1 00:00:01,134 --> 00:00:04,71 MAN: T minus 40 seconds. Everything looks good for launch. 2 00:00:06,840 --> 00:00:10,644 NARRATOR: Have you ever fantasized about going somewhere special? 3 00:00:10,677 --> 00:00:15,15 Somewhere far from crowds, off the beaten track? 4 00:00:15,48 --> 00:00:17,885 Somewhere out of this world? 5 00:00:17,918 --> 00:00:22,189 Is it time to catch a rocket to the red planet? 6 00:00:22,222 --> 00:00:26,126 MAN: Mars is filled with mysteries: volcanoes 75,000 feet tall, 7 00:00:26,159 --> 00:00:29,796 huge canyons, 3,000 miles across and 6 miles deep, 8 00:00:29,830 --> 00:00:32,900 all kinds of interesting features. 9 00:00:32,933 --> 00:00:35,369 NARRATOR: Awaiting you is some of the greatest scenery 10 00:00:35,402 --> 00:00:38,205 in our solar system, 11 00:00:38,238 --> 00:00:44,177 on a world where water once ruled, then vanished into thin air. 12 00:00:44,211 --> 00:00:49,616 Where lost microbe empires may still survive underground. 13 00:00:49,650 --> 00:00:53,987 We've seen the postcards, and we do wish we were there. 14 00:00:54,21 --> 00:00:57,457 MAN: Just the thought of being in this new world, 15 00:00:57,491 --> 00:01:00,894 seeing a landscape that no other person had seen before, 16 00:01:00,928 --> 00:01:05,32 | think there are a lot of astronauts that would sign up to that. 17 00:01:05,65 --> 00:01:09,937 NARRATOR: But don't be fooled: nothing about going to Mars will be easy. 18 00:01:09,970 --> 00:01:13,173 Danger awaits you on this desolate beauty, 19 00:01:13,206 --> 00:01:15,742 and perhaps Martians, too. 20 00:01:15,776 --> 00:01:19,947 MAN: If we find on Mars evidence of a second independent origin of life, 21 00:01:19,980 --> 00:01:23,283 that's hugely profound because it tells us right away 22 00:01:23,317 --> 00:01:26,420 that life is common in the universe. 23 00:01:26,453 --> 00:01:27,588 NARRATOR: Mars. 24 00:01:27,621 --> 00:01:33,327 Invaded by a robot and perhaps soon by an Earthling like you. 25 00:01:33,360 --> 00:01:35,329 MAN: Would | like to go to Mars? Oh, in a heartbeat. 26 00:01:35,362 --> 00:01:36,930 Absolutely. 27 00:01:36,964 --> 00:01:39,232 If there was any way for me to be going to Mars 28 00:01:39,266 --> 00:01:42,469 | wouldn't be screwing around with robots, you know, I'd want to go myself. 29 00:01:48,742 --> 00:01:50,744 NARRATOR: There has never been a better time 30 00:01:50,777 --> 00:01:55,415 to boldly go where no human has gone before: 31 00:01:55,449 --> 00:01:59,453 to follow in the footsteps of our robot pioneers 32 00:01:59,486 --> 00:02:03,256 and visit the planets of the solar system. 33 00:02:19,640 --> 00:02:22,576 NEIL ARMSTRONG: That's one small step for man... 34 00:02:22,609 --> 00:02:24,411 MAN: Oh, man, that's incredible! 35 00:02:24,444 --> 00:02:27,547 NARRATOR: It's been said that the first person on Mars 36 00:02:27,581 --> 00:02:32,486 is alive somewhere on Earth today. 37 00:02:32,519 --> 00:02:35,422 Imagine it's you. 38 00:02:35,455 --> 00:02:37,224 What do you need to know? 39 00:02:37,257 --> 00:02:40,293 How might you get there and what should you pack? 40 00:02:40,327 --> 00:02:41,962 What are some of the must-see sights 41 00:02:41,995 --> 00:02:44,965 and what should you avoid? 42 00:02:44,998 --> 00:02:51,104 Think of this as your personal travel guide to exploring the red planet. 43 00:02:54,608 --> 00:02:58,78 Mars has always had a mystique. 44 00:03:00,747 --> 00:03:04,751 It's one of the easier planets to spot in the night sky, 45 00:03:04,785 --> 00:03:08,789 a constant dot of red light moving through the heavens. 46 00:03:10,657 --> 00:03:14,194 And now we know for sure that of all the planets, 47 00:03:14,227 --> 00:03:19,99 this red, rocky one is the most similar to home. 48 00:03:19,132 --> 00:03:22,502 Here are polar caps and sun-baked deserts, 49 00:03:22,536 --> 00:03:26,673 giant volcanoes and mighty canyons. 50 00:03:26,707 --> 00:03:30,510 Mars even spins at about the same speed as Earth, 51 00:03:30,544 --> 00:03:34,881 making a Martian day only about 40 minutes longer than ours. 52 00:03:34,915 --> 00:03:39,352 Although it's further out from the sun and takes twice as long to circle it, 53 00:03:39,386 --> 00:03:43,290 the long Martian year has identifiable seasons. 54 00:03:44,758 --> 00:03:50,297 And what's more: our two planets share a common childhood. 55 00:03:50,330 --> 00:03:53,600 LYNN ROTHSCHILD: In many ways it's a sister of the Earth. 56 00:03:53,633 --> 00:03:58,371 It was formed at roughly the same time, about 4.5 billion years ago 57 00:03:58,405 --> 00:04:01,274 with a little change here and there. 58 00:04:03,276 --> 00:04:06,546 It also was formed of the same sorts of materials, 59 00:04:06,580 --> 00:04:09,850 bombarded by comets and asteroids. 60 00:04:12,185 --> 00:04:15,655 So it has the same delivery system we have. 61 00:04:21,328 --> 00:04:26,99 NARRATOR: Could life have been forged in the same way on both planets? 62 00:04:29,970 --> 00:04:33,540 When we sent the first probes to investigate in the 1960s, 63 00:04:33,573 --> 00:04:36,109 almost anything was possible. 64 00:04:38,311 --> 00:04:40,380 ROTHSCHILD: Originally in the popular imagination 65 00:04:40,413 --> 00:04:43,583 we thought that Mars might be inhabited by whole civilizations, 66 00:04:43,617 --> 00:04:46,853 building canals and so on. 67 00:04:46,887 --> 00:04:49,723 And then the Mariner flyby missions 68 00:04:49,756 --> 00:04:56,630 really painted a very grim black and white view of Mars as being barren. 69 00:04:56,663 --> 00:04:59,733 ANNOUNCER: The pictures and data recorded by Mariner 4 70 00:04:59,766 --> 00:05:03,770 revealed Mars to be a cold, barren planet. 71 00:05:03,804 --> 00:05:07,274 MAN: We should be coming up on terminal descent ignition. 72 00:05:07,307 --> 00:05:09,442 MAN: SCS is close to vertical. 73 00:05:09,476 --> 00:05:13,880 NARRATOR: Still, NASA was eager to look for signs of life. 74 00:05:13,914 --> 00:05:20,887 In 1976, the Viking spacecraft arrives from Earth for our first close encounter. 75 00:05:20,921 --> 00:05:25,292 And there are still hopes of a welcoming committee. 76 00:05:32,699 --> 00:05:35,435 But both Viking spacecraft send back photos 77 00:05:35,468 --> 00:05:38,405 of nothing but rocks and sand. 78 00:05:41,141 --> 00:05:44,611 BEN CLARK: We had cameras, so obviously if there was a yucca plant 79 00:05:44,644 --> 00:05:47,981 or | was hoping there would be a freeway in the distance, 80 00:05:48,14 --> 00:05:50,717 but what the main thrust of Viking was actually, 81 00:05:50,750 --> 00:05:53,19 was some chemical laboratories 82 00:05:53,53 --> 00:05:56,323 and they looked for the chemical signs of life. 83 00:05:58,225 --> 00:06:03,263 NARRATOR: Even the dirt seems devoid of life. 84 00:06:03,296 --> 00:06:04,497 ROTHSCHILD: There was always the chance 85 00:06:04,531 --> 00:06:06,800 that when they were so busy looking for microbes 86 00:06:06,833 --> 00:06:09,102 there could be a large organism looking over their shoulder 87 00:06:09,135 --> 00:06:10,837 that they completely missed. 88 00:06:10,871 --> 00:06:13,807 But now we have enormous amount of imagery 89 00:06:13,840 --> 00:06:17,77 that shows nothing like a large organism. 90 00:06:17,110 --> 00:06:18,178 There are no cats running around, 91 00:06:18,211 --> 00:06:21,81 there are no bisons, there are no palm trees. 92 00:06:21,114 --> 00:06:23,283 NARRATOR: It seems Mars is not the kind of planet 93 00:06:23,316 --> 00:06:25,886 that gives up its secrets easily. 94 00:06:28,722 --> 00:06:30,657 But if you dig a little deeper, 95 00:06:30,690 --> 00:06:36,62 you soon find that this is a world worthy of a closer look. 96 00:06:46,673 --> 00:06:48,909 There are some basic things you should know about Mars 97 00:06:48,942 --> 00:06:50,877 before leaving home. 98 00:06:54,80 --> 00:06:57,951 Most days will be clear and sunny and cold. 99 00:06:57,984 --> 00:07:04,324 The average temperature on Mars is as bitter as mid-winter in Antarctica. 100 00:07:04,357 --> 00:07:08,728 At about half the diameter of the Earth, Mars is a handy size. 101 00:07:08,762 --> 00:07:13,800 But it's much less dense than Earth, with about a third the gravity. 102 00:07:13,833 --> 00:07:18,171 Surprisingly, the actual surface area is almost exactly the same 103 00:07:18,204 --> 00:07:24,377 as all the dry land on Earth shrunk together without the oceans. 104 00:07:24,411 --> 00:07:29,215 Build a few freeways and you could drive around Mars in a couple of weeks. 105 00:07:45,31 --> 00:07:49,836 And driving around Mars is exactly what planetary scientist Steve Squyres 106 00:07:49,869 --> 00:07:52,872 has been doing since 2004. 107 00:07:55,342 --> 00:07:59,446 Not in person, but via NASA's two off-road robot rovers, 108 00:07:59,479 --> 00:08:01,948 Spirit and Opportunity. 109 00:08:04,918 --> 00:08:09,222 [applause] 110 00:08:09,255 --> 00:08:14,527 STEVE SQUYRES: It looks like nothing I've ever seen before in my life. 111 00:08:14,561 --> 00:08:16,963 NARRATOR: For all of us here on Earth, 112 00:08:16,997 --> 00:08:19,566 the snapshots sent back by these forward scouts 113 00:08:19,599 --> 00:08:24,137 are the next best thing to standing on Mars in a spacesuit. 114 00:08:29,75 --> 00:08:36,249 SQUYRES: We very consciously gave these robots some human-like qualities. 115 00:08:38,451 --> 00:08:40,920 The cameras are about this high off the ground; 116 00:08:40,954 --> 00:08:43,990 they are the same height as human eyes. 117 00:08:44,24 --> 00:08:48,728 The visual experience that you get from looking at the rovers’ pictures 118 00:08:48,762 --> 00:08:51,698 is intentionally like what you would get 119 00:08:51,731 --> 00:08:56,803 if you were looking out the visor of your helmet and a spacesuit on Mars. 120 00:09:00,440 --> 00:09:04,611 NARRATOR: In the four decades since our robots first arrived, 121 00:09:04,644 --> 00:09:07,480 the once fuzzy ball at the end of our telescopes 122 00:09:07,514 --> 00:09:11,885 has steadily focused into a red planet we can understand. 123 00:09:13,753 --> 00:09:16,556 And it's not a welcoming place. 124 00:09:18,458 --> 00:09:21,761 The problem is the atmosphere is so thin and cold 125 00:09:21,795 --> 00:09:26,666 that water exists only as solid ice in the ground or vapor in the air, 126 00:09:26,699 --> 00:09:30,503 not as a liquid on the surface. 127 00:09:30,537 --> 00:09:33,506 You might see some fine, wispy clouds high in the sky, 128 00:09:33,540 --> 00:09:36,543 but don't bother bringing an umbrella. 129 00:09:38,44 --> 00:09:42,282 The whole planet is drier than the dustiest desert on Earth. 130 00:09:42,315 --> 00:09:44,184 And there hasn't been a drop of rain here 131 00:09:44,217 --> 00:09:47,787 for millions, perhaps billions, of years. 132 00:09:50,23 --> 00:09:51,691 SQUYRES: The thing that fascinated me 133 00:09:51,724 --> 00:09:57,263 was that we could see valleys snaking across the surface 134 00:09:57,297 --> 00:10:01,167 that had clearly been carved by flowing water. 135 00:10:01,201 --> 00:10:04,404 So this is telling us that in the past it was different 136 00:10:04,437 --> 00:10:06,206 and not only that, it was different 137 00:10:06,239 --> 00:10:10,09 in a way that would have made it more suitable for life than it is today, 138 00:10:10,43 --> 00:10:12,645 and that I found truly compelling. 139 00:10:18,885 --> 00:10:20,687 CLARK: We are very convinced that at one time 140 00:10:20,720 --> 00:10:24,691 it was a very hospitable planet with liquid water 141 00:10:24,724 --> 00:10:29,562 and enough atmosphere to sustain a climate, 142 00:10:29,596 --> 00:10:32,198 and so now we're trying to understand how did it change, 143 00:10:32,232 --> 00:10:36,202 why did it change and what still might be on Mars? 144 00:10:39,606 --> 00:10:43,209 NARRATOR: These are deep Martian mysteries. 145 00:10:43,243 --> 00:10:46,579 lf Mars and Earth started as sister planets, 146 00:10:46,613 --> 00:10:51,317 did life once festoon the Martian surface? 147 00:10:51,351 --> 00:10:53,620 Might it still be there? 148 00:10:53,653 --> 00:10:57,190 And where did all the atmosphere and water go? 149 00:10:59,192 --> 00:11:02,529 Solving these puzzles has challenged our planetary explorers 150 00:11:02,562 --> 00:11:07,00 from the moment the first Martian postcards were sent back to Earth. 151 00:11:08,168 --> 00:11:10,737 SQUYRES: It's the fact that it is so much like Earth 152 00:11:10,770 --> 00:11:14,140 that kind of makes Mars such a special place. 153 00:11:22,282 --> 00:11:24,317 NARRATOR: Steve Squyres' Martian odyssey 154 00:11:24,350 --> 00:11:27,153 has taken him from pole to pole-- 155 00:11:27,187 --> 00:11:28,655 visiting those places on Earth 156 00:11:28,688 --> 00:11:32,392 that share at least some of the same characteristics: 157 00:11:32,425 --> 00:11:35,662 they are extremely dry, extremely cold, 158 00:11:35,695 --> 00:11:37,997 or extremely dead: 159 00:11:38,31 --> 00:11:41,167 Death Valley is one of his favorites. 160 00:11:42,468 --> 00:11:44,304 SQUYRES: This is actually a really important place. 161 00:11:44,337 --> 00:11:46,506 It's a place we call Mars Hill. 162 00:11:46,539 --> 00:11:49,742 We first found this place about 20 years ago. 163 00:11:49,776 --> 00:11:53,846 In those days the only successful landings that had taken place on Mars 164 00:11:53,880 --> 00:11:55,949 were the two Viking landers, 165 00:11:55,982 --> 00:12:00,887 and they landed in places that looked very much like this. 166 00:12:04,57 --> 00:12:06,893 NARRATOR: In order to plan for the current Mars mission 167 00:12:06,926 --> 00:12:09,662 and to test the cameras and other equipment, 168 00:12:09,696 --> 00:12:12,799 NASA needed a good Mars look-alike. 169 00:12:12,832 --> 00:12:15,134 They found it at Mars Hill. 170 00:12:15,168 --> 00:12:16,636 SQUYRES: To your eyes 171 00:12:16,669 --> 00:12:20,473 the main way in which Mars would look different from this scene 172 00:12:20,506 --> 00:12:22,08 would be the color. 173 00:12:22,41 --> 00:12:24,911 The color of the sky and the color of the rocks 174 00:12:24,944 --> 00:12:26,579 and the color of the soil. 175 00:12:26,613 --> 00:12:31,584 The colors on Mars are painted from a very narrow palette. 176 00:12:33,453 --> 00:12:36,623 NARRATOR: The color palette here is based on rust. 177 00:12:36,656 --> 00:12:41,394 Rich in iron oxides, the rocks and soil and the rusty dust 178 00:12:41,427 --> 00:12:47,133 are always blowing around in the freeze-dried atmosphere. 179 00:12:47,166 --> 00:12:51,271 You won't see any blue skies in the tourist brochures for Mars. 180 00:12:51,304 --> 00:12:54,507 Instead, they're amber. 181 00:12:54,540 --> 00:12:58,444 Not only do the dust particles add a rosy blush to the sky, 182 00:12:58,478 --> 00:13:00,46 they also scatter sunlight 183 00:13:00,79 --> 00:13:02,682 in a way that turns the color of the Martian sky 184 00:13:02,715 --> 00:13:05,918 upside down to human eyes: 185 00:13:05,952 --> 00:13:10,189 red by day and blue at dawn and dusk. 186 00:13:13,259 --> 00:13:16,329 This is a sunset as seen by Spirit: 187 00:13:16,362 --> 00:13:21,668 a cold blue sun dropping over a distant alien horizon. 188 00:13:23,503 --> 00:13:26,806 Looking up into the clear, starry skies from the surface, 189 00:13:26,839 --> 00:13:29,676 you would see Mars' two tiny moons: 190 00:13:29,709 --> 00:13:33,479 Phobos and the smaller Deimos. 191 00:13:33,513 --> 00:13:38,685 With all the grace of a space potato and barely 17 miles long, 192 00:13:38,718 --> 00:13:41,821 Phobos has been targeted as a potential stepping stone 193 00:13:41,854 --> 00:13:45,825 for the first human mission to Mars. 194 00:13:45,858 --> 00:13:53,466 A test run, before attempting the fuel-hungry and risky trip to the planet below. 195 00:13:53,499 --> 00:13:55,335 RICH ZUREK: To put humans on the surface of Mars, 196 00:13:55,368 --> 00:13:57,704 someone once joked there are only three issues-- 197 00:13:57,737 --> 00:13:59,939 getting them there, keeping them alive while they're there 198 00:13:59,972 --> 00:14:01,574 and getting them back. 199 00:14:04,310 --> 00:14:08,948 NARRATOR: Our Space Age dreams of off-world colonies on the moon and Mars 200 00:14:08,981 --> 00:14:12,85 faded with the cancellation of the Apollo program 201 00:14:12,118 --> 00:14:17,256 and the last trip to the lunar surface in 1972. 202 00:14:17,290 --> 00:14:19,125 It didn't stop us from traveling. 203 00:14:19,158 --> 00:14:25,531 We simply switched from astronauts to lower cost, lower risk robotic explorers. 204 00:14:25,565 --> 00:14:29,902 And when it comes to Mars, it's probably just as well. 205 00:14:33,439 --> 00:14:37,677 SQUYRES: Getting to Mars is just unbelievably hard. 206 00:14:37,710 --> 00:14:39,912 You know, we've learned that the hard way. 207 00:14:39,946 --> 00:14:42,949 Before--certainly you have to go back to the days before the rovers launched-- 208 00:14:42,982 --> 00:14:45,918 two thirds of the missions that have been flown to Mars had failed. 209 00:14:45,952 --> 00:14:47,587 And they failed for all kinds of reasons-- 210 00:14:47,620 --> 00:14:53,493 rockets that blew up and spacecraft that just vanished with hardly without a trace. 211 00:14:56,229 --> 00:15:00,66 MAN: 5, 4, 3, 2, 1... 212 00:15:00,99 --> 00:15:01,834 Engines start. 213 00:15:01,868 --> 00:15:05,138 We have liftoff from Earth to planet Mars. 214 00:15:08,207 --> 00:15:10,476 NARRATOR: If you are ever lucky enough to book a flight 215 00:15:10,510 --> 00:15:13,713 on the first rocket to the red planet, 216 00:15:13,746 --> 00:15:17,216 you'd better be sure you've packed everything. 217 00:15:17,250 --> 00:15:19,852 The one-way trip is at least six months, 218 00:15:19,886 --> 00:15:23,990 with no turning back if you've forgotten something. 219 00:15:24,23 --> 00:15:26,459 CLARK: We can go to the moon and get back in a week. 220 00:15:26,492 --> 00:15:30,530 It takes about three years to go to Mars and come back. 221 00:15:30,563 --> 00:15:32,64 You have to carry your food, 222 00:15:32,98 --> 00:15:37,03 you have to recycle your breathing oxygen and your water, 223 00:15:37,36 --> 00:15:40,440 so it's a very, very major undertaking. 224 00:15:43,776 --> 00:15:47,647 Within about three days, the Earth looks very small, 225 00:15:47,680 --> 00:15:50,817 and within a week, it's just another star 226 00:15:50,850 --> 00:15:54,720 and you suddenly are going to realize you're in very deep space 227 00:15:54,754 --> 00:15:58,391 and it's going to be a long time before you can go back. 228 00:16:01,694 --> 00:16:04,330 NARRATOR: Before we take this giant leap, 229 00:16:04,363 --> 00:16:06,833 we need to be able to carry everything needed 230 00:16:06,866 --> 00:16:10,303 for a three-year round trip with us. 231 00:16:12,305 --> 00:16:15,975 This is a much larger effort than getting to the moon. 232 00:16:16,08 --> 00:16:19,111 It's the Apollo mission on steroids. 233 00:16:19,145 --> 00:16:20,446 CLARK: At this point we know 234 00:16:20,480 --> 00:16:23,749 at least as much as the engineers knew 235 00:16:23,783 --> 00:16:29,655 at the time that they agreed to land on the moon, 236 00:16:29,689 --> 00:16:31,424 and they had only nine years. 237 00:16:31,457 --> 00:16:37,96 So | think once the nation decides they really want to land humans on Mars, 238 00:16:37,129 --> 00:16:41,67 the system can be designed and developed and built. 239 00:16:45,771 --> 00:16:48,741 NARRATOR: Fast forward to the future. 240 00:16:48,774 --> 00:16:51,777 After six months crossing the blackness of space, 241 00:16:51,811 --> 00:16:55,648 things suddenly get a lot more interesting. 242 00:16:56,916 --> 00:16:59,218 The combination of a high approach speed, 243 00:16:59,252 --> 00:17:02,955 a thin atmosphere and twice the gravity of the moon 244 00:17:02,989 --> 00:17:07,827 makes Mars one of the hardest places to land in the solar system. 245 00:17:07,860 --> 00:17:10,396 Even for robots. 246 00:17:11,964 --> 00:17:13,332 SQUYRES: You hit the top of the Martian atmosphere 247 00:17:13,366 --> 00:17:16,302 and you're going Mach 27-- 248 00:17:16,335 --> 00:17:18,304 27 times the speed of sound-- 249 00:17:18,337 --> 00:17:19,805 and for our vehicles 250 00:17:19,839 --> 00:17:21,507 between when we hit the top of the Martian atmosphere 251 00:17:21,541 --> 00:17:26,112 to when we were bouncing on the surface with the air bags was 6 minutes. 252 00:17:26,145 --> 00:17:29,181 It's a hell of a ride. 253 00:17:29,215 --> 00:17:31,851 You use a heat shield to slow you down 254 00:17:31,884 --> 00:17:35,421 to a leisurely Mach 2, twice the speed of sound. 255 00:17:35,454 --> 00:17:37,757 And then we throw out a supersonic parachute. 256 00:17:37,790 --> 00:17:39,191 NARRATOR: Everything is complex, 257 00:17:39,225 --> 00:17:42,662 and everything has to happen precisely on time. 258 00:17:45,631 --> 00:17:47,466 SQUYRES: The worst part is when you come into contact 259 00:17:47,500 --> 00:17:48,668 with the Martian surface. 260 00:17:48,701 --> 00:17:50,403 There's no runway, okay. 261 00:17:50,436 --> 00:17:52,572 There's no nice place to land, 262 00:17:52,605 --> 00:17:55,241 and you can't control very well where you're going to come down. 263 00:17:55,274 --> 00:17:58,644 So you're going to come down in a field of rocks like this. 264 00:17:58,678 --> 00:18:00,780 How do you guarantee 265 00:18:00,813 --> 00:18:06,485 that your billion-dollar spacecraft is actually going to survive that? 266 00:18:06,519 --> 00:18:10,489 The approach that worked for us with our rovers was great big air bags. 267 00:18:10,523 --> 00:18:11,924 Bounce, bounce, bounce, bounce, bounce, 268 00:18:11,958 --> 00:18:14,760 finally the vehicles comes to rest. 269 00:18:16,662 --> 00:18:18,931 The Vikings used rocket motors, 270 00:18:18,965 --> 00:18:20,933 and they just touched down gently on the surface 271 00:18:20,967 --> 00:18:22,34 and they were fortunate. 272 00:18:22,68 --> 00:18:23,536 It was just good luck. 273 00:18:23,569 --> 00:18:25,71 They landed in a field of boulders like this 274 00:18:25,104 --> 00:18:28,174 but they didn't land with one that was poking through the belly, 275 00:18:28,207 --> 00:18:29,642 and it all worked. 276 00:18:29,675 --> 00:18:33,646 You have to be good, and you have to be lucky. 277 00:18:33,679 --> 00:18:35,815 NARRATOR: Want to step outside to take in the scenery 278 00:18:35,848 --> 00:18:38,117 or pick up some rocks? 279 00:18:38,150 --> 00:18:40,786 As familiar as it might look beyond the porthole, 280 00:18:40,820 --> 00:18:44,390 Mars is dangerously alien. 281 00:18:44,423 --> 00:18:50,162 The upside is that the low gravity will give you super jumping abilities. 282 00:18:50,196 --> 00:18:54,734 The down, the almost complete lack of an atmosphere. 283 00:18:54,767 --> 00:18:58,904 This is not home: there is nothing here to breathe. 284 00:19:01,374 --> 00:19:02,642 To find similar conditions 285 00:19:02,675 --> 00:19:05,77 of low temperature and pressure on Earth, 286 00:19:05,111 --> 00:19:08,914 you have to travel three times higher than a commercial airplane, 287 00:19:08,948 --> 00:19:11,884 to the very edge of space. 288 00:19:14,654 --> 00:19:16,822 Planetary scientist Bob Brown 289 00:19:16,856 --> 00:19:21,527 shows why you should keep your helmet on when visiting Mars. 290 00:19:23,195 --> 00:19:25,331 BROWN: We have this, just a beaker full of water. 291 00:19:25,364 --> 00:19:28,334 We're going to put it in this little chamber. 292 00:19:32,238 --> 00:19:35,841 And attach a vacuum hose to the chamber. 293 00:19:35,875 --> 00:19:39,779 And haul the air out of the chamber. 294 00:19:45,751 --> 00:19:48,354 NARRATOR: As the pressure drops to Martian levels, 295 00:19:48,387 --> 00:19:51,891 the water boils at room temperature. 296 00:19:53,225 --> 00:19:56,128 BROWN: So If you were to take your helmet off on Mars, 297 00:19:56,162 --> 00:19:59,298 the liquid in your face, especially, would start to boil 298 00:19:59,331 --> 00:20:01,600 much the same as this liquid water started to boil. 299 00:20:01,634 --> 00:20:04,637 And | guess | don't have to describe what that might feel like 300 00:20:04,670 --> 00:20:06,505 or what it might look like. 301 00:20:09,41 --> 00:20:13,713 NARRATOR: A medical travel advisory might say to keep your suit tightly fitted, 302 00:20:13,746 --> 00:20:18,918 but so far no one's built a suit that'll work on Mars. 303 00:20:18,951 --> 00:20:22,655 Existing spacesuits are simply too bulky, too heavy 304 00:20:22,688 --> 00:20:24,290 and too complicated to wear 305 00:20:24,323 --> 00:20:29,28 for the sort of regular activity required on the unforgiving surface of Mars. 306 00:20:29,61 --> 00:20:30,830 CHRIS McKAY: Something we take for granted here. 307 00:20:30,863 --> 00:20:31,864 We get up in the morning, 308 00:20:31,897 --> 00:20:35,501 | put on a shirt and a pair of jeans and out I go. 309 00:20:35,534 --> 00:20:40,172 So it's got to be routine, easy to use. 310 00:20:40,206 --> 00:20:42,608 Many times | have been working out in the field 311 00:20:42,641 --> 00:20:44,577 in the Antarctic or the Arctic 312 00:20:44,610 --> 00:20:46,78 and | just have to take the gloves off, 313 00:20:46,112 --> 00:20:47,146 because I'm doing something 314 00:20:47,179 --> 00:20:50,750 that requires that quintessential human capability 315 00:20:50,783 --> 00:20:53,552 of touch and feel and hold. 316 00:20:53,586 --> 00:20:58,858 So my request to the engineers is give me a spacesuit with gloves 317 00:20:58,891 --> 00:21:01,293 that will keep me warm and keep me pressurized 318 00:21:01,327 --> 00:21:04,363 but still allow me to use my hands. 319 00:21:06,665 --> 00:21:08,868 NARRATOR: Not only will you want to move your fingers, 320 00:21:08,901 --> 00:21:10,970 you'll want to move around. 321 00:21:13,72 --> 00:21:14,907 NASA's lunar electric rover 322 00:21:14,940 --> 00:21:18,911 is a prototype for future missions to the moon and Mars. 323 00:21:21,80 --> 00:21:24,450 It's part vehicle and part spacesuit. 324 00:21:24,483 --> 00:21:27,853 MIKE GERNHARDT: | can just picture being there in a vehicle of this type 325 00:21:27,887 --> 00:21:31,157 and looking back at Earth in the distance 326 00:21:31,190 --> 00:21:33,659 and deciding to go EVA 327 00:21:33,692 --> 00:21:35,895 and be in boots on the surface in 10 minutes, 328 00:21:35,928 --> 00:21:39,832 which would just be a remarkable breakthrough. 329 00:21:39,865 --> 00:21:41,667 NARRATOR: Astronauts can cover more ground 330 00:21:41,700 --> 00:21:44,804 by living in the vehicle for weeks at time, 331 00:21:44,837 --> 00:21:46,972 stepping outside when they want to 332 00:21:47,06 --> 00:21:50,176 and back inside at the first sign of danger. 333 00:21:53,679 --> 00:21:56,315 SQUYRES: Mars does not have a powerful magnetic field 334 00:21:56,348 --> 00:21:57,483 the way Earth does, 335 00:21:57,516 --> 00:21:59,952 so there's radiation from the sun, 336 00:21:59,985 --> 00:22:05,57 also cosmic rays that are going to penetrate through spacesuits. 337 00:22:06,525 --> 00:22:08,661 NARRATOR: An astronaut might get a 30-minute warning 338 00:22:08,694 --> 00:22:10,863 of an incoming solar storm, 339 00:22:10,896 --> 00:22:15,768 but less predictable is the risk of being hit by a meteorite. 340 00:22:15,801 --> 00:22:18,871 Recent estimates based on fresh crater counts 341 00:22:18,904 --> 00:22:21,140 suggest that up to 200 new holes 342 00:22:21,173 --> 00:22:25,678 are blasted into the surface of Mars each year. 343 00:22:25,711 --> 00:22:32,51 And even the Martian moons are not guaranteed to stay in place. 344 00:22:32,84 --> 00:22:35,521 The days of Phobos are numbered. 345 00:22:35,554 --> 00:22:39,91 Possibly an asteroid that once strayed too close, 346 00:22:39,124 --> 00:22:43,362 the moon is trapped in a fatal gravitational embrace. 347 00:22:43,395 --> 00:22:48,500 Every passing century sees it drop six feet closer to death. 348 00:22:48,534 --> 00:22:53,472 In about 50 million years, its fall is expected to be complete. 349 00:22:59,945 --> 00:23:03,582 The aftermath, if anyone is around to see it, 350 00:23:03,616 --> 00:23:08,821 could be Mars with a bright ring of moon dust to rival Saturn's. 351 00:23:11,590 --> 00:23:15,527 But events like this are not your real danger. 352 00:23:15,561 --> 00:23:20,132 It's the day-to-day exposure to the cold, dry Martian environment 353 00:23:20,165 --> 00:23:23,102 that will make a long stay tricky. 354 00:23:23,135 --> 00:23:27,373 SQUYRES: It was 119 degrees Fahrenheit here yesterday. 355 00:23:27,406 --> 00:23:29,341 A really, really, really hot day on Mars, 356 00:23:29,375 --> 00:23:31,477 it would get up to about 30 degrees Fahrenheit, 357 00:23:31,510 --> 00:23:35,614 and at night it goes to more than 100 below. 358 00:23:35,648 --> 00:23:40,85 NARRATOR: Martian deserts are both frozen and sun-baked: 359 00:23:40,119 --> 00:23:43,389 with no ozone layer, UV levels are so high 360 00:23:43,422 --> 00:23:47,726 that any unprotected organism, even a Martian microbe, 361 00:23:47,760 --> 00:23:51,797 will be burnt to a crisp within minutes. 362 00:23:51,830 --> 00:23:56,235 A good hat is just not going to cut it. 363 00:23:56,268 --> 00:24:01,640 So why not leave all the dirty work of exploring Mars to robots? 364 00:24:02,708 --> 00:24:04,510 SQUYRES: One thing about humans 365 00:24:04,543 --> 00:24:08,647 is that they have a capability to improvise on the spot, 366 00:24:08,681 --> 00:24:10,482 even if you don't have the right tools with you, 367 00:24:10,516 --> 00:24:13,52 that robots lack. 368 00:24:13,85 --> 00:24:16,388 In Death Valley this stuff was wet, it got dry; 369 00:24:16,422 --> 00:24:18,757 when it dried, it cracked. 370 00:24:18,791 --> 00:24:24,196 We're investigating the idea that something similar happened on Mars. 371 00:24:24,229 --> 00:24:27,199 You know, I'd love to be able to do this on Mars, and we can't, 372 00:24:27,232 --> 00:24:31,370 but a human on the scene can improvise pretty well. 373 00:24:31,403 --> 00:24:35,708 NARRATOR: Getting down and dirty on Mars will mean exactly that. 374 00:24:41,280 --> 00:24:48,620 When an ill wind blows on the red planet, dust really does go everywhere. 375 00:24:48,654 --> 00:24:52,558 About once every three years, local storms go global 376 00:24:52,591 --> 00:24:57,162 and the dust can block your view for months. 377 00:24:57,196 --> 00:25:03,335 It happened the very first time we sent a probe into orbit in 1971. 378 00:25:03,369 --> 00:25:05,37 ZUREK: When Mariner 9 got to the planet 379 00:25:05,70 --> 00:25:06,372 there was a giant dust storm 380 00:25:06,405 --> 00:25:09,308 that had completely shrouded the surface from it. 381 00:25:10,442 --> 00:25:13,712 SMITH: They could see nothing, nothing, just dust. 382 00:25:13,746 --> 00:25:16,81 And as the dust started to recede 383 00:25:16,115 --> 00:25:18,350 all of a sudden these dots appeared. 384 00:25:18,384 --> 00:25:19,852 There were three of them lined up. 385 00:25:19,885 --> 00:25:21,787 What the heck are those? 386 00:25:21,820 --> 00:25:27,960 It turned out to be the peaks of the three great volcanoes on Mars. 387 00:25:27,993 --> 00:25:29,795 ZUREK: And that's when we began to realize 388 00:25:29,828 --> 00:25:35,67 just how varied the terrain and topography of Mars was. 389 00:25:35,100 --> 00:25:39,405 NARRATOR: This was the moment that Mars began to reveal itself: 390 00:25:39,438 --> 00:25:44,777 a world with a secret history and the spectacular scenery to match. 391 00:25:46,979 --> 00:25:51,917 Thanks to our sharp-eyed spacecraft, Mars is opening up like never before. 392 00:25:53,919 --> 00:25:59,825 These are real landscapes that humans will one day marvel at in person. 393 00:26:01,360 --> 00:26:03,629 SQUYRES: If you were going to Mars, you'd want to go for the scenery, right? 394 00:26:03,662 --> 00:26:05,30 | mean, you're not going for the culture, 395 00:26:05,64 --> 00:26:06,65 you're not going for the climate, 396 00:26:06,98 --> 00:26:08,200 so you definitely want to go for the scenery. 397 00:26:08,233 --> 00:26:11,703 One thing that people forget is that when we've landed on Mars 398 00:26:11,737 --> 00:26:14,39 we have to go to places that are safe, 399 00:26:14,73 --> 00:26:17,943 and safe equals pretty smooth and flat. 400 00:26:17,976 --> 00:26:21,747 NARRATOR: Here's a bit of Mars that's anything but smooth and flat: 401 00:26:21,780 --> 00:26:24,983 the magnificent Valles Marineris. 402 00:26:25,17 --> 00:26:27,219 This titanic canyon system, 403 00:26:27,252 --> 00:26:31,623 over 2,500 miles long and 6 miles deep, 404 00:26:31,657 --> 00:26:35,861 is probably the grandest geological feature in the solar system. 405 00:26:35,894 --> 00:26:40,32 It's clearly the red planet's must-see destination. 406 00:26:40,65 --> 00:26:41,467 DAVID SOUTHWOOD: As a human being 407 00:26:41,500 --> 00:26:46,271 it's the sheer gigantism of Mars that is amazing. 408 00:26:46,305 --> 00:26:51,877 The Valles Marineris beats the Grand Canyon hollow, 409 00:26:51,910 --> 00:26:56,482 and if you've ever seen the Grand Canyon, you will never forget it. 410 00:26:58,484 --> 00:26:59,885 NARRATOR: It's so colossal, 411 00:26:59,918 --> 00:27:05,390 the Grand Canyon would be easily swallowed by one of the smaller side branches. 412 00:27:05,424 --> 00:27:06,859 ZUREK: We're talking about something here 413 00:27:06,892 --> 00:27:12,764 that's the width of the United States or of Australia across here. 414 00:27:12,798 --> 00:27:15,734 SQUYRES: | think the Valles Marineris would be the place to go. 415 00:27:15,767 --> 00:27:20,772 Build a lodge right on the rim so you can look in. 416 00:27:20,806 --> 00:27:24,409 NARRATOR: The attraction goes beyond sheer scenic splendor: 417 00:27:24,443 --> 00:27:30,616 deeper than the canyon itself is the mystery surrounding its formation. 418 00:27:30,649 --> 00:27:34,553 This giant fissure, once filled by mighty lakes, 419 00:27:34,586 --> 00:27:38,690 has been scoured by floods of biblical proportions. 420 00:27:40,159 --> 00:27:41,860 SQUYRES: You can make estimates 421 00:27:41,894 --> 00:27:44,129 of how much water had to have been flowing 422 00:27:44,163 --> 00:27:45,197 to carve these things, 423 00:27:45,230 --> 00:27:49,835 and you get numbers like 100, 200 Amazon Rivers all cut loose at once. 424 00:27:49,868 --> 00:27:52,871 Big, big amounts of water flowing across the surface. 425 00:27:55,874 --> 00:27:57,776 NARRATOR: The other big attraction on Mars 426 00:27:57,809 --> 00:28:00,946 is the largest volcano, and highest mountain, 427 00:28:00,979 --> 00:28:03,949 in the solar system. 428 00:28:03,982 --> 00:28:08,387 Olympus Mons towers at an astounding 17 miles, 429 00:28:08,420 --> 00:28:11,723 three times higher than Everest. 430 00:28:11,757 --> 00:28:15,127 Its base covers more ground than the United Kingdom, 431 00:28:15,160 --> 00:28:17,596 and the massive caldera at its summit 432 00:28:17,629 --> 00:28:23,68 could easily swallow greater London, Paris and New York. 433 00:28:23,101 --> 00:28:25,70 SQUYRES: So things tend to be big on Mars. 434 00:28:25,103 --> 00:28:29,308 | think in part that's because the planet has lower gravity, 435 00:28:29,341 --> 00:28:32,544 so when you pile up lava, you can pile it three times higher 436 00:28:32,578 --> 00:28:34,313 because the gravity is three times less 437 00:28:34,346 --> 00:28:37,649 before it will start to collapse under its own weight. 438 00:28:40,18 --> 00:28:44,423 NARRATOR: Mars is a far more active world than previously thought. 439 00:28:44,456 --> 00:28:46,491 We see landslides of dust 440 00:28:46,525 --> 00:28:51,296 and gullies freshly carved by outflows of mysterious fluid. 441 00:28:53,98 --> 00:28:55,200 And this peculiar region has been claimed 442 00:28:55,234 --> 00:29:00,272 as a flash-frozen sea, complete with fossil icebergs. 443 00:29:01,940 --> 00:29:05,811 Likewise there are glaciers, geologically recent 444 00:29:05,844 --> 00:29:09,414 but now buried beneath a protective blanket of dust, 445 00:29:09,448 --> 00:29:12,951 waiting for the next change in climate. 446 00:29:12,985 --> 00:29:16,588 Still, most of the defining surface features of Mars 447 00:29:16,622 --> 00:29:20,692 were carved way back in the good old days. 448 00:29:22,160 --> 00:29:25,964 SMITH: Certainly something happened in the early history of Mars 449 00:29:25,998 --> 00:29:28,467 that led to great releases of water, 450 00:29:28,500 --> 00:29:31,169 and of course people wonder with that much water 451 00:29:31,203 --> 00:29:32,738 could there have been ancient oceans, 452 00:29:32,771 --> 00:29:34,740 could there have been environments 453 00:29:34,773 --> 00:29:36,541 that were very much like life environments 454 00:29:36,575 --> 00:29:38,777 on the early Earth? 455 00:29:41,647 --> 00:29:44,616 NARRATOR: Early Mars was a different world. 456 00:29:44,650 --> 00:29:49,988 A world with a thicker atmosphere; with weather and water. 457 00:29:50,22 --> 00:29:54,693 Possibly a vast, shallow northern ocean. 458 00:29:54,726 --> 00:29:57,562 This was really the time to go to Mars: 459 00:29:57,596 --> 00:30:00,132 when you didn't need a spacesuit, 460 00:30:00,165 --> 00:30:03,802 perhaps just an oxygen tank and some warm clothes. 461 00:30:05,570 --> 00:30:08,206 McKAY: When we reconstruct in our imaginations 462 00:30:08,240 --> 00:30:09,808 Mars of three billion years ago, 463 00:30:09,841 --> 00:30:13,845 we tend to make it like Earth, warm and cozy. 464 00:30:13,879 --> 00:30:15,714 But it wasn't. 465 00:30:15,747 --> 00:30:19,418 Mars, back in its wettest, warmest phase, 466 00:30:19,451 --> 00:30:23,488 was probably like Earth today in its coldest regions. 467 00:30:23,522 --> 00:30:25,290 So I'm imagining a place 468 00:30:25,324 --> 00:30:28,93 where the snow and ice is melting in the summer 469 00:30:28,126 --> 00:30:32,164 to form transient ponds and streams and ice-covered lakes. 470 00:30:32,197 --> 00:30:36,902 It's cold, it's wet, but it could be rich with life. 471 00:30:39,304 --> 00:30:40,639 NARRATOR: This is the Mars 472 00:30:40,672 --> 00:30:43,542 that we want our astronauts to get their hands on, 473 00:30:43,575 --> 00:30:46,178 to bring back and study-- 474 00:30:46,211 --> 00:30:48,113 the wet Mars of old, 475 00:30:48,146 --> 00:30:51,883 where we might find the evidence of life. 476 00:30:55,987 --> 00:31:00,592 If you want to find life on Mars, first you need to find water. 477 00:31:02,60 --> 00:31:06,398 And not all of the planet's water story is ancient history. 478 00:31:06,431 --> 00:31:09,201 There's been plenty of frozen underground evidence 479 00:31:09,234 --> 00:31:11,169 detected from orbit, 480 00:31:11,203 --> 00:31:15,807 but scientists needed to touch and taste it to be sure. 481 00:31:15,841 --> 00:31:20,979 In 2008, they finally got their opportunity when NASA's Phoenix lander 482 00:31:21,12 --> 00:31:25,517 made a daring approach to the high Martian Arctic. 483 00:31:25,550 --> 00:31:29,287 MAN: 50 meters. Land init sequence initiated. 484 00:31:29,321 --> 00:31:30,956 [applause] 485 00:31:30,989 --> 00:31:33,225 SMITH: There was not ever more excitement in my life 486 00:31:33,258 --> 00:31:35,360 than landing safely on Mars. 487 00:31:35,394 --> 00:31:36,628 I've been through the opposite. 488 00:31:36,661 --> 00:31:39,498 I've been through a landing that was not successful, 489 00:31:39,531 --> 00:31:43,668 and | did not want that to happen again. 490 00:31:45,637 --> 00:31:48,06 NARRATOR: The landing was not only perfect, 491 00:31:48,39 --> 00:31:51,76 but the engines exposed suspicious white patches 492 00:31:51,109 --> 00:31:54,279 directly underneath the spacecraft. 493 00:31:54,312 --> 00:31:58,950 Water ice was just a few scrapes away. 494 00:31:58,984 --> 00:32:00,752 SMITH: We did find water ice 495 00:32:00,786 --> 00:32:02,754 and we found that the soil in connection to it 496 00:32:02,788 --> 00:32:05,424 has calcium carbonate, 497 00:32:05,457 --> 00:32:09,594 a compound that forms in the presence of liquid water. 498 00:32:09,628 --> 00:32:11,163 If it had been wet, 499 00:32:11,196 --> 00:32:14,599 then we wanted to look for nutrients and food sources 500 00:32:14,633 --> 00:32:18,670 that could support microbes. 501 00:32:18,703 --> 00:32:21,873 NARRATOR: The water ice is proof of a valuable resource 502 00:32:21,907 --> 00:32:25,510 for any life forms still clinging beneath the surface, 503 00:32:25,544 --> 00:32:28,747 and for future travelers. 504 00:32:28,780 --> 00:32:32,851 SMITH: We now know that these plains that you see stretching behind me 505 00:32:32,884 --> 00:32:37,722 are underlain only 2 or 3 inches deep by a sheet of ice, 506 00:32:37,756 --> 00:32:39,791 all the way as far as you can see. 507 00:32:39,825 --> 00:32:41,59 Great hockey rink. 508 00:32:41,92 --> 00:32:46,398 If you had a hockey team on Mars, all you'd need is a broom. 509 00:32:50,902 --> 00:32:53,38 NARRATOR: The possibility of running into Martians 510 00:32:53,71 --> 00:32:54,372 received another boost 511 00:32:54,406 --> 00:32:58,276 from a very Mars-like part of our own planet, 512 00:32:58,310 --> 00:33:01,246 Chile's extraordinary Atacama Desert. 513 00:33:04,449 --> 00:33:10,21 McKAY: The Atacama is special because it is just so profoundly dry. 514 00:33:10,55 --> 00:33:13,825 Speaking roughly, it's 50 times drier than Death Valley. 515 00:33:13,859 --> 00:33:16,461 It is deader than Death Valley. 516 00:33:18,263 --> 00:33:21,166 It's the only place on Earth where Viking could have landed 517 00:33:21,199 --> 00:33:24,02 and searched for life in dirt on Earth and not found it, 518 00:33:24,35 --> 00:33:29,508 and instead found a reactive mixture of chemicals, the only place. 519 00:33:31,810 --> 00:33:36,248 NARRATOR: Even here, in the driest corner of the driest desert on Earth, 520 00:33:36,281 --> 00:33:39,117 life has confounded scientists. 521 00:33:39,150 --> 00:33:41,86 Cyanobacteria have been found 522 00:33:41,119 --> 00:33:46,358 living inside the rock-hard salt of a long gone lake. 523 00:33:46,391 --> 00:33:51,96 BENITO GOMEZ: This is a halite, it's a sodium chloride salt, 524 00:33:51,129 --> 00:33:54,299 which is colonized by cyanobacteria. 525 00:33:54,332 --> 00:33:58,904 It's dark green because they have this particular pigment 526 00:33:58,937 --> 00:34:03,775 protecting them from the excess of UV light. 527 00:34:03,808 --> 00:34:07,979 NARRATOR: Once in a blue moon, a fleeting early morning ground fog 528 00:34:08,13 --> 00:34:11,983 delivers some rare humidity to the air above the desert. 529 00:34:13,685 --> 00:34:17,822 This precious moisture is greedily sucked into the microscopic pores 530 00:34:17,856 --> 00:34:21,660 of the water-hungry rock salt. 531 00:34:21,693 --> 00:34:25,363 GOMEZ: This is a very rare event. 532 00:34:25,397 --> 00:34:28,767 So these bacteria are living in an environment 533 00:34:28,800 --> 00:34:34,39 where liquid water is available a few hours during one year. 534 00:34:34,72 --> 00:34:36,975 Very, very hard. 535 00:34:37,08 --> 00:34:39,210 NARRATOR: If we're looking for Martian bugs, 536 00:34:39,244 --> 00:34:44,49 we should search for life forms at least as tough and alien as this. 537 00:34:45,317 --> 00:34:48,186 ROTHSCHILD: I'm looking at Mars from the point of view of a microbe, 538 00:34:48,219 --> 00:34:51,790 and as a microbe | really need a very, very tiny amount of water. 539 00:34:51,823 --> 00:34:54,793 | could probably live my entire life happily 540 00:34:54,826 --> 00:34:59,297 in a tiny drop of water about the size of the point of a pen. 541 00:34:59,331 --> 00:35:01,166 Now we've shown over the years 542 00:35:01,199 --> 00:35:04,502 that organisms that live in salt crusts on the Earth 543 00:35:04,536 --> 00:35:06,371 have enough sunlight coming in 544 00:35:06,404 --> 00:35:09,307 so that they can go through their day-to-day activities 545 00:35:09,341 --> 00:35:11,676 but still be protected from the radiation, 546 00:35:11,710 --> 00:35:15,13 and we know there are salt crusts on Mars. 547 00:35:15,46 --> 00:35:18,116 NARRATOR: Mars has a long-term wobble to its orbit 548 00:35:18,149 --> 00:35:20,218 and every 5 million years or so, 549 00:35:20,251 --> 00:35:25,790 the poles end up tilting 45 degrees toward the sun. 550 00:35:25,824 --> 00:35:27,892 McKAY: A way of thinking about the Phoenix landing site 551 00:35:27,926 --> 00:35:30,195 is think about the polar regions on Earth. 552 00:35:30,228 --> 00:35:32,364 Imagine you're there in winter. 553 00:35:32,397 --> 00:35:35,233 It's very inhospitable, very cold, very alien. 554 00:35:35,266 --> 00:35:37,202 You think, how can anything survive here? 555 00:35:37,235 --> 00:35:40,338 Come back six months later and it's like a different world. 556 00:35:40,372 --> 00:35:42,540 The sun is shining, it's wet, it's warm, 557 00:35:42,574 --> 00:35:46,144 things are alive and scurrying around. 558 00:35:46,177 --> 00:35:50,582 So we may be being misled seeing this frozen, cold site, 559 00:35:50,615 --> 00:35:54,953 and in fact, we're just there at the wrong season. 560 00:35:54,986 --> 00:35:58,623 NARRATOR: We know that on Earth some bacteria can survive being frozen 561 00:35:58,657 --> 00:36:01,393 for millions of years. 562 00:36:01,426 --> 00:36:03,662 They can also eat perchlorate, 563 00:36:03,695 --> 00:36:09,67 the highly reactive chemical Phoenix found in the Martian soil. 564 00:36:09,100 --> 00:36:11,302 McKAY: Presumably, if there was life at the Phoenix site 565 00:36:11,336 --> 00:36:13,405 it had learned the same trick. 566 00:36:13,438 --> 00:36:16,341 And so there might be organisms that are literally eating the rocks 567 00:36:16,374 --> 00:36:19,377 and reacting with perchlorate below the surface 568 00:36:19,411 --> 00:36:21,246 shielded from the ultraviolet light 569 00:36:21,279 --> 00:36:24,349 just having a great old time five million years ago. 570 00:36:24,382 --> 00:36:26,985 The party is over because everybody froze, 571 00:36:27,18 --> 00:36:29,888 but in another five million years the party will start up again 572 00:36:29,921 --> 00:36:33,892 as the Martian summer comes to the north polar regions 573 00:36:33,925 --> 00:36:36,127 and the ice turns to water. 574 00:36:39,164 --> 00:36:42,300 NARRATOR: The party might not be over everywhere. 575 00:36:42,333 --> 00:36:46,371 The gas methane has been found both by spacecraft in orbit 576 00:36:46,404 --> 00:36:49,541 and by telescopes from Earth. 577 00:36:49,574 --> 00:36:52,844 It's chemically impossible for methane to survive for long 578 00:36:52,877 --> 00:36:54,713 in the Martian atmosphere, 579 00:36:54,746 --> 00:36:57,782 so it must have been released recently. 580 00:36:57,816 --> 00:37:00,485 SQUYRES: Now what makes methane? 581 00:37:00,518 --> 00:37:05,56 Cows make methane; it's probably not cows. 582 00:37:05,90 --> 00:37:08,326 Microbes of various sorts can release methane. 583 00:37:08,359 --> 00:37:10,595 There are a variety of geologic processes. 584 00:37:10,628 --> 00:37:13,765 Volcanoes can release methane. 585 00:37:13,798 --> 00:37:19,137 So the mere fact that there's methane doesn't say life, 586 00:37:19,170 --> 00:37:24,843 but either way the methane says that Mars is an active planet. 587 00:37:24,876 --> 00:37:29,47 It's either biologically active or it's geologically active or both. 588 00:37:31,349 --> 00:37:34,152 NARRATOR: The methane release appears to be seasonal 589 00:37:34,185 --> 00:37:38,356 and linked to areas of suspected sub-surface ice. 590 00:37:38,389 --> 00:37:41,192 Ice found exposed in fresh craters 591 00:37:41,226 --> 00:37:45,63 has proven that water lurks not only near the poles 592 00:37:45,96 --> 00:37:48,233 but also much closer to the equator. 593 00:37:48,266 --> 00:37:53,271 It's pretty clear that if the Viking landers had dug just 4 inches deeper, 594 00:37:53,304 --> 00:37:55,807 they would have reached this ice 595 00:37:55,840 --> 00:38:00,278 and perhaps a totally different conclusion about life on the red planet. 596 00:38:03,47 --> 00:38:05,984 ROTHSCHILD: So if Mars has any life at all, 597 00:38:06,17 --> 00:38:09,754 whether it is so small you can only see it with a microscope 598 00:38:09,788 --> 00:38:12,757 or if they had a mammoth, it wouldn't matter to me; 599 00:38:12,791 --> 00:38:17,695 it's the whole question of is there life at all on Mars. 600 00:38:19,831 --> 00:38:23,868 NARRATOR: Either way, there certainly will be life on Mars 601 00:38:23,902 --> 00:38:28,139 the moment the first human traveler arrives. 602 00:38:32,544 --> 00:38:36,848 In 2009, six men walked into a series of connected rooms 603 00:38:36,881 --> 00:38:39,384 inside a warehouse in the Moscow suburbs 604 00:38:39,417 --> 00:38:43,21 and shut the door behind them, for three months. 605 00:38:43,54 --> 00:38:46,958 They took all their food with them and drank recycled water. 606 00:38:46,991 --> 00:38:48,993 The only communication with the outside world 607 00:38:49,27 --> 00:38:52,397 was electronic, with a 20-minute delay. 608 00:38:54,799 --> 00:38:58,369 They were trying to simulate a flight to Mars. 609 00:39:01,439 --> 00:39:04,809 There is no room to screw up on a trip like this, 610 00:39:04,843 --> 00:39:06,678 mental or otherwise. 611 00:39:06,711 --> 00:39:11,15 Once on Mars you are likely to be stuck there for a year or more 612 00:39:11,49 --> 00:39:15,53 waiting for a window of opportunity to ride home. 613 00:39:15,86 --> 00:39:16,321 And, unlike a robot, 614 00:39:16,354 --> 00:39:21,25 the hopes and fears of the whole planet will be riding with you. 615 00:39:22,126 --> 00:39:24,195 SQUYRES: | think that humans are going to do a better job 616 00:39:24,229 --> 00:39:27,899 of exploring Mars ultimately than robots ever can. 617 00:39:27,932 --> 00:39:30,568 Robots move really slowly. 618 00:39:30,602 --> 00:39:33,504 Okay, what Spirit and Opportunity have done in 5 years on Mars 619 00:39:33,538 --> 00:39:36,808 two astronauts could probably have done in a week. 620 00:39:41,779 --> 00:39:44,48 NARRATOR: As fast and as smart as we are, 621 00:39:44,82 --> 00:39:49,53 we still need mechanical help to scout the course for Mars. 622 00:39:49,87 --> 00:39:55,293 The next robot rolling onto red dirt will be aptly named Curiosity. 623 00:39:55,326 --> 00:39:58,897 SQUYRES: It's the size of a small car, and it has a nuclear power source, 624 00:39:58,930 --> 00:40:02,500 so you don't have to worry about dust accumulating on solar arrays 625 00:40:02,533 --> 00:40:05,270 or anything like that. 626 00:40:05,303 --> 00:40:07,505 And most importantly it has the capability 627 00:40:07,538 --> 00:40:11,409 to look for trace quantities of organic molecules, 628 00:40:11,442 --> 00:40:15,680 SO we've gone beyond now looking for evidence of habitability 629 00:40:15,713 --> 00:40:19,550 to actually looking for evidence of the building blocks of life. 630 00:40:21,619 --> 00:40:25,690 NARRATOR: Whether it's alive or dead, a trip to this red planet 631 00:40:25,723 --> 00:40:29,193 has a lot to teach us about our lonely blue one 632 00:40:29,227 --> 00:40:31,429 and the universe beyond. 633 00:40:31,462 --> 00:40:33,364 ROTHSCHILD: Now, if you have two planets 634 00:40:33,398 --> 00:40:36,301 that are next to each other in the same solar system 635 00:40:36,334 --> 00:40:39,537 that both had independent origins of life, 636 00:40:39,570 --> 00:40:40,872 you would have to conclude 637 00:40:40,905 --> 00:40:44,609 that the chance of having life all over the universe, 638 00:40:44,642 --> 00:40:47,478 indeed even in other places in our solar system, 639 00:40:47,512 --> 00:40:49,80 would be very high. 640 00:40:49,113 --> 00:40:52,250 | think you could basically go to the bank and bet on it. 641 00:40:55,253 --> 00:40:57,889 McKAY: We're not going to Mars just to search for life, 642 00:40:57,922 --> 00:41:01,159 we're going to Mars to search for a second genesis of life. 643 00:41:01,192 --> 00:41:03,795 We'd like to find something that's different from us, 644 00:41:03,828 --> 00:41:06,331 that doesn't have the same genetic history 645 00:41:06,364 --> 00:41:08,499 and genetic code that we have. 646 00:41:08,533 --> 00:41:13,404 And, from my point of view, the more alien the better. 647 00:41:13,438 --> 00:41:17,842 ROTHSCHILD: Now, the second possibility is that we find life on Mars, 648 00:41:17,875 --> 00:41:21,846 but my goodness, it has a genetic code exactly like us, 649 00:41:21,879 --> 00:41:23,815 it uses DNA. 650 00:41:23,848 --> 00:41:26,484 It's too coincidental. 651 00:41:26,517 --> 00:41:29,220 This is representing our cousins. 652 00:41:29,253 --> 00:41:33,591 Life either arose on Earth and went to Mars, 653 00:41:33,624 --> 00:41:37,762 or actually more likely that life originated on Mars 654 00:41:37,795 --> 00:41:40,898 and it was transported on a meteorite or a comet 655 00:41:40,932 --> 00:41:42,433 to the Earth early on 656 00:41:42,467 --> 00:41:46,170 and in fact our home planet is Mars. 657 00:41:52,877 --> 00:41:55,813 NARRATOR: So, in some ways a voyage to Mars 658 00:41:55,847 --> 00:41:59,50 could be a voyage home. 659 00:41:59,83 --> 00:42:02,854 Our ancestors have made such bold trips before. 660 00:42:02,887 --> 00:42:04,922 When we walked out of Africa. 661 00:42:04,956 --> 00:42:08,760 When we sailed over the horizon. 662 00:42:08,793 --> 00:42:13,931 If it's technically possible, our ships will head out again. 663 00:42:18,403 --> 00:42:20,638 ZUREK: We've always wanted to see what's over the next hill, 664 00:42:20,671 --> 00:42:24,175 and Mars is that next "over the hill." 665 00:42:24,208 --> 00:42:27,812 Sure, you're going to have be in a suit, you're going to have to have a habitat, 666 00:42:27,845 --> 00:42:30,615 but it's a solid planet, it's got a surface, 667 00:42:30,648 --> 00:42:35,153 you can see, you can work, you can explore. 668 00:42:35,186 --> 00:42:36,821 CLARK: I've thought for about 30 years now 669 00:42:36,854 --> 00:42:38,756 that we could go to Mars, 670 00:42:38,790 --> 00:42:41,492 and usually when people ask me how long it would take, 671 00:42:41,526 --> 00:42:42,827 I say 15 years 672 00:42:42,860 --> 00:42:47,265 because we've been saying 15 years for the last about four decades. 673 00:42:51,269 --> 00:42:53,671 SQUYRES: A human mission to Mars can't happen soon enough for me. 674 00:42:53,704 --> 00:42:56,74 You know, I'm a robot guy. 675 00:42:56,107 --> 00:42:57,975 That's what | do with my career 676 00:42:58,09 --> 00:43:00,445 is build robots and send them to Mars, 677 00:43:00,478 --> 00:43:08,52 but | also think that we send things to Mars for reasons other than science. 678 00:43:09,53 --> 00:43:11,122 Our rovers Spirit and Opportunity 679 00:43:11,155 --> 00:43:15,760 were built by people who, like me, grew up in the ‘60s 680 00:43:15,793 --> 00:43:18,863 watching Mercury, Gemini, Apollo on TV as little kids 681 00:43:18,896 --> 00:43:22,700 and dreaming of sending spaceships to Mars someday, 682 00:43:22,733 --> 00:43:24,569 and now we do, 683 00:43:24,602 --> 00:43:27,572 and | think as people watch 684 00:43:27,605 --> 00:43:29,740 the first human explorers on the surface of Mars, 685 00:43:29,774 --> 00:43:32,710 they are going to be similarly inspired 686 00:43:32,743 --> 00:43:35,413 to do things that | can't even imagine at this point. 687 00:43:35,446 --> 00:43:39,517 It's going to be very costly, it's going to be dangerous, 688 00:43:39,550 --> 00:43:43,154 but | think it's something I'd certainly like to see happen. 689 00:43:46,357 --> 00:43:50,962 I'd love to see boot prints in our wheel tracks. 690 00:43:50,995 --> 00:43:53,431 | would love to see boot prints on Mars. 691 00:43:55,500 --> 00:43:58,836 NARRATOR: When the first human footprint is made on Mars, 692 00:43:58,870 --> 00:44:03,608 it will represent more than a giant stride into space. 693 00:44:03,641 --> 00:44:06,677 This one small impression will be proof 694 00:44:06,711 --> 00:44:09,947 that humanity is once again on the move; 695 00:44:09,981 --> 00:44:13,351 travelers once more moving beyond our comfort zone 696 00:44:13,384 --> 00:44:17,922 to explore new lands and new opportunities. 697 00:44:17,955 --> 00:44:24,929 And have no doubt, there are many worlds out there, ripe for exploration.