings to be fairly recent. 430 00:32:17,500 --> 00:32:20,467 Perhaps, only 100 million years old or so. 431 00:32:20,600 --> 00:32:24,600 And the Cassini spacecraft proved them right. 432 00:32:26,433 --> 00:32:30,400 What is Earth's own Roche limit? 433 00:32:31,967 --> 00:32:35,400 If the Moon were ever to come closer than 12,000 miles, 434 00:32:35,533 --> 00:32:39,166 which, by the way, it's absolutely in no danger of doing. 435 00:32:49,066 --> 00:32:51,600 And it's a good thing, too, 436 00:32:51,734 --> 00:32:55,867 because I like our Moon right where it is. 437 00:33:02,900 --> 00:33:05,333 There's only one other moon in the solar system that moves 438 00:33:05,467 --> 00:33:07,467 me like ours does. 439 00:33:07,600 --> 00:33:09,867 Maybe it's because it's the only one with a thick 440 00:33:10,000 --> 00:33:12,934 atmosphere like Earth's, and the kind of surface features, 441 00:33:13,066 --> 00:33:16,633 lakes and mountains, that remind me of home. 442 00:33:16,767 --> 00:33:20,734 All of this was hidden from view by a dense layer 443 00:33:20,867 --> 00:33:24,200 of orange smog, until the European Space Agency 444 00:33:24,333 --> 00:33:27,533 collaborated with NASA to send a spacecraft to land 445 00:33:27,667 --> 00:33:30,734 on his mysterious surface. 446 00:33:30,867 --> 00:33:34,000 Yes, that would be the one named after you, 447 00:33:34,133 --> 00:33:39,633 Christiaan Huygens, first to see that world through your telescope. 448 00:33:47,233 --> 00:33:50,266 After an interplanetary voyage of seven years, 449 00:33:50,400 --> 00:33:54,166 the Cassini-Huygens spacecraft arrived in the Saturn system, 450 00:33:54,300 --> 00:33:57,000 the fourth of our ships to venture there. 451 00:33:57,133 --> 00:34:02,066 But the first to send a probe to explore the surface of Saturn's moon, Titan 452 00:34:07,967 --> 00:34:11,166 and to reveal a moon of far greater complexity and splendor 453 00:34:11,300 --> 00:34:14,800 than our own rather dull and lifeless Moon. 454 00:34:26,200 --> 00:34:30,033 As Carl Sagan had predicted more than two decades before, 455 00:34:30,166 --> 00:34:32,800 there were seas of methane, and ethane, 456 00:34:32,934 --> 00:34:35,967 and there was water-ice. 457 00:34:37,633 --> 00:34:40,533 When Cassini first arrived in 2004 at Saturn's 458 00:34:40,667 --> 00:34:44,934 northern hemisphere, it was in the depths of winter. 459 00:34:45,066 --> 00:34:47,900 And the Sun didn't come out until five years later, 460 00:34:48,033 --> 00:34:51,433 when Saturn's northern spring began. 461 00:34:51,567 --> 00:34:55,600 Is it just me, or is this whirling hexagon at Saturn's 462 00:34:55,734 --> 00:35:00,000 North Pole every bit as exotic as the fantasies our ancient 463 00:35:00,133 --> 00:35:03,133 ancestors had of these worlds? 464 00:35:03,266 --> 00:35:06,033 The geometrically regular hexagonal shape of this 465 00:35:06,166 --> 00:35:10,333 feature brings to mind the handiwork of intelligence, 466 00:35:10,467 --> 00:35:15,400 terraforming, re-working the surface for some unknown purpose. 467 00:35:16,400 --> 00:35:19,500 But it's actually the result of the sudden change in wind 468 00:35:19,633 --> 00:35:24,367 speeds as vast upwellings of ammonia rise near the poles. 469 00:35:24,500 --> 00:35:27,100 It's the mother of all hurricanes, 470 00:35:27,233 --> 00:35:29,667 a frenzy of thunder and lightning, 471 00:35:29,800 --> 00:35:32,967 containing countless hurricanes within it. 472 00:35:33,500 --> 00:35:36,867 Spring can be a violent, stormy season, on Earth, too. 473 00:35:37,000 --> 00:35:40,600 But it was during Saturn's seven year-long summer that 474 00:35:40,734 --> 00:35:44,700 Cassini was commanded to take her own life. 475 00:36:03,400 --> 00:36:09,100 ♪ ♪ 476 00:36:09,233 --> 00:36:12,834 TYSON: There's a human conceit that at the moment of death, 477 00:36:12,967 --> 00:36:16,166 we re-live our greatest memories. 478 00:36:20,667 --> 00:36:24,200 You are riffling through the memory bank of a doomed robot, 479 00:36:24,333 --> 00:36:28,300 about to carry out the cruelest command. 480 00:36:43,834 --> 00:36:50,333 ♪ ♪ 481 00:37:11,467 --> 00:37:17,266 ♪ ♪ 482 00:37:38,266 --> 00:37:45,033 ♪ ♪ 483 00:38:05,000 --> 00:38:11,200 ♪ ♪ 484 00:38:31,166 --> 00:38:37,567 ♪ ♪ 485 00:38:38,100 --> 00:38:41,233 The mission planners at NASA's Jet Propulsion Laboratory 486 00:38:41,367 --> 00:38:44,500 call this the "ball of yarn," 487 00:38:44,633 --> 00:38:48,934 13 years of exploration through the Saturn system. 488 00:38:52,767 --> 00:38:57,433 From the time of her launch in 1997 and throughout her epic voyage, 489 00:38:57,567 --> 00:39:04,100 she has used the gravity assist conceived 100 years before by Yuri Kondratyuk. 490 00:39:05,233 --> 00:39:07,633 But it was her supply of rocket fuel that made it 491 00:39:07,767 --> 00:39:10,900 possible for her Earthbound controllers to steer her into 492 00:39:11,033 --> 00:39:14,333 new trajectories of exploration. 493 00:39:14,467 --> 00:39:19,200 In April of 2017, Cassini was running low on that fuel. 494 00:39:19,333 --> 00:39:22,800 It was time for her most daring maneuvers of all, 495 00:39:22,934 --> 00:39:26,734 before she was to be sent into a final death dive. 496 00:39:37,600 --> 00:39:40,900 These are the mission scientists of Cassini, 497 00:39:41,033 --> 00:39:42,934 some of whom have been working on the project since 498 00:39:43,066 --> 00:39:47,233 the 1990s, when it was no more than a dream. 499 00:39:47,367 --> 00:39:51,400 They know that Cassini must die. 500 00:39:51,533 --> 00:39:54,333 It's too dangerous to let her wander aimlessly. 501 00:39:54,467 --> 00:39:57,367 She might crash into one of the moons in the Saturn system 502 00:39:57,500 --> 00:39:59,934 where life might be hiding. 503 00:40:00,066 --> 00:40:02,967 This would violate NASA's planetary protection 504 00:40:03,100 --> 00:40:07,066 conventions on quarantine in the book of space laws. 505 00:40:07,767 --> 00:40:10,200 If left to chance, Cassini could alter the 506 00:40:10,333 --> 00:40:14,800 possible biological destiny of Titan or Enceladus. 507 00:40:17,367 --> 00:40:21,734 A terrible command must now be given. 508 00:40:30,333 --> 00:40:33,567 Cassini is so far away, it will take the message, 509 00:40:33,700 --> 00:40:35,600 traveling at the speed of light, 510 00:40:35,734 --> 00:40:38,066 more than an hour to reach her. 511 00:40:38,200 --> 00:40:41,333 Every microchip in her has been programmed to resist 512 00:40:41,467 --> 00:40:44,400 the commands she's now receiving. 513 00:40:44,533 --> 00:40:47,800 The inner-turmoil of the loyal robot commanded to defy 514 00:40:47,934 --> 00:40:51,500 her own instincts must be fierce. 515 00:40:51,633 --> 00:40:54,467 The same engineers who ordered her to protect herself 516 00:40:54,600 --> 00:40:59,633 in every situation now force her to plunge to her death. 517 00:41:01,233 --> 00:41:03,600 They must be obeyed. 518 00:41:03,734 --> 00:41:05,500 MAN (over radio): System lead ace. 519 00:41:05,633 --> 00:41:09,333 We have telemetry AOS at zero one. 520 00:41:09,467 --> 00:41:12,734 One, niner. One two. 521 00:41:14,467 --> 00:41:16,767 TYSON: She fights off the immense forces by struggling 522 00:41:16,900 --> 00:41:19,633 to right herself one last time. 523 00:41:19,767 --> 00:41:22,500 She fires her thrusters at 100%, 524 00:41:22,633 --> 00:41:25,367 all the while faithfully sending back more data than 525 00:41:25,500 --> 00:41:28,300 her designers ever hoped she would. 526 00:41:28,433 --> 00:41:30,100 WOMAN (over radio): Project Manager. Flight Director. 527 00:41:30,233 --> 00:41:31,633 MAN (over radio): Go ahead. 528 00:41:31,767 --> 00:41:35,200 WOMAN (over radio): Okay. We'd call loss of signal at 11:55:4. 529 00:41:36,767 --> 00:41:39,700 TYSON: She fights the brutal atmospheric resistance until 530 00:41:39,834 --> 00:41:42,133 her fuel tanks are empty, 531 00:41:42,266 --> 00:41:45,233 and there's no more fight left in her. 532 00:41:46,800 --> 00:41:51,066 MAN (over radio): Project manager on, maybe a trickle of telemetry left, but, 533 00:41:51,200 --> 00:41:55,700 just heard the signal from the spacecraft is gone 534 00:41:55,834 --> 00:41:59,934 and within the next 45 seconds so will be the spacecraft. 535 00:42:13,033 --> 00:42:18,033 ♪ ♪ 536 00:42:18,166 --> 00:42:23,367 TYSON: Official time of death: 11:55 universal time. 537 00:42:25,900 --> 00:42:30,400 There are all kinds of stories in the struggle to understand the cosmos. 538 00:42:30,533 --> 00:42:33,533 Sometimes your dreams die with you, 539 00:42:33,667 --> 00:42:38,066 but sometimes the scientists of another age pick them up, 540 00:42:38,200 --> 00:42:41,967 and take them to the Moon, and far beyond. 541 00:42:44,567 --> 00:42:48,433 The name of Yuri Kondratyuk was forgotten, 542 00:42:48,567 --> 00:42:52,233 but there was one who remembered. 543 00:42:55,266 --> 00:42:58,667 When Neil Armstrong returned from his trip to the Moon, 544 00:42:58,800 --> 00:43:02,333 he made a pilgrimage to the childhood home of the man 545 00:43:02,467 --> 00:43:05,567 who made his mythic voyage possible. 546 00:43:07,800 --> 00:43:12,533 ♪ ♪ 547 00:43:51,667 --> 00:43:54,633 Captioned by Cotter Captioning Services.