1 00:00:02,150 --> 00:00:04,826 I was just praying with my eyes closed 2 00:00:04,826 --> 00:00:06,383 that this was gonna work. 3 00:00:08,640 --> 00:00:11,590 Things, if they're gonna go wrong, do go wrong. 4 00:00:11,590 --> 00:00:13,280 This thing could fail, you know? 5 00:00:13,280 --> 00:00:15,800 If it doesn't work, it's over. 6 00:00:15,800 --> 00:00:17,090 Lights off. 7 00:00:17,090 --> 00:00:18,950 Exploring the solar system 8 00:00:18,950 --> 00:00:21,150 is not for the feint of heart. 9 00:00:21,150 --> 00:00:25,664 It requires courage, determination, and ingenuity. 10 00:00:25,664 --> 00:00:29,260 This is like the first renaissance voyage over the oceans, 11 00:00:29,260 --> 00:00:30,813 but it's to another planet. 12 00:00:33,050 --> 00:00:35,613 Can we send a spacecraft through that environment? 13 00:00:35,613 --> 00:00:37,767 There's no question whatsoever that this is 14 00:00:37,767 --> 00:00:40,410 one of the most difficult technological jobs 15 00:00:40,410 --> 00:00:42,250 that the human species has ever tried. 16 00:00:42,250 --> 00:00:45,663 It's a very violent, dangerous, deadly place. 17 00:00:46,833 --> 00:00:50,010 But the rewards of risking everything 18 00:00:50,010 --> 00:00:51,023 are worth it. 19 00:00:52,070 --> 00:00:53,480 Holy gosh. 20 00:00:53,480 --> 00:00:55,512 I was stunned. 21 00:00:55,512 --> 00:00:57,150 We found the holy grail. 22 00:00:57,150 --> 00:00:59,020 Mars has a sense of romance about it 23 00:00:59,020 --> 00:01:00,700 because it's a place, it's a planet, 24 00:01:00,700 --> 00:01:02,510 it's another world. 25 00:01:02,510 --> 00:01:07,510 79 moons, each one their own world of ice or rock. 26 00:01:08,500 --> 00:01:10,690 It's definitely the most interesting place 27 00:01:10,690 --> 00:01:12,200 in the solar system. 28 00:01:12,200 --> 00:01:14,760 Pluto is the Everest of the solar system. 29 00:01:14,760 --> 00:01:17,600 The farthest and coldest and hardest to reach. 30 00:01:17,600 --> 00:01:21,622 Wouldn't that be cool, if Pluto has or had life? 31 00:01:21,622 --> 00:01:25,650 We're thinking holy crap, Batman. 32 00:01:25,650 --> 00:01:27,030 This series reveals 33 00:01:27,030 --> 00:01:29,520 how we explored our solar system. 34 00:01:29,520 --> 00:01:32,650 I felt this is a more thrilling moment than Apollo 11. 35 00:01:32,650 --> 00:01:35,500 Told by the people who dared to do it. 36 00:01:35,500 --> 00:01:38,180 When I first saw the images I was amazed. 37 00:01:38,180 --> 00:01:41,690 We had a rock from Mars, a smoking gun. 38 00:01:41,690 --> 00:01:43,960 Risking reputations on missions 39 00:01:43,960 --> 00:01:46,070 that were decades in the planning, 40 00:01:46,070 --> 00:01:48,428 that could fail at any time. 41 00:01:48,428 --> 00:01:50,753 NASA are taking a big risk here. 42 00:01:52,111 --> 00:01:54,870 This is it, this is actually the end. 43 00:01:54,870 --> 00:01:56,713 It definitely led to a lot of tears. 44 00:01:57,660 --> 00:01:59,380 These are the missions that changed 45 00:01:59,380 --> 00:02:03,200 how we see the solar system, and ourselves. 46 00:02:03,200 --> 00:02:06,470 We are the only generation that will ever 47 00:02:06,470 --> 00:02:09,433 explore the solar system for the first time. 48 00:02:20,545 --> 00:02:23,128 (gentle music) 49 00:02:27,119 --> 00:02:31,020 As I take man's last step on the surface 50 00:02:31,020 --> 00:02:31,977 for some time to come, 51 00:02:31,977 --> 00:02:34,273 but we believe not too long in the future. 52 00:02:35,500 --> 00:02:38,645 I believe America's challenge of today 53 00:02:38,645 --> 00:02:42,883 has forged man's destiny of tomorrow. 54 00:02:50,020 --> 00:02:54,793 We leave as we came, and God willing as we shall return. 55 00:02:56,874 --> 00:02:59,874 With peace and hope for all mankind. 56 00:03:07,723 --> 00:03:10,340 The exploration of our solar system 57 00:03:10,340 --> 00:03:12,920 really is part of the quest to understand 58 00:03:12,920 --> 00:03:14,800 our place in the universe. 59 00:03:14,800 --> 00:03:17,933 And without or solar system, we wouldn't exist. 60 00:03:20,010 --> 00:03:25,010 Why did this one little blue-green planet 61 00:03:25,310 --> 00:03:29,470 appear around this perfectly ordinary star? 62 00:03:29,470 --> 00:03:33,930 Is this a story that is repeated time and again 63 00:03:33,930 --> 00:03:35,130 throughout the universe? 64 00:03:54,243 --> 00:03:58,826 The solar system is both vast and ancient. 65 00:04:00,960 --> 00:04:03,723 At least 4.5 billion years old. 66 00:04:07,350 --> 00:04:10,290 Now, for the first time in human history, 67 00:04:10,290 --> 00:04:15,290 we have images in stunning detail of all the major planets, 68 00:04:17,290 --> 00:04:20,790 and many moons, asteroids and comets, 69 00:04:20,790 --> 00:04:24,453 taken from space by machines of human design. 70 00:04:28,092 --> 00:04:30,210 From the surface of the sun 71 00:04:30,210 --> 00:04:34,340 to the frozen highlands of Pluto and beyond, 72 00:04:34,340 --> 00:04:37,070 these images bear witness to the talents 73 00:04:37,070 --> 00:04:39,550 of the men and women who went in search of 74 00:04:39,550 --> 00:04:41,913 answers to the biggest questions. 75 00:04:42,770 --> 00:04:46,993 And this episode is about how and why they went looking. 76 00:04:48,140 --> 00:04:52,781 The moment we discover that life developed somewhere else 77 00:04:52,781 --> 00:04:56,980 will be the greatest scientific discovery of all time. 78 00:05:17,690 --> 00:05:19,840 The sun at the center of the solar system 79 00:05:19,840 --> 00:05:21,853 is an incredibly hot object. 80 00:05:23,430 --> 00:05:26,403 This hot, raging ball of gas. 81 00:05:28,230 --> 00:05:30,540 In order to be able to truly see the sun, 82 00:05:30,540 --> 00:05:33,537 the interior, the surface, the atmosphere, 83 00:05:33,537 --> 00:05:35,479 we have to go into space. 84 00:05:35,479 --> 00:05:36,774 Status check. (dramatic music) 85 00:05:36,774 --> 00:05:38,232 Go gentlemen. 86 00:05:38,232 --> 00:05:40,565 First station is propulsion. 87 00:05:40,565 --> 00:05:41,529 Go. 88 00:05:41,529 --> 00:05:42,487 Hydraulics. 89 00:05:42,487 --> 00:05:43,320 Go. 90 00:05:43,320 --> 00:05:44,153 Locks. 91 00:05:44,153 --> 00:05:44,986 Go. 92 00:05:44,986 --> 00:05:47,160 This mission has been a long time coming, you know, 93 00:05:47,160 --> 00:05:49,583 that for 60 years we tried to do this mission. 94 00:05:50,472 --> 00:05:54,230 We're gonna go to the most extreme environment 95 00:05:54,230 --> 00:05:56,083 in our entire solar system. 96 00:05:56,920 --> 00:06:00,180 We're gonna go in and we're gonna touch the sun. 97 00:06:00,180 --> 00:06:05,038 Eight, seven, six, five, four, 98 00:06:05,038 --> 00:06:09,135 three, two, one, zero. 99 00:06:09,135 --> 00:06:12,870 Lift off of the mighty Delta IV Heavy rocket, 100 00:06:12,870 --> 00:06:15,073 with NASA's Parker Solar Probe, 101 00:06:15,073 --> 00:06:17,670 a daring mission to shed light on the mysteries 102 00:06:17,670 --> 00:06:19,493 of our closest star, the sun. 103 00:06:30,564 --> 00:06:33,231 (melodic music) 104 00:06:38,570 --> 00:06:41,700 Humanity I think has a general quest for knowledge. 105 00:06:41,700 --> 00:06:45,183 We tend to just ask questions and wonder why. 106 00:06:46,350 --> 00:06:49,560 The nature is to look up and to look around you 107 00:06:49,560 --> 00:06:52,130 and to want to understand your surroundings, 108 00:06:52,130 --> 00:06:54,110 and so the first thing anyone looked up 109 00:06:54,110 --> 00:06:56,320 and wondered about was the sun. 110 00:06:56,320 --> 00:06:58,840 I think it's been, over the years, 111 00:06:58,840 --> 00:07:03,780 seen as sometimes friend and at other times as foe. 112 00:07:03,780 --> 00:07:05,920 The sun is a constant in our lives. 113 00:07:05,920 --> 00:07:08,260 It rises every morning, it sets every night, 114 00:07:08,260 --> 00:07:10,150 and yet when you look at the sun, 115 00:07:10,150 --> 00:07:13,220 you will see that it is anything but constant. 116 00:07:13,220 --> 00:07:16,683 It is a continually changing, incredibly active star. 117 00:07:18,430 --> 00:07:21,010 The story of the sun is very much 118 00:07:21,010 --> 00:07:23,053 the story of the solar system. 119 00:07:23,960 --> 00:07:28,960 Finding out how it works is still a work in progress. 120 00:07:29,210 --> 00:07:31,140 That hazy atmosphere that you see during 121 00:07:31,140 --> 00:07:34,330 a total solar eclipse, the sun's corona, 122 00:07:34,330 --> 00:07:36,590 is hotter than the surface of the sun. 123 00:07:36,590 --> 00:07:37,820 And that really doesn't make sense, 124 00:07:37,820 --> 00:07:39,730 it breaks the laws of physics. 125 00:07:39,730 --> 00:07:42,880 You move away from a hot body, it should get colder, 126 00:07:42,880 --> 00:07:45,380 but something is happening in this region 127 00:07:45,380 --> 00:07:47,830 that really heats this material. 128 00:07:47,830 --> 00:07:50,768 And we don't know why. 129 00:07:50,768 --> 00:07:55,768 If it's that hot, why does the gas stay on the sun? 130 00:07:56,535 --> 00:07:59,103 Hot materials move really fast, 131 00:08:01,060 --> 00:08:03,870 and if the gas molecules are traveling 132 00:08:03,870 --> 00:08:06,237 faster than escape velocity, 133 00:08:06,237 --> 00:08:10,257 there should be a wind streaming away from the sun. 134 00:08:11,416 --> 00:08:14,880 And this radical idea was predicted 135 00:08:14,880 --> 00:08:17,923 by an American astronomer, Eugene Parker. 136 00:08:19,363 --> 00:08:21,630 (gentle music) 137 00:08:21,630 --> 00:08:25,910 In 1958, space was thought to be a hard vacuum. 138 00:08:25,910 --> 00:08:28,580 And while the light and heat from the sun 139 00:08:28,580 --> 00:08:30,660 could pass through space, 140 00:08:30,660 --> 00:08:33,030 the enormous gravity of the sun would prevent 141 00:08:33,030 --> 00:08:36,380 any matter, such as gas, from reaching us. 142 00:08:36,380 --> 00:08:38,483 But, Parker thought differently. 143 00:08:39,926 --> 00:08:44,926 The idea was contradicted by several observations. 144 00:08:46,530 --> 00:08:48,070 He went through the mathematics, 145 00:08:48,070 --> 00:08:49,430 he went through the physics, 146 00:08:49,430 --> 00:08:52,800 and he predicted the hot atmosphere of the sun 147 00:08:52,800 --> 00:08:54,810 has a high pressure, 148 00:08:54,810 --> 00:08:57,550 so the gas is wanting to push outwards. 149 00:08:57,550 --> 00:09:01,252 And there's a really important consequence of that. 150 00:09:01,252 --> 00:09:04,950 The gas streams out into the solar system. 151 00:09:04,950 --> 00:09:08,999 The sun is literally expanding into space. 152 00:09:08,999 --> 00:09:12,950 I realized that we had a supersonic expansion 153 00:09:12,950 --> 00:09:15,080 of the outer atmosphere of the sun. 154 00:09:15,080 --> 00:09:17,713 A completely radical idea. 155 00:09:19,066 --> 00:09:22,035 Eugene wrote up a scientific paper, 156 00:09:22,035 --> 00:09:24,620 submitted it to the Astrophysical Journal, 157 00:09:24,620 --> 00:09:27,120 and it got rejected. 158 00:09:27,120 --> 00:09:29,393 Hardly anybody took it seriously. 159 00:09:30,484 --> 00:09:35,484 I received several polite and not so polite declinations. 160 00:09:37,440 --> 00:09:39,520 Parker asked the then editor 161 00:09:39,520 --> 00:09:43,260 of the Astrophysical Journal, Subrahmanyan Chandrasekhar, 162 00:09:43,260 --> 00:09:45,020 to look at his paper again. 163 00:09:45,020 --> 00:09:48,120 Chandrasekhar couldn't find any mathematical flaws 164 00:09:48,120 --> 00:09:49,313 in Parker's work. 165 00:09:50,186 --> 00:09:53,287 The editor said to Eugene, "Do you really think 166 00:09:53,287 --> 00:09:55,490 "there's something in the work you've done?" 167 00:09:55,490 --> 00:09:56,910 And he said, "Yes." 168 00:09:56,910 --> 00:09:58,680 And the editor published it. 169 00:09:58,680 --> 00:10:01,053 But still, it's ridiculed. 170 00:10:02,716 --> 00:10:05,370 Just because the paper was published, 171 00:10:05,370 --> 00:10:07,913 had no positive effect. 172 00:10:09,165 --> 00:10:10,867 They were not behind it because they just 173 00:10:10,867 --> 00:10:12,733 believed it was wrong. 174 00:10:14,832 --> 00:10:17,415 Three, two, one, zero. 175 00:10:21,818 --> 00:10:24,691 Four years after I made the proposal 176 00:10:24,691 --> 00:10:28,283 there was a spacecraft flying to Venus. 177 00:10:30,010 --> 00:10:32,750 And they did indeed discover that the sun 178 00:10:32,750 --> 00:10:36,063 does have this outflow of gas coming from it. 179 00:10:37,270 --> 00:10:39,710 The solar wind does exist. 180 00:10:39,710 --> 00:10:40,990 The rest is history. 181 00:10:43,501 --> 00:10:46,334 (uplifting music) 182 00:10:49,520 --> 00:10:51,430 This discovery was momentous. 183 00:10:51,430 --> 00:10:55,040 All of a sudden space is no longer a void, 184 00:10:55,040 --> 00:10:57,970 it's no longer a vacuum, it's filled with material, 185 00:10:57,970 --> 00:11:00,243 it's filled with this wind from the sun. 186 00:11:01,342 --> 00:11:06,342 The speed of the solar winds, it's almost beyond belief. 187 00:11:06,410 --> 00:11:11,410 It's moving between 250 and 750 kilometers per second, 188 00:11:14,052 --> 00:11:18,843 and it has some really significant affects on our planet. 189 00:11:21,597 --> 00:11:24,880 In 2018, NASA launched a spacecraft 190 00:11:24,880 --> 00:11:27,078 called the Parker Solar Probe. 191 00:11:27,078 --> 00:11:28,911 Two, one. 192 00:11:28,911 --> 00:11:31,873 Lift off of the mighty Delta IV Heavy Rocket 193 00:11:31,873 --> 00:11:34,700 It's the only spacecraft ever to bear the name 194 00:11:34,700 --> 00:11:36,160 of a living scientist. 195 00:11:36,160 --> 00:11:38,930 To shed light on the mysteries of our closest star, 196 00:11:38,930 --> 00:11:39,763 the sun. 197 00:11:40,600 --> 00:11:43,223 Wow, go baby go. 198 00:11:43,223 --> 00:11:46,584 The sky lights up and you realize that 199 00:11:46,584 --> 00:11:48,203 it's never coming back. 200 00:11:50,369 --> 00:11:52,619 (applause) 201 00:11:59,900 --> 00:12:01,000 What a way to start. 202 00:12:09,390 --> 00:12:13,163 10, nine, eight, seven, six, five... 203 00:12:13,163 --> 00:12:16,000 Being the closest planet to the sun, 204 00:12:16,000 --> 00:12:18,740 Mercury is a world of extremes. 205 00:12:18,740 --> 00:12:21,490 But even here, explorers were to find something 206 00:12:21,490 --> 00:12:23,780 that few expected. 207 00:12:23,780 --> 00:12:25,850 When I became the head of planetary science, 208 00:12:25,850 --> 00:12:29,983 Messenger had launched, and it was on its way to Mercury. 209 00:12:32,078 --> 00:12:36,160 Messenger was all about exploring the full surface 210 00:12:36,160 --> 00:12:37,790 that we'd never seen before, 211 00:12:37,790 --> 00:12:39,640 but also we had to really think about how 212 00:12:39,640 --> 00:12:42,770 we develop our technology to survive this environment. 213 00:12:42,770 --> 00:12:44,870 One of the main concerns for us with an orbiter 214 00:12:44,870 --> 00:12:46,950 is we go from one side to the other 215 00:12:46,950 --> 00:12:49,317 in a very short time period, a few tens of minutes. 216 00:12:49,317 --> 00:12:52,010 The day side of Mercury +450 degrees, 217 00:12:52,010 --> 00:12:54,660 the night side about -180. 218 00:12:54,660 --> 00:12:57,780 So the extreme in temperature is over 600 degrees swing 219 00:12:57,780 --> 00:12:59,810 between one side and the other. 220 00:12:59,810 --> 00:13:01,200 The Messenger spacecraft 221 00:13:01,200 --> 00:13:05,354 went into orbit around Mercury seven years after launch. 222 00:13:05,354 --> 00:13:08,750 It was designed to study the smallest of the planets 223 00:13:08,750 --> 00:13:12,500 using a whole suit of sensitive instruments. 224 00:13:12,500 --> 00:13:14,650 What Messenger did was it provided, 225 00:13:14,650 --> 00:13:16,745 as its top science priority, 226 00:13:16,745 --> 00:13:21,373 a high resolution image of the entire surface of Mercury. 227 00:13:22,348 --> 00:13:26,590 But the mystery was that there were bright spots. 228 00:13:26,590 --> 00:13:30,300 There were small bright spots. 229 00:13:30,300 --> 00:13:32,960 And then one of the Messenger scientists 230 00:13:32,960 --> 00:13:37,230 took all of the bright spots and laid them down 231 00:13:37,230 --> 00:13:39,023 on the map of Mercury. 232 00:13:41,210 --> 00:13:45,130 Every single bright spot was inside of a crater 233 00:13:45,130 --> 00:13:47,363 that is permanently shadowed. 234 00:13:48,980 --> 00:13:53,980 We found what we believe is ice, water ice at Mercury. 235 00:13:54,620 --> 00:13:58,500 It's in one of the hottest regions in our solar system. 236 00:13:58,500 --> 00:14:00,982 So how did the ice get in there? 237 00:14:00,982 --> 00:14:03,160 Has it been through meteor strikes? 238 00:14:03,160 --> 00:14:05,110 'Cause meteors have water. 239 00:14:05,110 --> 00:14:07,980 Has it been through comets hitting the body? 240 00:14:07,980 --> 00:14:10,260 Comets have a lot of water. 241 00:14:10,260 --> 00:14:11,753 It's really an enigma. 242 00:14:19,980 --> 00:14:23,500 It used to be thought that Earth is the cradle for life, 243 00:14:23,500 --> 00:14:26,430 therefore all organic chemistry in the solar system 244 00:14:26,430 --> 00:14:29,000 is probably concentrated in the band 245 00:14:29,000 --> 00:14:31,903 that the Earth's orbit maps out around the sun. 246 00:14:33,060 --> 00:14:35,565 But we're now studying the water cycle, 247 00:14:35,565 --> 00:14:38,043 literally throughout the solar system. 248 00:14:41,320 --> 00:14:44,010 So when you're talking about where life is 249 00:14:44,010 --> 00:14:48,040 and where the kind of chemistry and ultimately biology 250 00:14:48,040 --> 00:14:51,310 that might produce something like this could take place, 251 00:14:51,310 --> 00:14:53,860 at the moment it's looking like it might be 252 00:14:53,860 --> 00:14:56,890 broader than just one little planet 253 00:14:56,890 --> 00:14:59,473 at the Goldilocks distance. 254 00:15:07,194 --> 00:15:09,944 (dramatic music) 255 00:15:17,303 --> 00:15:20,400 The Soviet Union, they understood the huge 256 00:15:20,400 --> 00:15:23,073 propaganda value of victories in space. 257 00:15:24,567 --> 00:15:26,470 The best way to prove superiority 258 00:15:27,659 --> 00:15:30,143 would be to get to Venus first. 259 00:15:32,930 --> 00:15:35,171 We should not forget that every launch 260 00:15:35,171 --> 00:15:39,673 is also perfecting essentially military technology. 261 00:15:41,370 --> 00:15:44,643 This was a giant military missile development program. 262 00:15:51,820 --> 00:15:53,923 Space exploration has a dark side. 263 00:15:57,910 --> 00:16:01,480 We can't deny that we rode to the moon 264 00:16:01,480 --> 00:16:03,963 and to the other planets on the wings of war. 265 00:16:06,900 --> 00:16:09,530 The reason we have these rockets that can 266 00:16:09,530 --> 00:16:12,550 launch payloads into orbit and beyond 267 00:16:12,550 --> 00:16:17,023 is because they were developed to destroy cities. 268 00:16:24,395 --> 00:16:26,700 The Cold War made possible 269 00:16:26,700 --> 00:16:30,059 ever more ambitions missions in the 60s and 70s, 270 00:16:30,059 --> 00:16:32,643 each a matter of national pride. 271 00:16:34,730 --> 00:16:37,053 None more so than Venera 9. 272 00:16:38,198 --> 00:16:43,010 This huge, complex spacecraft was built to enable Russia 273 00:16:43,010 --> 00:16:45,650 to be the first nation to send back an image 274 00:16:45,650 --> 00:16:47,703 from the surface of another planet. 275 00:16:48,930 --> 00:16:49,883 Venus. 276 00:16:53,640 --> 00:16:56,180 On 20th of October of 1975, 277 00:16:56,180 --> 00:16:59,730 this giant stack of spacecraft of Lander and Orbiter 278 00:16:59,730 --> 00:17:02,905 approached Venus and separated from each other. 279 00:17:02,905 --> 00:17:05,540 Immediately they started their separate missions 280 00:17:05,540 --> 00:17:07,883 which were culminating at the same time. 281 00:17:09,090 --> 00:17:11,508 The Orbiter approached Venus and started 282 00:17:11,508 --> 00:17:13,500 braking manually with its engines 283 00:17:13,500 --> 00:17:15,390 to slow down its speed just enough 284 00:17:15,390 --> 00:17:17,520 that the gravity field of Venus would 285 00:17:17,520 --> 00:17:20,720 capture it and leave it in the highly stretched 286 00:17:20,720 --> 00:17:22,810 elliptical orbit around the planet. 287 00:17:22,810 --> 00:17:26,120 This component of the Venera 9 spacecraft 288 00:17:26,120 --> 00:17:28,690 had become the first manmade object 289 00:17:28,690 --> 00:17:30,723 to enter orbit around Venus. 290 00:17:32,810 --> 00:17:35,530 But the mission was far from over. 291 00:17:35,530 --> 00:17:38,667 And at the same time, the Lander started going 292 00:17:38,667 --> 00:17:42,170 into the atmosphere of Venus on the side of the planet 293 00:17:42,170 --> 00:17:44,070 which was not visible from Earth, 294 00:17:44,070 --> 00:17:45,780 but thanks to the Orbiter, 295 00:17:45,780 --> 00:17:47,880 which was so high in the sky over Venus, 296 00:17:47,880 --> 00:17:51,110 it would later act as a relay station 297 00:17:51,110 --> 00:17:53,550 for the Lander to send pictures back 298 00:17:53,550 --> 00:17:55,903 to mission control on Earth. 299 00:17:55,903 --> 00:17:58,760 The Lander was a ball shaped capsule 300 00:17:58,760 --> 00:18:01,297 covered with a special ablative surface. 301 00:18:01,297 --> 00:18:04,510 And once it entered the atmosphere of Venus, 302 00:18:04,510 --> 00:18:07,496 it started breaking, layer by layer, 303 00:18:07,496 --> 00:18:09,350 burning the ablative surface, 304 00:18:09,350 --> 00:18:12,470 and at the same time slowing down tremendously 305 00:18:12,470 --> 00:18:14,610 from its usual entry speed. 306 00:18:14,610 --> 00:18:15,920 The searing heat shield 307 00:18:15,920 --> 00:18:20,410 decelerated the Lander from 10.7 kilometers per second 308 00:18:20,410 --> 00:18:23,433 to around 250 meters per second. 309 00:18:24,971 --> 00:18:27,160 Then, once it slowed down enough, 310 00:18:27,160 --> 00:18:29,420 it was safe enough to open small opening 311 00:18:29,420 --> 00:18:31,610 in the top of the capsule and release 312 00:18:31,610 --> 00:18:33,600 two small braking parachutes. 313 00:18:33,600 --> 00:18:36,620 One of those parachutes was then used to release 314 00:18:36,620 --> 00:18:40,520 the top part of the capsule and reveal the top of the Lander 315 00:18:40,520 --> 00:18:42,020 which was inside of that hood. 316 00:18:47,610 --> 00:18:48,900 The speed dropped from 317 00:18:48,900 --> 00:18:52,909 250 meters per second to 150 meters per second 318 00:18:52,909 --> 00:18:56,223 before a third parachute was deployed. 319 00:18:58,470 --> 00:19:01,130 And once that happened, there was an antenna, 320 00:19:01,130 --> 00:19:03,210 a transmission antenna exposed. 321 00:19:03,210 --> 00:19:04,990 And that allowed it to immediately start 322 00:19:04,990 --> 00:19:07,310 transmitting data to the Orbiter 323 00:19:07,310 --> 00:19:10,512 which in turn relayed back to the ground control. 324 00:19:10,512 --> 00:19:12,510 The third parachute brought 325 00:19:12,510 --> 00:19:16,123 the velocity of the Lander down to just 50 meter per second. 326 00:19:16,997 --> 00:19:20,060 And then that parachute was separated 327 00:19:20,060 --> 00:19:23,210 and it pulls out three canopy main parachute system, 328 00:19:23,210 --> 00:19:26,812 which allows the Lander really slow and gentle descent. 329 00:19:26,812 --> 00:19:29,913 After all the drama of its journey so far, 330 00:19:29,913 --> 00:19:32,709 the Lander would then spend 20 minutes 331 00:19:32,709 --> 00:19:36,170 calmly taking measurements of the atmosphere. 332 00:19:36,170 --> 00:19:39,603 But its brutal voyage was not over yet. 333 00:19:41,230 --> 00:19:44,297 When the probe is around 50 kilometers over the surface, 334 00:19:44,297 --> 00:19:48,247 a command is sent to cut the main lines of the parachute. 335 00:19:51,846 --> 00:19:54,300 And then you keep falling and the atmosphere 336 00:19:54,300 --> 00:19:57,720 gets hotter and hotter and more and more dense, 337 00:19:57,720 --> 00:20:01,185 to the point where it's 100 times as dense 338 00:20:01,185 --> 00:20:02,950 as the atmosphere on Earth, 339 00:20:02,950 --> 00:20:05,260 and that means that you're falling through, 340 00:20:05,260 --> 00:20:07,680 it's not quite a liquid but it's a gas that is 341 00:20:07,680 --> 00:20:09,560 approaching the properties of a liquid, 342 00:20:09,560 --> 00:20:11,283 and that would slow your fall. 343 00:20:13,243 --> 00:20:15,120 And then when you get to the surface 344 00:20:15,120 --> 00:20:17,170 it's almost like going through the ocean. 345 00:20:18,460 --> 00:20:20,540 Venera 9 wasn't the first Lander 346 00:20:20,540 --> 00:20:22,303 to get to the surface of Venus. 347 00:20:25,660 --> 00:20:28,893 But it was the first to send back pictures. 348 00:20:31,700 --> 00:20:35,720 Finally, this image, the first image ever seen 349 00:20:35,720 --> 00:20:39,653 by humans of the surface of another planet came back. 350 00:20:41,286 --> 00:20:43,600 Everybody, without any question, 351 00:20:43,600 --> 00:20:46,758 who was involved, were understanding the historic 352 00:20:46,758 --> 00:20:50,343 and scientific significance of that achievement. 353 00:20:52,330 --> 00:20:55,143 That was a real triumph of exploration. 354 00:21:10,850 --> 00:21:14,860 These rovers were not inanimate objects to us. 355 00:21:14,860 --> 00:21:17,160 We were part of them and they were part of us. 356 00:21:19,410 --> 00:21:20,970 The exploration of Mars 357 00:21:20,970 --> 00:21:23,223 has long been a top priority. 358 00:21:24,100 --> 00:21:28,423 In 2004, two rovers, Spirit and Opportunity, 359 00:21:28,423 --> 00:21:30,283 landed on the red planet. 360 00:21:31,220 --> 00:21:33,200 For the people who sent them there, 361 00:21:33,200 --> 00:21:36,363 it proved to be an emotional experience. 362 00:21:38,447 --> 00:21:41,970 Gusev Crater has a drainage channel 363 00:21:41,970 --> 00:21:44,570 that extends for thousands of kilometers 364 00:21:44,570 --> 00:21:47,710 through the ancient highlands and looks like 365 00:21:47,710 --> 00:21:50,163 it filled that crater up with a lake. 366 00:21:52,570 --> 00:21:55,810 This was a location where sedimentary rocks 367 00:21:55,810 --> 00:21:58,580 that could tell us about the environment 368 00:21:58,580 --> 00:22:00,703 when it was active would be. 369 00:22:05,270 --> 00:22:07,503 We got images pretty quickly. 370 00:22:11,943 --> 00:22:14,180 Unfortunately we got there and all we could see 371 00:22:14,180 --> 00:22:16,113 basically was volcanic stuff. 372 00:22:23,099 --> 00:22:26,270 Gusev was basically a basaltic plain, 373 00:22:26,270 --> 00:22:27,363 which is lava flow. 374 00:22:30,011 --> 00:22:31,540 So if the lake had ever been there 375 00:22:31,540 --> 00:22:33,693 it had been covered by volcanic materials. 376 00:22:38,620 --> 00:22:42,742 We were crestfallen that none of our predictions 377 00:22:42,742 --> 00:22:45,586 about what materials would be there, 378 00:22:45,586 --> 00:22:47,533 you know, that we were wrong. 379 00:22:52,560 --> 00:22:55,403 Opportunity was completely different. 380 00:22:59,840 --> 00:23:01,680 Opportunity really hit the bullseye 381 00:23:01,680 --> 00:23:04,460 because it landed in a place called Eagle Crater, 382 00:23:04,460 --> 00:23:06,860 in which mother nature has done you a big favor. 383 00:23:08,064 --> 00:23:10,180 At some point she slammed a meteorite 384 00:23:10,180 --> 00:23:11,490 into the surface of the planet, 385 00:23:11,490 --> 00:23:12,973 excavating this big hole. 386 00:23:14,372 --> 00:23:18,232 It basically gave you this archeological dig if you will. 387 00:23:18,232 --> 00:23:20,164 You land in the middle of it, 388 00:23:20,164 --> 00:23:22,060 and all you gotta do is look around 389 00:23:22,060 --> 00:23:23,610 and here's the history of Mars. 390 00:23:25,620 --> 00:23:27,663 And we saw sedimentary rocks. 391 00:23:33,930 --> 00:23:36,590 When geologists go out in the field here on Earth, 392 00:23:36,590 --> 00:23:39,160 they wanna look for layers of sediment 393 00:23:39,160 --> 00:23:41,063 that have accumulated over time. 394 00:23:43,420 --> 00:23:46,575 This is literally the historical pages 395 00:23:46,575 --> 00:23:48,903 of the book of the Earth. 396 00:23:50,213 --> 00:23:52,987 This level was where the dinosaurs were, 397 00:23:52,987 --> 00:23:55,610 and in this level they died, 398 00:23:55,610 --> 00:23:58,163 and in this level new life became. 399 00:23:59,552 --> 00:24:02,600 You can just read that book of history. 400 00:24:02,600 --> 00:24:06,400 There was this treasure trove of information 401 00:24:06,400 --> 00:24:08,980 and it just came flooding back. 402 00:24:08,980 --> 00:24:12,180 These were not igneous rocks, these were sedimentary rocks 403 00:24:12,180 --> 00:24:17,180 that would have been formed by liquid water. 404 00:24:17,600 --> 00:24:20,100 And it was a classic sedimentary sequence 405 00:24:20,100 --> 00:24:22,833 that we've seen on the Earth in many places. 406 00:24:26,130 --> 00:24:28,480 And this is where it really gets interesting. 407 00:24:30,570 --> 00:24:34,140 We see these little bead-like things in the soil. 408 00:24:34,140 --> 00:24:35,720 We thought what could these be? 409 00:24:35,720 --> 00:24:37,556 People started conjecturing. 410 00:24:37,556 --> 00:24:40,030 But when you put the infrared eyes on them 411 00:24:40,030 --> 00:24:43,180 we can see iron and oxygen in them. 412 00:24:43,180 --> 00:24:46,423 We're thinking holy crap, Batman. 413 00:24:47,440 --> 00:24:48,433 We found hematite. 414 00:24:52,073 --> 00:24:55,100 Hematite is a mineral here on Earth 415 00:24:55,100 --> 00:24:59,410 that's formed in water, and a lot of it, 416 00:24:59,410 --> 00:25:02,280 and moving water, that allows this mineral to be formed. 417 00:25:02,280 --> 00:25:05,393 And they were all over the place. 418 00:25:07,700 --> 00:25:08,593 Holy gosh. 419 00:25:09,608 --> 00:25:11,023 We found the holy grail. 420 00:25:16,450 --> 00:25:18,870 So the whole point of the Mars exploration rovers 421 00:25:18,870 --> 00:25:20,440 was roving. 422 00:25:20,440 --> 00:25:21,853 We wanna move. 423 00:25:26,700 --> 00:25:30,800 The rovers were expected to last just 90 days, 424 00:25:30,800 --> 00:25:34,170 but as both of them explored the martian surface, 425 00:25:34,170 --> 00:25:36,803 they proved they could go for much longer. 426 00:25:39,119 --> 00:25:43,693 They outdid their warranty by factors of hundreds. 427 00:25:46,135 --> 00:25:48,310 We're several years into the mission 428 00:25:48,310 --> 00:25:51,113 that we had wheel trouble with Spirit. 429 00:25:54,610 --> 00:25:57,423 Spirit had lost one drive wheel. 430 00:25:59,310 --> 00:26:02,893 In doing so we got stuck in a sandy crater, 431 00:26:03,913 --> 00:26:06,213 and it was very difficult. 432 00:26:07,169 --> 00:26:09,693 And that was the end of Spirit, yeah. 433 00:26:13,038 --> 00:26:17,670 But Opportunity just shines like a radiant star, 434 00:26:17,670 --> 00:26:20,983 'cause this rover keeps going and going and going. 435 00:26:24,460 --> 00:26:27,830 Opportunity had really began to show evidence 436 00:26:27,830 --> 00:26:29,614 of past water. 437 00:26:29,614 --> 00:26:32,770 We started to see the kind of mineral signatures 438 00:26:32,770 --> 00:26:34,260 that were the stuff of dreams, 439 00:26:34,260 --> 00:26:37,918 and support water as a persistent liquid phase. 440 00:26:37,918 --> 00:26:40,751 (mixed crosstalk) 441 00:26:48,080 --> 00:26:51,323 This is just this ongoing saga of water. 442 00:26:52,310 --> 00:26:53,823 Water, water everywhere. 443 00:26:57,040 --> 00:26:59,943 Then in 2012 a new rover drops into the party. 444 00:27:01,530 --> 00:27:02,510 Curiosity. 445 00:27:02,510 --> 00:27:03,840 Equipped with a drill and carrying 446 00:27:03,840 --> 00:27:05,843 an entire laboratory on its back. 447 00:27:06,720 --> 00:27:08,820 This machine rolled into town and immediately 448 00:27:08,820 --> 00:27:10,570 changed our view of the red planet. 449 00:27:13,150 --> 00:27:16,646 As we dug into the soils, and we found, 450 00:27:16,646 --> 00:27:20,679 to our delight, it had carbon, hydrogen, oxygen, 451 00:27:20,679 --> 00:27:23,970 nitrogen, phosphorous and sulfur. 452 00:27:23,970 --> 00:27:27,653 That's everything between these two fingers. 453 00:27:29,840 --> 00:27:34,840 All the right stuff that life is made of is on Mars. 454 00:27:39,010 --> 00:27:41,770 Meanwhile, after 15 years on the surface, 455 00:27:41,770 --> 00:27:46,610 Opportunity had covered a record breaking 45 kilometers, 456 00:27:46,610 --> 00:27:49,480 documenting every step of the way. 457 00:27:49,480 --> 00:27:51,500 It's this unstoppable machine. 458 00:27:51,500 --> 00:27:52,793 It just keeps driving. 459 00:27:59,690 --> 00:28:02,243 And then in June of 2018, 460 00:28:04,355 --> 00:28:06,463 here's a dust orbit in the distance. 461 00:28:11,390 --> 00:28:12,993 It turns out to be a whopper. 462 00:28:16,890 --> 00:28:18,823 The sun was almost blacked out. 463 00:28:21,570 --> 00:28:26,570 And at that point there was no power getting to the panels, 464 00:28:26,570 --> 00:28:28,790 and we tried for months and months and months 465 00:28:28,790 --> 00:28:30,493 until there was just nothing. 466 00:28:33,283 --> 00:28:35,940 And at that point you eventually, you know, 467 00:28:35,940 --> 00:28:37,090 you say that's the end. 468 00:28:52,770 --> 00:28:56,340 We had one final day where they called the team 469 00:28:56,340 --> 00:28:59,040 out to JPL, the Jet Propulsion Laboratory, 470 00:28:59,040 --> 00:29:00,770 where anybody that wanted to come and be there 471 00:29:00,770 --> 00:29:03,020 when they sent the final commands could come. 472 00:29:06,560 --> 00:29:09,890 We had all gathered in this area called the dark room 473 00:29:09,890 --> 00:29:11,870 overlooking mission operations, 474 00:29:11,870 --> 00:29:13,510 and we're watching the flight commanders 475 00:29:13,510 --> 00:29:15,850 sending off the last commands to the rover. 476 00:29:15,850 --> 00:29:18,863 We did basically four final pings. 477 00:29:23,499 --> 00:29:28,014 The light time delay comes and goes, we got no signal, 478 00:29:28,014 --> 00:29:30,373 and everybody just kinda sits there in silence. 479 00:29:35,500 --> 00:29:38,280 And then the manager of the mission, John Callas. 480 00:29:38,280 --> 00:29:41,250 This concludes operations for MER one, 481 00:29:41,250 --> 00:29:43,780 Spacecraft ID 253. 482 00:29:43,780 --> 00:29:47,930 Says, "Thank you for your 15 years of service." 483 00:29:47,930 --> 00:29:49,306 Thank you. 484 00:29:49,306 --> 00:29:51,240 But this is the end, 485 00:29:51,240 --> 00:29:53,993 so this is MER signing off the net. 486 00:29:54,917 --> 00:29:57,290 MER project off the net. 487 00:30:01,340 --> 00:30:03,360 In the darkroom it was just silent, 488 00:30:03,360 --> 00:30:04,660 everybody's kind of looking around 489 00:30:04,660 --> 00:30:08,293 and we're like this is it, this is actually the end. 490 00:30:13,561 --> 00:30:15,913 It definitely led to a lot of tears. 491 00:30:27,600 --> 00:30:31,430 We were there, we are there, our consciousness is there, 492 00:30:31,430 --> 00:30:34,453 our species consciousness is on Mars. 493 00:30:34,453 --> 00:30:37,383 We're already a multi planet species. 494 00:30:38,428 --> 00:30:41,011 (gentle music) 495 00:30:49,710 --> 00:30:51,780 Comets are the leftover rubble 496 00:30:51,780 --> 00:30:53,440 of the solar system. 497 00:30:53,440 --> 00:30:55,863 They never quite made it into planets, 498 00:30:56,764 --> 00:30:59,440 but they preserved the material that are 499 00:30:59,440 --> 00:31:02,520 the building blocks of everything we can touch, 500 00:31:02,520 --> 00:31:06,103 feel, taste, smell or see today. 501 00:31:09,206 --> 00:31:12,360 To learn more you want to go and rendezvous with a comet. 502 00:31:12,360 --> 00:31:14,147 You want to fly alongside it. 503 00:31:14,147 --> 00:31:15,960 And of course then the idea comes up 504 00:31:15,960 --> 00:31:17,840 you would want to touch down on the surface, 505 00:31:17,840 --> 00:31:20,063 you want to land there, sample material. 506 00:31:22,850 --> 00:31:27,850 To do all of that in one mission is incredibly gutsy. 507 00:31:29,260 --> 00:31:32,410 Dix, neuf, huit, sept. 508 00:31:32,410 --> 00:31:34,580 The first time I heard about the mission 509 00:31:34,580 --> 00:31:37,160 I thought they must be joking. 510 00:31:37,160 --> 00:31:39,200 Six, cinq. 511 00:31:39,200 --> 00:31:42,163 The Rosetta mission was incredibly ambitious. 512 00:31:43,870 --> 00:31:45,213 But we jumped on it. 513 00:31:49,418 --> 00:31:51,751 We launched in March 2004. 514 00:31:54,598 --> 00:31:58,173 The whole travel to the comet was an adventure for Rosetta. 515 00:32:00,340 --> 00:32:02,850 The comet is on an orbit with a different energy level 516 00:32:02,850 --> 00:32:04,330 compared to the one of the Earth, 517 00:32:04,330 --> 00:32:08,010 so we had to actually impart this energy to our spacecraft 518 00:32:08,010 --> 00:32:09,873 to get to the same orbit. 519 00:32:13,950 --> 00:32:16,495 So we did this thing, to use the planets 520 00:32:16,495 --> 00:32:20,810 and to use their gravity to slingshot us through space 521 00:32:20,810 --> 00:32:23,430 on a different trajectory with more speed 522 00:32:23,430 --> 00:32:25,430 in order to be able to get to the comet. 523 00:32:26,960 --> 00:32:29,433 After this, we came back to Earth. 524 00:32:30,720 --> 00:32:33,273 This one gave us the last big kick. 525 00:32:36,330 --> 00:32:39,010 We were really launched very fast 526 00:32:39,010 --> 00:32:40,807 but getting far from the sun. 527 00:32:49,740 --> 00:32:53,843 We could not keep all the systems on board active, 528 00:32:53,843 --> 00:32:56,310 because the illumination of our solar panels 529 00:32:56,310 --> 00:32:57,663 was getting very weak. 530 00:33:03,130 --> 00:33:05,983 So the decision was made in fact to turn it off. 531 00:33:08,920 --> 00:33:11,340 I hated that concept from the very beginning. 532 00:33:11,340 --> 00:33:12,970 I'd been fighting it for years. 533 00:33:12,970 --> 00:33:14,630 I was convinced we would never do it, 534 00:33:14,630 --> 00:33:15,543 it was too crazy. 535 00:33:17,530 --> 00:33:21,423 Switching off the radio signal is like cutting a vital link. 536 00:33:23,078 --> 00:33:25,960 We've been flying a spacecraft for seven years, 537 00:33:25,960 --> 00:33:28,810 it's hundreds of millions of kilometers away, 538 00:33:28,810 --> 00:33:29,643 and what do you do? 539 00:33:29,643 --> 00:33:30,476 You send a command to switch it off 540 00:33:30,476 --> 00:33:31,780 and wake it up three years later. 541 00:33:31,780 --> 00:33:34,100 It just doesn't make sense. 542 00:33:34,100 --> 00:33:36,060 And this is what we did. 543 00:33:36,060 --> 00:33:38,483 We spent two and a half years without contact. 544 00:33:40,730 --> 00:33:42,493 And we waited. 545 00:33:47,110 --> 00:33:50,250 We couldn't talk to it while it was in hibernation, 546 00:33:50,250 --> 00:33:54,480 we needed it to wake up, which it was due to do 547 00:33:54,480 --> 00:33:57,033 on the 20th January 2014. 548 00:33:58,562 --> 00:34:01,312 (alarms ringing) 549 00:34:03,654 --> 00:34:05,071 Wake up! 550 00:34:08,770 --> 00:34:11,773 We were sitting all in the control room, 551 00:34:11,773 --> 00:34:13,733 waiting for the signal to come, 552 00:34:14,610 --> 00:34:19,023 and this was probably the most tense moment of the mission. 553 00:34:21,049 --> 00:34:23,730 This was everything or nothing. 554 00:34:23,730 --> 00:34:24,793 Life or death. 555 00:34:26,214 --> 00:34:27,653 Why is it not coming? 556 00:34:34,165 --> 00:34:36,315 Everyone was getting very nervous. 557 00:34:38,470 --> 00:34:40,913 It was very difficult to bear. 558 00:34:43,750 --> 00:34:46,223 We started really getting worried. 559 00:34:48,970 --> 00:34:50,333 Have we lost the mission? 560 00:35:03,825 --> 00:35:06,773 Then suddenly a signal came. 561 00:35:06,773 --> 00:35:09,220 (applause) 562 00:35:09,220 --> 00:35:11,020 When the signal came it was a big relief 563 00:35:11,020 --> 00:35:12,300 for me personally. 564 00:35:12,300 --> 00:35:14,023 It was an explosion of joy. 565 00:35:15,230 --> 00:35:17,910 A little blip on a noise spectrum 566 00:35:17,910 --> 00:35:21,620 told us Rosetta was there and it was calling home. 567 00:35:24,380 --> 00:35:27,300 And this for me was the toughest emotion 568 00:35:27,300 --> 00:35:29,493 I went through on the story of Rosetta. 569 00:35:32,389 --> 00:35:33,956 We made it. 570 00:35:33,956 --> 00:35:34,873 Yes, yes. 571 00:35:35,888 --> 00:35:38,273 It's a big success for everyone. 572 00:35:39,810 --> 00:35:41,480 We have it, we're ready. 573 00:35:41,480 --> 00:35:43,438 We now have the spacecraft back, 574 00:35:43,438 --> 00:35:45,490 we can go and do the rest of this mission 575 00:35:45,490 --> 00:35:47,519 and finally get to the comet. 576 00:35:47,519 --> 00:35:49,769 (applause) 577 00:35:53,396 --> 00:35:56,050 But now the mission starts because now we have to 578 00:35:56,050 --> 00:35:58,280 get to the comet, fly around the comet, 579 00:35:58,280 --> 00:36:00,190 orbit the comet and land on the comet, 580 00:36:00,190 --> 00:36:01,863 all within the next 10 months. 581 00:36:05,364 --> 00:36:08,894 Rosetta took 10 years from launch 582 00:36:08,894 --> 00:36:11,750 til we finally got to the target 583 00:36:11,750 --> 00:36:13,263 that we were going to study. 584 00:36:16,580 --> 00:36:19,250 The comet we ended up deciding to go to 585 00:36:19,250 --> 00:36:22,033 was 67P/Churyumov-Gerasimenko. 586 00:36:27,130 --> 00:36:29,927 At the beginning the comet was just a very small dot. 587 00:36:33,207 --> 00:36:35,550 And then day by day the comet was growing 588 00:36:35,550 --> 00:36:37,233 in the field of view of the camera. 589 00:36:43,000 --> 00:36:45,873 You have this spacecraft visiting 590 00:36:45,873 --> 00:36:48,960 an a ambassador from the solar system 591 00:36:48,960 --> 00:36:52,190 from four and a half billion years ago. 592 00:36:52,190 --> 00:36:56,343 It's modern technology visiting an ancient relic. 593 00:36:59,480 --> 00:37:03,593 It's really profoundly emotional. 594 00:37:10,010 --> 00:37:12,372 We saw this incredible shape. 595 00:37:12,372 --> 00:37:15,853 Some people have described it as a rubber duck. 596 00:37:19,159 --> 00:37:21,938 It was amazing, it was beautiful. 597 00:37:21,938 --> 00:37:25,653 Scientists were just stunned with their mouths open. 598 00:37:33,800 --> 00:37:38,233 Comet 67P is about four kilometers in size. 599 00:37:41,942 --> 00:37:45,570 If you were standing on the bottom of the comet 600 00:37:45,570 --> 00:37:48,783 you might see a flat dusty plain. 601 00:37:51,810 --> 00:37:53,790 If you were standing on the head of the comet 602 00:37:53,790 --> 00:37:55,773 it might look more rocky. 603 00:37:56,890 --> 00:37:59,500 If you were standing on the neck of the comet 604 00:37:59,500 --> 00:38:02,188 you would be in this interesting valley, 605 00:38:02,188 --> 00:38:06,560 kilometer high cliffs on either side, 606 00:38:06,560 --> 00:38:11,120 and running along the neck between your legs 607 00:38:11,120 --> 00:38:12,983 is a huge crack. 608 00:38:15,860 --> 00:38:20,131 There's so many different types of surfaces and variety, 609 00:38:20,131 --> 00:38:23,010 you could spend the rest of your life 610 00:38:23,010 --> 00:38:24,847 exploring every little part of the comet 611 00:38:24,847 --> 00:38:27,583 and not see the same type of thing twice. 612 00:38:45,490 --> 00:38:47,770 Jupiter, the largest and most 613 00:38:47,770 --> 00:38:50,113 intimidating of the planets, 614 00:38:51,174 --> 00:38:55,163 is certainly one of the most beautiful and intriguing. 615 00:38:57,480 --> 00:39:01,282 In 1995, a spacecraft named Galileo arrived 616 00:39:01,282 --> 00:39:03,623 and soon got to work. 617 00:39:08,330 --> 00:39:11,937 The Galileo spacecraft carried along with it a probe, 618 00:39:11,937 --> 00:39:14,370 and it's sort of like this size. 619 00:39:14,370 --> 00:39:17,020 And it had a big heat shield to protect it around it. 620 00:39:18,020 --> 00:39:21,360 So in July 1995 we launched that probe 621 00:39:21,360 --> 00:39:24,160 and sent it in the direction of Jupiter. 622 00:39:24,160 --> 00:39:26,550 Now it didn't have engines so we weren't guiding it 623 00:39:26,550 --> 00:39:28,130 and saying, "Go there." 624 00:39:28,130 --> 00:39:31,243 We just sort of sent it on a trajectory towards Jupiter. 625 00:39:32,360 --> 00:39:36,630 Five months later, on the 7th of December 1995, 626 00:39:36,630 --> 00:39:39,893 the Galileo probe was due to arrive in Jupiter. 627 00:39:43,088 --> 00:39:46,850 There were no cameras on board, only sensors, 628 00:39:46,850 --> 00:39:48,650 and a little probe that was going to have 629 00:39:48,650 --> 00:39:51,673 an extremely violent introduction to Jupiter. 630 00:39:53,172 --> 00:39:57,217 It was coming in at something like 130,000 miles an hour. 631 00:39:58,595 --> 00:40:01,010 It was pulled in by the gravity of Jupiter, 632 00:40:01,010 --> 00:40:02,623 and we had to slow it down. 633 00:40:03,785 --> 00:40:07,840 And so this heat shield heated up to about three times 634 00:40:07,840 --> 00:40:09,940 the temperature of the surface of the sun. 635 00:40:11,222 --> 00:40:13,972 (dramatic music) 636 00:40:20,090 --> 00:40:23,037 And then eventually we kicked off that heat shield, 637 00:40:24,075 --> 00:40:25,653 put out some parachutes. 638 00:40:28,020 --> 00:40:31,040 So as it went down, we were able to get a sense 639 00:40:31,040 --> 00:40:32,093 of what it was like. 640 00:40:34,273 --> 00:40:38,447 What we were expecting was three separate layers of clouds. 641 00:40:43,018 --> 00:40:46,270 And we went down, it's like where are the clouds? 642 00:40:46,270 --> 00:40:47,103 Where are the clouds? 643 00:40:47,103 --> 00:40:48,200 We're not seeing the clouds. 644 00:40:48,200 --> 00:40:49,950 What's going on? 645 00:40:49,950 --> 00:40:52,423 So everybody was completely confused. 646 00:40:53,310 --> 00:40:56,160 Well the hint came from the ground. 647 00:40:56,160 --> 00:40:59,010 Telescopes on Earth were looking in the infrared, 648 00:40:59,010 --> 00:41:01,377 at Jupiter, at the same time we sent the probe in, 649 00:41:01,377 --> 00:41:05,890 and we realized that the probe went into a hotspot, 650 00:41:05,890 --> 00:41:08,173 somewhere where there's very little water. 651 00:41:09,140 --> 00:41:11,800 So I think we realized that our whole idea 652 00:41:11,800 --> 00:41:14,430 of exploring these planets with single probes 653 00:41:14,430 --> 00:41:17,330 is a little bit susceptible to going into the wrong place. 654 00:41:18,620 --> 00:41:21,220 By the time the probe had got down 655 00:41:21,220 --> 00:41:23,410 to about 160 kilometers, 656 00:41:23,410 --> 00:41:26,250 something like 23 times atmospheric pressure, 657 00:41:26,250 --> 00:41:29,270 it was now starting to get really hot. 658 00:41:29,270 --> 00:41:31,980 So at that point the electronics is just 659 00:41:31,980 --> 00:41:34,880 not working anymore and it stops communicating 660 00:41:34,880 --> 00:41:38,029 and sending signals back to the Earth. 661 00:41:38,029 --> 00:41:40,560 What happened to it after that? 662 00:41:40,560 --> 00:41:44,053 Well it was so hot that it basically vaporized. 663 00:41:46,175 --> 00:41:49,090 But let's imagine what it would be like 664 00:41:49,090 --> 00:41:51,370 if you could be in a pressurized capsule 665 00:41:51,370 --> 00:41:52,743 as you get deep down. 666 00:41:54,260 --> 00:41:56,430 I mean it's either a hang glider's nightmare 667 00:41:56,430 --> 00:42:00,812 or his dream, depending on how risky they wanna be. 668 00:42:00,812 --> 00:42:03,700 As you went deeper and deeper it would get 669 00:42:03,700 --> 00:42:05,910 a little calmer, a little less turbulent. 670 00:42:05,910 --> 00:42:09,002 The pressure would get higher and higher. 671 00:42:09,002 --> 00:42:11,763 It's so hot, everything's vaporous. 672 00:42:12,673 --> 00:42:14,800 Eventually you get down to material 673 00:42:14,800 --> 00:42:16,360 that are almost like rock clouds, 674 00:42:16,360 --> 00:42:18,910 and they're probably precipitating. 675 00:42:18,910 --> 00:42:23,030 Now when you get down something like 10% of the radius, 676 00:42:23,030 --> 00:42:24,880 you're now getting to the point where 677 00:42:24,880 --> 00:42:28,080 the pressures are about a million times 678 00:42:28,080 --> 00:42:30,240 Earth atmospheric pressure, 679 00:42:30,240 --> 00:42:33,350 and the density is getting really high. 680 00:42:33,350 --> 00:42:37,410 And at that point hydrogen changes its phase. 681 00:42:37,410 --> 00:42:39,363 It's no longer molecules, 682 00:42:39,363 --> 00:42:42,590 protons and electrons connected together, 683 00:42:42,590 --> 00:42:45,820 but the protons and the electrons are moving separately, 684 00:42:45,820 --> 00:42:48,500 and it becomes metallic. 685 00:42:48,500 --> 00:42:51,670 That is it becomes electrically conductive. 686 00:42:51,670 --> 00:42:54,320 I suspect it would look like mercury, 687 00:42:54,320 --> 00:42:57,263 a glob of mercury is what it would probably look like. 688 00:42:59,397 --> 00:43:03,100 If you existed, you would be unbelievably thin, 689 00:43:03,100 --> 00:43:04,433 flat out pancake. 690 00:43:05,780 --> 00:43:07,870 You get to the center of Jupiter, 691 00:43:07,870 --> 00:43:10,540 we're talking four times the temperature 692 00:43:10,540 --> 00:43:11,790 of the surface of the sun, 693 00:43:11,790 --> 00:43:15,100 50 million atmospheres in pressure, 694 00:43:15,100 --> 00:43:17,280 and a density that's denser than 695 00:43:17,280 --> 00:43:20,403 the heaviest metals that we have on Earth. 696 00:43:27,475 --> 00:43:29,307 One seconds and counting, 697 00:43:29,307 --> 00:43:31,040 this is Titan launch control. 698 00:43:31,040 --> 00:43:33,980 Without any doubt, the most risky element 699 00:43:33,980 --> 00:43:36,989 of any space mission is the launch. 700 00:43:36,989 --> 00:43:39,150 T minus 15 seconds. 701 00:43:39,150 --> 00:43:40,910 When you've put eight years of your life 702 00:43:40,910 --> 00:43:43,270 into designing and building and testing something 703 00:43:43,270 --> 00:43:45,160 which is going to go into space. 704 00:43:45,160 --> 00:43:46,390 Nine, eight, seven. 705 00:43:46,390 --> 00:43:48,650 And then seeing it on the top of a rocket 706 00:43:48,650 --> 00:43:50,990 that's being vibrated and accelerated 707 00:43:50,990 --> 00:43:53,223 on its way to Saturn, it is quite a feeling. 708 00:43:58,775 --> 00:44:03,183 When it did go off it created a huge amount of light, 709 00:44:03,183 --> 00:44:06,450 and then the rocket went behind the cloud. 710 00:44:06,450 --> 00:44:08,630 When it went behind that cloud it was very impressive. 711 00:44:08,630 --> 00:44:10,390 The whole cloud like lit up. 712 00:44:10,390 --> 00:44:13,043 We all thought oh goodness has something gone wrong? 713 00:44:14,769 --> 00:44:17,515 And then the nose cone came out and you went... 714 00:44:17,515 --> 00:44:20,348 (exhales sharply) 715 00:44:28,120 --> 00:44:30,640 Exploring a planet such as Saturn 716 00:44:30,640 --> 00:44:33,020 is a very risky business. 717 00:44:33,020 --> 00:44:35,610 This mission, called Cassini-Huygens, 718 00:44:35,610 --> 00:44:38,873 was one of the most technically demanding ever undertaken. 719 00:44:41,344 --> 00:44:44,710 When Cassini was approaching Saturn for the first time 720 00:44:44,710 --> 00:44:47,353 our experiment was systematically scanning 721 00:44:47,353 --> 00:44:49,900 back and forth planet Saturn. 722 00:44:49,900 --> 00:44:52,370 And we were amazed to discover that 723 00:44:52,370 --> 00:44:56,123 the system was filled with molecules of oxygen. 724 00:44:57,783 --> 00:45:01,362 And we mapped this out and we noticed 725 00:45:01,362 --> 00:45:03,449 that the peak in the distribution 726 00:45:03,449 --> 00:45:07,948 was just a distance four times Saturn's radius 727 00:45:07,948 --> 00:45:09,780 from the center of the system. 728 00:45:09,780 --> 00:45:11,970 We knew that the moon Enceladus 729 00:45:11,970 --> 00:45:13,973 was orbiting just at that distance. 730 00:45:15,520 --> 00:45:17,650 Enceladus is a tiny moon, 731 00:45:17,650 --> 00:45:20,901 just 500 kilometers in diameter. 732 00:45:20,901 --> 00:45:24,140 Enceladus originally was on the itinerary, 733 00:45:24,140 --> 00:45:25,830 but only marginally so. 734 00:45:25,830 --> 00:45:28,300 It was another very interesting Saturn moon. 735 00:45:28,300 --> 00:45:31,160 Small, very shiny, very white and very bright, 736 00:45:31,160 --> 00:45:33,610 but other than that, too small to be interesting. 737 00:45:37,940 --> 00:45:40,030 It was in the first close flyby 738 00:45:40,030 --> 00:45:42,240 that the magnetometer team detected 739 00:45:42,240 --> 00:45:45,113 something interesting that they didn't expect. 740 00:45:47,470 --> 00:45:49,510 It looks like it has an atmosphere. 741 00:45:49,510 --> 00:45:52,050 Anybody that knows anything about moons, 742 00:45:52,050 --> 00:45:53,513 that's too tiny, it can't have an atmosphere, 743 00:45:53,513 --> 00:45:55,553 it's way too small to hold anything. 744 00:45:57,635 --> 00:46:00,040 If you flew by the south pole 745 00:46:00,040 --> 00:46:01,540 it looked like there an atmosphere, 746 00:46:01,540 --> 00:46:03,323 but if you flew by at the equator 747 00:46:03,323 --> 00:46:05,820 you couldn't see anything at all. 748 00:46:05,820 --> 00:46:07,680 But then we went back again and again 749 00:46:07,680 --> 00:46:10,010 and all of a sudden realized that not only 750 00:46:10,010 --> 00:46:12,850 did it have an atmosphere, it was this icy atmosphere, 751 00:46:12,850 --> 00:46:15,883 but it had these plumes coming out of the southern pole. 752 00:46:21,215 --> 00:46:25,563 And here's water geysers, on a tiny moon. 753 00:46:29,590 --> 00:46:31,746 And that water that was coming out of 754 00:46:31,746 --> 00:46:34,759 what we later found out to be an interior ocean. 755 00:46:34,759 --> 00:46:37,430 Not only did it contain water vapor, 756 00:46:37,430 --> 00:46:42,370 but it had traces of ammonia, methane, H2, Co2, 757 00:46:42,370 --> 00:46:45,770 and then there was a whole host of organic compounds 758 00:46:45,770 --> 00:46:47,840 that we could also see. 759 00:46:47,840 --> 00:46:50,240 And now we could put all that information together 760 00:46:50,240 --> 00:46:53,030 to get a picture of the shape of the eruption, 761 00:46:53,030 --> 00:46:55,360 and also the material that's being erupted 762 00:46:55,360 --> 00:46:58,398 from inside of Enceladus, and amazingly enough, 763 00:46:58,398 --> 00:47:02,963 that material has the basic building blocks of life. 764 00:47:03,903 --> 00:47:07,420 This says to me that would be a good place to go 765 00:47:07,420 --> 00:47:09,823 and see if there's any form of life there. 766 00:47:22,920 --> 00:47:26,800 Far out near the edge of the solar system 767 00:47:26,800 --> 00:47:29,339 lies a world that until recently 768 00:47:29,339 --> 00:47:32,480 was completely unexplored. 769 00:47:32,480 --> 00:47:33,323 Pluto. 770 00:47:34,390 --> 00:47:36,221 As we were flying up to Pluto, 771 00:47:36,221 --> 00:47:38,710 and imaging it day after day 772 00:47:38,710 --> 00:47:40,480 and week after week on approach, 773 00:47:40,480 --> 00:47:44,193 we could see this bright feature on the surface. 774 00:47:49,860 --> 00:47:52,268 One morning we got an image back, 775 00:47:52,268 --> 00:47:55,120 and as soon as it came up on the big screen 776 00:47:55,120 --> 00:47:57,856 I remember a NASA official who said, 777 00:47:57,856 --> 00:48:00,427 "Do you see that looks like a heart?" 778 00:48:03,274 --> 00:48:05,570 And as we got closer and closer, 779 00:48:05,570 --> 00:48:08,763 amazingly it looked more and more like a heart. 780 00:48:11,010 --> 00:48:14,810 I think that's what emblazoned Pluto into the public mind 781 00:48:14,810 --> 00:48:18,425 as this amazing place at the frontier of our solar system. 782 00:48:18,425 --> 00:48:23,030 Pluto's heart measures 1,600 kilometers across 783 00:48:23,030 --> 00:48:26,175 and is composed of nitrogen ice. 784 00:48:26,175 --> 00:48:29,240 We believe that structure might be 785 00:48:29,240 --> 00:48:32,470 supported by water underneath the surface. 786 00:48:32,470 --> 00:48:35,470 (dramatic music) 787 00:48:35,470 --> 00:48:39,033 There could be an ocean underneath Pluto's surface. 788 00:48:40,215 --> 00:48:43,450 There probably is some kind of liquid water ocean. 789 00:48:43,450 --> 00:48:46,920 It's very deep down inside, but we think there's 790 00:48:46,920 --> 00:48:48,770 a pretty good chance that it's there. 791 00:48:49,730 --> 00:48:52,176 It's one of those things where if you find water, 792 00:48:52,176 --> 00:48:53,980 is there a chance for life? 793 00:48:53,980 --> 00:48:56,210 Wouldn't that be cool, if Pluto's actually 794 00:48:56,210 --> 00:48:58,470 one of those places in the solar system 795 00:48:58,470 --> 00:49:00,670 that has or had life. 796 00:49:00,670 --> 00:49:02,520 That's just mind blowing right there. 797 00:49:08,520 --> 00:49:10,740 The exploration of our solar system 798 00:49:10,740 --> 00:49:14,540 is far from over, but it has already taught us 799 00:49:14,540 --> 00:49:19,410 what a rich, varied and strange place it is. 800 00:49:19,410 --> 00:49:21,690 But perhaps the biggest realization 801 00:49:23,150 --> 00:49:28,150 is just how special and precious our home planet is. 802 00:49:29,099 --> 00:49:31,932 (uplifting music)