1 00:00:49,455 --> 00:00:50,820 SAGAN: Martians. 2 00:00:51,023 --> 00:00:54,720 Why so many speculations and fantasies about Martians... 3 00:00:54,927 --> 00:00:59,057 ...rather than Saturnians, say, or Plutonians? 4 00:00:59,265 --> 00:01:02,632 Because Mars seems, at first glance, very Earth-like. 5 00:01:02,835 --> 00:01:05,395 It's the nearest planet whose surface we can see. 6 00:01:05,604 --> 00:01:08,471 There are polar icecaps, drifting white clouds... 7 00:01:08,674 --> 00:01:11,905 ...raging dust storms, seasonally changing patterns... 8 00:01:12,111 --> 00:01:13,635 ...even a 24-hour day. 9 00:01:13,846 --> 00:01:18,010 It's tempting to think of it as an inhabited world. 10 00:01:19,451 --> 00:01:23,285 Mars has become a kind of mythic arena... 11 00:01:23,489 --> 00:01:27,755 ...onto which we've projected our earthly hopes and fears. 12 00:01:27,960 --> 00:01:31,521 The most tantalizing myths about Mars have proved wrong. 13 00:01:31,730 --> 00:01:34,995 So a few people have swung to the opposite extreme... 14 00:01:35,200 --> 00:01:38,169 ...and concluded that the planet is of little interest. 15 00:01:38,370 --> 00:01:41,771 They've begun to sing blues for the Red Planet. 16 00:01:41,974 --> 00:01:45,068 But the real Mars is a world of wonders. 17 00:01:45,277 --> 00:01:49,077 Its future prospects are far more intriguing... 18 00:01:49,281 --> 00:01:51,511 ...than our past apprehensions about it. 19 00:01:51,717 --> 00:01:55,380 In our time, we have sifted the sands of Mars... 20 00:01:55,588 --> 00:01:57,522 ...established a presence there... 21 00:01:57,723 --> 00:02:00,920 ...and fulfilled a century of dreams. 22 00:02:06,599 --> 00:02:10,968 The most startling dream of Mars was that of H.G. Wells... 23 00:02:11,170 --> 00:02:15,800 ...who in 1897 wrote The War of the Worlds. 24 00:02:16,809 --> 00:02:20,472 NARRATOR: "No one would have believed in the end of the 19th century... 25 00:02:20,679 --> 00:02:24,581 ...that this world was being watched keenly and closely... 26 00:02:24,783 --> 00:02:27,775 ...by intelligences greater than man's... 27 00:02:27,987 --> 00:02:30,547 ...and yet as mortal as his own. 28 00:03:05,290 --> 00:03:09,659 As men busied themselves about their various concerns... 29 00:03:09,862 --> 00:03:11,989 ...they were scrutinized and studied... 30 00:03:12,431 --> 00:03:14,695 ...perhaps almost as narrowly as a man... 31 00:03:14,900 --> 00:03:17,300 ...with a microscope might scrutinize... 32 00:03:17,503 --> 00:03:20,495 ...the transient creatures that swarm and multiply... 33 00:03:20,706 --> 00:03:22,571 ...in a drop of water. 34 00:03:35,421 --> 00:03:39,585 With infinite complacency, men went to and fro over this globe... 35 00:03:39,792 --> 00:03:41,726 ...about their little affairs... 36 00:03:42,394 --> 00:03:46,455 ...serene in their assurance of their empire over matter. 37 00:03:47,833 --> 00:03:52,202 It's possible that the infusoria under the microscope do the same. 38 00:03:52,671 --> 00:03:55,731 (CHILDREN SINGING) 39 00:04:10,322 --> 00:04:12,813 No one thought of the older worlds of space... 40 00:04:13,025 --> 00:04:14,890 ...as sources of human danger... 41 00:04:15,427 --> 00:04:18,863 ...or thought of them only to dismiss the idea of life upon them... 42 00:04:19,064 --> 00:04:21,726 ...as impossible or improbable. 43 00:04:35,314 --> 00:04:36,679 (CLAPPING) 44 00:04:48,660 --> 00:04:50,992 It is curious to recall... 45 00:04:51,196 --> 00:04:54,757 ...some of the mental habits of those departed days. 46 00:04:56,335 --> 00:04:58,462 At most, terrestrial men fancied... 47 00:04:58,670 --> 00:05:02,936 ...there might be other men upon Mars, perhaps inferior to themselves... 48 00:05:03,142 --> 00:05:06,111 ...and ready to welcome a missionary enterprise. 49 00:05:10,048 --> 00:05:12,141 Yet across the gulf of space... 50 00:05:12,351 --> 00:05:15,843 ...intellects vast and cool and unsympathetic... 51 00:05:16,054 --> 00:05:18,181 ...regarded this Earth with envious eyes... 52 00:05:18,757 --> 00:05:23,285 ...and slowly and surely drew their plans against us." 53 00:05:33,038 --> 00:05:35,063 (CHEERING) 54 00:05:39,912 --> 00:05:43,177 SAGAN: Wells' novel captured the popular imagination... 55 00:05:43,382 --> 00:05:45,612 ...in the late Victorian era. 56 00:05:45,818 --> 00:05:48,878 This was a time when the automobile was a novelty... 57 00:05:49,087 --> 00:05:50,554 ...when the pace of life... 58 00:05:50,756 --> 00:05:53,350 ...was still determined by the speed of the horse. 59 00:05:53,559 --> 00:05:57,723 Into this world, Wells introduced an interplanetary fantasy... 60 00:05:58,063 --> 00:06:02,159 ...with spaceships, ray guns and implacable aliens. 61 00:06:02,367 --> 00:06:06,531 These were original and disquieting possibilities. 62 00:06:09,541 --> 00:06:11,805 The Martians of H.G. Wells... 63 00:06:12,010 --> 00:06:15,639 ...were not merely minor variations on a human theme. 64 00:06:15,848 --> 00:06:18,874 Instead, they were the evolutionary product... 65 00:06:19,084 --> 00:06:22,383 ...of a totally alien environment. 66 00:06:30,696 --> 00:06:33,790 Forty years later, this fantasy was still able... 67 00:06:33,999 --> 00:06:38,436 ...to frighten millions in war-jittery America... 68 00:06:38,637 --> 00:06:42,664 ...when it was dramatized for radio by the young Orson Welles. 69 00:06:50,048 --> 00:06:52,915 A few years before The War of the Worlds was published... 70 00:06:53,118 --> 00:06:55,382 ...another, quite different vision of Martians... 71 00:06:55,587 --> 00:06:57,885 ...was forming in the mind of a wealthy Bostonian... 72 00:06:58,090 --> 00:07:00,115 ...named Percival Lowell. 73 00:07:02,594 --> 00:07:05,563 The Martians of H.G. Wells were a way for the novelist... 74 00:07:05,764 --> 00:07:09,530 ...to examine contemporary society through alien eyes. 75 00:07:09,735 --> 00:07:13,671 But the Martians of Percival Lowell were, he believed... 76 00:07:13,872 --> 00:07:15,430 ...very real. 77 00:07:19,478 --> 00:07:23,938 It was here that the most elaborate claims... 78 00:07:24,149 --> 00:07:27,516 ...in support of life on Mars were developed. 79 00:07:31,590 --> 00:07:35,617 Lowell dabbled in astronomy as a young man. 80 00:07:40,799 --> 00:07:43,427 He went off to Harvard. 81 00:07:46,571 --> 00:07:50,268 He had a semiofficial diplomatic appointment to Korea... 82 00:07:52,978 --> 00:07:55,469 ...and otherwise engaged in the usual pursuits... 83 00:07:55,681 --> 00:07:58,081 ...of the wealthy for his time. 84 00:07:59,017 --> 00:08:01,918 But his lifelong love... 85 00:08:02,287 --> 00:08:04,983 ...was the planet Mars. 86 00:08:06,425 --> 00:08:08,916 Lowell was electrified... 87 00:08:09,127 --> 00:08:12,187 ...by the announcement in 1877... 88 00:08:12,397 --> 00:08:15,457 ...by an Italian astronomer, Giovanni Schiaparelli... 89 00:08:15,667 --> 00:08:18,693 ...of canali on Mars. 90 00:08:19,338 --> 00:08:21,772 Schiaparelli had reported... 91 00:08:21,974 --> 00:08:24,841 ...during a close approach of Mars to the Earth... 92 00:08:25,043 --> 00:08:28,706 ...an intricate network of single and double straight lines... 93 00:08:28,914 --> 00:08:32,941 ...crisscrossing the bright areas of Mars. 94 00:08:34,953 --> 00:08:38,582 Now, canali in Italian means "channels" or "grooves"... 95 00:08:38,790 --> 00:08:43,022 ...but it was promptly translated into English as canals... 96 00:08:43,228 --> 00:08:46,197 ...a word which understandably has... 97 00:08:46,398 --> 00:08:49,333 ...a certain implication of intelligent design. 98 00:08:49,768 --> 00:08:53,864 A Mars-mania swept through Europe and America... 99 00:08:54,072 --> 00:08:57,803 ...and Percival Lowell found himself caught up in it. 100 00:08:59,511 --> 00:09:02,810 In 1892, his eyesight failing... 101 00:09:03,015 --> 00:09:07,679 ...Schiaparelli announced he was giving up observing Mars. 102 00:09:09,488 --> 00:09:12,889 Lowell resolved to continue the work. 103 00:09:14,426 --> 00:09:16,587 (ROOF CREAKS) 104 00:09:18,897 --> 00:09:21,991 He wanted a first-rate observing site... 105 00:09:22,367 --> 00:09:25,928 ...undisturbed by clouds or city lights... 106 00:09:26,138 --> 00:09:28,197 ...and marked by good seeing. 107 00:09:28,407 --> 00:09:32,241 "Seeing" is the astronomer's term for a steady atmosphere... 108 00:09:32,444 --> 00:09:35,743 ...through which the shimmering of an astronomical image... 109 00:09:35,947 --> 00:09:37,778 ...in the telescope is minimized. 110 00:09:45,290 --> 00:09:48,782 Lowell built his observatory far away from home... 111 00:09:48,994 --> 00:09:53,863 ...on Mars Hill, here in Flagstaff, Arizona. 112 00:10:10,549 --> 00:10:14,918 Lowell sketched the surface features of Mars... 113 00:10:15,620 --> 00:10:19,522 ...and particularly the canals, which mesmerized him. 114 00:10:19,858 --> 00:10:23,419 Now, observations of this sort aren't easy. 115 00:10:23,628 --> 00:10:26,119 You put in long hours at the telescope... 116 00:10:26,331 --> 00:10:28,390 ...in the chill of the early morning. 117 00:10:28,600 --> 00:10:31,398 Most of the time, the seeing is crummy. 118 00:10:31,603 --> 00:10:33,400 When the seeing is bad... 119 00:10:33,605 --> 00:10:36,574 ...the image of Mars blurs and distorts... 120 00:10:36,775 --> 00:10:39,266 ...and you have to ignore what you've observed. 121 00:10:39,478 --> 00:10:43,778 But occasionally the image steadies and the features of the planet... 122 00:10:43,982 --> 00:10:47,042 ...marvelously flash out at you. 123 00:10:47,252 --> 00:10:49,311 You must then remember what you've seen... 124 00:10:49,521 --> 00:10:51,580 ...and accurately commit it to paper. 125 00:10:51,790 --> 00:10:54,281 You must put your preconceptions aside... 126 00:10:54,493 --> 00:10:57,326 ...and with an open mind, set down the wonders... 127 00:10:57,529 --> 00:10:59,929 ...that Mars holds in store for us. 128 00:11:00,132 --> 00:11:03,727 This is Percival Lowell's own notebook. 129 00:11:03,935 --> 00:11:06,495 Here's what he thought he saw. 130 00:11:07,506 --> 00:11:11,374 Bright and dark areas, a hint of a polar cap... 131 00:11:11,643 --> 00:11:15,101 ...and canals. Lots and lots of canals. 132 00:11:20,886 --> 00:11:22,353 Lowell believed... 133 00:11:22,954 --> 00:11:27,584 ...that he was seeing a globe-girdling network... 134 00:11:27,792 --> 00:11:30,260 ...of great irrigation canals... 135 00:11:30,462 --> 00:11:33,329 ...carrying water from the melting polar caps... 136 00:11:33,532 --> 00:11:36,660 ...to the thirsty inhabitants of the equatorial cities. 137 00:11:37,235 --> 00:11:39,897 He believed the planet was inhabited... 138 00:11:40,105 --> 00:11:42,232 ...by an older and wiser race... 139 00:11:42,440 --> 00:11:45,102 ...perhaps very different from us. 140 00:11:45,310 --> 00:11:46,402 He believed... 141 00:11:46,611 --> 00:11:49,705 ...that the seasonal changes in the dark areas... 142 00:11:49,915 --> 00:11:53,373 ...were due to the growth and decay of vegetation. 143 00:11:53,585 --> 00:11:56,850 He believed that the planet was Earth-like. 144 00:11:59,224 --> 00:12:02,352 All in all, he believed too much. 145 00:12:12,804 --> 00:12:16,467 Lowell's Martians were a dying race. 146 00:12:16,675 --> 00:12:19,906 Their once-great cities had fallen into ruins. 147 00:12:20,111 --> 00:12:23,205 Lowell believed that the Martian climate was changing... 148 00:12:23,415 --> 00:12:26,612 ...that the precious water was trickling away into space... 149 00:12:26,818 --> 00:12:30,185 ...that the planet was becoming a desert world. 150 00:12:30,388 --> 00:12:34,324 The canals, he thought, were a last desperate measure... 151 00:12:34,526 --> 00:12:39,190 ...a heroic engineering effort to conserve the scarce water. 152 00:12:39,397 --> 00:12:43,231 But their technology, although far more advanced than ours... 153 00:12:43,435 --> 00:12:47,769 ...was inadequate to stem a planetary catastrophe. 154 00:13:32,751 --> 00:13:36,380 The most serious contemporary challenge to Lowell's ideas... 155 00:13:36,588 --> 00:13:38,317 ...came from an unlikely source: 156 00:13:38,523 --> 00:13:41,185 The biologist Alfred Russel Wallace... 157 00:13:41,393 --> 00:13:44,385 ...co-discoverer of evolution by natural selection. 158 00:13:44,596 --> 00:13:47,622 Wallace correctly showed that the air on Mars... 159 00:13:47,832 --> 00:13:49,993 ...was much too cold and thin... 160 00:13:50,201 --> 00:13:52,465 ...to permit the existence of liquid water. 161 00:13:52,671 --> 00:13:56,334 He wrote that "only a race of madmen... 162 00:13:56,541 --> 00:13:59,476 ...would build canals under such conditions." 163 00:14:01,579 --> 00:14:05,310 Lowell's Martians were benign and hopeful... 164 00:14:05,517 --> 00:14:07,348 ...even a little godlike... 165 00:14:07,552 --> 00:14:10,214 ...very different from the malevolent menace... 166 00:14:10,422 --> 00:14:14,950 ...posed by H.G. Wells and Orson Welles in The War of the Worlds. 167 00:14:15,260 --> 00:14:18,889 Both sets of ideas passed into the public imagination... 168 00:14:19,097 --> 00:14:21,895 ...through Sunday supplements and science fiction... 169 00:14:22,300 --> 00:14:26,464 ...and excited generations of 8-year-olds into fantasizing... 170 00:14:26,671 --> 00:14:29,663 ...that they themselves might one day voyage... 171 00:14:29,874 --> 00:14:31,899 ...to the distant planet Mars. 172 00:14:33,345 --> 00:14:35,711 I remember reading with breathless fascination... 173 00:14:35,914 --> 00:14:38,405 ...the Mars novels of Edgar Rice Burroughs. 174 00:14:38,616 --> 00:14:40,811 I journeyed with John Carter... 175 00:14:41,019 --> 00:14:43,715 ...gentleman adventurer from Virginia... 176 00:14:43,922 --> 00:14:48,052 ...to Barsoom, as Mars was known by its inhabitants. 177 00:14:48,960 --> 00:14:53,158 Wandering among the beasts of burden called thoats... 178 00:14:53,365 --> 00:14:56,095 ...winning the hand of the lovely Dejah Thoris... 179 00:14:56,301 --> 00:14:58,428 ...Princess of Helium... 180 00:14:58,636 --> 00:15:02,834 ...and befriending a 10-foot-high green fighting man... 181 00:15:03,041 --> 00:15:04,633 ...named Tars Tarkas... 182 00:15:04,843 --> 00:15:08,506 ...as the moons of Mars hurtled overhead... 183 00:15:08,713 --> 00:15:11,204 ...on a summer's evening on Barsoom. 184 00:15:43,081 --> 00:15:46,244 It aroused generations of 8-year-olds... 185 00:15:46,451 --> 00:15:47,713 ...myself among them... 186 00:15:47,919 --> 00:15:51,286 ...to consider the exploration of the planets as a real possibility... 187 00:15:51,489 --> 00:15:55,516 ...to wonder whether we ourselves might one day venture... 188 00:15:55,727 --> 00:15:58,161 ...to the distant planet Mars. 189 00:15:58,363 --> 00:16:02,265 John Carter got to Barsoom by standing in an open field... 190 00:16:02,467 --> 00:16:06,665 ...spreading his hands and wishing hard at Mars. 191 00:16:06,871 --> 00:16:10,637 I can remember spending many an hour in my boyhood... 192 00:16:10,842 --> 00:16:13,402 ...arms resolutely outstretched... 193 00:16:13,611 --> 00:16:16,478 ...in an open field in twilight... 194 00:16:16,681 --> 00:16:21,482 ...imploring what I believed to be Mars to transport me there. 195 00:16:22,187 --> 00:16:23,848 It never worked. 196 00:16:24,155 --> 00:16:26,521 There had to be some better way. 197 00:16:27,992 --> 00:16:31,587 And there was. The real road to Mars was opened... 198 00:16:31,796 --> 00:16:33,764 ...by a boy who loved skyrockets. 199 00:16:35,099 --> 00:16:36,794 (BAND PLAYS) 200 00:16:47,812 --> 00:16:50,838 Fourth of July celebrations in New England... 201 00:16:51,049 --> 00:16:54,177 ...are much the same today as they were in the 1890s. 202 00:17:10,935 --> 00:17:14,928 Then, as now, the highlight of the day's festivities... 203 00:17:15,139 --> 00:17:17,869 ...was a rousing fireworks display. 204 00:17:24,682 --> 00:17:28,778 That was the part that Robert Goddard liked the best. 205 00:17:30,121 --> 00:17:33,557 By the time he was 16, he was launching his own rockets. 206 00:17:34,759 --> 00:17:36,283 He wrote in his diary: 207 00:17:36,494 --> 00:17:39,725 "July 4, 1898: 208 00:17:40,064 --> 00:17:43,124 Fired cannon and firecrackers all day. 209 00:17:43,334 --> 00:17:46,167 In evening, had five rockets." 210 00:17:46,371 --> 00:17:48,896 - You gonna light it now? - Yes, I am. 211 00:17:58,416 --> 00:17:59,849 Wow! 212 00:18:00,351 --> 00:18:01,443 That same year... 213 00:18:01,786 --> 00:18:05,517 ...The War of the Worlds was being serialized in the Boston Post. 214 00:18:05,723 --> 00:18:08,556 Goddard eagerly read every word. 215 00:18:12,864 --> 00:18:15,389 The Boston newspapers were also reporting... 216 00:18:15,600 --> 00:18:18,398 ...intriguing conjectures by a Professor Lowell... 217 00:18:18,603 --> 00:18:21,367 ...whose lectures Goddard would later attend. 218 00:18:29,614 --> 00:18:33,345 The images of Mars spun by Wells and Lowell... 219 00:18:33,551 --> 00:18:35,815 ...beguiled the young Goddard... 220 00:18:37,221 --> 00:18:38,882 ...and at age 17... 221 00:18:39,090 --> 00:18:41,615 ...on October 19, 1899... 222 00:18:41,826 --> 00:18:44,659 ...they crystallized into an overwhelming vision... 223 00:18:44,862 --> 00:18:48,855 ...that provided the direction and purpose of his life. 224 00:18:55,840 --> 00:18:57,569 From the high branches... 225 00:18:57,775 --> 00:19:00,972 ...of an old cherry tree on his family's farm... 226 00:19:01,179 --> 00:19:06,048 ...Goddard saw a way to do more than just speculate about Mars. 227 00:19:14,759 --> 00:19:17,227 Before anyone had ever flown in an airplane... 228 00:19:17,428 --> 00:19:19,487 ...or listened to a radio... 229 00:19:19,697 --> 00:19:23,064 ...Goddard decided to invent a machine... 230 00:19:23,267 --> 00:19:26,828 ...that would voyage to the planet Mars. 231 00:19:58,770 --> 00:20:02,262 For the rest of his life, he was to commemorate that October day... 232 00:20:02,473 --> 00:20:04,964 ...as his anniversary day... 233 00:20:05,176 --> 00:20:07,974 ...the birthday of his great dream. 234 00:20:12,583 --> 00:20:16,781 By the 1920s, after years of studying physics and engineering... 235 00:20:16,988 --> 00:20:20,924 ...he was experimenting with liquid fuel rockets. 236 00:20:34,072 --> 00:20:37,439 In order to build a rocket capable of reaching high altitudes... 237 00:20:37,642 --> 00:20:41,840 ...Goddard had to create the principles of an entirely new technology. 238 00:20:42,046 --> 00:20:44,105 He invented the basic components... 239 00:20:44,315 --> 00:20:46,715 ...that propel, stabilize... 240 00:20:46,918 --> 00:20:49,409 ...and guide the modern rocket. 241 00:21:06,838 --> 00:21:09,671 It was painstaking and difficult work. 242 00:21:09,874 --> 00:21:13,139 But Goddard took the many setbacks in stride. 243 00:21:16,247 --> 00:21:18,715 He sifted the wreckage of each experiment... 244 00:21:18,916 --> 00:21:21,384 ...for clues to guide the next. 245 00:21:23,554 --> 00:21:27,251 Constantly refining old techniques and inventing new ones... 246 00:21:27,458 --> 00:21:31,861 ...he gradually raised the rocket from a dangerous toy... 247 00:21:32,230 --> 00:21:35,893 ...and set it on its way to becoming an interplanetary vehicle. 248 00:21:48,112 --> 00:21:51,013 Goddard died in 1945... 249 00:21:51,215 --> 00:21:53,706 ...before a rocket had ever left the planet Earth. 250 00:21:53,918 --> 00:21:56,318 Although Mars always remained his objective... 251 00:21:56,521 --> 00:21:59,581 ...Goddard knew that such a goal would be ridiculed. 252 00:21:59,791 --> 00:22:03,989 In public he advocated the more modest objective... 253 00:22:04,195 --> 00:22:06,527 ...of flying to the moon. 254 00:22:11,068 --> 00:22:14,799 Those boyhood dreams of voyages to the moon and Mars... 255 00:22:15,006 --> 00:22:17,566 ...shared by Goddard with his contemporary... 256 00:22:17,775 --> 00:22:21,176 ...a Russian scientist named Konstantin Tsiolkovsky... 257 00:22:21,379 --> 00:22:25,713 ...were fulfilled only a few decades after their deaths. 258 00:22:25,917 --> 00:22:30,149 But as it turned out, the first planet to be explored by rocket... 259 00:22:30,354 --> 00:22:31,651 ...was the Earth. 260 00:22:41,566 --> 00:22:43,591 Now, imagine yourself a visitor... 261 00:22:43,801 --> 00:22:46,429 ...from some other and quite alien planet. 262 00:22:46,637 --> 00:22:49,333 You approach the Earth with no preconceptions. 263 00:22:49,540 --> 00:22:53,032 Is the place inhabited? At what point can you decide? 264 00:22:53,244 --> 00:22:56,338 When we look at the whole Earth, there are no signs of life. 265 00:22:56,547 --> 00:22:59,141 We must examine it more closely. 266 00:22:59,350 --> 00:23:02,945 If there are intelligent beings, maybe they create structures... 267 00:23:03,154 --> 00:23:06,180 ...which can be seen at a resolution of a few kilometers. 268 00:23:06,390 --> 00:23:08,483 Yet at this level of detail... 269 00:23:08,693 --> 00:23:12,094 ...even a great river valley seems utterly lifeless. 270 00:23:12,630 --> 00:23:14,257 There is no sign of life... 271 00:23:14,465 --> 00:23:17,127 ...intelligent or otherwise in Washington, D. C... 272 00:23:18,469 --> 00:23:19,936 ...or Moscow... 273 00:23:22,240 --> 00:23:23,764 ...or Tokyo... 274 00:23:25,142 --> 00:23:26,040 ...or Peking. 275 00:23:26,244 --> 00:23:29,543 If there are intelligent beings, they have not much modified... 276 00:23:29,747 --> 00:23:33,615 ...the landscape into geometrical patterns at kilometer resolution. 277 00:23:33,818 --> 00:23:36,787 But when we improve the resolution tenfold... 278 00:23:36,988 --> 00:23:40,014 ...when we see detail as small as 100 meters across... 279 00:23:40,224 --> 00:23:41,851 ...the size of a football field... 280 00:23:42,059 --> 00:23:43,959 ...the situation changes. 281 00:23:48,599 --> 00:23:52,433 Many places on Earth seem suddenly to crystallize out... 282 00:23:52,637 --> 00:23:56,164 ...revealing an intricate pattern of straight lines... 283 00:23:56,374 --> 00:24:00,333 ...squares, rectangles and circles. 284 00:24:04,916 --> 00:24:08,682 Canals, roads, circular irrigation patterns... 285 00:24:08,886 --> 00:24:11,855 ...all suggest intelligent life with a passion... 286 00:24:12,056 --> 00:24:15,423 ...for Euclidean geometry and territoriality. 287 00:24:15,626 --> 00:24:18,925 On this scale, intelligent life can be discerned. 288 00:24:19,130 --> 00:24:20,256 Boston... 289 00:24:21,432 --> 00:24:23,195 ...and Washington... 290 00:24:25,336 --> 00:24:26,394 ...and New York. 291 00:24:26,604 --> 00:24:30,802 At 10-meter resolution, we also discover that the Earthlings... 292 00:24:31,008 --> 00:24:32,873 ...like to build up. 293 00:24:36,580 --> 00:24:39,549 At twilight or night, other things are visible: 294 00:24:39,750 --> 00:24:42,378 Oil well fires in the Persian Gulf... 295 00:24:42,753 --> 00:24:45,347 ...or the bright lights of large cities. 296 00:24:46,590 --> 00:24:49,650 At a meter resolution, we make out individual organisms: 297 00:24:49,860 --> 00:24:52,226 Seals on ice floes... 298 00:24:53,130 --> 00:24:55,394 ...or people on skis. 299 00:24:58,569 --> 00:25:02,005 Intelligent life on Earth first reveals itself... 300 00:25:02,206 --> 00:25:05,767 ...through the geometric regularity of its constructions. 301 00:25:05,977 --> 00:25:09,003 If Lowell's canal network existed, the conclusion that... 302 00:25:09,213 --> 00:25:13,172 ...intelligent beings inhabit that planet might be compelling. 303 00:25:13,384 --> 00:25:15,818 But there is no canal network. 304 00:25:16,020 --> 00:25:19,046 Our unmanned spacecraft have examined Mars... 305 00:25:19,256 --> 00:25:21,816 ...with 1000 times more detail... 306 00:25:22,026 --> 00:25:26,326 ...than any fleeting glimpse available through Percival Lowell's telescope. 307 00:25:26,530 --> 00:25:30,398 There is no question that his Martian canals were of intelligent origin. 308 00:25:30,601 --> 00:25:32,091 The only question was... 309 00:25:32,303 --> 00:25:35,636 ...which side of the telescope the intelligence was on. 310 00:25:35,840 --> 00:25:40,470 Where we have strong emotions, we are liable to fool ourselves. 311 00:25:40,678 --> 00:25:45,012 Yet even without the canals, the exploration of Mars evokes... 312 00:25:45,216 --> 00:25:47,377 ...the kind of rapture that... 313 00:25:47,585 --> 00:25:50,713 ...Columbus or Marco Polo must have felt. 314 00:25:53,591 --> 00:25:55,559 We see many impact craters... 315 00:25:55,760 --> 00:25:59,560 ...but we find no canals. None at all. 316 00:26:00,431 --> 00:26:02,661 There are fault lines in the surface... 317 00:26:02,867 --> 00:26:06,564 ...and complex patterns of ridges and valleys... 318 00:26:06,771 --> 00:26:10,229 ...but they're all far too small and in the wrong places... 319 00:26:10,441 --> 00:26:12,170 ...to be Lowell's canals. 320 00:26:12,376 --> 00:26:15,436 And they don't seem to be manufactured. 321 00:26:17,081 --> 00:26:18,708 There are many signs of water. 322 00:26:18,916 --> 00:26:22,579 Ancient river valleys wind their way among the craters. 323 00:26:22,787 --> 00:26:25,915 Nergal Valley, named after the Babylonian war god... 324 00:26:26,123 --> 00:26:30,287 ...is 1000 kilometers long and a billion years old. 325 00:26:30,494 --> 00:26:32,325 There seems to have been a time... 326 00:26:32,530 --> 00:26:35,693 ...when Mars was warmer and wetter than it is today. 327 00:26:36,901 --> 00:26:39,734 I wonder if life ever arose... 328 00:26:39,937 --> 00:26:44,636 ...in the muddy backwaters of these great river systems. 329 00:26:45,810 --> 00:26:48,108 The waters flowed at the same time... 330 00:26:48,312 --> 00:26:52,305 ...that the great volcanoes of the Tharsis Plateau were made. 331 00:26:52,950 --> 00:26:57,011 Before the present continents of Earth were formed... 332 00:26:57,221 --> 00:27:00,622 ...it was a very lively epoch on Mars. 333 00:27:02,326 --> 00:27:04,590 Equally old is the Mariner Valley... 334 00:27:04,795 --> 00:27:08,162 ...a strange, vast, mist-filled chasm. 335 00:27:08,365 --> 00:27:12,995 If it were on Earth, it would stretch from New York to Los Angeles. 336 00:27:13,204 --> 00:27:16,833 Landslides and avalanches are slowly eroding its walls... 337 00:27:17,041 --> 00:27:19,202 ...which collapse to the floor of the valley. 338 00:27:19,410 --> 00:27:22,243 There, the winds remove the particles... 339 00:27:22,446 --> 00:27:25,472 ...and create immense sand dune fields. 340 00:27:26,951 --> 00:27:29,317 Signs of high winds are all over Mars. 341 00:27:29,520 --> 00:27:32,250 Often craters have, trailing behind them... 342 00:27:32,456 --> 00:27:36,790 ...long streaks of bright or dark material, blown out by the winds... 343 00:27:36,994 --> 00:27:40,987 ...natural weathervanes on the Martian surface. 344 00:27:41,365 --> 00:27:44,300 For the sand to be blown about in the thin Martian atmosphere... 345 00:27:44,502 --> 00:27:46,129 ...the winds have to be fast... 346 00:27:46,337 --> 00:27:49,932 ...sometimes approaching half the speed of sound. 347 00:27:50,741 --> 00:27:54,507 But some of the patterns are so odd and intricate... 348 00:27:54,712 --> 00:27:58,239 ...that we cannot be sure they're caused by windblown sand. 349 00:27:58,449 --> 00:28:02,112 And there are other strange markings: 350 00:28:02,319 --> 00:28:04,651 Furrowed ground, almost resembling... 351 00:28:04,855 --> 00:28:07,915 ...a giant plowed field a billion years old... 352 00:28:08,125 --> 00:28:11,390 ...and one of the strangest features on Mars... 353 00:28:11,595 --> 00:28:13,859 ...the pyramids of Elysium... 354 00:28:14,064 --> 00:28:16,692 ...10 times taller than the pyramids of Egypt. 355 00:28:16,901 --> 00:28:20,132 Perhaps they're only mountains sculpted by the fierce winds... 356 00:28:20,337 --> 00:28:23,306 ...but perhaps they're something else. 357 00:28:32,650 --> 00:28:37,053 How marvelous it would be to glide over the surface of Mars... 358 00:28:37,254 --> 00:28:39,848 ...to fly over Olympus Mons... 359 00:28:40,057 --> 00:28:42,992 ...the largest known volcano in the solar system. 360 00:28:45,796 --> 00:28:47,855 The surface area of Mars is exactly... 361 00:28:48,065 --> 00:28:50,590 ...as large as the land area of the Earth. 362 00:28:50,801 --> 00:28:54,760 It will be a long time before this planet is thoroughly explored. 363 00:28:55,439 --> 00:28:59,273 The only canal of Percival Lowell that corresponds to anything real... 364 00:28:59,476 --> 00:29:01,307 ...is Mariner Valley. 365 00:29:02,246 --> 00:29:04,237 5000 kilometers long... 366 00:29:04,448 --> 00:29:06,678 ...it's a little hard to miss even from Earth. 367 00:29:06,884 --> 00:29:09,444 The Grand Canyon of Arizona would fit... 368 00:29:09,653 --> 00:29:12,213 ...into one of its minor tributaries. 369 00:29:12,423 --> 00:29:16,257 Someday we will careen through the corridors... 370 00:29:16,460 --> 00:29:19,691 ...of the Valley of the Mariners. 371 00:30:16,787 --> 00:30:20,348 To skim over the sand dunes of Mars is... 372 00:30:20,557 --> 00:30:23,253 ...as yet, only a dream. 373 00:30:36,106 --> 00:30:38,040 But we have, in fact... 374 00:30:38,242 --> 00:30:41,302 ...sent robot emissaries to Mars. 375 00:30:41,512 --> 00:30:44,447 Their names are Viking 1... 376 00:30:44,682 --> 00:30:46,445 ...and Viking 2. 377 00:30:47,184 --> 00:30:50,210 The problem was where to land them. 378 00:30:52,256 --> 00:30:56,158 We knew that the volcanoes of Tharsis were too high. 379 00:30:56,360 --> 00:30:58,294 The thin Martian atmosphere would not... 380 00:30:58,495 --> 00:31:01,259 ...support our descent parachute. 381 00:31:01,465 --> 00:31:05,799 The great Mariner Valley was too rough and unpredictable. 382 00:31:07,104 --> 00:31:09,129 The polar caps were too cold... 383 00:31:09,340 --> 00:31:12,332 ...for the lander's nuclear power plant to keep it warm. 384 00:31:12,676 --> 00:31:16,442 There were fascinating places that were too high... 385 00:31:16,647 --> 00:31:19,673 ...or too windy or too hard or too soft... 386 00:31:19,883 --> 00:31:22,283 ...or too rough or too cold. 387 00:31:23,053 --> 00:31:25,988 We worried about the safety of every landing site. 388 00:31:26,190 --> 00:31:28,658 Perhaps we were too cautious. 389 00:31:28,859 --> 00:31:31,259 Eventually we selected two places. 390 00:31:31,462 --> 00:31:34,920 One, optimistically named Utopia... 391 00:31:35,132 --> 00:31:36,656 ...for Viking 2... 392 00:31:36,867 --> 00:31:39,836 ...and another, 8000 kilometers away... 393 00:31:40,037 --> 00:31:43,939 ...not far from the confluents of four great channels... 394 00:31:44,141 --> 00:31:46,166 ...a landing site for Viking 1... 395 00:31:46,377 --> 00:31:48,675 ...called Chryse... 396 00:31:49,113 --> 00:31:52,241 ...Greek for "the land of gold." 397 00:31:58,021 --> 00:32:01,957 And so, after a voyage of 100 million kilometers... 398 00:32:02,159 --> 00:32:04,719 ...on July 20, 1976... 399 00:32:04,928 --> 00:32:07,658 ...Viking 1 landed right on target... 400 00:32:07,865 --> 00:32:09,526 ...in the Chryse Plain. 401 00:32:12,169 --> 00:32:15,070 It was less than 80 years since Robert Goddard... 402 00:32:15,272 --> 00:32:16,830 ...had his epiphanic vision... 403 00:32:17,040 --> 00:32:20,237 ...in a cherry tree in Massachusetts. 404 00:32:31,722 --> 00:32:35,954 After hibernating for a year during its interplanetary passage... 405 00:32:36,160 --> 00:32:39,721 ...Viking reawakened on another world. 406 00:32:42,065 --> 00:32:44,431 The first thing it did was to call home... 407 00:32:44,635 --> 00:32:47,297 ...reporting a safe arrival. 408 00:32:48,572 --> 00:32:51,006 It began to rouse itself... 409 00:32:51,208 --> 00:32:53,870 ...according to instructions memorized earlier. 410 00:32:54,077 --> 00:32:58,070 First, it put out a finger to test the Martian winds. 411 00:32:58,649 --> 00:33:01,117 Then, flexing its arm... 412 00:33:01,318 --> 00:33:04,549 ...it flung off a protective glove. 413 00:33:05,722 --> 00:33:09,715 Next, Viking prepared to sniff the air... 414 00:33:09,993 --> 00:33:12,018 ...and taste the soil. 415 00:33:13,096 --> 00:33:14,222 Finally... 416 00:33:14,431 --> 00:33:17,992 ...it opened its eyes for a look at its new surroundings. 417 00:33:18,235 --> 00:33:20,533 (WHIRRING) 418 00:33:25,008 --> 00:33:29,604 Viking's first picture assignment was to photograph its own foot. 419 00:33:29,980 --> 00:33:32,710 In case it were to sink into Martian quicksand... 420 00:33:32,916 --> 00:33:35,578 ...we wanted to know about it before it disappeared. 421 00:33:35,819 --> 00:33:39,983 Back on Earth, we waited breathlessly for the first images. 422 00:33:40,190 --> 00:33:44,490 Viking painted its picture in vertical strokes, line by line... 423 00:33:44,695 --> 00:33:47,493 ...until, with enormous relief, we saw the footpad... 424 00:33:47,698 --> 00:33:50,360 ...securely planted in the Martian soil. 425 00:33:50,567 --> 00:33:55,504 This was the first image ever returned from the surface of Mars. 426 00:34:01,211 --> 00:34:03,702 The cameras on each Viking lander revealed... 427 00:34:03,914 --> 00:34:06,382 ...a kind of rocky desert. 428 00:34:06,583 --> 00:34:08,380 Beyond the lander itself... 429 00:34:08,585 --> 00:34:10,416 ...we saw for the first time... 430 00:34:10,621 --> 00:34:13,021 ...the landscape of the Red Planet. 431 00:34:13,223 --> 00:34:16,886 It didn't look like an alien world. 432 00:34:17,227 --> 00:34:19,957 There were rocks and sand dunes... 433 00:34:20,163 --> 00:34:24,463 ...and gently rolling hills as natural and familiar... 434 00:34:24,668 --> 00:34:26,533 ...as any landscape on Earth. 435 00:34:27,037 --> 00:34:31,098 Forever after, Mars would be a place. 436 00:34:36,914 --> 00:34:40,975 We found that the Martian air was less than 1% as dense as ours... 437 00:34:41,184 --> 00:34:43,914 ...and made mostly of carbon dioxide. 438 00:34:44,121 --> 00:34:46,885 There were smaller amounts of nitrogen, argon... 439 00:34:47,090 --> 00:34:49,251 ...water vapor and oxygen. 440 00:34:49,626 --> 00:34:52,561 There was almost no ozone. So the surface wasn't protected... 441 00:34:52,763 --> 00:34:56,028 ...from the sun's ultraviolet light as it is on Earth. 442 00:34:56,833 --> 00:34:59,996 On the warmest days, it was distinctly chilly... 443 00:35:00,203 --> 00:35:04,640 ...and every night the temperatures plunged to 100 below. 444 00:35:04,841 --> 00:35:09,778 In winter, the surface was dusted with a thin layer of frost. 445 00:35:13,617 --> 00:35:17,849 The landing sites were chosen because they were safe and flat. 446 00:35:18,255 --> 00:35:21,486 Even so, Viking revolutionized our knowledge... 447 00:35:21,692 --> 00:35:23,660 ...of this rusty world. 448 00:35:25,262 --> 00:35:27,890 I would, of course, have been surprised to see... 449 00:35:28,098 --> 00:35:31,465 ...a grizzled prospector emerge from behind a dune... 450 00:35:31,668 --> 00:35:33,033 ...leading his mule. 451 00:35:33,236 --> 00:35:37,570 Yet the idea seemed strangely appropriate. 452 00:35:38,308 --> 00:35:40,242 But at least while we were watching... 453 00:35:40,444 --> 00:35:43,607 ...no prospector wandered by. 454 00:35:48,418 --> 00:35:52,582 We studied with exceptional care each picture the cameras radioed back. 455 00:35:52,789 --> 00:35:56,520 But there was no hint of the canals of Barsoom... 456 00:35:56,727 --> 00:35:58,922 ...no sultry princesses... 457 00:35:59,162 --> 00:36:03,155 ...no 10-foot-tall green fighting men... 458 00:36:03,934 --> 00:36:06,164 ...no thoats, no footprints... 459 00:36:06,370 --> 00:36:09,339 ...not even a cactus or a kangaroo rat. 460 00:36:09,773 --> 00:36:13,265 Perhaps there was life inside the rocks... 461 00:36:13,477 --> 00:36:15,035 ...or under the ground. 462 00:36:15,512 --> 00:36:19,004 If so, it had left no traces. 463 00:36:25,589 --> 00:36:28,752 For most of its history, the Earth had microbes... 464 00:36:28,959 --> 00:36:31,484 ...but no living things big enough to see. 465 00:36:32,162 --> 00:36:35,723 Perhaps the same is true for Mars. 466 00:36:52,849 --> 00:36:57,786 The Viking lander is a superbly instrumented and designed machine. 467 00:36:58,522 --> 00:37:03,084 It extends human capabilities to other and alien landscapes. 468 00:37:03,293 --> 00:37:07,525 By some standards, it's about as smart as a grasshopper. 469 00:37:07,731 --> 00:37:10,894 By others, only as intelligent as a bacterium. 470 00:37:11,101 --> 00:37:13,569 There's nothing demeaning in these comparisons. 471 00:37:13,770 --> 00:37:18,036 It took nature hundreds of millions of years to evolve a bacterium... 472 00:37:18,241 --> 00:37:20,539 ...and billions of years to make a grasshopper. 473 00:37:20,744 --> 00:37:23,235 With only a little experience in this business... 474 00:37:23,447 --> 00:37:25,506 ...we're getting pretty good at it. 475 00:37:27,517 --> 00:37:28,984 In both landing sites... 476 00:37:29,553 --> 00:37:32,386 ...in Chryse and Utopia... 477 00:37:32,589 --> 00:37:35,854 ...we've begun to dig in the sands of Mars. 478 00:37:36,226 --> 00:37:38,660 On a very small scale, such trenches... 479 00:37:38,862 --> 00:37:42,423 ...are the first human engineering works on another world. 480 00:37:53,643 --> 00:37:57,101 The robot arm retrieves soil samples... 481 00:37:57,314 --> 00:38:00,841 ...and deposits them into several sifters. 482 00:38:02,185 --> 00:38:05,552 Then the soil is carried to five experiments: 483 00:38:05,756 --> 00:38:07,587 Two on the chemistry of the soil... 484 00:38:07,791 --> 00:38:10,817 ...and three to look for microbial life. 485 00:38:12,129 --> 00:38:15,792 The Viking biology experiments represent a pioneering first effort... 486 00:38:15,999 --> 00:38:18,297 ...in the search for life on another world. 487 00:38:18,502 --> 00:38:21,733 The results are tantalizing, annoying... 488 00:38:21,938 --> 00:38:23,929 ...provocative, stimulating... 489 00:38:24,141 --> 00:38:26,336 ...and deeply ambiguous. 490 00:38:27,144 --> 00:38:29,908 By criteria established before a launch... 491 00:38:30,113 --> 00:38:33,571 ...two of the three Viking microbiology experiments... 492 00:38:33,784 --> 00:38:36,753 ...seem to have yielded positive results. 493 00:38:36,953 --> 00:38:41,322 First, when Martian soil samples are mixed together... 494 00:38:41,525 --> 00:38:43,755 ...with an organic soup from Earth... 495 00:38:43,960 --> 00:38:47,760 ...something in the soil seems to have broken food down... 496 00:38:47,964 --> 00:38:51,127 ...almost as if there were little Martian microbes... 497 00:38:51,334 --> 00:38:54,394 ...which metabolized, enjoyed... 498 00:38:54,604 --> 00:38:56,595 ...the soup from Earth. 499 00:38:57,274 --> 00:39:00,175 Second, when gases from Earth... 500 00:39:00,377 --> 00:39:02,470 ...were mixed together with Martian soil... 501 00:39:03,280 --> 00:39:07,478 ...something seems to have chemically combined the gases with soil... 502 00:39:07,684 --> 00:39:10,585 ...almost as if there were little Martian microbes capable... 503 00:39:10,787 --> 00:39:15,383 ...of synthesizing organic matter from atmospheric gases. 504 00:39:15,592 --> 00:39:17,389 But the situation is complex. 505 00:39:17,594 --> 00:39:19,152 Mars is not the Earth. 506 00:39:19,362 --> 00:39:24,265 As the legacy of Percival Lowell reminds us, we're liable to be fooled. 507 00:39:25,202 --> 00:39:28,137 Perhaps the ultraviolet light from the sun... 508 00:39:28,338 --> 00:39:30,363 ...strikes the Martian surface... 509 00:39:30,574 --> 00:39:34,977 ...and makes some chemical which can oxidize foodstuffs. 510 00:39:35,946 --> 00:39:38,540 Perhaps there is some catalyst in the soil... 511 00:39:38,748 --> 00:39:42,548 ...which can combine atmospheric gases with the soil... 512 00:39:42,752 --> 00:39:45,084 ...and make organic molecules. 513 00:39:45,722 --> 00:39:48,190 The red sands of Mars were excavated... 514 00:39:48,391 --> 00:39:51,189 ...seven times at the two different landing sites... 515 00:39:51,487 --> 00:39:56,186 ...as distant from each other as Boston is from Baghdad. 516 00:39:56,926 --> 00:40:00,225 Whatever was giving these results was probably all over Mars... 517 00:40:00,429 --> 00:40:04,297 ...but was it life, or just the chemistry of the soil? 518 00:40:04,667 --> 00:40:08,364 Studies suggest that a kind of clay known to exist on Mars... 519 00:40:08,571 --> 00:40:12,701 ...can serve as a catalyst to accelerate in the absence of life... 520 00:40:12,908 --> 00:40:16,935 ...chemical reactions which resemble the activities of life. 521 00:40:19,081 --> 00:40:22,141 It may be that in the early history of the Earth, before life... 522 00:40:22,351 --> 00:40:26,549 ...there were little cycles, chemical cycles running in the soil... 523 00:40:26,755 --> 00:40:29,849 ...something like photosynthesis and respiration... 524 00:40:30,059 --> 00:40:34,587 ...which were then incorporated by biology once life arose. 525 00:40:35,831 --> 00:40:40,530 There may be life elsewhere than in the two small sites we examined. 526 00:40:40,736 --> 00:40:45,173 Or perhaps there's life of a different sort all over Mars. 527 00:40:45,374 --> 00:40:49,003 Life is just a kind of chemistry of sufficient complexity... 528 00:40:49,211 --> 00:40:51,975 ...to permit reproduction and evolution. 529 00:40:52,181 --> 00:40:55,048 I wonder if we'll ever find a specimen of life based... 530 00:40:55,251 --> 00:40:57,116 ...not on organic molecules... 531 00:40:57,319 --> 00:41:01,119 ...but on something else, something more exotic. 532 00:41:04,193 --> 00:41:07,856 The Viking experiments found that the Martian soil is not... 533 00:41:08,063 --> 00:41:10,623 ...loaded with organic remains... 534 00:41:10,833 --> 00:41:13,324 ...of once living creatures. 535 00:41:13,536 --> 00:41:18,337 Maybe the surface's reactive chemistry has destroyed organic molecules... 536 00:41:18,541 --> 00:41:20,304 ...molecules based on carbon. 537 00:41:20,509 --> 00:41:22,409 Or maybe there's no life on Mars... 538 00:41:22,611 --> 00:41:25,978 ...and all Viking found was a funny soil chemistry. 539 00:41:26,181 --> 00:41:28,274 Or maybe there's life, okay... 540 00:41:28,484 --> 00:41:32,147 ...but it's not based on organic chemistry as much as life is on Earth. 541 00:41:33,389 --> 00:41:37,291 Personally, I don't think that's a very likely possibility. 542 00:41:37,493 --> 00:41:40,826 I'm a carbon chauvinist. I freely admit it. 543 00:41:41,030 --> 00:41:43,590 Carbon is tremendously abundant in the cosmos... 544 00:41:43,799 --> 00:41:47,030 ...and it makes marvelously complex organic molecules... 545 00:41:47,236 --> 00:41:49,431 ...that are terrifically good for life. 546 00:41:49,638 --> 00:41:52,004 I'm also a water chauvinist. 547 00:41:52,207 --> 00:41:55,267 It's an ideal solvent for organic molecules... 548 00:41:55,477 --> 00:41:59,243 ...and it stays liquid over a very wide range of temperatures. 549 00:41:59,448 --> 00:42:03,748 But sometimes I wonder, could my fondness... 550 00:42:03,953 --> 00:42:06,922 ...for these materials have anything to do with the fact... 551 00:42:07,122 --> 00:42:09,352 ...that I'm chiefly made up of them? 552 00:42:09,558 --> 00:42:14,086 Are we carbon and water-based because these materials were abundant... 553 00:42:14,296 --> 00:42:16,764 ...on the Earth at the time of the origin of life? 554 00:42:16,966 --> 00:42:20,629 Might life elsewhere be based on different stuff? 555 00:42:21,036 --> 00:42:22,799 (LIQUID GURGLES) 556 00:42:23,706 --> 00:42:27,904 I'm a collection of organic molecules called Carl Sagan. 557 00:42:28,110 --> 00:42:31,204 You're a collection of almost identical molecules... 558 00:42:31,413 --> 00:42:35,850 ...with a different collective label. But is that all? 559 00:42:36,051 --> 00:42:40,647 Is there nothing in here but molecules? 560 00:42:40,889 --> 00:42:45,826 Some people find that idea somehow demeaning to human dignity. 561 00:42:46,161 --> 00:42:50,393 But for myself, I find it elevating and exhilarating... 562 00:42:50,599 --> 00:42:53,033 ...to discover that we live in a universe... 563 00:42:53,235 --> 00:42:56,966 ...which permits the evolution of molecular machines... 564 00:42:57,172 --> 00:43:00,767 ...as intricate and subtle as we. 565 00:43:01,710 --> 00:43:06,272 The essence of life is not the atoms and small molecules that go into us... 566 00:43:06,482 --> 00:43:09,349 ...as the way, the ordering... 567 00:43:09,551 --> 00:43:12,179 ...the way those molecules are put together. 568 00:43:12,388 --> 00:43:14,879 Now, we sometimes read... 569 00:43:15,090 --> 00:43:18,150 ...that the chemicals which make up a human body are worth... 570 00:43:18,360 --> 00:43:22,296 ...on the open market, only 97 cents or $10, or some number like that. 571 00:43:22,631 --> 00:43:26,465 And it's depressing to find our bodies valued at so little. 572 00:43:26,669 --> 00:43:29,331 But these estimates are for humans... 573 00:43:29,538 --> 00:43:33,065 ...reduced to our simplest possible components. 574 00:43:36,145 --> 00:43:39,273 What is all this stuff in front of me? 575 00:43:39,481 --> 00:43:44,009 These are exactly the atoms that make up the human body... 576 00:43:44,219 --> 00:43:46,346 ...and in the right proportions too. 577 00:43:46,555 --> 00:43:51,219 We're made mostly of water, and that costs almost nothing. 578 00:43:51,427 --> 00:43:54,191 The carbon is counted as coal. 579 00:43:54,396 --> 00:43:57,126 The calcium in our bones is chalk. 580 00:43:57,332 --> 00:44:01,393 The nitrogen in our proteins is liquid air. 581 00:44:01,603 --> 00:44:04,766 The iron in our blood is rusty nails. 582 00:44:04,973 --> 00:44:07,498 Some phosphorus and some trace elements. 583 00:44:07,943 --> 00:44:09,604 If we didn't know better... 584 00:44:09,812 --> 00:44:13,873 ...we might be tempted to take all these items... 585 00:44:14,083 --> 00:44:17,985 ...and mix them together in a container like this. 586 00:44:40,175 --> 00:44:41,608 And stir. 587 00:44:41,977 --> 00:44:43,774 We could stir all we want... 588 00:44:43,979 --> 00:44:47,540 ...and at the end, all we'd have is some boring mixture of atoms. 589 00:44:47,750 --> 00:44:49,513 How could we expect anything else? 590 00:44:50,018 --> 00:44:53,545 The beauty of a living thing is not the atoms that go into it... 591 00:44:53,756 --> 00:44:55,724 ...but the way those atoms are put together: 592 00:44:55,924 --> 00:45:00,725 Information distilled over 4 billion years of biological evolution. 593 00:45:00,929 --> 00:45:03,898 Incidentally, all the organisms on the Earth are made... 594 00:45:04,099 --> 00:45:06,226 ...essentially of that stuff. 595 00:45:06,435 --> 00:45:08,960 An eyedropper full of that liquid... 596 00:45:09,171 --> 00:45:13,574 ...could be used to make a caterpillar or a petunia... 597 00:45:13,776 --> 00:45:17,007 ...if only we knew how to put the components together. 598 00:45:18,347 --> 00:45:23,284 All life on Earth is made from the same mixture of the same atoms. 599 00:45:23,819 --> 00:45:25,980 On another planet, the jars of life... 600 00:45:26,188 --> 00:45:30,090 ...might be filled with very different atoms and small molecules. 601 00:45:30,292 --> 00:45:34,228 But I think the life forms on many worlds will consist, by and large... 602 00:45:34,429 --> 00:45:36,624 ...of the same atoms that are popular here... 603 00:45:36,832 --> 00:45:39,027 ...maybe even the same big molecules. 604 00:45:39,234 --> 00:45:42,931 So I don't believe we can rescue the idea of life on Mars... 605 00:45:43,138 --> 00:45:46,699 ...by appealing to some exotic chemistry. 606 00:45:48,343 --> 00:45:51,335 Sometimes we hear about possible life forms... 607 00:45:51,547 --> 00:45:53,674 ...in which silicon replaces carbon... 608 00:45:53,882 --> 00:45:56,646 ...or perhaps, liquid ammonia replaces liquid water. 609 00:45:56,852 --> 00:45:59,252 But at Martian temperatures, there are no... 610 00:45:59,454 --> 00:46:03,754 ...plausible silicon-based molecules which might carry a genetic code. 611 00:46:03,959 --> 00:46:07,122 And ammonia is liquid only under higher pressures... 612 00:46:07,329 --> 00:46:09,092 ...and lower temperatures. 613 00:46:11,400 --> 00:46:15,461 Someday in the distant future we might have a collection of jars... 614 00:46:15,671 --> 00:46:19,801 ...each containing the elementary biochemistry of another world. 615 00:46:20,042 --> 00:46:23,375 I don't know if there'll be one labeled "Mars." 616 00:46:23,579 --> 00:46:24,876 But if there is... 617 00:46:25,080 --> 00:46:29,107 ...I bet it will be full of organic molecules. 618 00:46:32,921 --> 00:46:35,549 There's another way to search for life on Mars... 619 00:46:35,757 --> 00:46:38,191 ...to seek out the discoveries and delights... 620 00:46:38,393 --> 00:46:41,191 ...which that heterogeneous environment promises us. 621 00:46:41,396 --> 00:46:45,093 One of the things that a grasshopper can do but Viking can't... 622 00:46:45,300 --> 00:46:46,597 ...is move. 623 00:46:46,802 --> 00:46:49,202 We landed in the dull places on Mars. 624 00:46:49,404 --> 00:46:54,341 For all the solid, scientific findings and hints which Viking provided... 625 00:46:54,543 --> 00:46:59,344 ...we know that there are many places on the planet far more interesting. 626 00:46:59,548 --> 00:47:02,210 What we need is a roving vehicle... 627 00:47:02,417 --> 00:47:05,614 ...with advanced experiments in biology and organic chemistry... 628 00:47:05,821 --> 00:47:08,483 ...able to land in the safe but dull places... 629 00:47:08,690 --> 00:47:10,954 ...and wander to the interesting places. 630 00:47:21,303 --> 00:47:22,827 This roving vehicle... 631 00:47:23,038 --> 00:47:26,940 ...was developed by the Rensselaer Polytechnic Institute. 632 00:47:27,142 --> 00:47:30,600 It has a long list of dumb things it knows not to do. 633 00:47:30,812 --> 00:47:35,408 A Mars rover hasn't got time to ask if it should attempt a steep slope. 634 00:47:35,617 --> 00:47:37,847 Radio waves traveling at the speed of light... 635 00:47:38,053 --> 00:47:40,283 ...take 20 minutes for the roundtrip to Earth. 636 00:47:40,489 --> 00:47:43,424 By the time it got an answer, it might be... 637 00:47:43,625 --> 00:47:46,355 ...a heap of twisted metal at the bottom of a canyon. 638 00:47:46,561 --> 00:47:49,496 A rover has to think for itself. 639 00:47:54,937 --> 00:47:58,236 Imagine a rover with laser eyes like this one... 640 00:47:58,440 --> 00:48:01,876 ...but packed with sophisticated biological and chemical instruments... 641 00:48:02,077 --> 00:48:05,513 ...sampler arms, microscopes and television cameras... 642 00:48:05,714 --> 00:48:08,979 ...wandering over the Martian landscape. 643 00:48:10,519 --> 00:48:13,511 It could drive to its own horizon every day. 644 00:48:13,722 --> 00:48:16,987 A distant feature it barely resolves at sunrise... 645 00:48:17,192 --> 00:48:21,595 ...it can be sniffing and tasting by nightfall. 646 00:48:26,768 --> 00:48:30,260 Billions of people could watch the unfolding adventure... 647 00:48:30,472 --> 00:48:34,966 ...on their TV sets as the rover explores the ancient river bottoms... 648 00:48:35,177 --> 00:48:36,735 ...or cautiously approaches... 649 00:48:36,945 --> 00:48:40,312 ...the enigmatic pyramids of Elysium. 650 00:48:40,716 --> 00:48:44,015 A new age of discovery would have begun. 651 00:48:47,155 --> 00:48:49,680 Most of the human species would witness... 652 00:48:49,891 --> 00:48:53,088 ...the exploration of another world. 653 00:48:58,367 --> 00:49:01,268 Only 80 years ago, we could come no closer to Mars... 654 00:49:01,470 --> 00:49:04,803 ...than straining to see a tiny, shimmering image... 655 00:49:05,007 --> 00:49:07,567 ...through a telescope in Arizona. 656 00:49:07,776 --> 00:49:11,678 Now our instruments have actually touched down on the planet. 657 00:49:12,381 --> 00:49:17,148 Viking is a legacy of H.G. Wells... 658 00:49:17,352 --> 00:49:19,752 ...Percival Lowell, Robert Goddard. 659 00:49:19,955 --> 00:49:24,153 Science is a collaborative enterprise spanning the generations. 660 00:49:24,359 --> 00:49:29,092 When it permits us to see the far side of some new horizon... 661 00:49:29,297 --> 00:49:31,390 ...we remember those who prepared the way... 662 00:49:31,600 --> 00:49:34,228 ...seeing for them also. 663 00:49:36,738 --> 00:49:41,368 On each lander, there is a microdot on which is written very small... 664 00:49:41,576 --> 00:49:43,806 ...the names of 10,000 men and women... 665 00:49:44,012 --> 00:49:46,810 ...responsible for Viking's splendid achievement. 666 00:49:47,015 --> 00:49:50,507 One of the names on this microdot belonged to a friend of mine: 667 00:49:50,719 --> 00:49:54,587 A remarkable microbiologist named Wolf Vishniac. 668 00:49:54,790 --> 00:49:57,281 He was the first person to build a machine... 669 00:49:57,492 --> 00:49:59,926 ...to look for microbes on another world. 670 00:50:00,862 --> 00:50:03,626 His friends called it the "Wolf Trap." 671 00:50:03,832 --> 00:50:06,232 It contained a liquid nutrient... 672 00:50:06,435 --> 00:50:09,404 ...to which Martian soil would be added... 673 00:50:09,604 --> 00:50:11,629 ...and any microbes that liked the food... 674 00:50:11,840 --> 00:50:15,435 ...would grow in that nutrient medium and cloud it. 675 00:50:15,644 --> 00:50:18,442 The Wolf Trap was selected to go with Viking to Mars... 676 00:50:18,647 --> 00:50:22,879 ...but NASA is especially vulnerable to budget cuts... 677 00:50:23,085 --> 00:50:25,679 ...and it was removed as an economy measure. 678 00:50:25,887 --> 00:50:30,415 It was a terrible blow to Vishniac. He'd worked 12 years on it. 679 00:50:30,625 --> 00:50:34,186 Others might have stalked off the project... 680 00:50:34,396 --> 00:50:37,388 ...but Vishniac was a gentle and dedicated man. 681 00:50:37,599 --> 00:50:42,434 He decided instead to study the most Mars-like environment on this planet: 682 00:50:42,637 --> 00:50:47,336 The dry valleys of Antarctica, which were long thought to be lifeless. 683 00:50:51,713 --> 00:50:55,240 But Vishniac believed that if he could find microbes growing... 684 00:50:55,450 --> 00:50:58,749 ...in these arid polar wastes... 685 00:50:58,954 --> 00:51:02,515 ...the chances of life on Mars would improve. 686 00:51:05,760 --> 00:51:08,228 So in November 1973... 687 00:51:08,430 --> 00:51:10,660 ...Vishniac was left in a remote valley... 688 00:51:10,866 --> 00:51:14,165 ...in the Asgard Mountains of Antarctica. 689 00:51:14,936 --> 00:51:18,064 He set up hundreds of little sample collectors... 690 00:51:18,673 --> 00:51:22,769 ...simple versions of the Viking microbiology experiments. 691 00:51:23,545 --> 00:51:24,569 On December 10th... 692 00:51:24,779 --> 00:51:27,475 ...he left camp to retrieve some samples... 693 00:51:27,682 --> 00:51:29,411 ...and never returned. 694 00:51:30,018 --> 00:51:32,350 He had wandered to an unexplored area... 695 00:51:32,554 --> 00:51:34,317 ...apparently slipped on the ice... 696 00:51:34,523 --> 00:51:37,321 ...and fell more than 100 meters. 697 00:51:38,093 --> 00:51:40,755 Maybe something had caught his eye... 698 00:51:40,962 --> 00:51:43,692 ...a likely habitat for microbes... 699 00:51:43,899 --> 00:51:46,766 ...or a patch of green where none should be. 700 00:51:46,968 --> 00:51:49,232 The last entry in his notebook was: 701 00:51:49,437 --> 00:51:54,374 "Station 202 retrieved. 2230 hours. 702 00:51:54,676 --> 00:51:57,611 Soil temperature, minus 10 degrees. 703 00:51:57,812 --> 00:52:01,475 Air temperature, minus 16 degrees." 704 00:52:01,683 --> 00:52:05,449 It had been a typical summer temperature... 705 00:52:05,687 --> 00:52:07,086 ...for Mars. 706 00:52:07,689 --> 00:52:10,283 Some of his soil samples were later returned... 707 00:52:10,492 --> 00:52:12,323 ...and his colleagues discovered... 708 00:52:12,527 --> 00:52:15,621 ...that there is life in the dry valleys of Antarctica... 709 00:52:15,830 --> 00:52:18,924 ...that life is even more tenacious than we had imagined. 710 00:52:19,134 --> 00:52:23,969 That fact may turn out to be important for the future history of Mars. 711 00:52:29,044 --> 00:52:30,875 There will be a time... 712 00:52:31,079 --> 00:52:33,547 ...when Mars is thoroughly explored. 713 00:52:33,748 --> 00:52:36,876 What then? What should we do with Mars? 714 00:52:37,819 --> 00:52:41,846 If there is life on Mars, then I believe we should do nothing... 715 00:52:42,057 --> 00:52:43,888 ...to disturb that life. 716 00:52:44,826 --> 00:52:49,763 Mars, then, belongs to the Martians, even if they are microbes. 717 00:52:49,998 --> 00:52:52,558 But suppose that Mars is in fact lifeless. 718 00:52:52,767 --> 00:52:56,328 Might we in some sense be able to live there... 719 00:52:56,538 --> 00:52:59,769 ...to somehow make Mars habitable like the Earth... 720 00:52:59,975 --> 00:53:03,069 ...to terraform another world? 721 00:53:05,580 --> 00:53:08,481 As lovely a world as Mars is... 722 00:53:08,683 --> 00:53:10,446 ...it poses certain problems. 723 00:53:10,652 --> 00:53:13,177 There's too little oxygen, no liquid water... 724 00:53:13,388 --> 00:53:15,356 ...and too much ultraviolet light. 725 00:53:15,557 --> 00:53:19,891 But all that could be solved if we could make more air. 726 00:53:20,095 --> 00:53:24,191 With higher atmospheric pressures, liquid water would become possible. 727 00:53:24,399 --> 00:53:27,368 With more oxygen we could breathe the atmosphere. 728 00:53:27,569 --> 00:53:30,470 And ozone could form to shield the surface... 729 00:53:30,672 --> 00:53:33,072 ...from the solar ultraviolet light. 730 00:53:33,275 --> 00:53:35,835 The evidence for liquid water suggests... 731 00:53:36,044 --> 00:53:38,638 ...that Mars once had a denser atmosphere... 732 00:53:38,847 --> 00:53:41,077 ...which can't have all escaped to space. 733 00:53:41,283 --> 00:53:43,649 It has to be on the planet somewhere. 734 00:53:44,119 --> 00:53:46,178 In subsurface ice, surely... 735 00:53:46,388 --> 00:53:50,586 ...but most accessibly in the present polar caps. 736 00:53:52,727 --> 00:53:56,288 To vaporize the icecaps, we must heat them... 737 00:53:56,498 --> 00:54:01,435 ...preferably by covering them with something dark to absorb more sunlight. 738 00:54:01,670 --> 00:54:05,162 That thing ought to also be cheap and able to make copies of itself. 739 00:54:05,373 --> 00:54:10,037 Well, there are such things. We call them plants. 740 00:54:10,812 --> 00:54:15,181 We would need to evolve by artificial selection and genetic engineering... 741 00:54:15,383 --> 00:54:20,047 ...dark plants able to survive the severe Martian environment. 742 00:54:20,755 --> 00:54:22,586 Such plants could be seeded... 743 00:54:22,791 --> 00:54:25,817 ...on the vast expanse of the Martian polar icecaps... 744 00:54:26,127 --> 00:54:29,187 ...taking root, spreading, giving off oxygen... 745 00:54:29,397 --> 00:54:31,888 ...darkening the surface, melting the ice... 746 00:54:32,100 --> 00:54:35,433 ...and releasing the ancient Martian atmosphere... 747 00:54:35,637 --> 00:54:37,901 ...from its long captivity. 748 00:54:40,342 --> 00:54:44,244 We might even imagine a kind of Martian Johnny Appleseed... 749 00:54:44,446 --> 00:54:46,073 ...robot or human... 750 00:54:46,281 --> 00:54:50,513 ...roaming the frozen polar wastes in an endeavor which benefits... 751 00:54:50,719 --> 00:54:52,812 ...only the generations to come. 752 00:54:53,021 --> 00:54:56,821 It might take hundreds or thousands of years. 753 00:55:02,163 --> 00:55:04,757 We might, then, want to carry the liberated water... 754 00:55:04,966 --> 00:55:06,957 ...from the melting polar icecaps... 755 00:55:07,168 --> 00:55:09,568 ...to the warmer equatorial regions. 756 00:55:09,771 --> 00:55:11,739 And there's a way to do it: 757 00:55:11,940 --> 00:55:14,807 We would build canals. 758 00:55:15,276 --> 00:55:17,972 But that's exactly what Percival Lowell believed... 759 00:55:18,179 --> 00:55:20,306 ...was happening on Mars in his time. 760 00:55:20,515 --> 00:55:23,973 The idea of a canal network built by Martians... 761 00:55:24,185 --> 00:55:27,586 ...may turn out to be a kind of premonition... 762 00:55:27,789 --> 00:55:30,519 ...because, if the planet ever is terraformed... 763 00:55:30,725 --> 00:55:32,693 ...it will be done by human beings... 764 00:55:32,894 --> 00:55:36,591 ...whose permanent residence and planetary affiliation... 765 00:55:36,798 --> 00:55:38,095 ...is Mars. 766 00:55:38,299 --> 00:55:41,598 The Martians will be us. 767 00:56:14,035 --> 00:56:18,165 Mars today is strictly relevant to the global environment of the Earth. 768 00:56:18,373 --> 00:56:22,070 Its antiseptic surface is a cautionary tale of what happens... 769 00:56:22,277 --> 00:56:24,108 ...if you don't have an ozone layer. 770 00:56:24,312 --> 00:56:28,180 Its great dust storms and the resulting cooling of its surface... 771 00:56:28,383 --> 00:56:30,817 ...played a role in the discovery of nuclear winter... 772 00:56:31,019 --> 00:56:35,115 ...the catastrophic climate change on Earth predicted to follow nuclear war. 773 00:56:35,323 --> 00:56:39,225 So if you didn't have an ounce of adventuresome spirit in you... 774 00:56:39,427 --> 00:56:43,124 ...it would still make sense to support the exploration of Mars. 775 00:56:43,965 --> 00:56:46,729 In recent years, there's been... 776 00:56:46,935 --> 00:56:48,835 ...a groundswell of interest... 777 00:56:49,037 --> 00:56:53,474 ...in organizing the first expedition of humans to go to the planet Mars. 778 00:56:53,675 --> 00:56:57,702 We first need more robotic missions, including rovers... 779 00:56:57,912 --> 00:57:01,109 ...balloons and return- sample missions... 780 00:57:01,316 --> 00:57:04,217 ...and more experience in long duration space flight. 781 00:57:04,419 --> 00:57:06,284 But eventually, if all goes well... 782 00:57:06,488 --> 00:57:08,820 ...the interplanetary ship or ships... 783 00:57:09,023 --> 00:57:11,184 ...would be constructed in Earth orbit... 784 00:57:11,993 --> 00:57:14,723 ...launched on the long journey to Mars... 785 00:57:15,530 --> 00:57:18,761 ...and then a landing module would set down on the surface. 786 00:57:18,967 --> 00:57:20,366 The crew would emerge... 787 00:57:20,568 --> 00:57:24,561 ...making the first human footfalls on another planet. 788 00:57:25,874 --> 00:57:28,502 It would be very expensive, of course... 789 00:57:28,710 --> 00:57:31,372 ...although cheaper if many nations share the cost. 790 00:57:31,579 --> 00:57:35,845 The key issue in my mind is whether the unmet needs here on Earth... 791 00:57:36,050 --> 00:57:37,779 ...should take priority. 792 00:57:38,086 --> 00:57:41,522 But that's a question even more appropriately addressed... 793 00:57:41,723 --> 00:57:43,657 ...to the military budgets... 794 00:57:43,858 --> 00:57:47,726 ...now $1 trillion a year worldwide. 795 00:57:47,929 --> 00:57:49,920 You can buy a lot for that. 796 00:57:50,465 --> 00:57:54,299 Justifications for the Mars endeavor have been offered in terms of... 797 00:57:54,502 --> 00:57:56,026 ...scientific exploration... 798 00:57:56,237 --> 00:57:59,570 ...developing technology, international cooperation... 799 00:57:59,774 --> 00:58:02,242 ...education, the environment. 800 00:58:02,443 --> 00:58:06,880 Some see it as the obvious response to the future calling. 801 00:58:07,081 --> 00:58:10,414 Some even think we should go to investigate enigmatic landforms... 802 00:58:10,618 --> 00:58:13,553 ...including one that resembles an enormous human face. 803 00:58:14,155 --> 00:58:17,283 Personally, I think this, like hundreds of other... 804 00:58:17,492 --> 00:58:19,221 ...blocky mesas there... 805 00:58:19,427 --> 00:58:21,725 ...is sculpted by the high-speed winds. 806 00:58:21,930 --> 00:58:24,763 But if we're going anyway, there's no harm in taking a look. 807 00:58:24,966 --> 00:58:28,367 A remarkably diverse group of American leaders... 808 00:58:28,570 --> 00:58:30,765 ...has endorsed the Mars goal. 809 00:58:31,639 --> 00:58:34,608 I imagine the emissaries from Earth... 810 00:58:34,809 --> 00:58:37,107 ...citizens of many nations... 811 00:58:37,312 --> 00:58:40,440 ...wandering down an ancient river valley on Mars... 812 00:58:40,648 --> 00:58:44,084 ...trying to understand how a quite Earth-like world... 813 00:58:44,285 --> 00:58:47,743 ...was converted into a permanent ice age... 814 00:58:47,956 --> 00:58:52,120 ...and looking for signs of ancient life along the river banks. 815 00:58:52,827 --> 00:58:53,816 In the long run... 816 00:58:54,028 --> 00:58:56,895 ...the significance of such a mission is nothing less... 817 00:58:57,098 --> 00:59:01,432 ...than the conversion of humanity into a multiplanet species.