1 00:00:06,679 --> 00:00:09,359 Speaker 1: At the start of a new millennium. We're about to 2 00:00:09,439 --> 00:00:14,279 embark on the greatest adventure of all time. Five hundred 3 00:00:14,359 --> 00:00:18,239 million miles from Earth, a spacecraft will land on Jupiter's 4 00:00:18,399 --> 00:00:27,600 icy moon Europa its mission to search for alien life. 5 00:00:32,960 --> 00:00:36,679 As we reach out across the galaxy, our spacecraft will 6 00:00:36,719 --> 00:00:40,840 explore the most extreme environments to answer the ultimate question, 7 00:00:42,880 --> 00:01:30,040 are we alone? Our universe is made up of countless galaxies, 8 00:01:30,560 --> 00:01:37,560 each teeming with billions of stars like our Sun orbiting 9 00:01:37,599 --> 00:01:47,159 around them. Maybe billions of planets. Any Earth like planet 10 00:01:47,599 --> 00:01:50,959 could be home to an intelligent alien trying to communicate 11 00:01:51,079 --> 00:01:51,400 with us. 12 00:02:02,079 --> 00:02:05,200 Speaker 2: The Pentagon admitted just moments ago that a researcher at 13 00:02:05,239 --> 00:02:09,159 the Seti Institute in California has detected a radio signal 14 00:02:09,199 --> 00:02:10,960 from beyond the Solar System. 15 00:02:11,840 --> 00:02:17,240 Speaker 3: Deep space Metal de Madrid send Extra Terrestriya. 16 00:02:16,680 --> 00:02:21,000 Speaker 4: Danta Tinti and Ja Khatinti Chanhashenbugga tin Lu Tinti jump 17 00:02:21,039 --> 00:02:22,080 Patch's way. 18 00:02:22,039 --> 00:02:25,080 Speaker 5: Signal was first detected at three am this morning, and 19 00:02:25,159 --> 00:02:28,560 following confirmation from other radio telescope sites around the globe, 20 00:02:28,680 --> 00:02:32,199 the Pentagon allows that the extraterrestrial radio signal should be 21 00:02:32,280 --> 00:02:33,280 considered valid. 22 00:02:34,919 --> 00:02:37,520 Speaker 6: There are four hundred billion stars in our Milky Way 23 00:02:37,560 --> 00:02:40,840 galaxy and billions of other galaxies as well. It would 24 00:02:40,840 --> 00:02:43,120 be bizarre if we were the only life. 25 00:02:44,759 --> 00:02:48,479 Speaker 7: We're discovering that life forms exist in places and conditions 26 00:02:48,599 --> 00:02:51,560 that we couldn't have conceived of a few years ago. 27 00:02:53,039 --> 00:02:56,319 Speaker 8: Since a good proportion of stars seemed to have planets, 28 00:02:56,759 --> 00:03:00,159 we might expect primitive life to be lighte thread. 29 00:03:02,319 --> 00:03:06,400 Speaker 2: Scientist Robbert Plomer began to verify the exact origin of 30 00:03:06,400 --> 00:03:06,960 the signal. 31 00:03:10,400 --> 00:03:13,719 Speaker 9: What if we get a signal? What will happen? Will 32 00:03:13,879 --> 00:03:16,879 you still go to work tomorrow or will the world stop? 33 00:03:19,680 --> 00:03:26,960 It's the oldest unanswered question that our species has posed 34 00:03:27,000 --> 00:03:30,719 to itself. Is anybody else out there? 35 00:03:36,719 --> 00:03:39,280 Speaker 1: It's a question that Jill Tata has been trying to 36 00:03:39,360 --> 00:03:42,759 answer for over twenty years at the SETI Institute, an 37 00:03:42,840 --> 00:04:04,759 agency dedicated to the search for extraterrestrial intelligence all over 38 00:04:04,759 --> 00:04:08,479 the world. SETI researchers are more optimistic about picking up 39 00:04:08,520 --> 00:04:11,439 that first call from ET than ever before. 40 00:04:18,560 --> 00:04:22,279 Speaker 9: What's so terrific about now is the fact that we 41 00:04:22,360 --> 00:04:27,560 suddenly have the technology that allows scientists and engineers to 42 00:04:27,839 --> 00:04:32,800 try and answer this old question. For me, I can't 43 00:04:32,800 --> 00:04:34,399 imagine doing anything more important. 44 00:04:36,279 --> 00:04:39,839 Speaker 1: Set amongst the dense rainforests of Puerto Rico is the 45 00:04:39,959 --> 00:04:44,120 largest electronic ear on Earth. It's so sensitive it could 46 00:04:44,120 --> 00:04:50,240 pick up a mobile phone on Jupiter. The Araciba radio 47 00:04:50,319 --> 00:05:02,199 dish is one thousand feet across. Twice a year, the 48 00:05:02,279 --> 00:05:05,800 SETI researchers come to Arisibo to listen out for signals 49 00:05:05,839 --> 00:05:22,680 from deep space. Five thousand miles away across the Atlantic 50 00:05:23,279 --> 00:05:27,879 is the love All Dish at Jodrell Bank. This is 51 00:05:27,920 --> 00:05:30,160 the largest radio telescope in Britain. 52 00:05:35,800 --> 00:05:38,519 Speaker 7: The equipment we're using for this search is the most 53 00:05:38,560 --> 00:05:42,839 sophisticated that's ever been used. It's using two of the 54 00:05:42,839 --> 00:05:46,680 world's largest radio telescopes to make the most sensitive system 55 00:05:46,720 --> 00:05:49,519 that mankind has ever been able to use, or probably 56 00:05:49,519 --> 00:05:51,879 will be able to do for ten or twenty years. 57 00:05:51,680 --> 00:05:52,240 Speaker 10: In the future. 58 00:06:00,759 --> 00:06:05,000 Speaker 1: Together, these two dishes are targeting those distant stars most 59 00:06:05,160 --> 00:06:08,439 likely to be orbited by planets. They are trying to 60 00:06:08,480 --> 00:06:17,720 detect alien interstellar messages. But where on the radio dial 61 00:06:17,920 --> 00:06:23,560 will the extraterrestrials be broadcasting? The SETI Institute is currently 62 00:06:23,600 --> 00:06:27,160 scanning twenty eight million radio frequencies. 63 00:06:29,560 --> 00:06:33,759 Speaker 11: Talking about eavesdropping on aliens makes for easy dinner table conversation. 64 00:06:33,839 --> 00:06:37,079 In fact, doing it is quite hard. If you have 65 00:06:37,120 --> 00:06:39,319 twenty eight million channels. He can't just have twenty eight 66 00:06:39,319 --> 00:06:42,160 million guys with earphones awaiting the signal. You have to 67 00:06:42,199 --> 00:06:44,759 have very specialized computers that can look through all those 68 00:06:44,839 --> 00:06:47,560 channels at least once a second and make decisions about 69 00:06:47,680 --> 00:06:49,199 is there something interesting in there. 70 00:06:52,439 --> 00:06:57,480 Speaker 1: Their computers isolate any unusual signals from the constant background 71 00:06:57,560 --> 00:07:01,120 radio noise that swamps the Earth from corner of space. 72 00:07:02,199 --> 00:07:06,000 They're listening out for a special signal, one that suggests 73 00:07:06,040 --> 00:07:08,879 it's been sent by intelligent life. 74 00:07:09,319 --> 00:07:11,800 Speaker 11: You can imagine tuning the radio dial there and you 75 00:07:11,920 --> 00:07:16,079 hear this sh across it due to natural noise sources. 76 00:07:16,079 --> 00:07:18,920 Not very interesting, but every now and again, you could 77 00:07:18,920 --> 00:07:25,759 imagine coming across a squealedol. That squeal it's called a 78 00:07:25,839 --> 00:07:28,920 narrow band signal. That's exactly what we're looking for. Because 79 00:07:29,040 --> 00:07:32,360 only a transmitter, something that's been fabricated, can make a 80 00:07:32,399 --> 00:07:33,920 signal that's narrow band. 81 00:07:34,839 --> 00:07:38,240 Speaker 1: The researchers have to make sure the signal really is 82 00:07:38,319 --> 00:07:42,759 coming from deep space. They must eliminate any transmissions from 83 00:07:42,800 --> 00:07:51,160 passing aircraft, satellite, or military radar. It's only by using 84 00:07:51,240 --> 00:07:54,480 two dishes so far apart that they can calculate if 85 00:07:54,480 --> 00:08:01,680 the signal originates from beyond our solar system. This method 86 00:08:01,959 --> 00:08:09,199 has already picked out one distant signal, though this isn't 87 00:08:09,240 --> 00:08:13,079 from et, it's from one of our own interstellar spacecraft. 88 00:08:16,519 --> 00:08:20,720 In nineteen seventy two, Pioneer ten was launched on an 89 00:08:20,720 --> 00:08:25,240 epic journey to the giant planet Jupiter. It's mission long 90 00:08:25,319 --> 00:08:29,199 since over. Pioneer is now billions of miles beyond our 91 00:08:29,240 --> 00:08:33,519 Solar system, but its signal is still loud and clear. 92 00:08:36,480 --> 00:08:41,679 Speaker 9: Pioneer ten serves as a test case for us. In fact, 93 00:08:41,759 --> 00:08:45,679 it's so far away that its signal looks like a 94 00:08:45,720 --> 00:08:49,440 signal coming from a distant stares. 95 00:08:49,679 --> 00:08:53,279 Speaker 1: Every day the American and the British teams tune into 96 00:08:53,279 --> 00:08:57,720 the Pioneer signal. It's the most distant message they've ever received, 97 00:08:58,320 --> 00:09:00,960 but the scientist's hope for something far better. 98 00:09:02,279 --> 00:09:04,519 Speaker 11: Have we ever found a signal from space that was 99 00:09:04,600 --> 00:09:08,360 clearly due to extraterrestrial broadcasters? Well the answer is no. 100 00:09:08,440 --> 00:09:10,000 I mean, I wouldn't be sitting here if the answer 101 00:09:10,080 --> 00:09:12,320 weren't no. I'd be relaxing on the coach desserve having 102 00:09:12,360 --> 00:09:14,679 a drink. I'm sure we haven't found them yet. So far, 103 00:09:14,679 --> 00:09:15,639 the aliens have been coy. 104 00:09:17,200 --> 00:09:21,399 Speaker 1: Jill Tata and Seth Shostak have both dedicated their lives 105 00:09:21,399 --> 00:09:24,120 to listening out for a message they may never receive. 106 00:09:26,039 --> 00:09:29,080 Speaker 9: Every day when we go to the telescope, we have 107 00:09:29,159 --> 00:09:32,639 some sense of anticipation that we may in fact find 108 00:09:32,679 --> 00:09:36,399 the signal. We put champagne on ice in the refrigerator 109 00:09:36,440 --> 00:09:41,480 here and wherever we observe because we do plan for success. 110 00:09:44,480 --> 00:09:49,080 Speaker 1: The cosmic odds are stacked in their favor and improving 111 00:09:49,159 --> 00:09:53,879 with every new astronomical discovery. There's no shortage of places 112 00:09:53,919 --> 00:09:57,960 a message might come from our own galaxy. The Milky 113 00:09:58,000 --> 00:10:04,559 Way contains over a one hundred billion stars. If every 114 00:10:04,559 --> 00:10:07,320 one of those stars were a grain of salt, they 115 00:10:07,360 --> 00:10:13,759 would fill an Olympic sized swimming pool. How many of 116 00:10:13,799 --> 00:10:16,360 these stars have planets that could be home to an 117 00:10:16,399 --> 00:10:26,000 alien intelligence? Until recently, we could only guess. But over 118 00:10:26,039 --> 00:10:30,480 the last five years astronomers have made an extraordinary breakthrough. 119 00:10:31,200 --> 00:10:35,879 They've discovered over twenty planets outside our solar system, and 120 00:10:35,960 --> 00:10:43,080 they believe there may be literally billions more. 121 00:10:44,120 --> 00:10:47,440 Speaker 12: My guest would be that something like fifty percent of 122 00:10:47,480 --> 00:10:50,200 all the stars in our Milky Way galaxy, which itself 123 00:10:50,240 --> 00:10:54,039 contains one hundred billion stars, probably something like fifty percent 124 00:10:54,039 --> 00:10:55,120 of them harbor planets. 125 00:10:58,000 --> 00:11:01,720 Speaker 1: Jeff Massi is one of the world's most successful planet hunters. 126 00:11:02,440 --> 00:11:05,799 He and his colleagues have discovered more planets orbiting around 127 00:11:05,799 --> 00:11:14,279 other stars than orbit within our own Solar System. Standing 128 00:11:14,440 --> 00:11:18,240 high on the summit of an extinct Hawaiian volcano, the 129 00:11:18,399 --> 00:11:22,879 Giant Telescope is Mars's most penetrating eye on the universe. 130 00:11:26,200 --> 00:11:30,200 In nineteen ninety nine, his team made their most startling discovery. 131 00:11:31,120 --> 00:11:34,480 This time they found not just a single planet, but 132 00:11:34,679 --> 00:11:39,240 three worlds orbiting the same star, Upsilon Andromedy. 133 00:11:45,240 --> 00:11:49,600 Speaker 12: We have found now a complete system of planets, just 134 00:11:49,679 --> 00:11:51,759 like the system of planets we have around the Sun. 135 00:11:51,799 --> 00:11:55,159 These are not isolated freak planets that we had been finding, 136 00:11:55,320 --> 00:11:57,879 but at least in this one case, we now realize 137 00:11:58,039 --> 00:12:01,639 there's a complete system that is very reminiscent of the 138 00:12:01,759 --> 00:12:03,639 ordering of the planets around our Sun. 139 00:12:05,879 --> 00:12:09,879 Speaker 1: This new planetary system lies three hundred and twenty million 140 00:12:10,039 --> 00:12:15,559 million miles from Earth. The closest planet whirls round its 141 00:12:15,559 --> 00:12:20,240 star in just four days, the outermost in four years, 142 00:12:32,519 --> 00:12:36,159 so far, their equipment can only pick out the real heavyweights, 143 00:12:36,559 --> 00:12:40,360 planets the size of Jupiter, but the planet hunters are 144 00:12:40,399 --> 00:12:42,639 convinced there's greater treasure to be found. 145 00:12:46,759 --> 00:12:50,480 Speaker 12: There's almost no question that among the one hundred billion 146 00:12:50,519 --> 00:12:53,519 stars in our Milky Way galaxy there are not just 147 00:12:53,639 --> 00:12:56,159 the large planets that we've been finding, but of course 148 00:12:56,200 --> 00:13:00,440 smaller ones, probably indeed in greater numbers, and so earthlike 149 00:13:00,480 --> 00:13:02,919 planets are out there. 150 00:13:05,480 --> 00:13:09,960 Speaker 1: NASA's proposed Kepler mission may provide the definitive proof of 151 00:13:10,039 --> 00:13:16,519 Earth like planets in the early part of the twenty 152 00:13:16,519 --> 00:13:21,240 first century. This space telescope will continuously monitor one hundred 153 00:13:21,279 --> 00:13:27,919 and sixty thousand stars. Kepler's eagle eye will watch for 154 00:13:27,960 --> 00:13:31,519 any star that blinks, even when a planet as small 155 00:13:31,519 --> 00:13:37,000 as Earth passes in front of it. But if we 156 00:13:37,120 --> 00:13:40,799 do find an Earth like planet, there's no guarantee it 157 00:13:40,840 --> 00:13:46,519 will be home to intelligent aliens. It may be too hot, 158 00:13:46,879 --> 00:13:54,039 too cold, or to poisonous for et to survive, or 159 00:13:54,120 --> 00:13:57,480 perhaps alien life may have evolved on planets where the 160 00:13:57,519 --> 00:14:00,720 conditions would be far too inhospitable for humans. 161 00:14:10,440 --> 00:14:15,960 Speaker 3: One Hi tb hi oh bye bye hiy hight on 162 00:14:16,159 --> 00:14:19,960 bye on tcontob. 163 00:14:19,159 --> 00:14:23,480 Speaker 1: Kan to find out just how extreme an environment can 164 00:14:23,559 --> 00:14:27,919 be and still sustain life. NASA is researching the most 165 00:14:28,000 --> 00:14:34,679 hostile places on Earth before we set out to look 166 00:14:34,720 --> 00:14:38,320 for life on other planets. This research will direct us 167 00:14:38,360 --> 00:14:44,720 where to look. NASA scientist Tony Phillips is searching for 168 00:14:44,799 --> 00:14:48,799 primitive life in one of the coldest places in North America, 169 00:14:49,720 --> 00:14:52,519 high in the Eastern Sierras. 170 00:14:54,600 --> 00:14:56,639 Speaker 3: Right now, we're at the White Mountain Summit. We're at 171 00:14:56,679 --> 00:14:59,840 an altitude of over fourteen thousand feet. The pressure here 172 00:14:59,919 --> 00:15:04,240 is very low during the wintertime. The temperature here is 173 00:15:04,720 --> 00:15:07,759 comparable to the temperature at the South Pole during the 174 00:15:07,799 --> 00:15:11,039 South Pole ar summer, so the environment is very extreme. 175 00:15:16,320 --> 00:15:19,480 Not much lives here, but we suspect that there may 176 00:15:19,519 --> 00:15:22,279 be micro organisms living in the soil or living in 177 00:15:22,320 --> 00:15:26,039 the permafrost beneath the layer of rock, and no one 178 00:15:26,120 --> 00:15:28,039 knows whether they do or not. But that's what we're 179 00:15:28,080 --> 00:15:32,519 trying to find out. Hike Tevi Hike. 180 00:15:36,519 --> 00:15:39,639 Speaker 1: The NAZA scientists. I've discovered that life can survive in 181 00:15:39,720 --> 00:15:55,519 places where no one had expected. It now turns out 182 00:15:55,720 --> 00:15:59,120 that life can survive just about anywhere that there is water. 183 00:16:01,080 --> 00:16:03,840 It doesn't seem to matter how hostile. The environment is 184 00:16:11,559 --> 00:16:15,879 at Yellowstone Hot Springs in Wyoming. Dave D. Murray has 185 00:16:16,000 --> 00:16:20,080 proved that microbial life can even survive in boiling water, 186 00:16:20,679 --> 00:16:23,720 an extreme environment that we never thought possible before. 187 00:16:28,440 --> 00:16:30,639 Speaker 13: The limits for life are much broader than we had 188 00:16:30,639 --> 00:16:37,159 previously suspected. We've now discovered that life can exist up 189 00:16:37,159 --> 00:16:40,720 to one hundred and thirteen degrees centigrade, a higher temperature 190 00:16:40,720 --> 00:16:45,840 than we had dreamed about twenty years ago. But we 191 00:16:45,879 --> 00:16:48,159 find that that is actually a very nice place for 192 00:16:48,240 --> 00:16:49,600 certain organisms to live. 193 00:16:54,480 --> 00:16:58,159 Speaker 1: If life can survive at these temperatures, perhaps it can 194 00:16:58,200 --> 00:17:11,880 live anywhere. Mono Lake in California is one of the 195 00:17:11,920 --> 00:17:16,400 most hostile environments on Earth. Its scenic beauty is deceptive. 196 00:17:17,079 --> 00:17:20,160 The lake is so loaded with salt that it's poisonous 197 00:17:20,240 --> 00:17:26,240 to us. Jack Farmer has discovered that even here life 198 00:17:26,319 --> 00:17:27,240 can find a way. 199 00:17:29,920 --> 00:17:33,079 Speaker 14: In Mono Lake, the salinity of the water here is 200 00:17:33,440 --> 00:17:36,839 two and a half to three times seawater. In addition, 201 00:17:37,759 --> 00:17:39,720 the pH of the water here is around ten and 202 00:17:39,799 --> 00:17:43,880 a half, very alkalin, and yet that's not a barrier 203 00:17:43,920 --> 00:17:45,759 to life. Organisms are thriving here. 204 00:17:47,400 --> 00:17:50,000 Speaker 1: The lake is teeming with microbial life. 205 00:17:51,039 --> 00:17:53,400 Speaker 14: In the last decade, or so, we've begun to realize 206 00:17:53,440 --> 00:17:56,519 that it's really a microbial world. This world that we 207 00:17:56,599 --> 00:18:01,680 live in is dominated by microorganisms. To realize that that 208 00:18:01,920 --> 00:18:05,000 microbial life can occupy a whole range of environments that 209 00:18:05,039 --> 00:18:06,640 we never thought possible before. 210 00:18:07,640 --> 00:18:11,640 Speaker 1: The tenacity of life here in Earth's most extreme environments 211 00:18:11,960 --> 00:18:16,440 encourages many biologists to believe that life may be remarkably 212 00:18:16,519 --> 00:18:18,400 widespread throughout the universe. 213 00:18:20,400 --> 00:18:22,519 Speaker 14: I think the chances of finding life elsewhere in our 214 00:18:22,559 --> 00:18:25,680 Solar system are pretty good. Sometimes I say, well, maybe 215 00:18:25,720 --> 00:18:28,079 fifty to fifty, But I have to be honest, I 216 00:18:28,079 --> 00:18:30,119 don't really know how to put a probability on it, 217 00:18:30,559 --> 00:18:32,680 but I think anywhere where we had liquid water and 218 00:18:32,759 --> 00:18:36,240 the right organic compounds present, we've certainly had more than 219 00:18:36,359 --> 00:18:40,400 enough time to originate biological systems. The probability is probably 220 00:18:40,440 --> 00:18:41,359 pretty good. 221 00:18:43,480 --> 00:18:47,920 Speaker 1: For most of Earth's history, the only living things were microbes. 222 00:18:51,480 --> 00:18:55,359 As they search the universe, scientists expect to find planets 223 00:18:55,440 --> 00:18:58,759 crawling with microbial life long before they find one with 224 00:18:58,880 --> 00:19:04,480 intelligent life. Instead of meeting little green men, they're much 225 00:19:04,519 --> 00:19:18,559 more likely to meet little green slime. Our quest to 226 00:19:18,599 --> 00:19:23,119 discover life on other worlds began optimistically in the nineteen sixties, 227 00:19:23,559 --> 00:19:28,000 when a flotilla of spacecraft headed for our neighboring planet Mars, 228 00:19:31,799 --> 00:19:36,839 but their cameras revealed only craters and extinct volcanoes. Mars 229 00:19:36,920 --> 00:19:48,440 seemed a barren and lifeless world. This gloomy assessment was 230 00:19:48,480 --> 00:19:52,599 reinforced in nineteen seventy six when two Viking craft landed 231 00:19:52,599 --> 00:20:04,000 on the rocky Martian surface. They scooped up soil samples 232 00:20:04,039 --> 00:20:07,920 and analyzed them for any signs of microbial life. The 233 00:20:08,039 --> 00:20:20,279 results were negative. Mars seems extremely hostile to life. The 234 00:20:20,359 --> 00:20:24,279 average temperature is minus fifty three degrees celsius, and the 235 00:20:24,359 --> 00:20:29,000 thin atmosphere provides no barrier to the Sun's deadly ultraviolet rays. 236 00:20:31,640 --> 00:20:40,720 Even the rocks contain chemicals that can destroy living cells. 237 00:20:42,319 --> 00:20:46,359 But the idea of finding life on Mars continues to 238 00:20:46,440 --> 00:20:52,240 obsess many scientists. When Bruce Jaikowski started his research career, 239 00:20:52,440 --> 00:20:54,440 Viking had just landed. 240 00:20:56,079 --> 00:20:56,440 Speaker 3: Viking. 241 00:20:56,440 --> 00:21:00,200 Speaker 15: When it looked for life, it found none, and there 242 00:21:00,240 --> 00:21:02,680 was a real sense that there must be only one 243 00:21:02,680 --> 00:21:05,359 planet in our solar system that could support life, and 244 00:21:05,400 --> 00:21:08,319 that was the Earth. Things have changed dramatically since then, 245 00:21:08,480 --> 00:21:14,440 in particular the Revolution's in terrestrial biology and the possibility 246 00:21:14,480 --> 00:21:17,559 that life could have originated in some of these extreme environments. 247 00:21:20,680 --> 00:21:24,079 Speaker 1: Close up pictures of the Red planet have revealed tantalizing 248 00:21:24,119 --> 00:21:27,960 evidence that water once flowed across the surface of Mars. 249 00:21:30,799 --> 00:21:34,000 Speaker 15: We see clear geological evidence that there's been water on Mars. 250 00:21:35,799 --> 00:21:38,480 On some of the older surfaces. We see networks of 251 00:21:38,640 --> 00:21:42,079 valleys that look like river tributary systems where waters flowed 252 00:21:42,119 --> 00:21:47,240 through them and carved these long channels. The availability of 253 00:21:47,319 --> 00:21:50,000 water at the surface or in the crust, really, I think, 254 00:21:50,079 --> 00:21:51,839 is what makes it possible for life. 255 00:21:51,599 --> 00:21:52,039 Speaker 3: To be there. 256 00:21:54,000 --> 00:22:10,119 Speaker 1: The evidence came sooner than expected. On August seventh, nineteen 257 00:22:10,200 --> 00:22:16,440 ninety six, NASA called an unprecedented news conference. These scientists 258 00:22:16,480 --> 00:22:20,240 had examined a meteorite that had come from Mars and 259 00:22:20,279 --> 00:22:26,559 discovered something very strange lurking inside. One of the microbiologists 260 00:22:26,559 --> 00:22:28,119 on the team was Dave McKay. 261 00:22:28,599 --> 00:22:31,640 Speaker 4: We have a number of forms which it is very 262 00:22:31,680 --> 00:22:35,759 tempting for us to interpret as Martian microfossils. 263 00:22:38,480 --> 00:22:41,640 Speaker 1: The NASA team had been alerted by chemical residues in 264 00:22:41,680 --> 00:22:44,480 the rock that here on Earth can only be made 265 00:22:44,519 --> 00:22:49,680 by microbes. Then they picked out strange wormlike structures that 266 00:22:49,839 --> 00:23:01,119 looked like tiny fossilized life forms. It all began with 267 00:23:01,200 --> 00:23:08,160 a unique discovery on the snowy wastes of Antarctica. Each 268 00:23:08,240 --> 00:23:17,160 year a meteorite survey teams. Meteorites fall all over the Earth, 269 00:23:17,799 --> 00:23:20,759 but here the small, dark rocks are easy to spot 270 00:23:20,799 --> 00:23:33,160 on the pure white ice. In nineteen eighty four, the 271 00:23:33,279 --> 00:23:37,680 team picked up one meteorite ALH eighty four zero zero 272 00:23:37,839 --> 00:23:41,240 one that was to completely change our view of life 273 00:23:41,279 --> 00:23:51,359 in the Uni. It wasn't until nine years later that 274 00:23:51,440 --> 00:23:54,880 researchers discovered that the survey team had brought back a 275 00:23:54,960 --> 00:23:59,759 lump of mass, a rock formed four point five billion 276 00:23:59,839 --> 00:24:04,799 year years ago. Its origin was proved by traces of 277 00:24:04,839 --> 00:24:08,559 gas which exactly matched the composition of the Martian atmosphere 278 00:24:08,640 --> 00:24:10,200 measured by the Viking Landers. 279 00:24:14,079 --> 00:24:18,960 Speaker 16: This is an incredibly complex rock. It's much more complex 280 00:24:19,359 --> 00:24:23,559 than we first realized. It's more complex than most Earth 281 00:24:23,640 --> 00:24:27,559 rocks that people study, and this rock has been studied 282 00:24:27,799 --> 00:24:31,039 more than any rock in the history of the world. 283 00:24:33,119 --> 00:24:37,960 Speaker 1: Some scientists believe the microscopic structures are natural crystals, but 284 00:24:38,079 --> 00:24:42,039 for Mackay, the case for Martian life grows ever stronger. 285 00:24:43,359 --> 00:24:47,799 Speaker 4: These are fossils of little, tiny bacteria single cell organisms. 286 00:24:48,319 --> 00:24:52,240 They're not bones, They're little tiny cells that have turned 287 00:24:52,279 --> 00:24:58,240 to minerals. They're fossilized, but they look exactly like fossils 288 00:24:58,319 --> 00:24:59,359 from Earth rocks. 289 00:25:02,440 --> 00:25:04,880 Speaker 1: But the only way to find out for certain if 290 00:25:04,920 --> 00:25:07,880 there's ever been life on Mars is to go there 291 00:25:08,119 --> 00:25:13,480 and collect a sample. NAS emissions in two thousand three 292 00:25:13,559 --> 00:25:16,279 and two thousand and five will collect rocks from the 293 00:25:16,279 --> 00:25:18,880 red planet and then return them to Earth, where they'll 294 00:25:18,920 --> 00:25:30,359 be dissected for fossils. The surface of Mars is the 295 00:25:30,400 --> 00:25:36,400 same area as all the continents of Earth combined. There's 296 00:25:36,440 --> 00:25:39,319 an enormous choice of possible sights when it comes to 297 00:25:39,359 --> 00:26:01,559 collecting the priceless samples. Mojave Desert in California is one 298 00:26:01,599 --> 00:26:09,400 of the most inhospitable places on Earth. This dry lake 299 00:26:09,480 --> 00:26:13,359 bed was once covered in water. Its parched surface is 300 00:26:13,400 --> 00:26:16,880 the perfect place for Chris mackay to research where NASA 301 00:26:17,000 --> 00:26:20,079 should collect its first samples in order to look for 302 00:26:20,160 --> 00:26:23,000 fossils of microbes that once lived on Mars. 303 00:26:24,400 --> 00:26:26,319 Speaker 17: This lake bed is the sort of place we'd be 304 00:26:26,319 --> 00:26:28,240 looking for on Mars. Is a place to search for 305 00:26:28,279 --> 00:26:30,960 evidence of past life. It's a nice, big, easy to 306 00:26:31,000 --> 00:26:34,039 find target, easy to land in, easy to drive around on, 307 00:26:34,440 --> 00:26:36,960 easy to drill in. If there had been water and 308 00:26:37,000 --> 00:26:39,599 a lake like this on Mars, anything living in it 309 00:26:39,640 --> 00:26:41,480 as a dyed would settle to the bottom, and we'd 310 00:26:41,519 --> 00:26:43,960 be able to find it in the sediments. Here in 311 00:26:43,960 --> 00:26:46,359 the Mohave Desert, we might dig under the surface and 312 00:26:46,400 --> 00:26:49,079 find evidence of life. It's just a few years old, 313 00:26:49,319 --> 00:26:51,759 But on Mars these sediments would be three and a 314 00:26:51,799 --> 00:26:53,720 half to four billion years old, and we'd be looking 315 00:26:53,720 --> 00:26:56,440 for evidence of life that was on that planet when 316 00:26:56,440 --> 00:26:58,319 it was more like the Earth, when it had water. 317 00:27:05,920 --> 00:27:08,559 Here in this desert we find growing just underneath the 318 00:27:08,559 --> 00:27:13,799 surface of certain rocks, microorganisms algae. These organisms grow under 319 00:27:13,799 --> 00:27:16,240 the rocks because the rocks trap a little bit of 320 00:27:16,240 --> 00:27:18,839 moisture so it's not quite as dry. But they have 321 00:27:18,880 --> 00:27:21,640 to grow under the white stones because enough light can 322 00:27:21,680 --> 00:27:24,000 get through the white stones so they can photosynthesize. 323 00:27:25,319 --> 00:27:28,599 Speaker 1: This precarious existence could have been the way that life 324 00:27:28,640 --> 00:27:31,119 on Mars survived for billions of years. 325 00:27:34,799 --> 00:27:37,200 Speaker 17: Who would have been the last organism to live on Mars? 326 00:27:37,599 --> 00:27:40,519 Maybe an organism living underneath the rock. Maybe when we 327 00:27:40,559 --> 00:27:43,759 go to Mars we'll search for relics, for fossils, of 328 00:27:43,759 --> 00:27:45,599 this type of life. 329 00:27:47,680 --> 00:27:50,440 Speaker 1: But perhaps the search will turn up much more than 330 00:27:50,559 --> 00:27:55,279 just fossils. Despite the barren landscape, some biologists are now 331 00:27:55,359 --> 00:27:58,960 uttering what it was for many years a heresy that 332 00:27:59,160 --> 00:28:16,400 microbes may still be living on Mars. Today, microbiologist Todd 333 00:28:16,480 --> 00:28:21,359 Stephens has discovered the deep underground in Washington State, life 334 00:28:21,440 --> 00:28:28,680 is flourishing in apparently solid rock. Until the mid nineteen eighties, 335 00:28:29,000 --> 00:28:31,599 most people thought that the deepest you could dig down 336 00:28:31,680 --> 00:28:36,599 into the ground and find living organisms was around thirty feet, 337 00:28:37,759 --> 00:28:41,039 but Stephens is discovered that life on Earth can thrive 338 00:28:41,240 --> 00:28:47,480 as deep as two miles down. The Columbia River area 339 00:28:47,599 --> 00:28:51,839 of Washington State is covered in ancient lava flows thousands 340 00:28:51,839 --> 00:28:58,839 of feet thick. At the edge of a river gorge 341 00:28:58,960 --> 00:29:02,799 where the lava flows are exposed, Stephens has discovered how 342 00:29:02,839 --> 00:29:06,599 tiny micro organisms can live in solid rock. 343 00:29:08,319 --> 00:29:09,920 Speaker 18: Here at the bottom of the canyon, we can kind 344 00:29:09,920 --> 00:29:11,960 of get an idea of what their habitat looks like. 345 00:29:12,960 --> 00:29:16,960 Here we have the intersection between two basalt flows, and 346 00:29:17,359 --> 00:29:21,160 at one time water has flowed through this layer over 347 00:29:21,400 --> 00:29:24,599 tens of thousands of years and microorganisms live here. 348 00:29:25,440 --> 00:29:25,640 Speaker 8: Well. 349 00:29:25,680 --> 00:29:29,359 Speaker 18: This is exciting because if this is correct, this is 350 00:29:29,359 --> 00:29:32,160 a way that living organisms can live in places where 351 00:29:32,160 --> 00:29:33,960 the surface of the planet is not habitable. 352 00:29:38,960 --> 00:29:42,720 Speaker 1: On Mars, any microbes living deep in the rock would 353 00:29:42,720 --> 00:29:49,680 be well protected from the hostile surface environment. Stephens was 354 00:29:49,720 --> 00:29:53,279 researching the safe disposal of nuclear waste when he made 355 00:29:53,319 --> 00:29:56,519 his startling discovery about life deep underground. 356 00:29:57,799 --> 00:29:59,880 Speaker 10: This one has to be several hundred meter steep in the. 357 00:30:01,480 --> 00:30:04,559 Speaker 1: He took water samples here from boreholes that were drilled 358 00:30:04,599 --> 00:30:07,160 two miles down through the volcanic rock. 359 00:30:08,119 --> 00:30:09,960 Speaker 18: When we sampled the water that was coming out of 360 00:30:10,000 --> 00:30:13,240 the deep aquifers in this volcanic rock, we were kind 361 00:30:13,240 --> 00:30:15,559 of surprised to find that each leader of water contained 362 00:30:15,559 --> 00:30:19,359 between a million and one hundred million microbial cells. And 363 00:30:19,440 --> 00:30:21,480 we know that the vast majority are actually attached to 364 00:30:21,519 --> 00:30:23,519 the rock, so there's many more than that down there. 365 00:30:27,799 --> 00:30:31,519 Speaker 1: To prove they could survive without sunlight, Stephens bred the 366 00:30:31,559 --> 00:30:36,880 microbes in his laboratory, simulating their subterranean world. His results 367 00:30:36,960 --> 00:30:42,880 confirmed life's amazing ability to live anywhere there's water. These 368 00:30:42,920 --> 00:30:48,200 bacteria stained red feed off hydrogen gas created when water 369 00:30:48,279 --> 00:30:55,960 reacts with the volcanic rock. Even more exciting, these bacteria 370 00:30:56,079 --> 00:30:59,359 bears striking resemblance to the apparent fossils found in the 371 00:30:59,400 --> 00:31:17,400 Mars meat. You're right, perhaps the descendants of these fossilized 372 00:31:17,440 --> 00:31:31,039 microbes are still living deep under the Martian surface. The 373 00:31:31,160 --> 00:31:35,759 temperature on Mars is well below freezing, any life near 374 00:31:35,799 --> 00:31:44,000 the surface would be frozen solid. Astrophysicist Richard Hoover has 375 00:31:44,039 --> 00:31:47,720 made the astonishing discovery that microbial life can be re 376 00:31:47,920 --> 00:31:51,680 animated even after it's been frozen for thousands of years. 377 00:32:00,400 --> 00:32:03,680 The Fox Tunnel in Alaska is one of the coldest 378 00:32:03,680 --> 00:32:13,880 places on Earth. It was originally excavated for gold mining 379 00:32:14,000 --> 00:32:16,599 and dug out of the permafrost, where even the soil 380 00:32:16,720 --> 00:32:20,240 one hundred and fifty feet below the surface is frozen solid. 381 00:32:22,400 --> 00:32:26,319 Speaker 10: We have found microorganisms in the permafrost of Earth that 382 00:32:26,519 --> 00:32:29,480 are alive, and yet they have been frozen for up 383 00:32:29,519 --> 00:32:34,960 to three million years. Therefore, it is possible that there 384 00:32:34,960 --> 00:32:38,799 may be microorganisms frozen in the permafrost of Mars. 385 00:32:46,880 --> 00:32:51,039 Speaker 1: By warming samples from the permafrost, Hoover can revive these 386 00:32:51,119 --> 00:32:58,720 dormant organisms. It's not just microbes that wake up when 387 00:32:58,720 --> 00:33:02,400 the temperature rises. Even plants like moss can be brought 388 00:33:02,440 --> 00:33:04,359 back to life. 389 00:33:04,559 --> 00:33:06,839 Speaker 10: I have here a moss that was frozen in the 390 00:33:06,880 --> 00:33:10,960 permafrost for forty thousand years, and after it was extracted 391 00:33:11,000 --> 00:33:16,799 from the permafrost, the moss started to grow. It realized 392 00:33:16,839 --> 00:33:19,839 that the weather had gotten better and it was time 393 00:33:19,920 --> 00:33:20,519 to grow again. 394 00:33:28,680 --> 00:33:31,880 Speaker 1: As they're warmed up, any samples of life collected from 395 00:33:31,960 --> 00:33:44,119 Mars by NASA may also be revived. Returning a piece 396 00:33:44,200 --> 00:33:48,759 of Mars to Earth will require the strictest quarantine. It 397 00:33:48,839 --> 00:33:51,279 may be the most risky venture the human race has 398 00:33:51,319 --> 00:33:55,480 ever undertaken. No one knows what might happen if Martian 399 00:33:55,559 --> 00:33:57,519 bugs were released onto our planet. 400 00:34:01,279 --> 00:34:05,519 Speaker 4: If there's life on Mars, we have to be cautious 401 00:34:05,680 --> 00:34:10,079 because that life is not understood, and as we know, 402 00:34:10,519 --> 00:34:16,599 microbial life can be quite dangerous. Both viruses and bacteria 403 00:34:16,719 --> 00:34:20,320 could be dangerous to humans. It can also hurt the environment. 404 00:34:23,400 --> 00:34:27,079 Speaker 1: Unlike the meteorites, which have been sterilized by natural radiation 405 00:34:27,239 --> 00:34:30,480 as they travel through space, these rocks will have been 406 00:34:30,519 --> 00:34:32,639 transported directly from Mars. 407 00:34:35,559 --> 00:34:38,400 Speaker 4: They will be treated as if they might have an 408 00:34:38,400 --> 00:34:44,360 incredibly dangerous microbe in them. We don't know that, we 409 00:34:44,400 --> 00:34:47,000 don't think that'll be true, but we can't afford to 410 00:34:47,039 --> 00:34:47,920 take the chance. 411 00:34:56,400 --> 00:35:00,840 Speaker 15: Three two whe Bishop. 412 00:35:00,559 --> 00:35:04,079 Speaker 8: And with good of Atlanta Law. 413 00:35:05,599 --> 00:35:08,840 Speaker 1: In nineteen eighty nine, space shuttle Atlantis set off on 414 00:35:08,880 --> 00:35:11,400 a mission that may lead us to the first definitive 415 00:35:11,400 --> 00:35:17,760 discovery of life beyond our own planet. On board was 416 00:35:17,760 --> 00:35:21,400 the unmanned Galileo spacecraft, bound for the king of the 417 00:35:21,440 --> 00:35:28,280 planet's Jupiter. In this remote, frozen region five hundred million 418 00:35:28,360 --> 00:35:31,599 miles from the Sun. The last thing the mission scientists 419 00:35:31,599 --> 00:35:39,800 were expecting to find was signs of life. Giant Jupiter 420 00:35:40,280 --> 00:35:43,280 is big enough to swallow the Earth a thousand times over. 421 00:35:44,320 --> 00:35:48,400 Its family of moons forms a miniature solar system. The 422 00:35:48,480 --> 00:35:57,519 four biggest are io Ganymede, Callisto, and Europia Brilliant white. 423 00:35:57,599 --> 00:36:02,000 Europa is completely covered in ice. It surface crisscrossed by 424 00:36:02,079 --> 00:36:08,679 strange grooves. Many scientists now believe that this frozen world 425 00:36:08,719 --> 00:36:11,400 is the most likely place in our solar system to 426 00:36:11,480 --> 00:36:23,280 be harboring extraterrestrial life. The nearest equivalent to the surface 427 00:36:23,280 --> 00:36:25,760 of Europa are the glaciers of the Arctic. 428 00:36:32,679 --> 00:36:36,840 Speaker 10: The microorganisms that are found in the glaciers and in 429 00:36:36,920 --> 00:36:40,519 the polar ice caps give us a good model for 430 00:36:40,679 --> 00:36:44,480 the types of microorganisms that might be found someday when 431 00:36:44,480 --> 00:36:51,920 we bring back samples from Europa. I have become very 432 00:36:51,960 --> 00:36:55,119 excited when I look at the beautiful pictures of Galileo 433 00:36:55,360 --> 00:36:59,159 of the surface of Europa because we see magnificent colors, 434 00:37:01,440 --> 00:37:04,840 and those colors are very similar to colors that we 435 00:37:04,920 --> 00:37:09,239 see in bacteria and algae on Earth due to the 436 00:37:09,280 --> 00:37:23,320 pigments of these microorganisms. When we do get samples back, 437 00:37:23,360 --> 00:37:25,440 we will have a good idea of what types of 438 00:37:25,440 --> 00:37:27,960 things to look for, and we will have the ability 439 00:37:28,000 --> 00:37:34,440 to recognize the microorganisms when we find them. 440 00:37:34,480 --> 00:37:37,519 Speaker 1: The microbes of Europa would have to be far tougher 441 00:37:37,559 --> 00:37:42,199 than their Arctic counterparts. They'd have to survive lethal doses 442 00:37:42,239 --> 00:37:48,519 of radiation generated by Jupiter's powerful magnetism. 443 00:37:48,800 --> 00:37:51,320 Speaker 10: We know that there are microorganisms on Earth that have 444 00:37:51,440 --> 00:37:56,199 evolved to have the ability to withstand intense levels of radiation. 445 00:37:57,039 --> 00:38:01,559 There are bacteria that grow on the cooling of nuclear reactors, 446 00:38:04,599 --> 00:38:09,280 and if in fact organisms live on Europa, then they 447 00:38:09,320 --> 00:38:12,320 would have had the ability to adapt to these high 448 00:38:12,440 --> 00:38:17,000 radiation levels. So we must always be cautious about saying 449 00:38:17,039 --> 00:38:20,880 that life cannot do things, because quite frequently we find 450 00:38:20,920 --> 00:38:23,760 that life does exactly what we think it's not capable 451 00:38:23,800 --> 00:38:24,199 of doing. 452 00:38:28,440 --> 00:38:31,880 Speaker 1: The cracked ice surface may suggest something even more exciting. 453 00:38:32,760 --> 00:38:35,239 Heat from the core of the Moon may have melted 454 00:38:35,280 --> 00:38:42,239 the ice from below, just like the cracked octag iceed 455 00:38:42,239 --> 00:38:46,159 sheet on Earth, Europa's ICE's surface may overlie a huge 456 00:38:46,239 --> 00:38:47,079 ocean of water. 457 00:38:52,920 --> 00:38:55,960 Speaker 19: All life as we know it utterly depends on liquid water. 458 00:38:57,239 --> 00:38:59,559 Europa may be the only other place in the Solar 459 00:38:59,599 --> 00:39:01,840 System where there's an ocean of water, and that means 460 00:39:01,880 --> 00:39:03,679 it's the most exciting place to go and look for 461 00:39:03,719 --> 00:39:04,400 life Elsewhere. 462 00:39:07,039 --> 00:39:10,440 Speaker 1: Beneath the icy crust of Europa could lie an ocean 463 00:39:10,480 --> 00:39:17,719 as deep as sixty miles. This cold, dark environment seems 464 00:39:17,760 --> 00:39:22,360 a fruitless place to look for living organisms, but the 465 00:39:22,360 --> 00:39:25,320 depths of the Earth's oceans prove that life can once 466 00:39:25,360 --> 00:39:35,719 again flourish in the most unexpected places. In the nineteen seventies, 467 00:39:36,199 --> 00:39:40,440 the lights and cameras of deep diving submersibles discovered vents 468 00:39:40,639 --> 00:39:56,519 erupting hot water from the ocean floor where no sunlight 469 00:39:56,639 --> 00:40:01,840 ever penetrates and the surrounding water verges on. These volcanic 470 00:40:01,960 --> 00:40:05,039 vents support the most exotic life forms on Earth. 471 00:40:14,840 --> 00:40:18,079 Speaker 19: It's certainly possible that those sorts of hydrothermal events exist 472 00:40:18,199 --> 00:40:23,000 on Europa. There may well be teeming communities of organisms 473 00:40:23,280 --> 00:40:26,800 at hydrothermal vents at the very bottom of Europa's oceans. 474 00:40:28,239 --> 00:40:31,920 Now on Europa, that's one hundred kilometers down. The oceans 475 00:40:31,920 --> 00:40:34,719 on Europe are much deeper than they are on Earth, 476 00:40:35,079 --> 00:40:36,840 so those are not going to be easy to reach 477 00:40:36,880 --> 00:40:37,679 and investigate. 478 00:40:42,559 --> 00:40:46,920 Speaker 1: Around twenty ten, NASA plans to send its most ambitious 479 00:40:47,000 --> 00:40:56,360 unmanned mission ever, touching down where scientists suspect the ICE's thinnest. 480 00:40:56,760 --> 00:41:00,199 The Europa Lander will lower a probe that melts down 481 00:41:00,239 --> 00:41:29,039 through several miles of ice. A second probe, a hydrobot, 482 00:41:29,239 --> 00:41:35,400 will swim down to the bottom of the ocean. As 483 00:41:35,440 --> 00:41:39,400 it descends, it will transmit live pictures back to Earth. 484 00:41:54,559 --> 00:41:59,000 The hydrobot will be programmed to seek out hydrothermal vents, 485 00:41:59,679 --> 00:42:06,079 the most likely place to find life. This will be 486 00:42:06,360 --> 00:42:11,199 the most alien environment we have ever explored. Will it 487 00:42:11,199 --> 00:42:16,239 be teeming with tiny microbes or perhaps oh to fully 488 00:42:16,280 --> 00:42:29,559 developed alien creatures. Even if we do discover life in 489 00:42:29,599 --> 00:42:33,599 our Solar system, scientists believe that it will be fairly primitive. 490 00:42:36,079 --> 00:42:38,960 If we want to find complex life forms like us, 491 00:42:39,440 --> 00:42:42,199 we'll have to look far beyond our neighboring planets. 492 00:42:44,159 --> 00:42:46,840 Speaker 15: If we want to think about intelligent life, we need 493 00:42:46,880 --> 00:42:50,440 to look past our solar system. We need to look 494 00:42:50,599 --> 00:42:54,679 at the possibility of earthlike planets orbiting other stars and 495 00:42:54,960 --> 00:42:57,920 whether life might have originated there, And then we need 496 00:42:57,960 --> 00:43:01,159 to think about communicating with them. 497 00:43:01,199 --> 00:43:06,199 Speaker 1: Any nearby aliens would already know that we are here. 498 00:43:06,280 --> 00:43:09,360 For the last seventy five years, Earth has been leaking 499 00:43:09,519 --> 00:43:12,719 radio and television transmissions out into space. 500 00:43:14,039 --> 00:43:17,800 Speaker 15: Dragging the sound. 501 00:43:21,519 --> 00:43:26,280 Speaker 1: Our broadcasts reached the nearest stars four years after they 502 00:43:26,280 --> 00:43:27,480 are transmitted on Earth. 503 00:43:31,159 --> 00:43:32,719 Speaker 10: Pounds of Nazi, one. 504 00:43:32,559 --> 00:43:34,000 Speaker 8: Of the circumstances that were. 505 00:43:35,039 --> 00:43:39,239 Speaker 1: Our oldest signals, broadcast in the nineteen twenties, have traveled 506 00:43:39,320 --> 00:43:42,199 past one hundred thousand stars in our galaxy. 507 00:43:45,039 --> 00:43:46,159 Speaker 7: Of the entire. 508 00:43:46,000 --> 00:43:56,480 Speaker 1: World beyond this point, seventy five light years from Earth, 509 00:43:57,119 --> 00:44:19,039 no one would have any idea of our existence. Alien 510 00:44:19,119 --> 00:44:25,039 civilizations may be far older than the human race. Dan 511 00:44:25,159 --> 00:44:29,559 Wortheimer is pioneering a completely new approach to intercepting their 512 00:44:29,559 --> 00:44:30,760 interstellar messages. 513 00:44:33,880 --> 00:44:36,280 Speaker 6: We don't really know what other civilizations are going to 514 00:44:36,320 --> 00:44:37,840 be doing, so we ought to try a lot of 515 00:44:37,880 --> 00:44:40,519 different strategies and not put all our eggs in one basket. 516 00:44:41,599 --> 00:44:44,840 Perhaps other civilizations, instead of sending US radio waves, are 517 00:44:44,880 --> 00:44:47,559 sending us light waves, perhaps from very bright lasers. 518 00:44:51,199 --> 00:44:55,760 Speaker 1: Wortheimer is hoping to intercept laser light messages that extraterrestrials 519 00:44:55,800 --> 00:45:03,760 are beaming across the universe. On Earth, we can produce 520 00:45:03,880 --> 00:45:07,119 laser light signals a million times brighter than our sun. 521 00:45:08,039 --> 00:45:10,679 We have already transmitted our own laser beams to the 522 00:45:10,719 --> 00:45:13,800 Moon and back. If we can do it, worth Timer 523 00:45:13,800 --> 00:45:20,000 believes that et can do it even better. Here at 524 00:45:20,000 --> 00:45:23,760 the Loisner Observatory in California, his telescope is linked to 525 00:45:23,800 --> 00:45:26,840 a high speed computer that's searching for a spike of 526 00:45:26,920 --> 00:45:31,159 a pure color of light, the telltale signature of a laser. 527 00:45:33,920 --> 00:45:37,199 Over the next few years, this telescope will scan two thousand, 528 00:45:37,360 --> 00:45:38,599 five hundred stars. 529 00:45:40,159 --> 00:45:43,760 Speaker 6: We're looking for a very bright pulse. It would only 530 00:45:43,800 --> 00:45:46,639 be on for perhaps a billionth of a second. It's 531 00:45:46,719 --> 00:45:48,800 like looking for the kind of flash that you'd see 532 00:45:48,840 --> 00:45:51,719 from a lighthouse. As the beam comes around, you'd see 533 00:45:51,760 --> 00:45:54,159 a sharp pulse, very bright, and then it would go 534 00:45:54,199 --> 00:45:55,840 off for a while, but then you might see it again. 535 00:45:57,760 --> 00:46:01,519 Speaker 1: Hidden in these short pulses could be a whole encyclopedia 536 00:46:01,599 --> 00:46:04,559 of information, coded like our own computers. 537 00:46:11,559 --> 00:46:14,039 Speaker 6: If they send us a signal intentionally, it's likely that 538 00:46:14,119 --> 00:46:17,440 they will make it easy for us to understand that message. 539 00:46:18,159 --> 00:46:19,800 It will have language lessons. 540 00:46:19,440 --> 00:46:21,519 Speaker 10: Lots of pictures, vocabulary. 541 00:46:21,039 --> 00:46:23,599 Speaker 6: Lessons, and then they would send us a huge amount 542 00:46:23,599 --> 00:46:27,400 of information, all their music, their poetry, their literature, their science, 543 00:46:27,440 --> 00:46:29,679 their medicine. That would be an amazing feet. 544 00:46:33,760 --> 00:46:43,199 Speaker 1: It's an opinion that may be naive. The aliens could 545 00:46:43,280 --> 00:46:46,719 turn out to be worse than any science fiction nightmare. 546 00:46:49,840 --> 00:46:53,800 Speaker 8: I think it would be a disaster. The extra terrestrials 547 00:46:53,840 --> 00:46:56,400 would probably be far an advance of US. 548 00:46:58,159 --> 00:47:02,599 Speaker 1: Astrophysicist Stephen Hawking believes that not all aliens will be friendly. 549 00:47:03,719 --> 00:47:06,440 We should take heed of past experiences on Earth. 550 00:47:07,440 --> 00:47:11,039 Speaker 8: The history of advanced tress is meeting more primitive people 551 00:47:11,079 --> 00:47:14,639 on this Lanet's not very happy when they were of 552 00:47:14,679 --> 00:47:22,400 the same species. I think we should keep our heads slow. 553 00:47:30,480 --> 00:47:32,559 Speaker 6: I don't think that other civilizations are going to come 554 00:47:32,559 --> 00:47:34,639 and eat us. There are not that many raw materials 555 00:47:34,679 --> 00:47:37,079 on Earth. There are much bigger planets. And also I 556 00:47:37,119 --> 00:47:39,800 suspect that advanced civilizations are not killing each other the 557 00:47:39,800 --> 00:47:40,280 way we are. 558 00:47:44,320 --> 00:47:47,719 Speaker 1: But even if they are aggressive. The sheer size of 559 00:47:47,760 --> 00:47:50,639 the universe makes it unlikely that we will meet an 560 00:47:50,679 --> 00:47:59,920 extraterrestrial in person. Imagine yourself as one of the crew 561 00:48:00,159 --> 00:48:05,199 this Faster than Light spaceship of the future. Hollywood and 562 00:48:05,280 --> 00:48:08,239 science fiction try to convince us that it's easy to 563 00:48:08,280 --> 00:48:10,880 travel to the stars faster than the speed of light. 564 00:48:18,159 --> 00:48:21,039 So far, the fastest we can manage in our current 565 00:48:21,079 --> 00:48:25,519 spacecraft is forty thousand miles per hour. At this rate, 566 00:48:25,880 --> 00:48:29,000 it would take seventy thousand years to reach even the 567 00:48:29,119 --> 00:48:36,440 nearest stars. The only realistic way to make contact is 568 00:48:36,440 --> 00:48:41,280 to eavesdrop on alien signals, and we may be communicating 569 00:48:41,320 --> 00:48:43,840 with aliens sooner than we think. 570 00:48:45,239 --> 00:48:47,920 Speaker 6: I'm optimistic. In the long run, probably in our lifetimes, 571 00:48:47,960 --> 00:48:50,159 maybe fifty or one hundred years, we will be in 572 00:48:50,239 --> 00:48:51,880 contact with other civilizations. 573 00:48:56,280 --> 00:48:59,440 Speaker 7: If we did find signal, it's bound to have a 574 00:48:59,480 --> 00:49:03,039 fantastic effect on our human civilization. I don't think it 575 00:49:03,079 --> 00:49:06,000 be any worry or any panic, but we would know 576 00:49:06,639 --> 00:49:08,760 for the first time that other life exists. 577 00:49:13,360 --> 00:49:16,079 Speaker 9: We may find out that we are just one of 578 00:49:16,239 --> 00:49:20,519 many civilizations in the universe. Well, we may find out 579 00:49:20,800 --> 00:49:25,719 in the end that we are extremely unique. So maybe 580 00:49:25,760 --> 00:49:30,679 we're alone, maybe we're not. Either way, the answer is 581 00:49:30,719 --> 00:50:02,440 really significant at evening w