1 00:00:48,730 --> 00:00:52,564 SAGAN: Imagine that we are travelers from the stars... 2 00:00:52,767 --> 00:00:55,099 ...bound for the sun. 3 00:00:55,303 --> 00:01:00,240 We would discover it surrounded by four giant, cloudy, gas worlds: 4 00:01:00,742 --> 00:01:04,269 Blue Neptune and its frozen moon, Triton. 5 00:01:07,148 --> 00:01:11,346 And then farther in, Uranus and its dark rings... 6 00:01:11,553 --> 00:01:14,852 ...made perhaps of organic matter. 7 00:01:30,204 --> 00:01:34,766 Saturn, the jewel of the solar system... 8 00:01:35,209 --> 00:01:39,111 ...set within concentric rings... 9 00:01:39,314 --> 00:01:44,013 ...composed of a billion icy moons. 10 00:01:55,797 --> 00:02:00,496 And finally, flanked by massive satellites... 11 00:02:00,702 --> 00:02:04,001 ...the largest planet, Jupiter. 12 00:02:04,472 --> 00:02:06,337 Its multicolored clouds... 13 00:02:06,541 --> 00:02:09,806 ...studded with flashes of lightning. 14 00:02:14,782 --> 00:02:16,613 Still farther in... 15 00:02:16,985 --> 00:02:19,249 ...closer to the sun... 16 00:02:19,621 --> 00:02:22,215 ...there are no more giant planets... 17 00:02:22,590 --> 00:02:25,957 ...only a host of lesser worlds... 18 00:02:26,160 --> 00:02:28,492 ...made of rock and metal... 19 00:02:28,696 --> 00:02:32,291 ...some with a thin envelope of air. 20 00:02:32,500 --> 00:02:34,127 They huddle about the sun... 21 00:02:34,335 --> 00:02:37,600 ...with almost no internal heat of their own... 22 00:02:38,172 --> 00:02:41,471 ...tiny places with solid surfaces... 23 00:02:41,676 --> 00:02:45,544 ...one of which is a blue and pretty world... 24 00:02:45,747 --> 00:02:47,305 ...called Earth. 25 00:02:48,383 --> 00:02:50,010 Half-covered with clouds... 26 00:02:50,218 --> 00:02:52,277 ...it is the home planet of travelers... 27 00:02:52,487 --> 00:02:55,820 ...who have just learned to sail the sea of space... 28 00:02:56,157 --> 00:02:58,455 ...to investigate close-up... 29 00:02:58,660 --> 00:03:01,356 ...Jupiter, Saturn, Uranus and Neptune... 30 00:03:01,562 --> 00:03:06,329 ...its brothers and sisters in the family of the sun. 31 00:03:13,241 --> 00:03:16,733 Human voyages of exploration to the outer solar system... 32 00:03:16,944 --> 00:03:21,210 ...are controlled, so far, from a single place on the planet Earth... 33 00:03:21,783 --> 00:03:23,444 ...the Jet Propulsion Laboratory... 34 00:03:23,651 --> 00:03:26,211 ...of the National Aeronautics and Space Administration... 35 00:03:26,421 --> 00:03:28,981 ...in Pasadena, California. 36 00:03:34,162 --> 00:03:38,121 Here on Sunday, July 8th, 1979... 37 00:03:38,332 --> 00:03:40,266 ...the Voyager 2 spacecraft... 38 00:03:40,468 --> 00:03:43,926 ...began its close passage by Jupiter and its moons. 39 00:03:50,478 --> 00:03:51,968 General science systems... 40 00:03:52,180 --> 00:03:53,943 JPL MAN: ...are you ready with status check? 41 00:03:54,148 --> 00:03:55,206 Yes, I am. 42 00:03:55,583 --> 00:03:57,483 SAGAN: The spacecraft had been instructed... 43 00:03:57,685 --> 00:03:59,448 ...how to explore the Jupiter system... 44 00:03:59,654 --> 00:04:01,622 ...by a sequence of commands radioed earlier... 45 00:04:01,823 --> 00:04:03,484 ...to its onboard computers. 46 00:04:03,691 --> 00:04:05,625 Power, 450 watts. 47 00:04:05,893 --> 00:04:07,360 Power is go at this time. 48 00:04:07,562 --> 00:04:09,154 DSE systems. 49 00:04:12,767 --> 00:04:14,860 LACP mode is far and counter. 50 00:04:15,136 --> 00:04:16,967 We are at take 210. 51 00:04:17,171 --> 00:04:20,572 Direction last recorded was reversed, and the track is track one. 52 00:04:20,775 --> 00:04:24,142 Here we check how faithful an emissary Voyager is. 53 00:04:25,012 --> 00:04:26,946 Does it understand the commands? 54 00:04:27,148 --> 00:04:29,309 How is its health, its temperature... 55 00:04:29,584 --> 00:04:30,983 ...its brains... 56 00:04:31,185 --> 00:04:32,174 ...its heart? 57 00:04:33,087 --> 00:04:35,180 Yes, detailed science is coming up... 58 00:04:35,957 --> 00:04:37,822 "A" systems... 59 00:04:38,226 --> 00:04:40,160 ...completed the status check... 60 00:04:40,361 --> 00:04:42,386 ...and the spacecraft is go. 61 00:04:42,597 --> 00:04:43,586 Roger. Thank you. 62 00:04:43,798 --> 00:04:48,235 SAGAN: The modern ships that sail to the planets are unmanned. 63 00:04:48,436 --> 00:04:50,165 They are beautifully constructed... 64 00:04:50,371 --> 00:04:53,636 ...semi-intelligent robots. 65 00:04:54,242 --> 00:04:56,972 Voyager's eyes are two television cameras... 66 00:04:57,178 --> 00:05:01,808 ...designed to take many thousands of pictures in the solar system. 67 00:05:02,016 --> 00:05:05,747 Along with other instruments, they are mounted on a scan platform... 68 00:05:05,953 --> 00:05:08,615 ...which points at passing planets. 69 00:05:08,990 --> 00:05:13,791 Voyager's brains are three integrated computers set amidships. 70 00:05:13,995 --> 00:05:16,896 It communicates with Earth through a radio antenna... 71 00:05:17,098 --> 00:05:19,032 ...mounted like a sail. 72 00:05:19,233 --> 00:05:22,100 Voyager bears a message for any alien civilization... 73 00:05:22,303 --> 00:05:25,795 ...it may one day encounter in interstellar space. 74 00:05:26,641 --> 00:05:31,010 Its louvers open and shut to help control the onboard temperature. 75 00:05:32,180 --> 00:05:34,944 But Voyager cruises so far from the sun... 76 00:05:35,149 --> 00:05:37,310 ...that it cannot depend on solar power. 77 00:05:37,518 --> 00:05:41,079 Instead, it has a small nuclear power plant... 78 00:05:41,289 --> 00:05:44,417 ...quarantined from the rest of the ship. 79 00:05:53,901 --> 00:05:56,870 Many things can go wrong in such pioneering missions. 80 00:05:57,338 --> 00:05:59,533 So people are a little uneasy... 81 00:05:59,740 --> 00:06:02,072 ...at Voyager mission control. 82 00:06:02,476 --> 00:06:06,037 Jupiter is surrounded by a shell of invisible but extremely dangerous... 83 00:06:06,247 --> 00:06:08,238 ...high-energy charged particles. 84 00:06:08,950 --> 00:06:10,747 If Voyager flies too close... 85 00:06:10,952 --> 00:06:14,080 ...its delicate electronics will be fried. 86 00:06:14,288 --> 00:06:17,485 A collision with a small boulder in the rings of Jupiter... 87 00:06:17,692 --> 00:06:20,855 ...could send the spacecraft tumbling wildly out of control... 88 00:06:21,062 --> 00:06:24,793 ...its antenna unable to find the Earth, its data lost forever. 89 00:06:30,004 --> 00:06:32,131 Voyager 1 and Voyager 2... 90 00:06:32,340 --> 00:06:36,436 ...were launched a month apart in late summer of 1977. 91 00:06:36,644 --> 00:06:38,942 After many alarms and close calls... 92 00:06:39,146 --> 00:06:42,877 ...they successfully arrived months apart at the Jupiter system... 93 00:06:43,084 --> 00:06:44,608 ...where they worked brilliantly... 94 00:06:44,819 --> 00:06:47,686 ...providing the first close-up views of mighty Jupiter... 95 00:06:47,889 --> 00:06:50,722 ...and its four large and mysterious moons: 96 00:06:50,925 --> 00:06:54,554 Io, the innermost of the four... 97 00:06:55,096 --> 00:06:56,586 ...Europa... 98 00:06:56,831 --> 00:07:00,096 ...and moving away from Jupiter... 99 00:07:00,301 --> 00:07:01,768 ...Ganymede... 100 00:07:03,170 --> 00:07:06,571 ...and the outermost big moon... 101 00:07:06,774 --> 00:07:08,139 ...Callisto. 102 00:07:09,844 --> 00:07:14,144 In a mission that costs a penny a world... 103 00:07:14,348 --> 00:07:17,681 ...for every human on the planet Earth. 104 00:07:24,091 --> 00:07:26,355 Voyager's passage by Jupiter... 105 00:07:26,560 --> 00:07:29,757 ...accelerated it towards the planet Saturn. 106 00:07:29,964 --> 00:07:33,024 Saturn's gravity will propel it on to Uranus... 107 00:07:33,234 --> 00:07:37,000 ...and in this game of cosmic billiards, after Uranus... 108 00:07:37,204 --> 00:07:41,402 ...it will plunge on past Neptune, leaving the solar system... 109 00:07:41,609 --> 00:07:44,009 ...and becoming an interstellar spacecraft... 110 00:07:44,211 --> 00:07:47,009 ...destined to wander forever... 111 00:07:47,214 --> 00:07:49,808 ...the great ocean between the stars. 112 00:07:50,017 --> 00:07:53,817 And if Voyager should, sometime in its distant future... 113 00:07:54,021 --> 00:07:58,720 ...encounter beings from some other civilization in space... 114 00:07:58,926 --> 00:08:01,360 ...it bears a message. 115 00:08:01,562 --> 00:08:05,430 A phonograph record. Golden, delicate... 116 00:08:06,500 --> 00:08:08,195 ...with instruction for use. 117 00:08:08,469 --> 00:08:13,099 And on this record are a sampling of pictures, sounds, greetings... 118 00:08:13,741 --> 00:08:16,005 ...and an hour and a half of exquisite music... 119 00:08:16,210 --> 00:08:18,770 ...the Earth's greatest hits. 120 00:08:18,980 --> 00:08:20,914 A gift across the cosmic ocean... 121 00:08:21,115 --> 00:08:25,279 ...from one island of civilization to another. 122 00:08:26,887 --> 00:08:30,015 The record bears in English... 123 00:08:30,224 --> 00:08:33,125 ...an additional handwritten greeting that says: 124 00:08:33,694 --> 00:08:38,427 "To the makers of music, all worlds, all times." 125 00:08:38,733 --> 00:08:42,134 These voyages of exploration and discovery... 126 00:08:42,503 --> 00:08:45,404 ...are the latest in a long series which have characterized... 127 00:08:45,606 --> 00:08:48,973 ...and distinguished the human species. 128 00:08:49,176 --> 00:08:51,406 In the 15th and 16th centuries... 129 00:08:51,612 --> 00:08:54,979 ...you could travel from Spain to the Azores in a few days. 130 00:08:55,182 --> 00:08:58,151 The same time it takes now to cross that little channel... 131 00:08:58,352 --> 00:09:00,411 ...from the Earth to the moon. 132 00:09:01,422 --> 00:09:04,789 It took, then, a few months to traverse the Atlantic Ocean... 133 00:09:04,992 --> 00:09:07,654 ...and reach what was called the "New World"... 134 00:09:07,862 --> 00:09:08,851 ...the Americas. 135 00:09:09,063 --> 00:09:12,829 Today it takes a few months to cross the inner solar system... 136 00:09:13,034 --> 00:09:16,094 ...and reach Mars and Venus, truly and literally... 137 00:09:16,303 --> 00:09:18,498 ...new worlds awaiting us. 138 00:09:19,840 --> 00:09:21,637 In the 17th and 18th centuries... 139 00:09:21,842 --> 00:09:26,074 ...you could travel from Holland to China, say, in a year or two... 140 00:09:26,280 --> 00:09:28,339 ...the same time it takes now for Voyager... 141 00:09:28,549 --> 00:09:30,949 ...to travel from the Earth to Jupiter. 142 00:09:34,722 --> 00:09:38,214 And in comparison to the resources of the society... 143 00:09:38,426 --> 00:09:41,759 ...it cost more then to send sailing ships to the Far East... 144 00:09:41,962 --> 00:09:45,489 ...than it does now to send spaceships to the planets. 145 00:09:49,236 --> 00:09:51,227 The passion to explore... 146 00:09:51,439 --> 00:09:53,771 ...is at the heart of being human. 147 00:09:53,974 --> 00:09:56,704 This impulse to go, to see, to know... 148 00:09:56,911 --> 00:09:59,436 ...has found expression in every culture. 149 00:10:01,182 --> 00:10:04,640 Africa was circumnavigated by Phoenician sailors... 150 00:10:04,852 --> 00:10:07,446 ...in the employ of an Egyptian pharaoh... 151 00:10:07,655 --> 00:10:10,681 ...in the 7th century B.C. 152 00:10:11,959 --> 00:10:14,393 The islands of the Pacific were settled... 153 00:10:14,595 --> 00:10:18,031 ...by skilled and heroic navigators from Indonesia. 154 00:10:19,500 --> 00:10:22,094 Great fleets of ocean-going junks... 155 00:10:22,303 --> 00:10:25,170 ...left the ports of Ming Dynasty China... 156 00:10:25,372 --> 00:10:28,136 ...to explore India and Africa. 157 00:10:28,843 --> 00:10:31,539 A century later, three ships left Spain... 158 00:10:31,745 --> 00:10:34,111 ...under the command of an Italian navigator... 159 00:10:34,315 --> 00:10:36,408 ...to discover the Americas. 160 00:10:37,284 --> 00:10:40,151 And then a Portuguese expedition succeeded... 161 00:10:40,354 --> 00:10:43,983 ...in sailing all the way around this blue globe. 162 00:10:45,426 --> 00:10:48,020 These voyagers of many cultures... 163 00:10:48,229 --> 00:10:50,891 ...were the first planetary explorers. 164 00:10:51,098 --> 00:10:54,192 They have bound the Earth up into one world. 165 00:10:54,401 --> 00:10:56,460 In our exploration of other worlds... 166 00:10:56,670 --> 00:10:59,298 ...we follow in their footsteps. 167 00:11:01,408 --> 00:11:04,468 Our present spaceships are the harbingers... 168 00:11:04,678 --> 00:11:09,615 ...the vanguard of future human expeditions to the planets. 169 00:11:10,217 --> 00:11:13,186 We have traveled this way before... 170 00:11:13,387 --> 00:11:16,550 ...and there is much to be learned... 171 00:11:16,757 --> 00:11:20,659 ...by studying those great voyages of a few centuries ago. 172 00:11:34,808 --> 00:11:36,366 In the 17th century... 173 00:11:36,577 --> 00:11:39,045 ...the citizens of the new Dutch Republic... 174 00:11:39,246 --> 00:11:43,808 ...pursued a course of vigorous planetary exploration. 175 00:11:45,486 --> 00:11:47,886 Holland was then a revolutionary society. 176 00:11:48,088 --> 00:11:51,057 It had just declared its independence from the powerful... 177 00:11:51,258 --> 00:11:53,249 ...but stagnant Spanish empire... 178 00:11:53,460 --> 00:11:55,655 ...and with a newfound self-confidence... 179 00:11:55,863 --> 00:11:58,798 ...Holland embraced, more fully than any other nation of its time... 180 00:11:58,999 --> 00:12:02,457 ...the spirit of the European Enlightenment. 181 00:12:07,208 --> 00:12:10,837 It was a rational, orderly and creative society. 182 00:12:11,045 --> 00:12:14,446 But because Spanish ports and vessels were closed to the Dutch... 183 00:12:14,648 --> 00:12:16,809 ...the economic survival of the tiny republic... 184 00:12:17,017 --> 00:12:21,249 ...depended on its ability to construct, man and operate... 185 00:12:21,455 --> 00:12:24,185 ...a great fleet of commercial sailing vessels. 186 00:12:28,495 --> 00:12:30,326 The Dutch East India Company... 187 00:12:30,531 --> 00:12:33,625 ...was a combined governmental and commercial enterprise... 188 00:12:33,834 --> 00:12:36,462 ...which sent shipping to the far corners of the world... 189 00:12:36,670 --> 00:12:41,164 ...to acquire rare commodities and resell them at a profit in Europe. 190 00:12:41,375 --> 00:12:44,970 Such voyages were the life's blood of the republic. 191 00:12:48,949 --> 00:12:53,181 Navigational charts and maps were classified as state secrets. 192 00:12:53,554 --> 00:12:56,682 Ships sometimes left with sealed sailing orders... 193 00:12:56,890 --> 00:12:59,882 ...the crews embarking for an unknown destination... 194 00:13:00,094 --> 00:13:03,894 ...more than a year away on the far side of the planet. 195 00:13:06,734 --> 00:13:09,999 These expeditions were not only commercial exploitations... 196 00:13:10,204 --> 00:13:12,263 ...although there was certainly plenty of that. 197 00:13:12,473 --> 00:13:15,704 Beside the usual appeals of ambition, greed... 198 00:13:15,909 --> 00:13:18,639 ...national pride and the thirst for adventure... 199 00:13:19,013 --> 00:13:22,847 ...the Dutch were also motivated by a powerful scientific curiosity... 200 00:13:23,050 --> 00:13:25,678 ...and a fascination with all things new. 201 00:13:25,886 --> 00:13:28,821 New lands, new peoples... 202 00:13:29,023 --> 00:13:30,650 ...new plants and animals. 203 00:13:36,330 --> 00:13:39,731 This building, then the Amsterdam town hall... 204 00:13:39,933 --> 00:13:43,061 ...still attests to the hardy self-assurance... 205 00:13:43,270 --> 00:13:45,204 ...of its 17th-century architects. 206 00:13:45,406 --> 00:13:48,864 Its lavish crystal adornments still reflect... 207 00:13:49,076 --> 00:13:52,068 ...the glittering pride they felt in their accomplishments... 208 00:13:52,279 --> 00:13:53,712 ...and their prosperity. 209 00:13:53,914 --> 00:13:57,315 It took shiploads of marble to build this place. 210 00:13:57,518 --> 00:14:01,614 Constantin Huygens, a poet and diplomat of the time... 211 00:14:01,822 --> 00:14:05,280 ...said that this town hall dispelled what he called... 212 00:14:05,492 --> 00:14:08,859 ..."the Gothic squint and squalor." 213 00:14:10,664 --> 00:14:15,499 The Middle Ages had ended, the Enlightenment had begun. 214 00:14:19,073 --> 00:14:21,303 Up there, do you see... 215 00:14:21,508 --> 00:14:25,945 ...is Atlas supporting the heavens on his shoulders. 216 00:14:26,547 --> 00:14:28,174 And beneath... 217 00:14:29,616 --> 00:14:32,585 ...is Justice with a golden sword... 218 00:14:32,786 --> 00:14:35,448 ...and golden scales flanked... 219 00:14:36,390 --> 00:14:39,450 ...by Death and Punishment. 220 00:14:39,960 --> 00:14:44,158 And who is it that Justice is trampling underfoot? 221 00:14:44,365 --> 00:14:48,734 Why, it's Avarice and Envy... 222 00:14:48,936 --> 00:14:51,666 ...the gods of the merchants. 223 00:14:51,872 --> 00:14:55,933 The Dutch knew that the unrestrained pursuit of profit... 224 00:14:56,143 --> 00:14:59,874 ...posed serious threats to the soul of the nation. 225 00:15:01,081 --> 00:15:03,549 A less allegorical symbol... 226 00:15:03,751 --> 00:15:06,447 ...is down here, on the floor. 227 00:15:09,757 --> 00:15:12,954 It is a great inlaid map... 228 00:15:13,160 --> 00:15:17,859 ...stretching from West Africa to the Pacific Ocean. 229 00:15:18,065 --> 00:15:21,933 The whole world was then Holland's arena. 230 00:15:23,470 --> 00:15:26,337 In a typical year, many sailing vessels... 231 00:15:26,540 --> 00:15:29,839 ...set out halfway around the world for the Far East... 232 00:15:30,043 --> 00:15:34,104 ...on voyages of exploration and discovery, of trade... 233 00:15:34,314 --> 00:15:37,112 ...journeys taking years to accomplish. 234 00:15:37,317 --> 00:15:41,276 Down the west coast of Africa, through what they called the Ethiopian sea... 235 00:15:41,488 --> 00:15:44,286 ...skirting the southern coast of Africa... 236 00:15:44,491 --> 00:15:47,221 ...through the Straits of Madagascar... 237 00:15:47,428 --> 00:15:51,228 ...and on past the southern tip of India... 238 00:15:51,432 --> 00:15:56,335 ...to the Spice Islands and present-day Indonesia. 239 00:16:01,442 --> 00:16:05,037 Another set of voyages went south then east, to New Holland... 240 00:16:05,245 --> 00:16:07,770 ...later renamed Australia. 241 00:16:13,320 --> 00:16:17,381 And still other journeys ventured through the Straits of Malacca... 242 00:16:17,858 --> 00:16:20,486 ...to the Empire of China. 243 00:16:22,129 --> 00:16:26,998 But Holland was a small country forced to live by its wits. 244 00:16:27,201 --> 00:16:29,897 There was a strong pacifist element in its foreign policy. 245 00:16:30,704 --> 00:16:34,435 Never before or since has Holland boasted such a galaxy... 246 00:16:34,641 --> 00:16:38,338 ...of scientists, mathematicians, philosophers and artists. 247 00:16:40,347 --> 00:16:43,783 This was the time of the great painters, Rembrandt... 248 00:16:44,952 --> 00:16:46,647 ...and Vermeer. 249 00:16:48,155 --> 00:16:52,922 Because Holland was tolerant of unorthodox opinions... 250 00:16:53,126 --> 00:16:55,890 ...it was a refuge for intellectuals... 251 00:16:56,096 --> 00:17:00,430 ...fleeing the thought control and censorship of other parts of Europe... 252 00:17:00,767 --> 00:17:04,533 ...much as the United States benefited enormously in the 1930s... 253 00:17:04,738 --> 00:17:07,400 ...from the exodus of intellectuals... 254 00:17:07,608 --> 00:17:09,803 ...from Nazi-dominated Europe. 255 00:17:10,010 --> 00:17:12,604 And so it was that 17th-century Holland... 256 00:17:12,813 --> 00:17:16,374 ...was the home of the great Jewish philosopher Spinoza... 257 00:17:16,583 --> 00:17:18,983 ...who Einstein admired so much... 258 00:17:19,186 --> 00:17:22,019 ...of René Descartes, a pivotal figure... 259 00:17:22,222 --> 00:17:25,282 ...in the history of philosophy and of mathematics... 260 00:17:25,492 --> 00:17:29,758 ...and the home of a political scientist named John Locke... 261 00:17:29,963 --> 00:17:33,194 ...who was to have a powerful... 262 00:17:33,400 --> 00:17:35,265 ...and profound influence... 263 00:17:35,469 --> 00:17:39,565 ...on a group of philosophically inclined revolutionaries... 264 00:17:39,773 --> 00:17:43,573 ...named Paine, Hamilton, Adams... 265 00:17:43,777 --> 00:17:45,938 ...Franklin and Jefferson. 266 00:17:48,649 --> 00:17:51,117 The Dutch University of Leyden... 267 00:17:51,318 --> 00:17:56,119 ...offered a professorship to an Italian scientist named Galileo... 268 00:17:56,323 --> 00:17:59,156 ...who had been forced by the Catholic Church... 269 00:17:59,359 --> 00:18:01,122 ...under threat of torture... 270 00:18:01,328 --> 00:18:04,229 ...to recant the heretical position... 271 00:18:04,431 --> 00:18:08,959 ...that the Earth went around the sun and not vice versa. 272 00:18:09,269 --> 00:18:11,703 Galileo had close ties with Holland. 273 00:18:11,905 --> 00:18:13,736 His first astronomical telescope was based... 274 00:18:13,941 --> 00:18:16,933 ...on a spyglass of Dutch manufacture. 275 00:18:17,144 --> 00:18:21,205 And with it, he discovered the craters of the moon... 276 00:18:21,415 --> 00:18:26,114 ...the phases of Venus and the four large moons of Jupiter. 277 00:18:28,522 --> 00:18:30,649 Becoming an exploratory power... 278 00:18:30,857 --> 00:18:34,953 ...made Holland a vital intellectual and cultural center as well. 279 00:18:35,162 --> 00:18:39,724 The improvement of sailing technology spurred technology in general. 280 00:18:40,334 --> 00:18:44,361 A key problem in navigation was the determination of longitude. 281 00:18:44,571 --> 00:18:46,539 Latitude could be determined easily... 282 00:18:46,740 --> 00:18:49,709 ...the farther south, the more southern constellations you could see. 283 00:18:50,310 --> 00:18:54,303 But longitude required precise timekeeping. 284 00:18:56,750 --> 00:18:57,717 An accurate shipboard clock... 285 00:18:57,918 --> 00:19:00,478 ...would continue to keep time in your home port. 286 00:19:00,687 --> 00:19:03,815 The rising and setting of stars would give you the local time... 287 00:19:04,024 --> 00:19:06,515 ...and the difference between the two... 288 00:19:06,727 --> 00:19:09,218 ...would tell you how far east or west you had gone. 289 00:19:12,599 --> 00:19:15,227 Technological advance required the freest... 290 00:19:15,435 --> 00:19:16,925 ...possible pursuit of knowledge. 291 00:19:17,337 --> 00:19:21,273 So Holland became the leading publisher and bookseller in Europe... 292 00:19:21,475 --> 00:19:23,534 ...translating works written in other languages... 293 00:19:23,744 --> 00:19:26,941 ...and printing books that had been censored elsewhere. 294 00:19:28,615 --> 00:19:31,140 Adventures into exotic lands... 295 00:19:31,351 --> 00:19:33,785 ...and encounters with strange societies... 296 00:19:33,987 --> 00:19:35,545 ...shook complacency. 297 00:19:37,724 --> 00:19:39,954 They challenged the prevailing wisdom... 298 00:19:40,160 --> 00:19:43,561 ...and showed that ideas accepted for thousands of years... 299 00:19:43,764 --> 00:19:45,959 ...might be fundamentally in error. 300 00:19:58,278 --> 00:20:02,271 In a time when kings and emperors ruled much of the planet... 301 00:20:02,482 --> 00:20:05,940 ...the Dutch Republic was governed, more than any other world power... 302 00:20:06,153 --> 00:20:07,552 ...by the people. 303 00:20:13,794 --> 00:20:17,321 They enjoyed a certain material well-being. 304 00:20:17,531 --> 00:20:19,624 But the interiors of their houses... 305 00:20:19,833 --> 00:20:22,563 ...celebrated by a generation of Dutch painters... 306 00:20:22,769 --> 00:20:26,796 ...suggest restraint and discretion. 307 00:20:33,447 --> 00:20:36,814 The officers of these ships of exploration and trade... 308 00:20:37,017 --> 00:20:39,315 ...would return from their long voyages... 309 00:20:39,519 --> 00:20:41,817 ...share in the goods they had acquired... 310 00:20:42,255 --> 00:20:46,419 ...and discuss the wonders they had encountered. 311 00:20:52,666 --> 00:20:56,625 Holland prospered in its freedom of thought. 312 00:21:09,783 --> 00:21:13,241 In Italy, Galileo had announced other worlds. 313 00:21:13,453 --> 00:21:17,412 Giordano Bruno had speculated on intelligent life elsewhere. 314 00:21:17,624 --> 00:21:21,116 For this they were made to suffer brutally. 315 00:21:22,729 --> 00:21:25,789 But in Holland, the astronomer Christiaan Huygens... 316 00:21:25,999 --> 00:21:30,527 ...who strongly supported both ideas, was showered with honors. 317 00:21:32,773 --> 00:21:36,573 Christiaan was the son of Constantin Huygens. 318 00:21:38,044 --> 00:21:40,535 The elder Huygens distinguished himself... 319 00:21:40,747 --> 00:21:44,046 ...as a master diplomat of the age, a man of letters... 320 00:21:44,251 --> 00:21:48,312 ...a close friend and translator of the English poet, John Donne. 321 00:21:50,724 --> 00:21:55,661 Constantin was also an accomplished composer and musician. 322 00:22:08,441 --> 00:22:10,875 It was Constantin who had discovered a young painter... 323 00:22:11,077 --> 00:22:13,068 ...named Rembrandt van Rijn... 324 00:22:13,280 --> 00:22:16,613 ...in several of whose works he subsequently appears. 325 00:22:17,684 --> 00:22:19,584 He opened the doors of his house... 326 00:22:19,786 --> 00:22:21,651 ...to artists, musicians, writers... 327 00:22:21,855 --> 00:22:24,255 ...statesmen and scientists. 328 00:22:25,025 --> 00:22:27,050 A feast of goods and ideas... 329 00:22:27,260 --> 00:22:30,093 ...from all over the world awaited them. 330 00:22:32,465 --> 00:22:35,263 The philosopher Descartes, who visited him here... 331 00:22:35,468 --> 00:22:37,163 ...said of Constantin Huygens... 332 00:22:37,370 --> 00:22:40,032 ..."I could not believe that a single mind... 333 00:22:40,240 --> 00:22:42,970 ...could occupy itself with so many things... 334 00:22:43,176 --> 00:22:46,475 ...and acquit itself so well in all of them." 335 00:22:47,514 --> 00:22:49,948 He even excelled at the art of parenthood. 336 00:22:50,150 --> 00:22:52,414 He was a tender and loving father. 337 00:22:52,619 --> 00:22:56,111 His son, Christiaan, flourished in this rich environment... 338 00:22:56,323 --> 00:22:59,724 ...demonstrating extraordinary talents for languages, drawing... 339 00:22:59,926 --> 00:23:03,726 ...law, science, engineering mathematics and music. 340 00:23:07,400 --> 00:23:10,528 "The world is my country," he said... 341 00:23:10,737 --> 00:23:13,763 ..."science my religion." 342 00:23:18,879 --> 00:23:22,110 Light was the motif of the age... 343 00:23:22,315 --> 00:23:26,479 ...the symbolic enlightenment of freedom of thought and religion... 344 00:23:26,686 --> 00:23:29,951 ...the light that suffused the paintings of the time... 345 00:23:30,156 --> 00:23:33,421 ...and light as an object of scientific study. 346 00:23:33,727 --> 00:23:36,662 The microscope was invented in Holland at this time... 347 00:23:36,863 --> 00:23:40,697 ...and became a drawing-room curiosity. 348 00:23:41,701 --> 00:23:43,896 Its inventor was a friend of Christiaan Huygens... 349 00:23:44,104 --> 00:23:46,197 ...a man named Anton Leeuwenhoek. 350 00:23:55,782 --> 00:23:58,512 The first microscopes were developed from... 351 00:23:58,718 --> 00:24:00,845 ...magnifying glasses used by drapers... 352 00:24:01,054 --> 00:24:04,285 ...to examine the quality of cloth. 353 00:24:10,931 --> 00:24:12,421 Leeuwenhoek and Huygens... 354 00:24:12,632 --> 00:24:15,362 ...are the grandfathers of much of modern medicine. 355 00:24:16,836 --> 00:24:19,828 Because, to his amazement... 356 00:24:20,040 --> 00:24:22,668 ...Leeuwenhoek discovered a universe... 357 00:24:22,876 --> 00:24:24,366 ...in a drop of water: 358 00:24:24,577 --> 00:24:28,445 The microbes, which he described as "animalcules"... 359 00:24:28,648 --> 00:24:31,208 ...and thought "cute." 360 00:24:39,359 --> 00:24:41,054 Leeuwenhoek and Huygens... 361 00:24:41,261 --> 00:24:44,025 ...were among the first people to see human sperm cells... 362 00:24:44,230 --> 00:24:48,132 ...a hitherto hidden microcosm of the human life cycle. 363 00:24:49,202 --> 00:24:52,330 Leeuwenhoek had discovered the microbial world. 364 00:24:52,906 --> 00:24:56,364 Huygens had argued from his telescopic observations... 365 00:24:56,576 --> 00:24:58,601 ...that Mars was another world... 366 00:24:58,812 --> 00:25:01,804 ...and probably, an inhabited one. 367 00:25:08,054 --> 00:25:10,545 What a waste of a planet, he thought... 368 00:25:10,757 --> 00:25:13,191 ...if Mars were barren. 369 00:25:15,929 --> 00:25:19,296 So the Viking search for microbes on Mars... 370 00:25:19,499 --> 00:25:23,458 ...can be traced directly back to Huygens and Leeuwenhoek... 371 00:25:23,670 --> 00:25:26,138 ...in 17th-century Holland. 372 00:25:30,677 --> 00:25:34,135 The telescope and the microscope developed here... 373 00:25:34,347 --> 00:25:37,111 ...represent an extension of human vision... 374 00:25:37,317 --> 00:25:39,717 ...to the realms of the very small... 375 00:25:39,919 --> 00:25:41,944 ...and the very large. 376 00:25:45,191 --> 00:25:49,025 Our observations of atoms and galaxies... 377 00:25:49,229 --> 00:25:52,130 ...were launched in this time and place. 378 00:25:55,769 --> 00:25:58,237 From the bending of light through a lens... 379 00:25:58,438 --> 00:26:00,235 ...Huygens advanced the idea... 380 00:26:00,440 --> 00:26:02,931 ...that light was a kind of wave. 381 00:26:03,143 --> 00:26:05,111 He ground and polished lenses... 382 00:26:05,311 --> 00:26:08,712 ...for the successively larger telescopes he constructed... 383 00:26:08,915 --> 00:26:12,248 ...although it did take him a time to figure out... 384 00:26:12,452 --> 00:26:14,443 ...how to use them properly. 385 00:26:23,863 --> 00:26:26,354 Huygens was the first person to see a surface feature... 386 00:26:26,566 --> 00:26:28,124 ...on the planet Mars. 387 00:26:28,601 --> 00:26:30,364 He was the first person to speculate... 388 00:26:31,071 --> 00:26:33,369 ...that Venus is completely covered with clouds. 389 00:26:34,174 --> 00:26:38,076 He was the first person to understand the nature of the rings of Saturn. 390 00:26:38,278 --> 00:26:40,371 "Saturn is surrounded," he wrote... 391 00:26:40,580 --> 00:26:42,207 ..."by a thin, flat ring... 392 00:26:42,415 --> 00:26:45,907 ...which nowhere touches the body of the planet." 393 00:26:57,197 --> 00:26:59,028 His discoveries with the telescope... 394 00:26:59,232 --> 00:27:01,996 ...who by themselves have ensured his place... 395 00:27:02,202 --> 00:27:04,796 ...in the history of human accomplishment. 396 00:27:13,513 --> 00:27:17,108 Huygens was the discoverer of Titan... 397 00:27:17,317 --> 00:27:19,581 ...the largest moon of Saturn. 398 00:27:26,526 --> 00:27:30,587 The immense size and changing clouds of Jupiter entranced him. 399 00:27:33,967 --> 00:27:36,231 Astronomers, as well as navigators... 400 00:27:36,436 --> 00:27:40,338 ...need accurate clocks to time the movement of the heavens. 401 00:27:40,540 --> 00:27:43,907 Huygens was the inventor of many precision timepieces... 402 00:27:44,110 --> 00:27:46,510 ...including the pendulum clock. 403 00:27:54,654 --> 00:27:58,750 To illustrate the sun-centered universe of Copernicus... 404 00:27:58,958 --> 00:28:02,587 ...he built computers that reproduced the clockwork of the heavens... 405 00:28:03,363 --> 00:28:05,524 ...from Mercury to Saturn. 406 00:28:10,870 --> 00:28:13,532 The machines he designed, he signed... 407 00:28:13,740 --> 00:28:16,732 ..."Christiaan Huygens, inventor." 408 00:28:19,345 --> 00:28:21,313 He was delighted that the Copernican system... 409 00:28:21,514 --> 00:28:24,005 ...was widely accepted in everyday life in Holland... 410 00:28:24,250 --> 00:28:28,118 ...and acknowledged by astronomers, except those, he wrote... 411 00:28:28,321 --> 00:28:31,119 ...who "were a bit slow-witted or under the superstitions... 412 00:28:31,324 --> 00:28:35,021 ...imposed by merely human authority. 413 00:28:37,597 --> 00:28:41,624 Across the sea of space... 414 00:28:42,068 --> 00:28:44,059 ...the stars... 415 00:28:44,671 --> 00:28:46,605 ...are other suns." 416 00:28:46,806 --> 00:28:50,367 A point which Huygens appreciated perfectly well. 417 00:28:51,344 --> 00:28:56,281 He reasoned that if our planetary system... 418 00:28:56,583 --> 00:28:59,780 ...involved the sun and planets going around it... 419 00:28:59,986 --> 00:29:03,444 ...that those other suns should likewise have a retinue... 420 00:29:03,656 --> 00:29:05,385 ...of planets going around them... 421 00:29:05,592 --> 00:29:09,528 ...and also that many of the other planets were inhabited. 422 00:29:09,796 --> 00:29:11,764 He set forth these conclusions... 423 00:29:11,965 --> 00:29:14,957 ...in a remarkable book... 424 00:29:15,168 --> 00:29:17,830 ...bearing the triumphant title... 425 00:29:18,037 --> 00:29:21,473 ...The Celestial Worlds Discovered. 426 00:29:21,674 --> 00:29:23,141 The subtitle is... 427 00:29:23,343 --> 00:29:25,402 ..."Conjectures Concerning... 428 00:29:25,612 --> 00:29:30,447 ...the Inhabitants, Plants and Productions... 429 00:29:30,650 --> 00:29:33,915 ...of the Worlds in the Planets." 430 00:29:34,921 --> 00:29:38,755 He wrote this book sometime shortly before his death... 431 00:29:38,958 --> 00:29:42,724 ...in the year 1690, in this study. 432 00:29:49,836 --> 00:29:50,996 By and large... 433 00:29:51,571 --> 00:29:54,631 ...he imagined that the environments of the other planets... 434 00:29:54,841 --> 00:29:57,639 ...and also the inhabitants of the other planets... 435 00:29:57,844 --> 00:30:02,304 ...were pretty much like those of 17th-century Europe. 436 00:30:02,715 --> 00:30:04,910 I wonder if he imagined... 437 00:30:05,118 --> 00:30:07,848 ...traveling to those other worlds which he had been... 438 00:30:08,054 --> 00:30:10,352 ...the first to examine close-up... 439 00:30:10,556 --> 00:30:12,490 ...through the telescope. 440 00:30:13,126 --> 00:30:16,892 Perhaps he dreamt that voyages of discovery to the planets... 441 00:30:17,096 --> 00:30:20,793 ...would one day be like the voyages of geographical discovery... 442 00:30:21,000 --> 00:30:23,434 ...in his time and place. 443 00:30:25,905 --> 00:30:29,033 He did imagine of extraterrestrial beings... 444 00:30:30,243 --> 00:30:33,144 ..."that their whole bodies, and every part of them... 445 00:30:33,346 --> 00:30:36,907 ...may be quite distinct and different from ours. 446 00:30:37,116 --> 00:30:40,108 'Its a very ridiculous opinion," he says... 447 00:30:40,320 --> 00:30:42,447 ..."that it is impossible a rational soul... 448 00:30:42,655 --> 00:30:46,113 ...should dwell in any other shape than ours." 449 00:30:46,859 --> 00:30:49,157 You could be smart, Huygens was saying... 450 00:30:49,362 --> 00:30:51,091 ...even if you looked funny. 451 00:30:51,397 --> 00:30:53,262 But he then went on to argue... 452 00:30:53,466 --> 00:30:55,832 ...that they didn't look all that funny... 453 00:30:56,035 --> 00:30:58,503 ...that extraterrestrial beings must have... 454 00:30:58,705 --> 00:31:01,105 ...hands and feet and stand upright... 455 00:31:01,307 --> 00:31:03,172 ...and have writing and geometry. 456 00:31:03,376 --> 00:31:05,844 Even that the four moons of Jupiter... 457 00:31:06,045 --> 00:31:10,175 ...the Galilean satellites, were there in order to provide... 458 00:31:10,383 --> 00:31:13,045 ...a navigational aid, a convenience... 459 00:31:13,252 --> 00:31:15,812 ...for the sailors in the Jovian oceans. 460 00:31:16,155 --> 00:31:18,749 Well, maybe. 461 00:31:18,958 --> 00:31:20,892 (WOOD CREAKS) 462 00:31:25,832 --> 00:31:29,962 That bit of speculation is probably wrong, but... 463 00:31:30,169 --> 00:31:32,603 ...think of a citizen of the 17th century... 464 00:31:32,805 --> 00:31:35,273 ...with the courage and insight... 465 00:31:35,475 --> 00:31:39,138 ...to imagine other landscapes and other intelligences. 466 00:31:39,345 --> 00:31:42,075 Might there really be mariners... 467 00:31:42,281 --> 00:31:44,442 ...on a million other worlds? 468 00:31:47,487 --> 00:31:49,387 In his book, Huygens wrote: 469 00:31:49,589 --> 00:31:53,548 "What a wonderful and amazing scheme have we here... 470 00:31:53,760 --> 00:31:57,059 ...of the magnificent vastness of the universe. 471 00:31:57,263 --> 00:32:00,926 So many suns. So many earths. 472 00:32:01,134 --> 00:32:05,332 And every one of them stocked with so many animals. 473 00:32:05,605 --> 00:32:08,005 Adorned with so many seas. 474 00:32:08,207 --> 00:32:10,801 How must our wonder and admiration be increased... 475 00:32:11,310 --> 00:32:15,610 ...when we consider the prodigious distance and multitude... 476 00:32:15,815 --> 00:32:17,112 ...of the stars?" 477 00:32:23,956 --> 00:32:27,722 The Dutch called their ships "flying boats"... 478 00:32:27,927 --> 00:32:30,828 ...and the Voyager spacecraft are their descendants... 479 00:32:31,030 --> 00:32:33,328 ...true flying boats... 480 00:32:33,533 --> 00:32:36,263 ...bound for the stars, and on the way... 481 00:32:36,469 --> 00:32:39,768 ...exploring some of those worlds which Christiaan Huygens... 482 00:32:39,972 --> 00:32:41,405 ...a man from Earth... 483 00:32:41,607 --> 00:32:44,474 ...knew and loved so well. 484 00:32:46,345 --> 00:32:48,210 Travelers' tales: 485 00:32:48,414 --> 00:32:49,813 A main commodity... 486 00:32:50,016 --> 00:32:54,214 ...returned by those sailing ship voyages of centuries ago... 487 00:32:54,420 --> 00:32:56,820 ...were stories. 488 00:32:57,156 --> 00:33:01,490 Stories of alien lands and exotic creatures. 489 00:33:04,931 --> 00:33:08,594 They evoked a sense of wonder and stimulated further exploration. 490 00:33:08,801 --> 00:33:11,395 Those tales of strange worlds... 491 00:33:11,604 --> 00:33:14,835 ...enabled some Europeans to see themselves anew. 492 00:33:15,274 --> 00:33:18,710 There had been accounts of headless people, foot people... 493 00:33:18,911 --> 00:33:20,344 ...cyclops people. 494 00:33:21,380 --> 00:33:24,281 Now the Dutch brought back fantastic stories... 495 00:33:24,517 --> 00:33:26,280 ...of giant hunters... 496 00:33:27,220 --> 00:33:28,847 ...dodoes... 497 00:33:29,355 --> 00:33:31,414 ...rhinos... 498 00:33:31,924 --> 00:33:33,448 ...leopards... 499 00:33:33,659 --> 00:33:36,924 ...and other creatures. 500 00:33:39,732 --> 00:33:44,328 Modern voyagers also return travelers' tales: 501 00:33:44,670 --> 00:33:49,607 Tales of a world shattered like a crystal sphere. 502 00:33:50,376 --> 00:33:52,867 A place where the ground is covered... 503 00:33:53,079 --> 00:33:57,641 ...with what looks like a network of giant cobwebs. 504 00:34:01,020 --> 00:34:04,080 A world with an underground ocean. 505 00:34:05,424 --> 00:34:08,359 Tiny moons shaped like potatoes. 506 00:34:09,762 --> 00:34:12,458 A yellow and red pockmarked land... 507 00:34:12,665 --> 00:34:14,496 ...with lakes of molten sulfur... 508 00:34:14,700 --> 00:34:18,693 ...and volcanic eruptions 300 kilometers high. 509 00:34:22,475 --> 00:34:24,102 And a place called Jupiter... 510 00:34:24,310 --> 00:34:27,643 ...so large that a thousand Earths would fit inside. 511 00:34:27,847 --> 00:34:31,078 There are no mountains, valleys, volcanoes or rivers there. 512 00:34:31,284 --> 00:34:34,014 Just a vast ocean of gas and clouds. 513 00:34:34,220 --> 00:34:37,883 Everything we see on Jupiter is floating in the sky. 514 00:34:40,960 --> 00:34:44,293 But there's much that is fascinating about Jupiter. 515 00:34:44,630 --> 00:34:48,066 As the solar system condensed out of interstellar gas and dust... 516 00:34:48,267 --> 00:34:52,704 ...Jupiter acquired most of the matter not ejected into interstellar space... 517 00:34:52,905 --> 00:34:56,204 ...and which didn't fall inwards to form the sun. 518 00:34:56,409 --> 00:35:01,312 Jupiter is made mostly of hydrogen and helium, just like the sun... 519 00:35:01,514 --> 00:35:06,110 ...and had Jupiter been a few dozen times more massive... 520 00:35:06,319 --> 00:35:07,786 ...the matter in it... 521 00:35:07,987 --> 00:35:12,424 ...might have undergone thermonuclear reactions in the interior... 522 00:35:12,625 --> 00:35:16,857 ...and Jupiter would have begun to shine by its own light. 523 00:35:17,063 --> 00:35:21,056 Jupiter is a star that failed. 524 00:35:21,400 --> 00:35:22,799 Had it become a star... 525 00:35:23,002 --> 00:35:25,562 ...we would be living in a double-star system... 526 00:35:25,771 --> 00:35:27,864 ...with two suns in our sky... 527 00:35:28,074 --> 00:35:31,737 ...and the nights would come more rarely. 528 00:35:31,944 --> 00:35:36,040 Deep below the clouds of Jupiter, the weights of the layers of atmosphere... 529 00:35:36,248 --> 00:35:39,115 ...produce pressures which are much greater... 530 00:35:39,318 --> 00:35:42,116 ...than any that are found anywhere on the Earth. 531 00:35:42,355 --> 00:35:44,255 The clouds are this layer here. 532 00:35:44,457 --> 00:35:47,517 The deep interior is this high-pressure place. 533 00:35:47,727 --> 00:35:49,354 The pressure is so large... 534 00:35:49,562 --> 00:35:54,090 ...that electrons are squeezed off hydrogen atoms, producing... 535 00:35:55,101 --> 00:35:59,162 ...liquid metallic hydrogen. 536 00:35:59,472 --> 00:36:04,171 But at the very core of Jupiter, there may be a lump... 537 00:36:04,377 --> 00:36:05,435 ...of rock and iron... 538 00:36:05,645 --> 00:36:10,082 ...a giant Earth-like world under astonishing pressures... 539 00:36:10,282 --> 00:36:14,912 ...hidden forever at the center of the largest planet. 540 00:36:17,223 --> 00:36:18,690 Just before Voyager... 541 00:36:18,891 --> 00:36:23,658 ...encountered Jupiter, you could see that giant planet at night... 542 00:36:23,863 --> 00:36:28,800 ...shining in the sky as our ancestors have for the last million years. 543 00:36:29,101 --> 00:36:31,831 And on my way to study the Voyager data... 544 00:36:32,038 --> 00:36:34,506 ...arriving at the Jet Propulsion Laboratory... 545 00:36:34,707 --> 00:36:37,801 ...I thought that Jupiter would never be the same again. 546 00:36:38,010 --> 00:36:41,969 Never again just a point of light in the night sky... 547 00:36:42,181 --> 00:36:46,515 ...but forever after, a place to be explored and known. 548 00:36:49,655 --> 00:36:54,183 To see the first close-up images of a world never before known... 549 00:36:54,393 --> 00:36:58,591 ...is a great joy in the life of a planetary scientist. 550 00:37:00,833 --> 00:37:05,236 In the early morning hours of July 9th, 1979, on the real-time... 551 00:37:05,438 --> 00:37:08,407 ...television monitors at the Jet Propulsion Laboratory... 552 00:37:08,607 --> 00:37:11,735 ...we began to learn about a world called Europa. 553 00:37:11,977 --> 00:37:14,036 These are the modern explorers. 554 00:37:14,246 --> 00:37:15,975 Men and women trained... 555 00:37:16,182 --> 00:37:19,117 ...in astronomy, physics, geology or engineering. 556 00:37:19,318 --> 00:37:22,287 Many devoting five to eight years to this single mission. 557 00:37:22,488 --> 00:37:26,049 JPL MAN: Cassen's model for Europa says if you start with a liquid... 558 00:37:26,258 --> 00:37:29,022 ...you can put in enough energy to keep it liquid. 559 00:37:30,429 --> 00:37:34,490 But Cassen said in order for there to be enough heating going on... 560 00:37:34,700 --> 00:37:38,932 ...you had to start the heating before Europa basically cooled off. 561 00:37:40,339 --> 00:37:42,671 But what about relief from the cracks? 562 00:37:45,845 --> 00:37:49,679 ...and Europa there's a twin, a pair there... 563 00:37:50,683 --> 00:37:54,016 You can't look at a world so different from ours... 564 00:37:54,220 --> 00:37:56,279 ...without wondering how both were made. 565 00:37:56,489 --> 00:37:58,514 Just rotate it out a little bit. 566 00:37:59,959 --> 00:38:03,827 Voyager presented us with six new worlds in the Jupiter system alone. 567 00:38:04,797 --> 00:38:08,858 The more you learn about other worlds, the better you understand our own. 568 00:38:09,068 --> 00:38:14,005 We speculate, criticize, argue, calculate, reflect and wonder. 569 00:38:14,340 --> 00:38:18,106 We return again to the astonishing data, and slowly... 570 00:38:18,310 --> 00:38:20,676 ...we begin to understand. 571 00:38:31,757 --> 00:38:35,124 The Dutch sailing ships brought back rare and valuable commodities... 572 00:38:35,327 --> 00:38:37,318 ...from the new worlds they visited. 573 00:38:37,530 --> 00:38:39,464 Our Voyager spaceships... 574 00:38:39,665 --> 00:38:42,327 ...return rare and valuable information... 575 00:38:42,535 --> 00:38:46,266 ...to computerized wharves on this shore of the sea of space. 576 00:38:47,039 --> 00:38:51,942 Here the data are stored, enhanced, processed and treasured. 577 00:38:52,645 --> 00:38:56,240 Maps of alien lands will be generated from this information. 578 00:38:56,448 --> 00:39:00,544 In this electric warehouse are tens of thousands of images... 579 00:39:00,753 --> 00:39:03,586 ...of previously unknown worlds. 580 00:39:05,758 --> 00:39:09,159 How does a picture from the outer solar system get to us? 581 00:39:09,361 --> 00:39:12,728 Sunlight shines on Europa, and is reflected back to space... 582 00:39:12,932 --> 00:39:14,763 ...where some strikes the phosphors... 583 00:39:14,967 --> 00:39:18,232 ...of the Voyager television cameras, generating an image. 584 00:39:18,437 --> 00:39:21,668 The image is radioed back across the immense distance... 585 00:39:21,874 --> 00:39:24,035 ...of half a billion kilometers... 586 00:39:24,243 --> 00:39:27,440 ...to a radio telescope on Earth. One in Australia, say. 587 00:39:27,646 --> 00:39:30,410 The telescope then passes the information... 588 00:39:30,616 --> 00:39:33,608 ...via communications satellite in Earth orbit... 589 00:39:33,819 --> 00:39:35,514 ...to Southern California. 590 00:39:35,721 --> 00:39:39,680 There, it's transmitted by a set of microwave relay towers... 591 00:39:39,892 --> 00:39:43,259 ...to a computer at the Jet Propulsion Laboratory... 592 00:39:44,096 --> 00:39:46,997 ...and there it is processed. 593 00:39:54,273 --> 00:39:56,867 The picture is like a newspaper wire photo... 594 00:39:57,076 --> 00:40:00,978 ...made of a million individual dots of differing shades of gray... 595 00:40:01,180 --> 00:40:03,910 ...so fine and close together that at a distance... 596 00:40:04,116 --> 00:40:06,949 ...the constituent dots are invisible. 597 00:40:07,152 --> 00:40:09,780 We see only their cumulative effect. 598 00:40:11,023 --> 00:40:14,083 The information specifies how bright or dark... 599 00:40:14,293 --> 00:40:15,920 ...each dot is to be. 600 00:40:16,128 --> 00:40:19,188 After processing, the dots are stored on a magnetic disk... 601 00:40:19,398 --> 00:40:21,832 ...something like a phonograph record. 602 00:40:22,067 --> 00:40:25,901 By this day, there were already 11,000 pictures from Voyager 2 in our... 603 00:40:26,105 --> 00:40:27,766 ...electronic library. 604 00:40:28,774 --> 00:40:32,505 Finally, the end product of this remarkable set... 605 00:40:32,711 --> 00:40:34,941 ...of links and relays... 606 00:40:36,048 --> 00:40:39,643 ...is a hard copy which comes out of this machine showing... 607 00:40:40,052 --> 00:40:42,987 ...in this case, the wonders of Europa... 608 00:40:43,188 --> 00:40:47,420 ...which were recorded for the first time in human history, today. 609 00:40:47,960 --> 00:40:50,986 It is absolutely astonishing. 610 00:40:51,964 --> 00:40:56,526 Voyager 1 got very good pictures of the other three big moons... 611 00:40:56,735 --> 00:41:00,102 ...Galilean satellites of Jupiter, but not of Europa. 612 00:41:00,306 --> 00:41:03,241 It was left to Voyager 2 today... 613 00:41:03,442 --> 00:41:06,536 ...to get the first close-up pictures of Europa... 614 00:41:06,745 --> 00:41:10,272 ...where we see things that are only a few kilometers across. 615 00:41:10,482 --> 00:41:13,645 At first glance, it looks like nothing so much as... 616 00:41:13,852 --> 00:41:18,789 ...the canal network of Mars that Lowell imagined existed on that planet. 617 00:41:19,258 --> 00:41:24,195 We see an amazing, intricate network of crisscrossing... 618 00:41:24,463 --> 00:41:26,761 ...straight and curved lines. 619 00:41:26,966 --> 00:41:29,025 Are these straight lines ridges? 620 00:41:29,234 --> 00:41:30,326 Are they troughs? 621 00:41:30,536 --> 00:41:33,562 Is it connected with plate tectonics on the Earth? 622 00:41:33,772 --> 00:41:38,072 How does it illuminate the other satellites of the Jovian system? 623 00:41:38,377 --> 00:41:41,676 At this moment, the vaunted technology... 624 00:41:41,880 --> 00:41:44,178 ...has produced something astonishing. 625 00:41:44,383 --> 00:41:46,681 But it remains for... 626 00:41:47,186 --> 00:41:51,555 ...the limitations and cleverness of another device... 627 00:41:51,757 --> 00:41:54,692 ...the human brain, to figure it out. 628 00:41:56,862 --> 00:42:00,923 Fortunately, we have plenty of pictures to help us. 629 00:42:01,900 --> 00:42:05,927 What about Gene's idea of geysers down the troughs? 630 00:42:06,138 --> 00:42:08,265 Geysers down the troughs? 631 00:42:09,475 --> 00:42:11,534 LARR Y SODERBLOM: You need a mechanism to drive it. 632 00:42:11,744 --> 00:42:15,043 SAGAN: Larry Soderblom, Voyager imaging team. 633 00:42:15,247 --> 00:42:20,150 LARR Y: An idea was proposed a while ago that we might have a sort of... 634 00:42:20,352 --> 00:42:22,547 ...champagne-bottle model. And that's... 635 00:42:22,755 --> 00:42:26,088 You seal the crust and have liquid underneath that solid crust. 636 00:42:26,592 --> 00:42:30,028 Do you have then a condition which is an explosive effervescence? 637 00:42:30,362 --> 00:42:32,523 SAGAN: Lonnie Lane, deputy project scientist. 638 00:42:33,799 --> 00:42:37,530 You have enough resolution in some of these pictures that... 639 00:42:37,736 --> 00:42:40,170 ...you don't see anything spread laterally. 640 00:42:40,372 --> 00:42:43,000 Do we have the high-resolution piece? 641 00:42:43,275 --> 00:42:45,869 -It was right here. -There it is. 642 00:42:46,078 --> 00:42:49,013 We'll pick out the relief, and if we're going to see... 643 00:42:49,214 --> 00:42:50,511 ...the things we recognize... 644 00:42:50,716 --> 00:42:53,412 SAGAN: Weeks after the pictures from Europa were received... 645 00:42:53,619 --> 00:42:55,712 ...we were still debating what was in them. 646 00:42:55,921 --> 00:42:58,890 It's as if we almost got to the... 647 00:42:59,725 --> 00:43:01,158 Look at the mesas here. 648 00:43:01,760 --> 00:43:04,923 We almost got the resolution needed to see the craters. 649 00:43:05,130 --> 00:43:08,566 The craters which would last indefinitely on a crust this thin. 650 00:43:08,767 --> 00:43:10,291 Apart from the réseaus... 651 00:43:10,502 --> 00:43:15,337 ...there's a set of very fine small dots, markings... 652 00:43:15,541 --> 00:43:17,736 ...mostly in the mottled terrain. 653 00:43:17,943 --> 00:43:21,538 Like those guys. Do you think those are... 654 00:43:21,747 --> 00:43:25,205 ...sites of outgassing, calderas, fumaroles, solfataras? 655 00:43:25,417 --> 00:43:28,545 I don't know, but I'll tell you one thing I just found... 656 00:43:30,789 --> 00:43:32,188 Look right here. 657 00:43:33,759 --> 00:43:35,124 It disappeared. 658 00:43:36,228 --> 00:43:38,389 See the central peak? 659 00:43:38,597 --> 00:43:40,497 See the little hole? 660 00:43:43,168 --> 00:43:45,636 I think it's an impact crater. Look at the central peak. 661 00:43:45,838 --> 00:43:47,931 SAGAN: There are almost no impact craters. 662 00:43:48,140 --> 00:43:49,767 Wait, we just found one. 663 00:43:49,975 --> 00:43:51,203 Almost none. 664 00:43:52,311 --> 00:43:56,441 Therefore, finding one which is alleged to be the exception... 665 00:43:56,648 --> 00:43:59,640 ...maybe it's not the exception, but something else. 666 00:43:59,852 --> 00:44:04,016 Perhaps, but you asked about those little holes that we can't make out. 667 00:44:06,158 --> 00:44:09,525 The big craters go away by some rheological deformation... 668 00:44:09,728 --> 00:44:12,561 ...and the little ones stay but are out of our resolution. 669 00:44:12,764 --> 00:44:16,666 That's because they're one-tenth the depth of the rigid crust. 670 00:44:16,869 --> 00:44:18,063 Well, maybe. 671 00:44:19,304 --> 00:44:22,000 SAGAN: Computer processing of the pictures has revealed... 672 00:44:22,207 --> 00:44:25,438 ...a few features on Europa which seem to be impact craters. 673 00:44:25,644 --> 00:44:26,702 But something... 674 00:44:26,912 --> 00:44:29,210 ...has wiped out the big craters. 675 00:44:29,414 --> 00:44:31,746 Computer processing also played a major role... 676 00:44:31,950 --> 00:44:35,977 ...in an amazing Voyager discovery made on the moon next to Europa... 677 00:44:36,188 --> 00:44:38,952 ...a world called lo. 678 00:44:40,492 --> 00:44:43,791 Even from Earth we could tell that lo had a strange color. 679 00:44:43,996 --> 00:44:47,363 We knew that somehow sulfur had been removed from its surface... 680 00:44:47,566 --> 00:44:51,229 ...and ejected into a great doughnut of gas orbiting Jupiter. 681 00:44:51,436 --> 00:44:55,304 Then Voyager 1 sailed close to lo. 682 00:44:57,709 --> 00:45:01,941 There were a few places on lo which looked like the mouths of volcanoes... 683 00:45:02,147 --> 00:45:03,842 ...but it was hard to be sure. 684 00:45:04,716 --> 00:45:08,208 Then, Linda Morabito, a member of the Voyager navigation team... 685 00:45:08,420 --> 00:45:11,287 ...used a computer to enhance the edge of lo... 686 00:45:11,490 --> 00:45:14,015 ...in order to bring out the stars behind. 687 00:45:14,226 --> 00:45:18,128 Four days after the Voyager 1 encounter with Jupiter... 688 00:45:18,330 --> 00:45:22,130 ...I was looking at an optical navigation frame. 689 00:45:22,334 --> 00:45:26,464 In enhancing this particular quadrant, what became very evident to me... 690 00:45:26,672 --> 00:45:28,731 ...was an anomalous crescent... 691 00:45:28,941 --> 00:45:32,308 ...in the upper left-hand corner, just off the limb of lo. 692 00:45:32,511 --> 00:45:33,705 SAGAN: What was it? 693 00:45:33,912 --> 00:45:36,312 The plume was in exactly the position... 694 00:45:36,515 --> 00:45:38,540 ...of one of the suspected volcanoes. 695 00:45:38,951 --> 00:45:42,352 We realized then that what we were observing... 696 00:45:42,554 --> 00:45:46,615 ...was a volcanic plume and, in fact, a volcanic eruption. 697 00:45:48,694 --> 00:45:53,393 SAGAN: Voyager had discovered the first active volcano beyond the Earth. 698 00:45:55,767 --> 00:45:58,201 We then found that lo has many volcanoes. 699 00:45:58,403 --> 00:46:01,497 There are at least nine intermittently active plumes... 700 00:46:01,707 --> 00:46:04,335 ...and hundreds, maybe thousands, of extinct ones. 701 00:46:04,543 --> 00:46:08,536 The plumes can eject sulfur and other atoms off lo altogether... 702 00:46:08,880 --> 00:46:12,441 ...and account for the sulfur clouds surrounding Jupiter. 703 00:46:13,185 --> 00:46:17,952 Rivers of molten sulfur flow down the sides of the volcanic mountains... 704 00:46:18,156 --> 00:46:21,216 ...and are the probable source of Io's distinctive colors. 705 00:46:21,426 --> 00:46:26,159 The volcanoes may be tapping some vast underground ocean of liquid sulfur... 706 00:46:26,365 --> 00:46:30,734 ...beneath a surface that is only a few thousand years old. 707 00:46:34,640 --> 00:46:38,098 So far, in our voyages to the outer solar system... 708 00:46:38,343 --> 00:46:40,811 ...we humans have stayed home... 709 00:46:41,013 --> 00:46:44,244 ...and sent robots and computers to explore in our stead. 710 00:46:44,449 --> 00:46:47,509 Someday, perhaps, we'll go ourselves. 711 00:46:48,620 --> 00:46:49,814 But suppose... 712 00:46:50,422 --> 00:46:53,357 ...like those Dutch sea captains of the 17th century... 713 00:46:53,558 --> 00:46:56,994 ...the computers aboard Voyager could keep a ship's log. 714 00:46:57,195 --> 00:47:01,291 That log, a combination of the events of Voyagers 1 and 2... 715 00:47:01,500 --> 00:47:04,367 ...might read something like this: 716 00:47:06,805 --> 00:47:11,504 Day 1: After much concern about provisions and instruments... 717 00:47:11,710 --> 00:47:15,942 ...we successfully lift off from Cape Canaveral on our long journey... 718 00:47:16,148 --> 00:47:18,742 ...to the planets and the stars. 719 00:47:27,159 --> 00:47:31,357 Day 13: We have taken the first photograph of the Earth and moon... 720 00:47:31,563 --> 00:47:35,090 ...as worlds together in space. A pretty pair. 721 00:47:39,104 --> 00:47:42,631 Day 170: A problem in the deployment of the boom... 722 00:47:42,841 --> 00:47:45,139 ...that supports the science scan platform. 723 00:47:45,344 --> 00:47:47,141 If the problem is not solved... 724 00:47:47,346 --> 00:47:49,940 ...we will be unable to take most of our pictures. 725 00:47:54,186 --> 00:47:59,123 Day 207: Boom problem solved, but failure of main radio transmitter. 726 00:47:59,658 --> 00:48:01,751 If the backup transmitter also fails... 727 00:48:01,960 --> 00:48:05,225 ...no one on Earth will ever hear from us again. 728 00:48:06,264 --> 00:48:07,458 Day 215: 729 00:48:07,666 --> 00:48:09,964 We cross the orbit of Mars... 730 00:48:10,168 --> 00:48:12,295 ...and enter the main asteroid belt. 731 00:48:13,905 --> 00:48:18,171 Day 570: We can now make out finer detail on Jupiter... 732 00:48:18,377 --> 00:48:22,040 ...than the largest telescopes on Earth have ever obtained. 733 00:48:27,052 --> 00:48:28,679 Day 640: 734 00:48:28,887 --> 00:48:32,618 The cloud patterns are distinctive and gorgeous. 735 00:48:32,824 --> 00:48:34,451 No painter trapped on Earth... 736 00:48:34,659 --> 00:48:37,457 ...ever imagined a world so strange and lovely. 737 00:48:40,699 --> 00:48:44,226 The white clouds are ammonia crystals, high and cold. 738 00:48:44,436 --> 00:48:47,166 We do not know the nature of the red-brown clouds. 739 00:48:47,372 --> 00:48:49,966 Maybe phosphorous or sulfur as a stain. 740 00:48:50,175 --> 00:48:54,612 Perhaps organic molecules of the sort that led, four billion years ago... 741 00:48:54,813 --> 00:48:57,680 ...back on Earth, to the origin of life. 742 00:48:57,883 --> 00:49:00,579 And what is the great red spot? 743 00:49:01,086 --> 00:49:02,075 (COMPUTER HUMS) 744 00:49:03,355 --> 00:49:06,449 It is an immense swirling column of gas... 745 00:49:06,658 --> 00:49:08,853 ...reaching high above adjacent clouds. 746 00:49:09,060 --> 00:49:11,893 So large that it could hold half a dozen Earths. 747 00:49:12,097 --> 00:49:15,533 Its motion hypnotizes us. 748 00:49:19,304 --> 00:49:23,104 Some think that the red spot is a great spinning storm... 749 00:49:23,308 --> 00:49:25,674 ...a million years old. 750 00:49:28,914 --> 00:49:33,851 Day 650: Encounter. A day of wonders. 751 00:49:37,055 --> 00:49:39,148 The ship maneuvers so we can take pictures... 752 00:49:39,357 --> 00:49:41,985 ...of the multi-ringed basin on Callisto. 753 00:49:46,965 --> 00:49:51,493 Images of the astonishing lined surface of Ganymede. 754 00:49:56,074 --> 00:49:58,804 A close passage by Europa. 755 00:50:01,179 --> 00:50:03,647 And, a view of volcanic lo. 756 00:50:07,419 --> 00:50:10,855 We successfully negotiate the treacherous radiation belts... 757 00:50:11,056 --> 00:50:14,492 ...and accomplish the ring plane crossing. 758 00:50:15,627 --> 00:50:18,095 Looking back, we marvel at the rings... 759 00:50:18,296 --> 00:50:23,063 ...and see the sun emerge from behind the giant planet. 760 00:50:28,039 --> 00:50:32,976 We are outward bound on our mission to explore the outer solar system. 761 00:50:33,879 --> 00:50:35,870 Ten thousand years from now... 762 00:50:36,081 --> 00:50:39,608 ...Voyager will plunge onward to the stars. 763 00:50:40,752 --> 00:50:45,382 We have made the ships that sail the sea of space. 764 00:50:49,261 --> 00:50:50,888 We travel past Jupiter... 765 00:50:51,096 --> 00:50:54,395 ...three quarters of a billion kilometers from the sun... 766 00:50:54,933 --> 00:50:57,959 ...Saturn, one and a half billion, Uranus, three billion... 767 00:50:58,169 --> 00:51:02,799 ...and Neptune, four and a half billion kilometers away. 768 00:51:05,877 --> 00:51:07,276 In our ship of the mind... 769 00:51:07,479 --> 00:51:11,745 ...we retrace the itinerary of the two Voyager spacecraft... 770 00:51:11,950 --> 00:51:15,647 ...on their journeys to Saturn and beyond. 771 00:51:17,722 --> 00:51:20,987 Saturn was first glimpsed through the telescope by Galileo. 772 00:51:21,192 --> 00:51:24,127 Its rings first understood by Huygens. 773 00:51:24,329 --> 00:51:28,698 But only now do we begin to penetrate its deeper mysteries. 774 00:51:34,673 --> 00:51:38,575 Saturn is the second largest planet in the solar system. 775 00:51:39,444 --> 00:51:43,676 Like Jupiter, it is cloud-covered, and rotates once every 10 hours. 776 00:51:43,882 --> 00:51:47,215 It has a weaker magnetic field, a weaker radiation belt... 777 00:51:47,419 --> 00:51:49,683 ...and a grand, magnificent... 778 00:51:49,888 --> 00:51:53,085 ...exquisite system of rings. 779 00:51:54,793 --> 00:51:57,557 The rings are composed of billions of tiny moons... 780 00:51:57,762 --> 00:52:00,560 ...each circling Saturn in its own orbit. 781 00:52:01,266 --> 00:52:05,498 The biggest gap in the rings is called the Cassini Division... 782 00:52:05,704 --> 00:52:08,798 ...after the colleague of Huygens who first discovered it. 783 00:52:09,741 --> 00:52:11,299 There are many other gaps... 784 00:52:11,509 --> 00:52:14,535 ...each produced by the periodic gravitational tugs... 785 00:52:14,746 --> 00:52:16,737 ...of one of the larger outer moons. 786 00:52:33,865 --> 00:52:36,356 From just beneath the ring plane... 787 00:52:36,568 --> 00:52:40,231 ...we see a sky full of moons. 788 00:53:00,058 --> 00:53:04,654 Within the rings, the individual moons become visible. 789 00:53:06,531 --> 00:53:10,092 They are orbiting chunks of snow and ice... 790 00:53:11,436 --> 00:53:13,802 ...each perhaps a meter across. 791 00:53:19,344 --> 00:53:22,939 In young parts of the ring system, there hasn't been enough time... 792 00:53:23,148 --> 00:53:27,517 ...for collisions to round the edges of these fragments... 793 00:53:27,719 --> 00:53:30,210 ...the snowballs of Saturn. 794 00:54:16,234 --> 00:54:21,001 Far from the rings, bathed in its red light... 795 00:54:22,307 --> 00:54:26,073 ...we encounter Saturn's immense cloud-covered moon... 796 00:54:26,277 --> 00:54:27,505 ...Titan. 797 00:54:40,458 --> 00:54:42,892 It has an atmosphere denser than that of Mars... 798 00:54:43,695 --> 00:54:45,526 ...and a thick layer of red clouds... 799 00:54:45,730 --> 00:54:49,291 ...which are probably composed of complex organic molecules... 800 00:54:49,501 --> 00:54:53,164 ...produced by solar ultraviolet light and other energy sources... 801 00:54:53,371 --> 00:54:55,066 ...from the methane-rich air. 802 00:55:02,413 --> 00:55:05,678 No ship from Earth has ever penetrated those clouds... 803 00:55:05,884 --> 00:55:10,446 ...and viewed, close-up, the surface of this tantalizing world. 804 00:55:16,795 --> 00:55:20,162 It seems likely that the ground is covered, encrusted... 805 00:55:20,365 --> 00:55:24,426 ...with organic molecules raining from the sky. 806 00:55:30,408 --> 00:55:34,708 There may be volcanoes and valleys of ice... 807 00:55:34,913 --> 00:55:37,711 ...and, just perhaps... 808 00:55:37,916 --> 00:55:42,785 ...hiding in the warm places, some very different kind of life. 809 00:55:50,862 --> 00:55:52,921 Near an ice cliff of Titan... 810 00:55:53,131 --> 00:55:56,498 ...through a rare break in the clouds of organic molecules... 811 00:55:56,701 --> 00:56:01,536 ...we can see, looming and lovely, the ringed planet, Saturn. 812 00:56:03,007 --> 00:56:07,341 It is a view that will still be appreciated centuries from now... 813 00:56:07,579 --> 00:56:09,740 ...by our descendants, who will know it well. 814 00:56:09,948 --> 00:56:12,348 As well as we have come to know... 815 00:56:12,550 --> 00:56:15,883 ...Hudson's Bay and the Barents Sea... 816 00:56:16,087 --> 00:56:20,080 ...Indonesia, and Australia and New York. 817 00:56:20,925 --> 00:56:25,521 They will look back to when Titan was first seen by Voyager spaceships... 818 00:56:25,730 --> 00:56:28,893 ...on their epic journeys past the giant planets... 819 00:56:29,100 --> 00:56:30,795 ...out of the solar system... 820 00:56:31,002 --> 00:56:34,802 ...to the great dark between the stars. 821 00:56:52,257 --> 00:56:54,282 Since Cosmos was first shown... 822 00:56:54,492 --> 00:56:58,394 ...Voyager spacecraft have explored the systems of the planets... 823 00:56:58,596 --> 00:57:01,360 ...Saturn, Uranus, and Neptune... 824 00:57:01,566 --> 00:57:06,435 ...and have now passed the outermost planets on their way to the stars. 825 00:57:06,871 --> 00:57:10,568 We inserted the flavor of those encounters in our captain's log. 826 00:57:11,342 --> 00:57:13,367 But with image processing... 827 00:57:13,578 --> 00:57:17,810 ...we've been able to reconstruct astonishing movies... 828 00:57:18,082 --> 00:57:19,743 ...of some of these worlds. 829 00:57:19,951 --> 00:57:23,352 Here, for example, is Jupiter, with its great red spot. 830 00:57:24,923 --> 00:57:28,188 And volcanic lo, spinning before us. 831 00:57:29,193 --> 00:57:34,130 Icy Enceladus, a tiny moon of Saturn, on much of which, somehow... 832 00:57:34,599 --> 00:57:36,533 ...the craters have melted. 833 00:57:37,735 --> 00:57:40,101 And Miranda, of Uranus. 834 00:57:41,639 --> 00:57:44,369 Austere, blue Neptune. 835 00:57:46,711 --> 00:57:50,112 Or consider Titan, the giant moon of Saturn. 836 00:57:50,315 --> 00:57:53,682 We've taken the nitrogen and methane in its atmosphere... 837 00:57:53,885 --> 00:57:57,377 ...irradiated it in the lab with electrons of the sort that are... 838 00:57:57,588 --> 00:58:00,250 ...beamed at Titan from Saturn's magnetic field... 839 00:58:00,458 --> 00:58:03,154 ...and we made this stuff... 840 00:58:03,761 --> 00:58:08,198 ...which matches, almost perfectly, the observed properties of the Titan haze. 841 00:58:08,399 --> 00:58:09,491 What is it? 842 00:58:09,701 --> 00:58:12,135 It's a mixture of complex organic molecules. 843 00:58:12,337 --> 00:58:15,534 You drop some into water and, among other things, you make... 844 00:58:15,740 --> 00:58:18,334 ...amino acids, the building blocks of proteins. 845 00:58:18,543 --> 00:58:21,478 So the starting materials of life... 846 00:58:21,679 --> 00:58:25,877 ...are raining from the skies of Titan, like manna from heaven. 847 00:58:26,084 --> 00:58:28,746 I can't wait until the Cassini mission... 848 00:58:28,953 --> 00:58:33,219 ...sends an entry probe through the organic haze of Titan... 849 00:58:33,424 --> 00:58:35,551 ...to its enigmatic surface. 850 00:58:35,960 --> 00:58:40,897 The Voyager spacecraft rush on past the planets and to the stars... 851 00:58:41,132 --> 00:58:43,259 ...still returning data. 852 00:58:43,801 --> 00:58:46,463 As it left the planetary part of the solar system... 853 00:58:46,671 --> 00:58:48,935 ...Voyager 1 turned back... 854 00:58:49,140 --> 00:58:53,008 ...to take one last portrait of the planets of the solar system. 855 00:58:53,678 --> 00:58:56,613 ...and one of those pictures was of the Earth. 856 00:58:56,814 --> 00:59:01,251 A tiny blue dot, set in a sunbeam. 857 00:59:01,886 --> 00:59:03,217 Here it is. 858 00:59:03,421 --> 00:59:05,946 That's where we live. That's home. 859 00:59:06,157 --> 00:59:10,025 We humans are one species, and this is our world. 860 00:59:10,528 --> 00:59:12,860 It is our responsibility to cherish it. 861 00:59:13,064 --> 00:59:17,023 Of all the worlds in our solar system, the only one, so far as we know... 862 00:59:17,235 --> 00:59:19,135 ...graced by life.