1 00:00:11,663 --> 00:00:18,366 ♪ ♪ 2 00:00:27,636 --> 00:00:28,941 MAN [over radio]: Systems this is prop. 3 00:00:29,116 --> 00:00:31,292 I read you 500, do you read me? 4 00:00:31,466 --> 00:00:34,817 TYSON: These people are watching their life's work come to an end. 5 00:00:34,991 --> 00:00:36,297 MAN [over radio]: The team is on its way to point. 6 00:00:36,471 --> 00:00:37,994 TYSON: On another world. 7 00:00:38,168 --> 00:00:41,476 MAN [over radio]: All right. Roger that. 8 00:00:48,700 --> 00:00:53,096 TYSON: They were all young when they sent her on her way. 9 00:00:55,055 --> 00:01:00,277 These men and women have been traveling vicariously with her for more than two decades. 10 00:01:07,763 --> 00:01:13,334 And now, her work is done, so she must die. 11 00:01:17,555 --> 00:01:20,384 But before she takes the fatal plunge, 12 00:01:20,558 --> 00:01:25,346 they've given her one final, epic challenge. 13 00:01:36,008 --> 00:01:41,449 [theme music plays]. 14 00:02:01,686 --> 00:02:08,128 ♪ ♪ 15 00:02:28,191 --> 00:02:34,154 ♪ ♪ 16 00:02:47,906 --> 00:02:50,866 TYSON: Gravity has a big bag of tricks, 17 00:02:51,040 --> 00:02:54,609 none lovelier than the ring systems of worlds. 18 00:02:54,783 --> 00:02:59,222 Our own solar system, alone, has four ringed planets. 19 00:03:03,139 --> 00:03:07,970 This one, with the romantic name J-1407B, 20 00:03:08,144 --> 00:03:12,235 is the first we've found circling another sun. 21 00:03:12,409 --> 00:03:15,847 Why haven't we found more ringed planets in our galaxy? 22 00:03:19,895 --> 00:03:23,638 Is it that the rings are so unusual, 23 00:03:23,812 --> 00:03:26,597 or are the methods we use to find exoplanets not very 24 00:03:26,771 --> 00:03:30,819 good at seeing the ring systems that may surround them? 25 00:03:31,863 --> 00:03:35,084 J-1407B's ring system is so vast, 26 00:03:35,258 --> 00:03:38,348 that it eclipsed its star for days. 27 00:03:38,957 --> 00:03:43,353 These rings extend across an astonishing 112 million miles. 28 00:03:44,093 --> 00:03:48,619 They would more than fill the distance between Earth and the sun. 29 00:03:50,055 --> 00:03:53,972 But as enormous as they are, they're shockingly thin. 30 00:03:54,146 --> 00:03:58,629 If the ring system of J-1407B were the size of a dinner plate, 31 00:03:58,803 --> 00:04:01,676 it would have to be 100 times thinner, 32 00:04:01,850 --> 00:04:04,505 as thin as a human hair. 33 00:04:07,377 --> 00:04:10,337 This surprising contrast between the immense territory 34 00:04:10,511 --> 00:04:12,730 of a ring system, and its thinness, 35 00:04:12,904 --> 00:04:15,907 is just as striking in our own solar system. 36 00:04:16,865 --> 00:04:20,172 The outermost ring of Neptune is so dainty, 37 00:04:20,347 --> 00:04:23,088 that it was first thought to be the fragments of a ring. 38 00:04:23,263 --> 00:04:26,309 Not a ring, but a collection of arcs. 39 00:04:26,483 --> 00:04:29,399 That was, until NASA's Voyager 2 spacecraft revealed 40 00:04:29,573 --> 00:04:32,663 that the so-called arcs were clumps, 41 00:04:32,837 --> 00:04:35,884 the thicker parts of a fainter, complete ring. 42 00:04:40,497 --> 00:04:43,370 It's funny that the weirdest planet in the solar system has 43 00:04:43,544 --> 00:04:46,111 attracted the least attention. 44 00:04:46,286 --> 00:04:49,027 Voyager 2 is the only spacecraft that has ever been 45 00:04:49,201 --> 00:04:52,204 sent on a reconnaissance mission to Uranus, 46 00:04:52,379 --> 00:04:55,904 one of the two ice giant planets that circle the sun. 47 00:04:57,558 --> 00:04:59,777 During its 20-year-long summers, 48 00:04:59,951 --> 00:05:02,824 the sun never sets on Uranus. 49 00:05:02,998 --> 00:05:05,130 The winters are equally as long, 50 00:05:05,305 --> 00:05:08,873 20 years of unbroken night. 51 00:05:12,137 --> 00:05:16,098 Unlike its fellow gas planets, Uranus is cold-hearted. 52 00:05:16,272 --> 00:05:19,319 It doesn't generate any internal heat. 53 00:05:27,022 --> 00:05:30,634 Uranus is one crazy world. 54 00:05:30,808 --> 00:05:33,463 The outer edge of Uranus's atmosphere is so hot, 55 00:05:33,637 --> 00:05:37,902 it's hotter than 500 degrees Fahrenheit. 56 00:05:41,123 --> 00:05:44,605 But Uranus also has the coldest clouds in the solar system, 57 00:05:44,779 --> 00:05:48,173 I'm talking nearly 400 degrees below zero. 58 00:05:55,267 --> 00:05:58,227 What kind of ocean is this? 59 00:05:58,401 --> 00:06:00,229 Is it made of ammonia? 60 00:06:00,403 --> 00:06:02,927 Water? 61 00:06:03,101 --> 00:06:07,932 Some scientists think it may be an ocean of liquid diamonds. 62 00:06:08,106 --> 00:06:12,546 Note to space agencies, might be worth another visit. 63 00:06:18,203 --> 00:06:21,903 Then there's that thing about it being sideways. 64 00:06:22,077 --> 00:06:27,561 Uranus revolves around the sun at a roughly 90 degree angle to its own orbital plane. 65 00:06:27,735 --> 00:06:31,826 What could have happened to Uranus that it got knocked on its ass? 66 00:06:33,088 --> 00:06:37,658 Our best guess is that it went something like this. 67 00:06:43,141 --> 00:06:46,493 Uranus was in a terrible accident. 68 00:06:47,102 --> 00:06:50,497 [crashing]. 69 00:06:50,801 --> 00:06:53,674 [crashing]. 70 00:06:53,848 --> 00:06:59,941 After the second blow, the rotational axis of Uranus tipped 98 degrees. 71 00:07:03,597 --> 00:07:05,642 There's another world in our solar system that we don't 72 00:07:05,816 --> 00:07:09,037 think of as having a ring. 73 00:07:09,211 --> 00:07:12,127 The rings of Jupiter were so dim that no ground-based 74 00:07:12,301 --> 00:07:14,869 telescope ever saw them. 75 00:07:15,043 --> 00:07:18,742 They were discovered when Voyager 1 came flying by. 76 00:07:24,226 --> 00:07:28,230 Our Saturn is graced by the loveliest, largest, 77 00:07:28,404 --> 00:07:32,930 and brightest ring system of any around our sun. 78 00:07:33,365 --> 00:07:36,499 It's the most distant planet that can be seen with the naked eye, 79 00:07:36,673 --> 00:07:39,981 and it made quite an impression on our ancestors. 80 00:07:49,164 --> 00:07:53,081 When I think of the Babylonians of 3,500 years ago looking up 81 00:07:53,255 --> 00:07:55,605 at the planets and stars, 82 00:07:55,779 --> 00:07:58,260 I wonder how unlikely it would have seemed that one of their 83 00:07:58,434 --> 00:08:01,916 species would actually send an emissary to that 84 00:08:02,090 --> 00:08:05,223 distant point of light. 85 00:08:13,754 --> 00:08:18,193 We are in the Deep Space Network room at NASA's Jet Propulsion Laboratory. 86 00:08:19,063 --> 00:08:24,286 In this place, the most ambitious voyages of discovery are directed and monitored. 87 00:08:25,766 --> 00:08:28,072 Why are these people so emotional? 88 00:08:28,246 --> 00:08:30,422 They have committed their professional lives to 89 00:08:30,597 --> 00:08:34,688 a collaboration with this robot. 90 00:08:41,738 --> 00:08:44,959 And now that partnership of decades is about to end 91 00:08:45,133 --> 00:08:48,223 in a most violent way. 92 00:08:48,397 --> 00:08:50,834 The pathway from our Earthbound helplessness to 93 00:08:51,008 --> 00:08:55,186 our presence in Saturn's skies is about to unfold. 94 00:09:03,630 --> 00:09:07,503 TYSON: What is that shimmering, unsteady thing we're looking at? 95 00:09:07,677 --> 00:09:12,160 That's what Galileo Galilei asked himself in 1610 when he 96 00:09:12,334 --> 00:09:15,555 became the first human to see Saturn as more than 97 00:09:15,729 --> 00:09:18,993 just a point of light. 98 00:09:21,778 --> 00:09:24,433 So, this is the telescope that made the modern 99 00:09:24,607 --> 00:09:27,436 scientific revolution possible. 100 00:09:27,610 --> 00:09:30,657 You know, you really started something. 101 00:09:30,831 --> 00:09:34,791 You looked through that thing and found the cosmos. 102 00:09:35,836 --> 00:09:39,143 That's not to say you didn't make your share of mistakes. 103 00:09:39,317 --> 00:09:42,059 You guessed wrong at what you thought you saw, 104 00:09:42,233 --> 00:09:44,671 believing that Saturn sported two symmetrical moons 105 00:09:44,845 --> 00:09:47,325 on either side of it. 106 00:09:47,499 --> 00:09:50,285 Two years later, when you took a second look, 107 00:09:50,459 --> 00:09:54,724 you were shocked to find that your "moons" had vanished. 108 00:09:54,898 --> 00:09:57,858 This was because both worlds, Earth and Saturn, 109 00:09:58,032 --> 00:10:02,079 were in motion, and the two worlds had changed in position to each other. 110 00:10:02,253 --> 00:10:05,779 You were now looking at Saturn's rings, edge-on. 111 00:10:06,475 --> 00:10:10,000 The Saturn ring system is 175,000 miles across, 112 00:10:10,174 --> 00:10:14,352 but on average only a few hundred feet thick. 113 00:10:14,526 --> 00:10:18,835 They were too thin for your fledgling telescope to see. 114 00:10:22,360 --> 00:10:25,973 But two years after that, you took a third look. 115 00:10:26,147 --> 00:10:30,238 Now, you thought that the planet had arms. 116 00:10:45,383 --> 00:10:51,781 ♪ ♪ 117 00:10:56,177 --> 00:10:58,788 40 years passed, until a Dutch astronomer named 118 00:10:58,962 --> 00:11:01,704 Christiaan Huygens took another look at Saturn with 119 00:11:01,878 --> 00:11:05,229 his own greatly improved telescope. 120 00:11:18,852 --> 00:11:21,463 Huygens was the first to know that worlds could 121 00:11:21,637 --> 00:11:25,728 be circled by rings, and Saturn was one of them. 122 00:11:25,902 --> 00:11:28,470 He also discovered Saturn's largest moon, 123 00:11:28,644 --> 00:11:32,039 which would later be known as Titan. 124 00:11:32,648 --> 00:11:35,303 When it finally came time for us to visit that world, 125 00:11:35,477 --> 00:11:39,350 our spacecraft bore Huygens's name. 126 00:11:41,004 --> 00:11:43,572 In science, there are the Galileos, the Newtons, 127 00:11:43,746 --> 00:11:45,661 the Darwins, the Einsteins. 128 00:11:45,835 --> 00:11:49,012 And then there's another kind of great scientist. 129 00:11:49,186 --> 00:11:51,623 Not the kind that paints a whole new picture of nature, 130 00:11:51,798 --> 00:11:54,235 but, like Christiaan Huygens, 131 00:11:54,409 --> 00:11:56,585 someone who has much to contribute, 132 00:11:56,759 --> 00:11:59,936 filling in a blank or two on that vast canvas. 133 00:12:00,110 --> 00:12:04,332 Such a scientist was Giovanni Domenico Cassini. 134 00:12:06,856 --> 00:12:10,730 He was born early in the 17th century in the town of Perinaldo, 135 00:12:10,904 --> 00:12:13,645 in what is now Italy. 136 00:12:13,820 --> 00:12:16,344 Cassini didn't start out as a scientist. 137 00:12:16,518 --> 00:12:20,870 He began his career as a pseudo-scientist, an astrologer. 138 00:12:21,523 --> 00:12:24,526 Astrology is a collection of ideas based on the notion that 139 00:12:24,700 --> 00:12:28,008 worlds have certain human personality traits, 140 00:12:28,182 --> 00:12:30,706 and that the influence of these distant worlds, 141 00:12:30,880 --> 00:12:33,448 depending on which are rising and falling at the time 142 00:12:33,622 --> 00:12:36,625 of your birth, will determine who you are and 143 00:12:36,799 --> 00:12:39,149 what your fate will be. 144 00:12:39,323 --> 00:12:41,064 It's another form of prejudice, 145 00:12:41,238 --> 00:12:43,240 making unfounded assumptions about who a person 146 00:12:43,414 --> 00:12:46,896 is without bothering to get to know them. 147 00:12:47,854 --> 00:12:51,205 Astronomy and astrology used to be the same thing, 148 00:12:51,379 --> 00:12:53,250 until there was a great awakening to our 149 00:12:53,424 --> 00:12:57,167 actual circumstances in the cosmos. 150 00:12:57,864 --> 00:13:00,692 In 1543, Nicolaus Copernicus, 151 00:13:00,867 --> 00:13:03,217 a Polish cleric demonstrated that, 152 00:13:03,391 --> 00:13:05,088 contrary to popular belief, 153 00:13:05,262 --> 00:13:08,265 we were not the center of the universe... 154 00:13:08,439 --> 00:13:11,965 the Earth and the other planets travelled around the sun. 155 00:13:12,139 --> 00:13:15,272 Demoting the Earth from the center of the universe 156 00:13:15,446 --> 00:13:18,798 was a severe blow to human self-esteem. 157 00:13:18,972 --> 00:13:20,625 More than a century later, 158 00:13:20,800 --> 00:13:23,063 some people still hadn't gotten over it, 159 00:13:23,237 --> 00:13:26,066 and Giovanni Cassini was one of them. 160 00:13:26,240 --> 00:13:29,373 Cassini accepted a terrific job offer, 161 00:13:29,547 --> 00:13:31,680 an appointment by Louis the XIV, 162 00:13:31,854 --> 00:13:34,944 the legendary sun King of France, 163 00:13:35,118 --> 00:13:40,254 Louis believed himself to be an absolute ruler whose dominion was God's will. 164 00:13:40,428 --> 00:13:43,083 But he was also the first monarch in Europe to recognize 165 00:13:43,257 --> 00:13:45,476 the great power of science. 166 00:13:45,650 --> 00:13:49,654 He knew it was vital to national security. 167 00:13:51,091 --> 00:13:54,050 Louis the XIV was inventing the first modern, 168 00:13:54,224 --> 00:13:57,271 governmental, scientific research institute, 169 00:13:57,445 --> 00:14:00,665 The Paris Observatory. 170 00:14:09,761 --> 00:14:12,286 Cassini told the absolute ruler that he would not be 171 00:14:12,460 --> 00:14:16,681 staying long in Paris, a year or two, at most. 172 00:14:19,032 --> 00:14:22,862 But when the King placed his new observatory at Cassini's disposal, 173 00:14:23,036 --> 00:14:27,214 he lost all interest in returning home to Italy ever again. 174 00:14:27,388 --> 00:14:30,478 For the next 125 years, 175 00:14:30,652 --> 00:14:34,961 the Paris Observatory would be led by a Cassini. 176 00:14:37,746 --> 00:14:40,749 Cassini rewarded his patron with a map of the Moon 177 00:14:40,923 --> 00:14:44,318 that remained cutting-edge for a century. 178 00:14:44,492 --> 00:14:47,277 King Louis financed a research expedition to South America 179 00:14:47,451 --> 00:14:50,193 to obtain more accurate measurements of longitude, 180 00:14:50,367 --> 00:14:53,762 intel of enormous value to the captains of his far-flung 181 00:14:53,936 --> 00:14:57,592 fleet and to astronomers. 182 00:14:58,375 --> 00:15:01,117 Cassini took all these data and became the first person 183 00:15:01,291 --> 00:15:04,120 to calculate the scale of the Copernican solar system 184 00:15:04,294 --> 00:15:06,993 that he had once rejected. 185 00:15:07,167 --> 00:15:09,473 With his increasingly powerful telescopes, 186 00:15:09,647 --> 00:15:12,346 he discovered the length of a day on Jupiter 187 00:15:12,520 --> 00:15:16,176 and the bands and spots on that planet's surface. 188 00:15:16,350 --> 00:15:19,788 Cassini discovered Jupiter's Great Red Spot independently 189 00:15:19,962 --> 00:15:22,704 of Robert Hooke in England, and to this day, 190 00:15:22,878 --> 00:15:25,489 they share the credit. 191 00:15:25,663 --> 00:15:29,580 Cassini went on to determine the length of the day on Mars. 192 00:15:31,278 --> 00:15:35,151 He was only off by three minutes. 193 00:15:35,325 --> 00:15:38,067 When he returned to his observations of Jupiter, 194 00:15:38,241 --> 00:15:41,070 he was stumped by the contradictions in them. 195 00:15:41,244 --> 00:15:45,074 The eclipses by Jupiter's moons did not begin when they were supposed to, 196 00:15:45,248 --> 00:15:48,860 they varied from observation to observation. 197 00:15:49,035 --> 00:15:52,212 Could it be that it was due to changes in the distance 198 00:15:52,386 --> 00:15:56,694 of the Earth from Jupiter, as the two worlds moved through the solar system? 199 00:15:57,608 --> 00:16:00,568 If that were true, then light could not travel at 200 00:16:00,742 --> 00:16:05,007 an infinite speed because it was taking longer to reach Earth. 201 00:16:05,181 --> 00:16:08,706 Was the speed of light finite? 202 00:16:08,880 --> 00:16:13,015 This idea was just too crazy for Cassini, too revolutionary. 203 00:16:13,189 --> 00:16:15,496 He rejected it out of hand. 204 00:16:15,670 --> 00:16:18,107 If he had followed the evidence wherever it led, 205 00:16:18,281 --> 00:16:20,631 he would have given us the yardstick for the cosmos that 206 00:16:20,805 --> 00:16:24,244 we still use 350 years later. 207 00:16:24,418 --> 00:16:27,116 But Cassini, ever the conservative, 208 00:16:27,290 --> 00:16:31,077 dismissed the idea as being just too wacky. 209 00:16:32,730 --> 00:16:34,819 Several years later, a Danish astronomer, 210 00:16:34,994 --> 00:16:39,520 Ole Romer, became Cassini's assistant at the Paris Observatory. 211 00:16:39,694 --> 00:16:42,958 Romer made his own observations of the eclipses 212 00:16:43,132 --> 00:16:46,440 of some of Jupiter's moons and found the same discrepancies 213 00:16:46,614 --> 00:16:49,573 in the data that Cassini had dismissed. 214 00:16:49,747 --> 00:16:52,620 But Romer recognized them for what they were, 215 00:16:52,794 --> 00:16:56,232 Pieces of evidence for the finite speed of light. 216 00:16:58,495 --> 00:17:00,802 There was a time, however, when Cassini's faithfulness 217 00:17:00,976 --> 00:17:04,284 to the data was so extreme, that he was willing to risk the 218 00:17:04,458 --> 00:17:07,113 displeasure of King Louis. 219 00:17:07,287 --> 00:17:11,508 The monarch asked Cassini to calculate the exact area of his realm. 220 00:17:11,682 --> 00:17:14,859 No one had ever attempted to make an accurate map, 221 00:17:15,034 --> 00:17:17,514 much less a topographical one that would feature all 222 00:17:17,688 --> 00:17:20,039 the mountains and rivers and valleys of France, 223 00:17:20,213 --> 00:17:22,519 or of any other country for that matter. 224 00:17:22,693 --> 00:17:26,132 Cassini rose to the task, but discovered results that 225 00:17:26,306 --> 00:17:29,613 could not possibly please the King. 226 00:17:35,271 --> 00:17:36,707 [sighs]. 227 00:17:39,971 --> 00:17:41,843 Cassini told the King, 228 00:17:42,017 --> 00:17:45,499 "“I have some rather disappointing news for you, Your Highness. 229 00:17:47,240 --> 00:17:52,114 We all thought that France was a whole lot bigger than our studies, revealed. 230 00:17:52,723 --> 00:17:57,815 I'm afraid, Your Majesty, your kingdom is much smaller than heretofore thought."” 231 00:17:58,860 --> 00:18:00,644 [grunts]. 232 00:18:00,818 --> 00:18:02,603 [gasps]. 233 00:18:02,777 --> 00:18:04,648 TYSON: The King surprised everyone with his great good humor, 234 00:18:04,822 --> 00:18:08,087 saying, "“Why, Cassini, you've robbed me of more land 235 00:18:08,261 --> 00:18:11,699 than all the armies of my enemies combined."” 236 00:18:12,308 --> 00:18:16,704 [laughing]. 237 00:18:17,574 --> 00:18:20,708 TYSON: And then, there is his work on Saturn. 238 00:18:24,277 --> 00:18:28,585 He was the first person to know what the rings of Saturn really were. 239 00:18:28,759 --> 00:18:31,719 He proposed that they were not solid, 240 00:18:31,893 --> 00:18:34,374 but instead composed of countless satellites orbiting 241 00:18:34,548 --> 00:18:37,377 the planet, and he observed that there was 242 00:18:37,551 --> 00:18:40,858 a division between the rings. 243 00:18:41,337 --> 00:18:45,559 Cassini filled in some of the big blanks in our understanding of Saturn, 244 00:18:45,733 --> 00:18:50,172 but how could we possibly ever get there? 245 00:18:52,305 --> 00:18:55,264 Accomplishing that mythic quest was left to one whose 246 00:18:55,438 --> 00:18:58,702 tragic life would have been completely forgotten, 247 00:18:58,876 --> 00:19:02,097 if not for what you are about to see. 248 00:19:13,369 --> 00:19:16,851 TYSON: Weighing in at more than 12,000 pounds at launch, 249 00:19:17,025 --> 00:19:20,811 NASA's Cassini spacecraft is the size of a bus. 250 00:19:20,985 --> 00:19:25,251 That figure included 70 pounds of plutonium 238 fuel, 251 00:19:25,425 --> 00:19:28,863 enough to last her for more than 20 years. 252 00:19:29,429 --> 00:19:32,823 But that's not what powered her mythic odyssey. 253 00:19:32,997 --> 00:19:37,611 She rode gravity's rainbow all the way to the outer-solar system. 254 00:19:42,442 --> 00:19:45,358 The lineage of the greatest of human achievements stretches 255 00:19:45,532 --> 00:19:48,317 further back than we might assume. 256 00:19:48,491 --> 00:19:52,713 Some of their roots are buried deep inside the tomb of lost hope. 257 00:19:54,149 --> 00:19:57,065 But somehow, dreams rise. 258 00:19:57,239 --> 00:20:00,329 The epic missions of the first golden age of space exploration, 259 00:20:00,503 --> 00:20:01,939 and likely the next, 260 00:20:02,113 --> 00:20:04,942 were made possible by a man whose two names, 261 00:20:05,116 --> 00:20:08,772 one real, one fake, are equally forgotten. 262 00:20:13,951 --> 00:20:15,736 [knocking]. 263 00:20:15,910 --> 00:20:16,737 [grunts]. 264 00:20:16,911 --> 00:20:18,608 [knocking]. 265 00:20:18,782 --> 00:20:22,395 Alexander Shargei's early years are not well-documented, 266 00:20:22,569 --> 00:20:25,963 but it is believed that his mother, a political activist, 267 00:20:26,137 --> 00:20:30,229 was taken from him when he was only five years old. 268 00:20:36,060 --> 00:20:40,630 He took refuge in his father's physics and mathematics textbooks. 269 00:20:40,804 --> 00:20:43,807 But by the time Alexander was 13, 270 00:20:43,981 --> 00:20:46,723 the boy had lost his father, too. 271 00:20:46,897 --> 00:20:50,205 He lived with his grandmother, and despite great hardship, 272 00:20:50,379 --> 00:20:53,382 he managed to be accepted at the most prestigious high school, 273 00:20:53,556 --> 00:20:55,602 and afterwards gained admission to the 274 00:20:55,776 --> 00:20:58,518 best engineering institute in the Ukraine. 275 00:20:58,692 --> 00:21:01,869 But only two months after he arrived there, in 1914, 276 00:21:02,043 --> 00:21:04,263 he was drafted into the Czar's army to fight 277 00:21:04,437 --> 00:21:06,134 in the First World War. 278 00:21:06,308 --> 00:21:12,053 [explosions, gunfire]. 279 00:21:17,363 --> 00:21:23,891 [explosions, gunfire]. 280 00:21:27,111 --> 00:21:29,331 In the hell of war at the front, 281 00:21:29,505 --> 00:21:32,508 Alexander Shargei conceived a scientific strategy 282 00:21:32,682 --> 00:21:36,251 for exploring the Moon, not intended as fiction, 283 00:21:36,425 --> 00:21:39,167 but as blueprint. 284 00:21:42,910 --> 00:21:44,607 [engine blast]. 285 00:21:46,305 --> 00:21:49,220 [engine blast]. 286 00:21:58,752 --> 00:22:01,058 [engine blast]. 287 00:22:02,495 --> 00:22:05,498 But Shargei's hell didn't end with the war. 288 00:22:05,672 --> 00:22:08,544 Now, Shargei was forced to navigate the treacherous 289 00:22:08,718 --> 00:22:11,808 political mine fields of revolutionary Russia. 290 00:22:11,982 --> 00:22:15,072 He was much better at figuring out how to get to the Moon. 291 00:22:15,638 --> 00:22:17,945 Former officers in the Czar's army and those, 292 00:22:18,119 --> 00:22:20,034 such as Shargei, who were forced to join 293 00:22:20,208 --> 00:22:22,210 the counter-revolutionary White Army, 294 00:22:22,384 --> 00:22:25,344 were assumed to be "“enemies of the people."” 295 00:22:28,912 --> 00:22:31,741 [shouting in Russian]. 296 00:22:31,915 --> 00:22:34,875 TYSON: Shargei could find no peace in the Soviet Union, 297 00:22:35,049 --> 00:22:39,053 so in desperation he tried to escape to Poland. 298 00:22:45,276 --> 00:22:48,323 Shargei, weakened by illness, was stopped by guards 299 00:22:48,497 --> 00:22:52,283 and turned back from the border. 300 00:23:09,039 --> 00:23:12,042 TYSON: These were dangerous times, 301 00:23:12,216 --> 00:23:16,133 and there was no telling what would get you into serious trouble. 302 00:23:21,617 --> 00:23:24,794 No one knows where Shargei spent the next three years. 303 00:23:24,968 --> 00:23:27,275 He simply vanished. 304 00:23:27,449 --> 00:23:32,062 When at last he emerged, Alexander Shargei was no more. 305 00:23:32,889 --> 00:23:35,326 In his desperation to be left alone, 306 00:23:35,501 --> 00:23:38,025 he took the name of a dead man. 307 00:23:38,199 --> 00:23:41,463 He was now Yuri Kondratyuk. 308 00:23:43,073 --> 00:23:44,988 He finally published the book he had been dreaming 309 00:23:45,162 --> 00:23:48,252 about since his time in the trenches. 310 00:23:48,427 --> 00:23:50,385 No publisher was interested, 311 00:23:50,559 --> 00:23:53,388 so he printed it at his own expense. 312 00:23:54,694 --> 00:23:59,960 It was Kondratyuk's letter to a future no one else could see. 313 00:24:00,656 --> 00:24:04,660 He wrote it "“To Whoever Will Read This Paper in Order to 314 00:24:04,834 --> 00:24:08,751 Build an Interplanetary Rocket."” 315 00:24:10,927 --> 00:24:12,538 In the late 1920s, 316 00:24:12,712 --> 00:24:16,542 Kondratyuk was enlisted to design a grain elevator. 317 00:24:16,716 --> 00:24:19,196 The Soviet Union was going through a metal shortage, 318 00:24:19,370 --> 00:24:22,635 so Kondratyuk's challenge was to build the largest grain 319 00:24:22,809 --> 00:24:26,943 elevator possible without using more than a single nail. 320 00:24:28,423 --> 00:24:32,383 It ended up being so big, they named it "“the Mastodon."” 321 00:24:35,604 --> 00:24:39,434 Such was the nightmare logic of Stalin's Soviet Union. 322 00:24:39,608 --> 00:24:42,089 You could do the heroic in service to the state, 323 00:24:42,263 --> 00:24:45,092 successfully execute the seemingly impossible order 324 00:24:45,266 --> 00:24:48,530 to build a colossus with but a single nail. 325 00:24:48,704 --> 00:24:50,489 And when it was done, 326 00:24:50,663 --> 00:24:53,448 you could be imprisoned for sabotage. 327 00:24:53,622 --> 00:24:57,234 Who but an enemy of the state would do such a reckless thing 328 00:24:57,408 --> 00:25:02,109 as building a colossal grain elevator with only a single nail. 329 00:25:03,197 --> 00:25:05,634 It made no difference to Kondratyuk's fate that the 330 00:25:05,808 --> 00:25:08,594 grain elevator functioned for another 60 years, 331 00:25:08,768 --> 00:25:12,119 until it burned down. 332 00:25:12,598 --> 00:25:16,384 Kondratyuk was sentenced to three years in a special prison camp, 333 00:25:16,558 --> 00:25:19,082 something new, called a sharashka, 334 00:25:19,256 --> 00:25:24,348 where scientists and engineers slaved away on the nation's most ambitious projects. 335 00:25:25,349 --> 00:25:29,049 Kondratyuk threw himself into a wind power project, 336 00:25:29,223 --> 00:25:34,097 but still he dreamed of exploring the solar system. 337 00:25:37,013 --> 00:25:40,190 Soon after that, he met Sergei Korolev, 338 00:25:40,364 --> 00:25:44,804 who also dreamed of leaving Earth to explore the cosmos. 339 00:25:44,978 --> 00:25:49,722 Korolev would later become the father of the Soviet rocket program. 340 00:25:50,592 --> 00:25:53,377 Korolev wanted to enlist Kondratyuk in his fledgling 341 00:25:53,552 --> 00:25:57,120 rocket program, but Kondratyuk was so terrified 342 00:25:57,294 --> 00:26:00,733 that any change in his status might result in closer scrutiny by 343 00:26:00,907 --> 00:26:04,563 the secret police, he declined. 344 00:26:04,737 --> 00:26:09,045 If the authorities discovered that Kondratyuk was really Shargei, 345 00:26:09,219 --> 00:26:12,919 there was no telling what they would do to him. 346 00:26:14,094 --> 00:26:16,052 When Germany attacked Russia, 347 00:26:16,226 --> 00:26:19,490 Kondratyuk volunteered for armed service at the front, 348 00:26:19,665 --> 00:26:22,406 where he led a communications outfit. 349 00:26:22,581 --> 00:26:26,019 His precise fate is unknown, but he is believed to have 350 00:26:26,193 --> 00:26:30,719 died in battle on a February night in 1942. 351 00:26:32,155 --> 00:26:37,944 Alexander Shargei, aka Yuri Kondratyuk, was only 44. 352 00:26:38,727 --> 00:26:41,208 That was the end of his story, 353 00:26:41,382 --> 00:26:44,341 but not his dream. 354 00:26:44,515 --> 00:26:47,518 In the early days of the Apollo program, 355 00:26:47,693 --> 00:26:50,826 the scientists and engineers struggled to figure out how 356 00:26:51,000 --> 00:26:55,483 a rocket could leave the Earth and land directly on the Moon. 357 00:26:55,657 --> 00:26:57,616 They were stymied. 358 00:26:57,790 --> 00:26:59,922 They couldn't figure it out. 359 00:27:00,096 --> 00:27:03,578 You need a big powerful rocket to reach the Moon. 360 00:27:03,752 --> 00:27:05,406 How could you land such a thing on the surface 361 00:27:05,580 --> 00:27:08,627 of another world without crashing it? 362 00:27:11,673 --> 00:27:14,371 Being able to guarantee that it could take off again and 363 00:27:14,545 --> 00:27:19,115 bring your crew safely home, was even more of a longshot. 364 00:27:19,289 --> 00:27:21,770 This approach, known as "“Direct Ascent," 365 00:27:21,944 --> 00:27:27,167 seemed like a dead-end to a NASA engineer named John Houbolt and his colleagues. 366 00:27:28,429 --> 00:27:32,085 One version of the story goes, two space scientists had kept 367 00:27:32,259 --> 00:27:36,045 the spark of Kondratyuk's dream alive. 368 00:27:36,219 --> 00:27:40,049 They delivered his 40 year-old manuscript to Houbolt. 369 00:27:52,322 --> 00:27:55,195 KONDRATYUK: First of all, to the question of the work, 370 00:27:55,369 --> 00:27:57,937 let it not frighten you... 371 00:28:02,637 --> 00:28:05,596 Speaking about the possibility of flight implementation, 372 00:28:05,771 --> 00:28:09,426 just only remember that there is nothing improbable on the 373 00:28:09,600 --> 00:28:12,473 theoretical side of the flight of a rocket into space... 374 00:28:12,647 --> 00:28:14,605 MAN [over radio]: One, zero. 375 00:28:14,780 --> 00:28:21,308 [engine blast]. 376 00:28:42,111 --> 00:28:48,378 [engine blast]. 377 00:28:57,431 --> 00:28:59,738 ASTRONAUT [over radio]: 37 degrees. 378 00:28:59,912 --> 00:29:01,348 MAN [over radio]: It's still looking very good. 379 00:29:01,522 --> 00:29:03,350 You're go. 380 00:29:03,524 --> 00:29:07,223 ASTRONAUT [over radio]: We got an alarm. Bravo One. 381 00:29:07,702 --> 00:29:09,617 MAN 2 [over radio]: Bravo One. Rocket 1201 alarm. 382 00:29:09,791 --> 00:29:11,184 MAN [over radio]: 1201 alarm. 383 00:29:11,358 --> 00:29:12,751 MAN 3 [over radio]: Standby for go, Flight. 384 00:29:12,925 --> 00:29:14,665 MAN [over radio]: Okay, we're go. 385 00:29:14,840 --> 00:29:16,189 MAN 2 [over radio]: We're go. Sync tight. We're go. 386 00:29:16,363 --> 00:29:17,886 MAN 3 [over radio]: Altitude 1600. 387 00:29:18,060 --> 00:29:19,496 MAN 2 [over radio]: Eagle looking great. 388 00:29:19,670 --> 00:29:20,933 ASTRONAUT [over radio]: Tranquility base here. 389 00:29:21,107 --> 00:29:24,806 The eagle has landed. 390 00:29:24,980 --> 00:29:27,374 The surface appears to be very fine grained 391 00:29:27,548 --> 00:29:28,679 as you get close to it. 392 00:29:28,854 --> 00:29:30,943 It's almost like a powder. 393 00:29:34,990 --> 00:29:37,340 TYSON: NASA picked up Kondratyuk's vision of a 394 00:29:37,514 --> 00:29:41,692 Lunar Orbiter Rendezvous and took it all the way to the Moon. 395 00:29:42,389 --> 00:29:46,132 But Kondratyuk's horizon extended far beyond. 396 00:29:48,177 --> 00:29:51,093 Kondratyuk envisioned the first reconnaissance of 397 00:29:51,267 --> 00:29:54,531 the solar system by swinging round the planets, 398 00:29:54,705 --> 00:29:57,491 and using the force of their gravity to slingshot 399 00:29:57,665 --> 00:30:00,494 the craft farther out into space. 400 00:30:01,016 --> 00:30:04,672 He dreamt that we would swing from world to world as 401 00:30:04,846 --> 00:30:08,067 our ancestors had done from tree to tree, 402 00:30:10,591 --> 00:30:15,335 bending gravity to human needs on a slightly grander scale. 403 00:30:15,509 --> 00:30:19,818 But what gravity giveth, it can also taketh away. 404 00:30:29,088 --> 00:30:33,353 TYSON: Why do some worlds have rings, and others don't? 405 00:30:35,877 --> 00:30:38,314 Why no rings for Earth? 406 00:30:38,488 --> 00:30:40,751 Or Mars? 407 00:30:40,926 --> 00:30:43,885 We wouldn't recognize Saturn without them. 408 00:30:44,059 --> 00:30:46,409 He looks naked without his rings, 409 00:30:46,583 --> 00:30:49,456 but how did he get them in the first place? 410 00:30:49,630 --> 00:30:53,112 This is exactly what the French astronomer EÉdouard Roche asked 411 00:30:53,286 --> 00:30:57,856 himself when he looked at Saturn through his telescope in 1848. 412 00:31:02,512 --> 00:31:05,951 Roche speculated that Saturn's rings were the debris of a moon, 413 00:31:06,125 --> 00:31:08,562 or moons, that had ventured too close, 414 00:31:08,736 --> 00:31:12,174 and were pulled apart by the massive planet. 415 00:31:18,311 --> 00:31:25,100 ♪ ♪ 416 00:31:27,537 --> 00:31:31,977 Roche was able to devise an equation that applies to all worlds. 417 00:31:32,151 --> 00:31:34,762 It tells you how closely a body can come to a planet 418 00:31:34,936 --> 00:31:38,461 before it's pulled apart by the planet's tidal forces of gravity, 419 00:31:38,635 --> 00:31:42,204 and is turned into a ring. 420 00:31:44,032 --> 00:31:47,427 That's the Roche limit. 421 00:31:47,601 --> 00:31:50,212 But until NASA's Cassini spacecraft executed a series 422 00:31:50,386 --> 00:31:52,998 of daredevil maneuvers in the Saturn system, 423 00:31:53,172 --> 00:31:55,087 there was a vigorous scientific debate about 424 00:31:55,261 --> 00:31:57,480 when his rings formed. 425 00:31:57,654 --> 00:31:59,352 Some astronomers suggested they were nearly 426 00:31:59,526 --> 00:32:01,789 as old as the planet itself. 427 00:32:01,963 --> 00:32:04,923 More than 4 billion years ago, when the planet coalesced out 428 00:32:05,097 --> 00:32:08,970 of the disc of gas and dust that surrounded the newborn sun, 429 00:32:09,144 --> 00:32:13,932 a moon, or moons, likely violated Saturn's Roche limit... 430 00:32:15,542 --> 00:32:18,414 Others thought the rings to be fairly recent. 431 00:32:18,588 --> 00:32:21,504 Perhaps, only 100 million years old or so. 432 00:32:21,678 --> 00:32:25,682 And the Cassini spacecraft proved them right. 433 00:32:27,510 --> 00:32:31,427 What is Earth's own Roche limit? 434 00:32:33,081 --> 00:32:36,476 If the Moon were ever to come closer than 12,000 miles, 435 00:32:36,650 --> 00:32:40,219 which, by the way, it's absolutely in no danger of doing. 436 00:32:50,142 --> 00:32:52,622 And it's a good thing, too, 437 00:32:52,796 --> 00:32:56,931 because I like our Moon right where it is. 438 00:33:03,938 --> 00:33:06,332 There's only one other moon in the solar system that moves 439 00:33:06,506 --> 00:33:08,508 me like ours does. 440 00:33:08,682 --> 00:33:10,901 Maybe it's because it's the only one with a thick 441 00:33:11,076 --> 00:33:13,948 atmosphere like Earth's, and the kind of surface features, 442 00:33:14,122 --> 00:33:17,604 lakes and mountains, that remind me of home. 443 00:33:17,778 --> 00:33:21,782 All of this was hidden from view by a dense layer 444 00:33:21,956 --> 00:33:25,264 of orange smog, until the European Space Agency 445 00:33:25,438 --> 00:33:28,571 collaborated with NASA to send a spacecraft to land 446 00:33:28,745 --> 00:33:31,792 on his mysterious surface. 447 00:33:31,966 --> 00:33:35,056 Yes, that would be the one named after you, 448 00:33:35,230 --> 00:33:40,714 Christiaan Huygens, first to see that world through your telescope. 449 00:33:48,330 --> 00:33:51,377 After an interplanetary voyage of seven years, 450 00:33:51,551 --> 00:33:55,207 the Cassini-Huygens spacecraft arrived in the Saturn system, 451 00:33:55,381 --> 00:33:58,079 the fourth of our ships to venture there. 452 00:33:58,253 --> 00:34:03,084 But the first to send a probe to explore the surface of Saturn's moon, Titan 453 00:34:09,047 --> 00:34:12,224 and to reveal a moon of far greater complexity and splendor 454 00:34:12,398 --> 00:34:15,836 than our own rather dull and lifeless Moon. 455 00:34:27,282 --> 00:34:31,069 As Carl Sagan had predicted more than two decades before, 456 00:34:31,243 --> 00:34:33,810 there were seas of methane, and ethane, 457 00:34:33,984 --> 00:34:37,031 and there was water-ice. 458 00:34:38,728 --> 00:34:41,557 When Cassini first arrived in 2004 at Saturn's 459 00:34:41,731 --> 00:34:45,996 northern hemisphere, it was in the depths of winter. 460 00:34:46,171 --> 00:34:48,956 And the Sun didn't come out until five years later, 461 00:34:49,130 --> 00:34:52,394 when Saturn's northern spring began. 462 00:34:52,568 --> 00:34:56,616 Is it just me, or is this whirling hexagon at Saturn's 463 00:34:56,790 --> 00:35:01,011 North Pole every bit as exotic as the fantasies our ancient 464 00:35:01,186 --> 00:35:04,145 ancestors had of these worlds? 465 00:35:04,319 --> 00:35:07,061 The geometrically regular hexagonal shape of this 466 00:35:07,235 --> 00:35:11,370 feature brings to mind the handiwork of intelligence, 467 00:35:11,544 --> 00:35:16,462 terraforming, re-working the surface for some unknown purpose. 468 00:35:17,463 --> 00:35:20,553 But it's actually the result of the sudden change in wind 469 00:35:20,727 --> 00:35:25,384 speeds as vast upwellings of ammonia rise near the poles. 470 00:35:25,558 --> 00:35:28,082 It's the mother of all hurricanes, 471 00:35:28,256 --> 00:35:30,693 a frenzy of thunder and lightning, 472 00:35:30,867 --> 00:35:34,088 containing countless hurricanes within it. 473 00:35:34,610 --> 00:35:37,918 Spring can be a violent, stormy season, on Earth, too. 474 00:35:38,092 --> 00:35:41,574 But it was during Saturn's seven year-long summer that 475 00:35:41,748 --> 00:35:45,752 Cassini was commanded to take her own life. 476 00:36:04,423 --> 00:36:10,124 ♪ ♪ 477 00:36:10,298 --> 00:36:13,780 TYSON: There's a human conceit that at the moment of death, 478 00:36:13,954 --> 00:36:17,175 we re-live our greatest memories. 479 00:36:21,744 --> 00:36:25,226 You are riffling through the memory bank of a doomed robot, 480 00:36:25,400 --> 00:36:29,317 about to carry out the cruelest command. 481 00:36:44,854 --> 00:36:51,383 ♪ ♪ 482 00:37:12,491 --> 00:37:18,279 ♪ ♪ 483 00:37:39,300 --> 00:37:46,089 ♪ ♪ 484 00:38:05,979 --> 00:38:12,246 ♪ ♪ 485 00:38:32,179 --> 00:38:38,620 ♪ ♪ 486 00:38:39,099 --> 00:38:42,276 The mission planners at NASA's Jet Propulsion Laboratory 487 00:38:42,450 --> 00:38:45,540 call this the "“ball of yarn,"” 488 00:38:45,714 --> 00:38:49,979 13 years of exploration through the Saturn system. 489 00:38:53,809 --> 00:38:58,466 From the time of her launch in 1997 and throughout her epic voyage, 490 00:38:58,640 --> 00:39:05,125 she has used the gravity assist conceived 100 years before by Yuri Kondratyuk. 491 00:39:06,256 --> 00:39:08,650 But it was her supply of rocket fuel that made it 492 00:39:08,824 --> 00:39:11,871 possible for her Earthbound controllers to steer her into 493 00:39:12,045 --> 00:39:15,353 new trajectories of exploration. 494 00:39:15,527 --> 00:39:20,183 In April of 2017, Cassini was running low on that fuel. 495 00:39:20,358 --> 00:39:23,839 It was time for her most daring maneuvers of all, 496 00:39:24,013 --> 00:39:27,756 before she was to be sent into a final death dive. 497 00:39:38,680 --> 00:39:41,901 These are the mission scientists of Cassini, 498 00:39:42,075 --> 00:39:43,946 some of whom have been working on the project since 499 00:39:44,120 --> 00:39:48,255 the 1990s, when it was no more than a dream. 500 00:39:48,429 --> 00:39:52,433 They know that Cassini must die. 501 00:39:52,607 --> 00:39:55,393 It's too dangerous to let her wander aimlessly. 502 00:39:55,567 --> 00:39:58,308 She might crash into one of the moons in the Saturn system 503 00:39:58,483 --> 00:40:00,963 where life might be hiding. 504 00:40:01,137 --> 00:40:04,010 This would violate NASA's planetary protection 505 00:40:04,184 --> 00:40:08,144 conventions on quarantine in the book of space laws. 506 00:40:08,841 --> 00:40:11,191 If left to chance, Cassini could alter the 507 00:40:11,365 --> 00:40:15,848 possible biological destiny of Titan or Enceladus. 508 00:40:18,459 --> 00:40:22,811 A terrible command must now be given. 509 00:40:31,385 --> 00:40:34,606 Cassini is so far away, it will take the message, 510 00:40:34,780 --> 00:40:36,651 traveling at the speed of light, 511 00:40:36,825 --> 00:40:39,132 more than an hour to reach her. 512 00:40:39,306 --> 00:40:42,440 Every microchip in her has been programmed to resist 513 00:40:42,614 --> 00:40:45,486 the commands she's now receiving. 514 00:40:45,660 --> 00:40:48,881 The inner-turmoil of the loyal robot commanded to defy 515 00:40:49,055 --> 00:40:52,537 her own instincts must be fierce. 516 00:40:52,711 --> 00:40:55,496 The same engineers who ordered her to protect herself 517 00:40:55,670 --> 00:41:00,675 in every situation now force her to plunge to her death. 518 00:41:02,285 --> 00:41:04,636 They must be obeyed. 519 00:41:04,810 --> 00:41:06,551 MAN [over radio]: System lead ace. 520 00:41:06,725 --> 00:41:10,380 We have telemetry AOS at zero one. 521 00:41:10,555 --> 00:41:13,775 One, niner. One two. 522 00:41:15,560 --> 00:41:17,736 TYSON: She fights off the immense forces by struggling 523 00:41:17,910 --> 00:41:20,652 to right herself one last time. 524 00:41:20,826 --> 00:41:23,568 She fires her thrusters at 100%, 525 00:41:23,742 --> 00:41:26,440 all the while faithfully sending back more data than 526 00:41:26,614 --> 00:41:29,356 her designers ever hoped she would. 527 00:41:29,530 --> 00:41:31,140 WOMAN [over radio]: Project Manager. Flight Director. 528 00:41:31,314 --> 00:41:33,142 MAN [over radio]: Go ahead. 529 00:41:33,316 --> 00:41:36,232 WOMAN [over radio]: Okay. We'd call loss of signal at 11:55:46. 530 00:41:37,886 --> 00:41:40,759 TYSON: She fights the brutal atmospheric resistance until 531 00:41:40,933 --> 00:41:43,196 her fuel tanks are empty, 532 00:41:43,370 --> 00:41:46,329 and there's no more fight left in her. 533 00:41:47,983 --> 00:41:52,118 MAN [over radio]: Project manager on, maybe a trickle of telemetry left, but, 534 00:41:52,292 --> 00:41:56,731 just heard the signal from the spacecraft is gone 535 00:41:56,905 --> 00:42:00,953 and within the next 45 seconds so will be the spacecraft. 536 00:42:14,096 --> 00:42:19,101 ♪ ♪ 537 00:42:19,275 --> 00:42:24,454 TYSON: Official time of death: 11:55 universal time. 538 00:42:27,022 --> 00:42:31,461 There are all kinds of stories in the struggle to understand the cosmos. 539 00:42:31,636 --> 00:42:34,595 Sometimes your dreams die with you, 540 00:42:34,769 --> 00:42:39,121 but sometimes the scientists of another age pick them up, 541 00:42:39,295 --> 00:42:43,038 and take them to the Moon, and far beyond. 542 00:42:45,693 --> 00:42:49,523 The name of Yuri Kondratyuk was forgotten, 543 00:42:49,697 --> 00:42:53,266 but there was one who remembered. 544 00:42:56,356 --> 00:42:59,707 When Neil Armstrong returned from his trip to the Moon, 545 00:42:59,881 --> 00:43:03,363 he made a pilgrimage to the childhood home of the man 546 00:43:03,537 --> 00:43:06,584 who made his mythic voyage possible. 547 00:43:08,847 --> 00:43:13,591 ♪ ♪ 548 00:43:53,065 --> 00:43:54,980 Captioned by Cotter Captioning Services.