1 00:00:02,436 --> 00:00:05,804 NARRATOR: Four billion miles from Earth, 2 00:00:05,806 --> 00:00:09,975 a spacecraft closes in on its target, 3 00:00:09,977 --> 00:00:14,780 a mysterious object far beyond all the known planets 4 00:00:14,782 --> 00:00:17,816 that could reveal new secrets 5 00:00:17,818 --> 00:00:20,419 about the birth of the solar system. 6 00:00:20,421 --> 00:00:21,487 (explosion echoes) 7 00:00:21,489 --> 00:00:23,689 But the mission is risky. 8 00:00:23,691 --> 00:00:25,257 ALAN STERN: Even being hit 9 00:00:25,259 --> 00:00:28,160 by something smaller than a single pellet of rice 10 00:00:28,162 --> 00:00:30,562 at 32,000 miles an hour 11 00:00:30,564 --> 00:00:33,499 would be catastrophic, 12 00:00:33,501 --> 00:00:34,867 and we would lose the mission. 13 00:00:34,869 --> 00:00:37,903 NARRATOR: The spacecraft that brought us to Pluto 14 00:00:37,905 --> 00:00:43,642 is now attempting an even more challenging final quest. 15 00:00:43,644 --> 00:00:46,078 Can it succeed? 16 00:00:46,080 --> 00:00:48,047 FRED PELLETIER: There's only one shot, 17 00:00:48,049 --> 00:00:50,649 and if you make a mistake, that could be it. 18 00:00:51,752 --> 00:00:53,485 NARRATOR: "Pluto and Beyond." 19 00:00:53,487 --> 00:00:56,889 Right now, on "NOVA." 20 00:00:56,891 --> 00:01:02,861 ¶ ¶ 21 00:01:02,863 --> 00:01:06,698 NARRATOR: January 1, 2019. 22 00:01:06,700 --> 00:01:10,002 It's the arrival of a new year. 23 00:01:10,004 --> 00:01:11,703 ¶ ¶ 24 00:01:11,705 --> 00:01:14,840 But here at Mission Ops, the mood is tense. 25 00:01:16,610 --> 00:01:20,012 The team is feeling a little stressed. 26 00:01:20,014 --> 00:01:21,680 NARRATOR: A team of scientists, 27 00:01:21,682 --> 00:01:25,050 along with their families and friends, 28 00:01:25,052 --> 00:01:27,419 are waiting in anticipation... 29 00:01:27,421 --> 00:01:28,787 I'm getting a little bit nervous. 30 00:01:28,789 --> 00:01:31,156 NARRATOR: ...for the arrival of a signal 31 00:01:31,158 --> 00:01:36,361 from a tiny spacecraft on a dangerous mission. 32 00:01:36,363 --> 00:01:40,532 Its name: New Horizons. 33 00:01:40,534 --> 00:01:42,201 We are really pressing the limits here. 34 00:01:43,771 --> 00:01:45,170 NARRATOR: "New Horizons" is attempting 35 00:01:45,172 --> 00:01:48,040 to fly by a mysterious object 36 00:01:48,042 --> 00:01:52,044 far beyond the planets we've come to know, 37 00:01:52,046 --> 00:01:56,448 a billion miles beyond Pluto, 38 00:01:56,450 --> 00:02:00,385 in the outback of the solar system. 39 00:02:00,387 --> 00:02:04,156 STERN: This is the farthest exploration in the history of humankind, 40 00:02:04,158 --> 00:02:08,560 and nobody's planning anything like it ever again. 41 00:02:12,133 --> 00:02:14,900 CATHY OLKIN: This is really challenging. 42 00:02:14,902 --> 00:02:17,936 We're going to a small object that we don't know a lot about. 43 00:02:19,440 --> 00:02:21,039 NARRATOR: In fact, 44 00:02:21,041 --> 00:02:25,077 one of the biggest, baddest space telescopes in our arsenal, 45 00:02:25,079 --> 00:02:26,478 the Hubble, 46 00:02:26,480 --> 00:02:31,283 can only capture a pixelated image of this tiny speck. 47 00:02:31,285 --> 00:02:36,555 Its official name is 2014 M.U.69, 48 00:02:36,557 --> 00:02:38,657 but the New Horizons team 49 00:02:38,659 --> 00:02:43,028 also calls it by the Latin name Ultima Thule. 50 00:02:43,030 --> 00:02:45,330 STERN: We gave it this nickname Ultima Thule 51 00:02:45,332 --> 00:02:46,865 that means "beyond the farthest frontiers." 52 00:02:46,867 --> 00:02:50,135 JOEL PARKER: And in fact, it really is 53 00:02:50,137 --> 00:02:52,371 beyond the known world 54 00:02:52,373 --> 00:02:54,773 or part of our solar system that we have explored. 55 00:02:56,744 --> 00:03:01,146 NARRATOR: Here, objects like Ultima Thule have been frozen in time 56 00:03:01,148 --> 00:03:03,348 since the solar system formed 57 00:03:03,350 --> 00:03:07,152 four-and-a-half billion years ago. 58 00:03:07,154 --> 00:03:10,522 STERN: We believe this object, like many others out there, 59 00:03:10,524 --> 00:03:15,027 are actually planetary embryos. 60 00:03:15,029 --> 00:03:18,697 And to study those objects will give us a great window 61 00:03:18,699 --> 00:03:21,133 into the process of planetary formation. 62 00:03:26,340 --> 00:03:28,140 NARRATOR: For the New Horizons team, 63 00:03:28,142 --> 00:03:31,410 taking their spacecraft into the unknown 64 00:03:31,412 --> 00:03:35,047 is not only a monumental task, 65 00:03:35,049 --> 00:03:37,216 it's risky. 66 00:03:37,218 --> 00:03:39,585 An object the size of a pea or even smaller 67 00:03:39,587 --> 00:03:44,823 would be capable of literally taking out the spacecraft. 68 00:03:44,825 --> 00:03:47,292 NARRATOR: Tests have revealed that as the spacecraft travels 69 00:03:47,294 --> 00:03:50,062 at 36,000 miles an hour, 70 00:03:50,064 --> 00:03:53,632 even something as small as a grain of sand 71 00:03:53,634 --> 00:03:56,635 could rip a hole right through it. 72 00:03:56,637 --> 00:03:58,237 ALICE BOWMAN: At this point in the mission, 73 00:03:58,239 --> 00:04:00,973 you really have to be prepared for anything. 74 00:04:00,975 --> 00:04:03,609 ¶ ¶ 75 00:04:03,611 --> 00:04:04,643 NARRATOR: But for now, 76 00:04:04,645 --> 00:04:09,014 all the team can do is wait, 77 00:04:09,016 --> 00:04:13,719 and hope that years of work will pay off 78 00:04:13,721 --> 00:04:18,323 and that the tiny explorer manages to stay on target-- 79 00:04:18,325 --> 00:04:20,926 and survive. 80 00:04:20,928 --> 00:04:22,394 HAL WEAVER: I love this spacecraft. 81 00:04:22,396 --> 00:04:24,396 I've put my blood, sweat, and tears 82 00:04:24,398 --> 00:04:26,298 into helping to put this thing together, 83 00:04:26,300 --> 00:04:31,270 going back to 2002. 84 00:04:31,272 --> 00:04:33,038 It's just made us feel so proud. 85 00:04:33,040 --> 00:04:38,277 NARRATOR: Proud, because when it comes to exploring our solar system, 86 00:04:38,279 --> 00:04:41,179 New Horizons is already a pioneer. 87 00:04:45,586 --> 00:04:49,054 January 19, 2006. 88 00:04:49,056 --> 00:04:53,792 New Horizons is prepared for launch at Cape Canaveral. 89 00:04:53,794 --> 00:04:55,727 MAN: Two... one. 90 00:04:55,729 --> 00:04:57,963 We have ignition and lift-off 91 00:04:57,965 --> 00:05:00,599 of NASA's New Horizons spacecraft 92 00:05:00,601 --> 00:05:04,069 on a voyage to visit the planet Pluto and beyond. 93 00:05:04,071 --> 00:05:08,940 NARRATOR: The spacecraft sets out on a journey to reach not one, 94 00:05:08,942 --> 00:05:11,743 but two distant targets. 95 00:05:11,745 --> 00:05:16,148 ¶ ¶ 96 00:05:16,150 --> 00:05:21,286 Along the way, Alice Bowman, missions operations manager-- 97 00:05:21,288 --> 00:05:24,189 also known as MOM-- 98 00:05:24,191 --> 00:05:25,557 will help guide it through a voyage 99 00:05:25,559 --> 00:05:28,593 that will last more than a decade. 100 00:05:28,595 --> 00:05:33,598 BOWMAN: We talk about the spacecraft as if it's our child. 101 00:05:33,600 --> 00:05:37,602 When we launched, you know, we referred to it as a baby. 102 00:05:37,604 --> 00:05:40,272 When it does something that we don't expect, 103 00:05:40,274 --> 00:05:43,241 we relate it perhaps to terrible twos 104 00:05:43,243 --> 00:05:44,876 or something like that, 105 00:05:44,878 --> 00:05:47,746 so it really, it becomes part of us. 106 00:05:49,516 --> 00:05:52,384 NARRATOR: 78 days after launch, 107 00:05:52,386 --> 00:05:57,489 New Horizons passes the orbit of the red planet, Mars. 108 00:05:57,491 --> 00:06:03,061 Just two months later, it flies through the asteroid belt. 109 00:06:03,063 --> 00:06:05,464 In a year, it passes by Jupiter, 110 00:06:05,466 --> 00:06:10,202 where it captures spectacular images of a volcanic eruption 111 00:06:10,204 --> 00:06:13,805 on the gas giant's moon Io. 112 00:06:13,807 --> 00:06:15,941 STERN: It was the first time that time-lapse 113 00:06:15,943 --> 00:06:18,009 had ever been made of any volcano 114 00:06:18,011 --> 00:06:20,212 anywhere in the universe off the Earth. 115 00:06:20,214 --> 00:06:22,681 So it was really unique. 116 00:06:22,683 --> 00:06:27,819 NARRATOR: The spacecraft travels another two-and-a-half billion miles 117 00:06:27,821 --> 00:06:30,889 past the orbits of three more giant planets-- 118 00:06:30,891 --> 00:06:36,828 Saturn, Uranus, and Neptune. 119 00:06:36,830 --> 00:06:40,532 Finally, nine years after launch, 120 00:06:40,534 --> 00:06:44,669 New Horizons closes in on its first fly-by target-- 121 00:06:44,671 --> 00:06:47,105 Pluto and its moons. 122 00:06:49,476 --> 00:06:55,080 They have only been observed from billions of miles away, 123 00:06:55,082 --> 00:06:58,850 our best images nothing more than a blur. 124 00:07:00,354 --> 00:07:07,459 Until, in the summer of 2015, it slowly comes into view. 125 00:07:07,461 --> 00:07:10,262 MARC BUIE: Every day, it was getting bigger and bigger and bigger 126 00:07:10,264 --> 00:07:12,898 and starting to reveal this world. 127 00:07:12,900 --> 00:07:14,933 It was an incredible ride. 128 00:07:16,703 --> 00:07:19,571 NARRATOR: The mission is proceeding without a hitch. 129 00:07:19,573 --> 00:07:21,973 All is working as planned, 130 00:07:21,975 --> 00:07:22,908 but then... 131 00:07:25,145 --> 00:07:30,916 On July 4, 2015, just ten days before the Pluto fly-by... 132 00:07:30,918 --> 00:07:32,284 WEAVER: I got a call 133 00:07:32,286 --> 00:07:35,120 from the New Horizons principal investigator, Alan Stern. 134 00:07:35,122 --> 00:07:38,056 I could hear that he was panting. 135 00:07:38,058 --> 00:07:42,027 He was running down the hallway here at APL. 136 00:07:42,029 --> 00:07:43,762 He said, "We lost contact with the spacecraft," 137 00:07:43,764 --> 00:07:45,997 and I said, "You've got to be kidding." 138 00:07:45,999 --> 00:07:48,333 You know, this has never happened before. 139 00:07:48,335 --> 00:07:50,535 You just feel, you know, 140 00:07:50,537 --> 00:07:52,270 that pit in the bottom of your stomach. 141 00:07:53,740 --> 00:07:56,408 GLEN FOUNTAIN: Your pulse goes up a little bit. 142 00:07:56,410 --> 00:07:57,676 Could it be, you know, 143 00:07:57,678 --> 00:08:00,645 these millions of miles away, we hit something? 144 00:08:00,647 --> 00:08:03,982 NARRATOR: Is the spacecraft still in one piece? 145 00:08:03,984 --> 00:08:07,486 The team races to figure out what's gone wrong. 146 00:08:07,488 --> 00:08:09,554 WEAVER: It took a little while, but we realized 147 00:08:09,556 --> 00:08:12,858 exactly what had happened is, we had overloaded the computer. 148 00:08:12,860 --> 00:08:14,993 MARK HOLDRIDGE: That's sort of like 149 00:08:14,995 --> 00:08:16,495 your worst nightmare 150 00:08:16,497 --> 00:08:18,797 a week before an encounter. 151 00:08:20,434 --> 00:08:22,067 BOWMAN: We knew that we could fix it. 152 00:08:22,069 --> 00:08:23,468 The question was: 153 00:08:23,470 --> 00:08:25,537 Were we going to be able to do that in enough time? 154 00:08:27,140 --> 00:08:29,875 FOUNTAIN: Alice, I swear, didn't get any sleep, 155 00:08:29,877 --> 00:08:31,142 but she said she slept on the floor 156 00:08:31,144 --> 00:08:32,811 for a few minutes one night. 157 00:08:32,813 --> 00:08:34,045 (Bowman laughs) 158 00:08:34,047 --> 00:08:35,780 For a couple of nights, slept there, 159 00:08:35,782 --> 00:08:38,049 you know, just like a child that's sick. 160 00:08:38,051 --> 00:08:42,454 You want to be there to help it recover along the way. 161 00:08:42,456 --> 00:08:43,922 NARRATOR: The team works round the clock, 162 00:08:43,924 --> 00:08:48,627 re-uploading instructions to the spacecraft's computer. 163 00:08:48,629 --> 00:08:50,896 WEAVER: Alice Bowman, our mission operations manager, 164 00:08:50,898 --> 00:08:51,897 and her team 165 00:08:51,899 --> 00:08:53,932 did a fantastic job 166 00:08:53,934 --> 00:08:56,334 of putting everything back together again 167 00:08:56,336 --> 00:08:57,969 with only six hours to spare. 168 00:08:59,373 --> 00:09:02,974 NARRATOR: Just in time for the fly-by. 169 00:09:02,976 --> 00:09:04,676 ¶ ¶ 170 00:09:04,678 --> 00:09:06,144 Okay, we're in lock with carrier. 171 00:09:06,146 --> 00:09:09,047 NARRATOR: July 14, 2015. 172 00:09:11,084 --> 00:09:14,486 Three billion miles from Earth, 173 00:09:14,488 --> 00:09:17,289 New Horizons should have just flown above Pluto's surface, 174 00:09:17,291 --> 00:09:19,491 taking pictures and gathering data. 175 00:09:20,827 --> 00:09:22,527 But did it make it? 176 00:09:22,529 --> 00:09:25,397 Stand by for telemetry. 177 00:09:25,399 --> 00:09:28,934 NARRATOR: Alice waits to hear back from the spacecraft-- 178 00:09:28,936 --> 00:09:32,070 a sign it has safely completed the fly-by. 179 00:09:33,340 --> 00:09:34,873 New Horizons is so far away, 180 00:09:34,875 --> 00:09:38,343 it takes four-and-a-half hours 181 00:09:38,345 --> 00:09:39,511 for that signal to reach Earth. 182 00:09:41,815 --> 00:09:43,882 MOM on Pluto 1. 183 00:09:43,884 --> 00:09:46,284 We have a healthy spacecraft. 184 00:09:46,286 --> 00:09:49,788 We've recorded data of the Pluto system. 185 00:09:49,790 --> 00:09:54,726 (cheering and applauding) 186 00:10:00,300 --> 00:10:03,301 It was a huge sense of relief and accomplishment. 187 00:10:03,303 --> 00:10:06,071 I think mostly accomplishment. 188 00:10:06,073 --> 00:10:11,209 (cheering and applauding) 189 00:10:11,211 --> 00:10:12,544 We did it. 190 00:10:12,546 --> 00:10:14,646 MAN: We did, we did. It's just great. 191 00:10:14,648 --> 00:10:17,415 ¶ ¶ 192 00:10:17,417 --> 00:10:21,453 NARRATOR: The first up-close images come in. 193 00:10:22,923 --> 00:10:25,790 And they shock the world. 194 00:10:25,792 --> 00:10:30,962 ¶ ¶ 195 00:10:30,964 --> 00:10:33,665 JOEL PARKER: When the images first came down from New Horizons, 196 00:10:33,667 --> 00:10:37,168 I was stunned, excited, tired-- 197 00:10:37,170 --> 00:10:40,138 every emotion and feeling you can imagine, 198 00:10:40,140 --> 00:10:45,744 but really just amazed at what they looked like. 199 00:10:45,746 --> 00:10:50,115 NARRATOR: This tiny world, with a diameter less than 1,500 miles, 200 00:10:50,117 --> 00:10:53,218 turns out to be incredibly complex, 201 00:10:53,220 --> 00:10:57,689 with mountains more than a mile high. 202 00:10:57,691 --> 00:10:59,124 JOEL PARKER: The Rocky Mountains here are beautiful, 203 00:10:59,126 --> 00:11:00,992 and the Flatirons in the background, 204 00:11:00,994 --> 00:11:03,595 but instead of rock, 205 00:11:03,597 --> 00:11:06,965 the mountains on Pluto were made of ice, 206 00:11:06,967 --> 00:11:08,533 and at those temperatures, 207 00:11:08,535 --> 00:11:11,703 ice is so cold, it's like bedrock. 208 00:11:13,840 --> 00:11:17,409 NARRATOR: Pluto's most famous feature, its heart, 209 00:11:17,411 --> 00:11:24,115 contains a massive glacier that flows across its surface. 210 00:11:24,117 --> 00:11:26,317 OLKIN: I certainly did not expect 211 00:11:26,319 --> 00:11:29,854 a glacier of nitrogen and methane ices. 212 00:11:29,856 --> 00:11:32,323 Never in a million years did I expect that. 213 00:11:34,628 --> 00:11:35,927 JOHN SPENCER: We're seeing processes, 214 00:11:35,929 --> 00:11:38,196 some of which look quite familiar from the Earth, 215 00:11:38,198 --> 00:11:40,265 but are happening in a completely alien environment 216 00:11:40,267 --> 00:11:42,567 with completely alien materials. 217 00:11:43,937 --> 00:11:48,707 NARRATOR: Pluto even has volcanoes made of ice. 218 00:11:48,709 --> 00:11:51,409 OLKIN: There is something that looks very much like an ice volcano 219 00:11:51,411 --> 00:11:52,911 on Pluto. 220 00:11:52,913 --> 00:11:55,847 We didn't see it erupt, but it sure looks like a volcano. 221 00:11:57,617 --> 00:12:01,052 NARRATOR: Using images and data collected by the spacecraft, 222 00:12:01,054 --> 00:12:04,823 the team created this simulation of what it would feel like 223 00:12:04,825 --> 00:12:08,827 to fly over Pluto's surface. 224 00:12:08,829 --> 00:12:09,994 STERN: Some of the geologists on our team 225 00:12:09,996 --> 00:12:12,530 have taken to calling Pluto the new Mars, 226 00:12:12,532 --> 00:12:16,434 because it's every bit as complicated as Mars. 227 00:12:16,436 --> 00:12:19,871 NARRATOR: What could be driving such geological diversity 228 00:12:19,873 --> 00:12:22,240 on such a tiny world? 229 00:12:23,910 --> 00:12:30,115 One theory: Pluto's surface may change with the seasons. 230 00:12:30,117 --> 00:12:33,017 Pluto doesn't really have the sort of four seasons 231 00:12:33,019 --> 00:12:34,385 that we have. 232 00:12:34,387 --> 00:12:36,955 We have very even seasons: 233 00:12:36,957 --> 00:12:39,858 We have a hot summer and a cold winter 234 00:12:39,860 --> 00:12:43,228 that's about the same length of time in each one, 235 00:12:43,230 --> 00:12:46,231 because Earth is in a circular orbit around the sun. 236 00:12:46,233 --> 00:12:47,632 Pluto's not. 237 00:12:47,634 --> 00:12:50,969 It's in this very eccentric orbit around the sun. 238 00:12:50,971 --> 00:12:54,239 NARRATOR: As Pluto, along with its largest moon, Charon, 239 00:12:54,241 --> 00:12:55,607 gets closer to the sun, 240 00:12:55,609 --> 00:12:58,676 its surface warms. 241 00:12:58,678 --> 00:13:03,314 But as it continues on its 248-year orbit, 242 00:13:03,316 --> 00:13:06,284 getting farther and farther from the sun, 243 00:13:06,286 --> 00:13:09,387 its surface becomes colder. 244 00:13:09,389 --> 00:13:11,356 So there are these extreme seasons. 245 00:13:11,358 --> 00:13:16,861 In summer, ices on the surface can evaporate. 246 00:13:16,863 --> 00:13:19,430 In winter, they can re-condense, 247 00:13:19,432 --> 00:13:23,468 so when you see it today, it is not going to look the same 248 00:13:23,470 --> 00:13:24,836 as it looks in a hundred years, 249 00:13:24,838 --> 00:13:26,137 when it's in the opposite season. 250 00:13:27,908 --> 00:13:30,608 NARRATOR: But there could be another strikingly different reason 251 00:13:30,610 --> 00:13:35,046 for Pluto's complex surface. 252 00:13:35,048 --> 00:13:36,581 Based on measurements 253 00:13:36,583 --> 00:13:38,917 of its density and chemical composition, 254 00:13:38,919 --> 00:13:41,753 scientists believe it has a rocky core. 255 00:13:43,657 --> 00:13:46,558 All rock contains radioactive elements, 256 00:13:46,560 --> 00:13:49,227 which as they decay, release heat. 257 00:13:52,065 --> 00:13:53,464 So there's a continual flow of heat 258 00:13:53,466 --> 00:13:57,569 from the interior of Pluto to the, to the outside. 259 00:13:57,571 --> 00:13:59,571 But it's a very small amount of heat, 260 00:13:59,573 --> 00:14:00,738 because Pluto is pretty small-- 261 00:14:00,740 --> 00:14:01,940 it doesn't have that much rock in it. 262 00:14:03,577 --> 00:14:07,512 But we think that even that tiny amount of internal heat 263 00:14:07,514 --> 00:14:10,114 is enough to move mountains, literally. 264 00:14:11,818 --> 00:14:14,018 NARRATOR: And it may also be enough heat 265 00:14:14,020 --> 00:14:16,287 to create something extraordinary 266 00:14:16,289 --> 00:14:19,424 beneath Pluto's icy crust. 267 00:14:20,594 --> 00:14:21,893 CALEB SCHARF: Right now, 268 00:14:21,895 --> 00:14:25,463 Pluto is covered in frozen water and frozen nitrogen 269 00:14:25,465 --> 00:14:27,298 and a few other compounds. 270 00:14:27,300 --> 00:14:29,934 It's quite possible that in the past, 271 00:14:29,936 --> 00:14:33,438 there was enough heat internal to Pluto 272 00:14:33,440 --> 00:14:38,243 to melt some of that ice and create a layer of ocean. 273 00:14:40,380 --> 00:14:44,148 SPENCER: We suspect that Pluto has an ocean of liquid water 274 00:14:44,150 --> 00:14:45,984 deep in the interior, 275 00:14:45,986 --> 00:14:48,419 hundreds of miles below the surface. 276 00:14:51,258 --> 00:14:53,124 SCHARF: It raises what seems like 277 00:14:53,126 --> 00:14:55,026 an extraordinary possibility, 278 00:14:55,028 --> 00:14:59,831 that if you have liquid water and rock deep inside Pluto 279 00:14:59,833 --> 00:15:01,666 in contact with each other, 280 00:15:01,668 --> 00:15:06,871 well, that's an environment that life could exist in. 281 00:15:06,873 --> 00:15:08,907 STERN: I think one of the most mind-blowing things 282 00:15:08,909 --> 00:15:11,809 is to hear the astrobiologists talk about the fact 283 00:15:11,811 --> 00:15:14,812 that that could be an abode for life, potentially. 284 00:15:17,050 --> 00:15:20,084 Here we have a world whose surface is just 40 degrees 285 00:15:20,086 --> 00:15:21,753 above absolute zero. 286 00:15:21,755 --> 00:15:25,423 It's three billion miles from the sun. 287 00:15:25,425 --> 00:15:28,493 You would never expect life at those kinds of temperatures. 288 00:15:30,897 --> 00:15:33,231 NARRATOR: Whatever's causing the extraordinary geology 289 00:15:33,233 --> 00:15:34,399 on Pluto's surface 290 00:15:34,401 --> 00:15:38,269 will be debated for years to come. 291 00:15:38,271 --> 00:15:39,604 STERN: There are a lot of theories 292 00:15:39,606 --> 00:15:41,539 and there are a lot of ideas, 293 00:15:41,541 --> 00:15:42,640 and we don't know which one is right 294 00:15:42,642 --> 00:15:43,708 or if none of them are right. 295 00:15:47,180 --> 00:15:50,581 We're in this wonderful position of knowing volumes 296 00:15:50,583 --> 00:15:53,584 compared to what we knew before, 297 00:15:53,586 --> 00:15:55,920 but it's maddening, because unlike Mars, 298 00:15:55,922 --> 00:15:57,088 which is around the corner, 299 00:15:57,090 --> 00:15:59,157 and you could fly to very quickly again, 300 00:15:59,159 --> 00:16:02,160 it's a big undertaking to cross the entire solar system. 301 00:16:02,162 --> 00:16:03,962 ¶ ¶ 302 00:16:03,964 --> 00:16:06,731 NARRATOR: As its historic fly-by comes to an end, 303 00:16:06,733 --> 00:16:09,934 and the tiny spacecraft leaves Pluto, 304 00:16:09,936 --> 00:16:12,437 New Horizons looks back 305 00:16:12,439 --> 00:16:16,908 to take one last breathtaking image. 306 00:16:16,910 --> 00:16:19,610 My real favorite, favorite picture 307 00:16:19,612 --> 00:16:23,147 is one after we flew by Pluto, 308 00:16:23,149 --> 00:16:27,986 and we're looking back and we see the horizon of Pluto, 309 00:16:27,988 --> 00:16:32,023 with the sun lighting the atmosphere from behind. 310 00:16:32,025 --> 00:16:37,295 You can see layers of haze and shadows of mountains 311 00:16:37,297 --> 00:16:39,630 streaming across the surface, 312 00:16:39,632 --> 00:16:44,068 and that is where you really understand 313 00:16:44,070 --> 00:16:46,938 that Pluto is a world. 314 00:16:49,109 --> 00:16:50,808 BUIE: Whenever I see that picture, 315 00:16:50,810 --> 00:16:53,678 it's as if I'm sitting on the spacecraft, 316 00:16:53,680 --> 00:16:57,081 looking out the window as Pluto goes whizzing by, 317 00:16:57,083 --> 00:16:59,951 and it, more than any other picture that we took, 318 00:16:59,953 --> 00:17:01,552 puts me there. 319 00:17:03,590 --> 00:17:07,358 STERN: That photograph for me is the crowning achievement. 320 00:17:07,360 --> 00:17:08,693 We were really there 321 00:17:08,695 --> 00:17:10,862 and we really did it. 322 00:17:10,864 --> 00:17:12,864 And we made our own little contribution 323 00:17:12,866 --> 00:17:15,867 not just to science, but actually to history. 324 00:17:18,638 --> 00:17:22,673 NARRATOR: That history begins back in 1930, 325 00:17:22,675 --> 00:17:26,044 when Pluto is discovered by Clyde Tombaugh, 326 00:17:26,046 --> 00:17:30,848 a young farm boy with a passion for astronomy. 327 00:17:30,850 --> 00:17:33,618 For nearly a century, Clyde has the honor 328 00:17:33,620 --> 00:17:38,589 of being the only American to discover a planet. 329 00:17:38,591 --> 00:17:40,925 But almost from the get-go, 330 00:17:40,927 --> 00:17:43,261 many astronomers aren't buying it, 331 00:17:43,263 --> 00:17:46,497 because when it comes to being a planet, 332 00:17:46,499 --> 00:17:49,333 size matters. 333 00:17:49,335 --> 00:17:50,701 KONSTANTIN BATYGIN: When you discover an astronomical object 334 00:17:50,703 --> 00:17:52,470 far, far away, 335 00:17:52,472 --> 00:17:55,173 you have no direct way of measuring its mass. 336 00:17:55,175 --> 00:17:58,709 You don't actually know how massive it is. 337 00:17:58,711 --> 00:18:00,578 And so people speculated about, 338 00:18:00,580 --> 00:18:03,481 maybe Pluto was one Earth mass, 339 00:18:03,483 --> 00:18:06,217 and then people kept revising their estimate 340 00:18:06,219 --> 00:18:07,618 down and down and down. 341 00:18:07,620 --> 00:18:09,887 Until people realized, "Oh, my gosh, 342 00:18:09,889 --> 00:18:14,392 this thing is really, really small." 343 00:18:14,394 --> 00:18:18,663 NARRATOR: It turns out Pluto is smaller than Earth's moon, 344 00:18:18,665 --> 00:18:21,966 but size wasn't Pluto's only problem. 345 00:18:21,968 --> 00:18:25,002 So was its location. 346 00:18:25,004 --> 00:18:27,905 A tiny little planet in the outer solar system 347 00:18:27,907 --> 00:18:31,509 just didn't make sense. 348 00:18:31,511 --> 00:18:33,311 DAVID JEWITT: Pluto was regarded as a planet, 349 00:18:33,313 --> 00:18:36,247 but it was always regarded as a kind of funny planet, 350 00:18:36,249 --> 00:18:39,016 a weird planet, somewhat out of place. 351 00:18:39,018 --> 00:18:41,452 So the sun sits in the middle. 352 00:18:41,454 --> 00:18:44,188 The sun is this massive body made of hydrogen, 353 00:18:44,190 --> 00:18:46,724 it's a million times the mass of the Earth 354 00:18:46,726 --> 00:18:49,427 and about a hundred times the diameter of the Earth, 355 00:18:49,429 --> 00:18:51,028 and it's orbited by planets, 356 00:18:51,030 --> 00:18:53,698 which are moving in nearly circular orbits. 357 00:18:53,700 --> 00:18:55,366 And then at the very edge, 358 00:18:55,368 --> 00:18:58,736 the outer edge of this system of planets, 359 00:18:58,738 --> 00:19:00,104 we knew of Pluto. 360 00:19:00,106 --> 00:19:02,707 Pluto is not really like a terrestrial planet, 361 00:19:02,709 --> 00:19:05,977 because it's got quite a bit of ice in it. 362 00:19:05,979 --> 00:19:08,146 Pluto is not at all like a giant planet, 363 00:19:08,148 --> 00:19:10,815 because it's tiny and it's not made of gas-- 364 00:19:10,817 --> 00:19:12,517 it's made of solid material. 365 00:19:12,519 --> 00:19:14,152 And it also has a very strange orbit 366 00:19:14,154 --> 00:19:17,388 with a high ellipticity and a high inclination. 367 00:19:17,390 --> 00:19:20,358 It's tilted up relative to the plane of the solar system. 368 00:19:20,360 --> 00:19:23,261 Beyond Pluto, uh... 369 00:19:23,263 --> 00:19:25,163 there was nothing, 370 00:19:25,165 --> 00:19:27,265 and people actually didn't think about that in general, 371 00:19:27,267 --> 00:19:30,201 because it's just an empty space. 372 00:19:30,203 --> 00:19:33,437 And next stop, uh, the stars. 373 00:19:33,439 --> 00:19:36,307 NARRATOR: Is the solar system's little misfit 374 00:19:36,309 --> 00:19:38,609 really alone out there? 375 00:19:38,611 --> 00:19:40,178 For decades to come, 376 00:19:40,180 --> 00:19:43,614 astronomers look for another planet beyond Pluto. 377 00:19:45,185 --> 00:19:46,951 But as hard as they look-- 378 00:19:46,953 --> 00:19:50,988 and they look hard-- 379 00:19:50,990 --> 00:19:54,091 no one finds anything. 380 00:19:54,093 --> 00:19:57,895 Until two astronomers, David Jewitt and Jane Luu, 381 00:19:57,897 --> 00:20:00,264 take on the challenge. 382 00:20:00,266 --> 00:20:01,666 JEWITT: The original thought that we had 383 00:20:01,668 --> 00:20:06,304 was simply that the outer solar system is weirdly empty. 384 00:20:08,474 --> 00:20:10,408 NARRATOR: David and Jane get access 385 00:20:10,410 --> 00:20:13,477 to one of the most powerful telescopes on the planet, 386 00:20:13,479 --> 00:20:17,448 and they start a search that will take a lot longer 387 00:20:17,450 --> 00:20:21,485 than either one of them expects. 388 00:20:23,122 --> 00:20:25,523 While it's easy to see distant stars, 389 00:20:25,525 --> 00:20:27,592 because they radiate their own light, 390 00:20:27,594 --> 00:20:31,596 other celestial bodies are much harder to see. 391 00:20:31,598 --> 00:20:35,032 That's because light has to travel all the way 392 00:20:35,034 --> 00:20:36,701 from our sun to the object, 393 00:20:36,703 --> 00:20:39,270 reflect off its surface, 394 00:20:39,272 --> 00:20:42,873 and then make the long journey back to Earth. 395 00:20:42,875 --> 00:20:46,210 By then, it's barely visible. 396 00:20:46,212 --> 00:20:49,847 David and Jane hope that advances in digital detectors, 397 00:20:49,849 --> 00:20:52,950 which are far more sensitive to light than film, 398 00:20:52,952 --> 00:20:57,521 will help them see a whole lot more. 399 00:20:58,758 --> 00:21:04,295 August 1992, Mauna Kea Observatory, Hawaii. 400 00:21:04,297 --> 00:21:08,766 After searching for six years, they finally find an object 401 00:21:08,768 --> 00:21:11,068 moving in the night sky. 402 00:21:11,070 --> 00:21:13,004 JEWITT: Here is the set 403 00:21:13,006 --> 00:21:14,171 of discovery images for the first object. 404 00:21:14,173 --> 00:21:15,840 So you can see this object 405 00:21:15,842 --> 00:21:17,508 drifting from this picture 406 00:21:17,510 --> 00:21:18,976 to this one to this one. 407 00:21:18,978 --> 00:21:20,711 It's drifting slowly to the left. 408 00:21:20,713 --> 00:21:26,317 NARRATOR: A tiny object beyond Pluto orbiting the sun. 409 00:21:26,319 --> 00:21:28,853 Then they find more. 410 00:21:28,855 --> 00:21:31,489 And more. 411 00:21:31,491 --> 00:21:34,558 So the space beyond Neptune is basically, 412 00:21:34,560 --> 00:21:37,161 is full of objects that we just didn't know about before 413 00:21:37,163 --> 00:21:38,296 because they're too faint. 414 00:21:38,298 --> 00:21:41,565 NARRATOR: David and Jane discover 415 00:21:41,567 --> 00:21:45,469 an entirely new region of the solar system. 416 00:21:45,471 --> 00:21:47,638 Now known as the Kuiper Belt, 417 00:21:47,640 --> 00:21:50,574 it's believed to be home to hundreds of thousands, 418 00:21:50,576 --> 00:21:55,479 possibly millions, of icy objects-- 419 00:21:55,481 --> 00:21:58,883 including Pluto. 420 00:21:58,885 --> 00:22:03,087 JEWITT: The Kuiper Belt has a thousand times more objects in it 421 00:22:03,089 --> 00:22:05,156 than we have in the asteroid belt, 422 00:22:05,158 --> 00:22:07,525 completely unknown until these first observations. 423 00:22:10,330 --> 00:22:14,165 BATYGIN: The Kuiper Belt stretches out billions of miles. 424 00:22:16,202 --> 00:22:18,069 It is just difficult to imagine 425 00:22:18,071 --> 00:22:21,539 how expansive this field of icy debris is. 426 00:22:23,376 --> 00:22:28,713 NARRATOR: Think of it as a giant doughnut surrounding the planets, 427 00:22:28,715 --> 00:22:31,382 on average, each Kuiper Belt object 428 00:22:31,384 --> 00:22:35,252 separated from the next by a million miles. 429 00:22:37,056 --> 00:22:40,391 That's how massive the Kuiper Belt is. 430 00:22:40,393 --> 00:22:44,695 BROWN: The day that the first new Kuiper Belt object 431 00:22:44,697 --> 00:22:46,364 was discovered by Dave Jewitt and Jane Luu, 432 00:22:46,366 --> 00:22:49,533 it clicked in everybody who was paying attention's head, 433 00:22:49,535 --> 00:22:53,637 it was, like, "Oh there's a ton of objects out there. 434 00:22:53,639 --> 00:22:56,474 "That's what Pluto is part of, Pluto's part of the Kuiper Belt. 435 00:22:56,476 --> 00:22:59,443 It suddenly all makes sense." 436 00:22:59,445 --> 00:23:04,715 JOEL PARKER: For me, Pluto was the harbinger of things to come. 437 00:23:04,717 --> 00:23:06,083 We didn't realize 438 00:23:06,085 --> 00:23:08,486 that its being an oddball was telling us something, 439 00:23:08,488 --> 00:23:10,221 it was telling us the secret 440 00:23:10,223 --> 00:23:12,923 of the third zone of the solar system. 441 00:23:12,925 --> 00:23:16,494 This really sort of restructures our understanding 442 00:23:16,496 --> 00:23:19,930 of how our solar system is built and how we should think 443 00:23:19,932 --> 00:23:22,700 about the membership of our solar system. 444 00:23:22,702 --> 00:23:24,668 ¶ ¶ 445 00:23:24,670 --> 00:23:28,672 NARRATOR: August 2006, Prague. 446 00:23:28,674 --> 00:23:32,109 Just a few months after New Horizons set out 447 00:23:32,111 --> 00:23:35,279 to explore the ninth planet of the solar system, 448 00:23:35,281 --> 00:23:38,949 an international association of astronomers 449 00:23:38,951 --> 00:23:40,885 votes to demote Pluto. 450 00:23:43,489 --> 00:23:47,057 And the official planet count goes back down to eight. 451 00:23:48,728 --> 00:23:52,163 While some members of the public are outraged, 452 00:23:52,165 --> 00:23:55,766 not everyone sees this as a demotion. 453 00:23:55,768 --> 00:23:57,301 (crowd chanting) 454 00:23:57,303 --> 00:23:58,569 PITTS: One could argue 455 00:23:58,571 --> 00:24:00,438 that Pluto actually made out better with this change, 456 00:24:00,440 --> 00:24:02,940 because in its previous instance, 457 00:24:02,942 --> 00:24:05,976 it was the smallest planet of the solar system. 458 00:24:07,480 --> 00:24:09,980 It now has become the king of the Kuiper Belt, 459 00:24:09,982 --> 00:24:12,917 and so, in a sense, its status has gone up. 460 00:24:15,588 --> 00:24:18,722 NARRATOR: Over the last few decades, astronomers have discovered 461 00:24:18,724 --> 00:24:23,461 that Kuiper Belt objects vary in size, shape, 462 00:24:23,463 --> 00:24:25,429 and also in their orbits. 463 00:24:26,933 --> 00:24:31,302 There are larger objects, like Pluto. 464 00:24:31,304 --> 00:24:35,639 These are known as dwarf planets. 465 00:24:35,641 --> 00:24:38,008 We've discovered that the outer solar system 466 00:24:38,010 --> 00:24:39,710 is littered with small planets. 467 00:24:39,712 --> 00:24:42,313 These are typically rocky and icy objects. 468 00:24:42,315 --> 00:24:46,717 Many have atmospheres, many, possibly most, have moons. 469 00:24:46,719 --> 00:24:50,888 There's a great variety in terms of their physical properties, 470 00:24:50,890 --> 00:24:52,656 their colors, their compositions-- 471 00:24:52,658 --> 00:24:54,225 many of the things we're used to 472 00:24:54,227 --> 00:24:56,393 in the planets we're familiar with, 473 00:24:56,395 --> 00:24:59,096 but in miniature. 474 00:24:59,098 --> 00:25:01,332 I think a decent analogy is, when you see a Chihuahua, 475 00:25:01,334 --> 00:25:02,466 it's still a dog, 476 00:25:02,468 --> 00:25:03,901 because it has the characteristics 477 00:25:03,903 --> 00:25:06,136 of the canine species, 478 00:25:06,138 --> 00:25:07,738 just in miniature. 479 00:25:09,942 --> 00:25:13,844 NARRATOR: Then there are objects like Ultima Thule. 480 00:25:13,846 --> 00:25:17,081 Astronomers think these objects have been frozen in time 481 00:25:17,083 --> 00:25:20,050 since the birth of our solar system 482 00:25:20,052 --> 00:25:24,388 four-and-a-half billion years ago. 483 00:25:24,390 --> 00:25:26,423 ALEX PARKER: So what we think we're seeing is a fossil structure 484 00:25:26,425 --> 00:25:28,893 that's left over from the formation of the solar system. 485 00:25:28,895 --> 00:25:32,029 It's this tiny remnant of the ancient past that we can visit. 486 00:25:33,633 --> 00:25:37,701 PITTS: Objects like M.U.69 retain the pristine conditions 487 00:25:37,703 --> 00:25:40,738 of the early solar system. 488 00:25:40,740 --> 00:25:41,839 This now lets us 489 00:25:41,841 --> 00:25:44,041 look at these objects with the idea 490 00:25:44,043 --> 00:25:48,012 that an examination of them will help us better understand 491 00:25:48,014 --> 00:25:49,980 what the early solar system was like. 492 00:25:51,817 --> 00:25:56,453 NARRATOR: Unfortunately, our best images of these primordial objects 493 00:25:56,455 --> 00:25:59,623 are only single pixels of dim light, 494 00:25:59,625 --> 00:26:02,726 almost impossible to see. 495 00:26:04,263 --> 00:26:06,697 If only we could get a spacecraft 496 00:26:06,699 --> 00:26:10,000 out to the Kuiper Belt to take a closer look. 497 00:26:10,002 --> 00:26:14,838 But of course, there's one already out there. 498 00:26:14,840 --> 00:26:17,341 SPENCER: When we launched the New Horizons spacecraft 499 00:26:17,343 --> 00:26:18,976 back in 2006, 500 00:26:18,978 --> 00:26:21,245 we knew we wanted to fly to an object beyond Pluto, 501 00:26:21,247 --> 00:26:23,280 but we didn't have a particular object 502 00:26:23,282 --> 00:26:25,716 that we knew we could reach with our spacecraft. 503 00:26:25,718 --> 00:26:29,386 So we started doing deep searches of the sky 504 00:26:29,388 --> 00:26:31,322 beyond Pluto. 505 00:26:34,794 --> 00:26:38,395 NARRATOR: April 2011. 506 00:26:38,397 --> 00:26:40,264 While New Horizons is traveling 507 00:26:40,266 --> 00:26:42,099 through the solar system, 508 00:26:42,101 --> 00:26:45,703 at the Southwest Research Institute in Boulder, Colorado, 509 00:26:45,705 --> 00:26:49,940 Marc Buie leads the search for New Horizons' next target. 510 00:26:49,942 --> 00:26:53,777 But the teams faces extraordinary limitations. 511 00:26:55,281 --> 00:27:00,718 The region their spacecraft can safely reach is extremely small. 512 00:27:00,720 --> 00:27:02,119 OLKIN: There's certain things we don't have 513 00:27:02,121 --> 00:27:03,120 an infinite supply of, 514 00:27:03,122 --> 00:27:04,755 like fuel. 515 00:27:04,757 --> 00:27:06,023 And our thrusters, 516 00:27:06,025 --> 00:27:09,326 we only want to put so many thruster counts on them. 517 00:27:11,130 --> 00:27:14,064 NARRATOR: Thrusters make it possible to redirect your spacecraft 518 00:27:14,066 --> 00:27:16,900 as you zero in on a target. 519 00:27:16,902 --> 00:27:20,971 Without them, there's no way to steer the ship. 520 00:27:20,973 --> 00:27:23,207 If you use them beyond the lifetime 521 00:27:23,209 --> 00:27:24,975 that they were designed for, 522 00:27:24,977 --> 00:27:26,610 they could have a failure. 523 00:27:29,248 --> 00:27:34,351 NARRATOR: But an aging spacecraft is just one of many challenges. 524 00:27:34,353 --> 00:27:35,919 Where you need to look 525 00:27:35,921 --> 00:27:39,256 is probably one of the hardest spots in the sky to look. 526 00:27:39,258 --> 00:27:42,693 It's right in the middle of the Milky Way. 527 00:27:42,695 --> 00:27:45,329 SPENCER: The densest star fields in the entire sky, 528 00:27:45,331 --> 00:27:48,198 where you would see a million stars brighter 529 00:27:48,200 --> 00:27:49,733 than the objects you were looking for, 530 00:27:49,735 --> 00:27:54,672 and you had to try and sift it out between all those stars. 531 00:27:54,674 --> 00:27:58,475 NARRATOR: They search for several years, 532 00:27:58,477 --> 00:28:00,277 and find nothing. 533 00:28:02,248 --> 00:28:05,215 BUIE: We were starting to say, "What's going to happen? 534 00:28:05,217 --> 00:28:09,420 "We have to find an object in 2014. 535 00:28:09,422 --> 00:28:11,655 "If we don't find one in 2014, 536 00:28:11,657 --> 00:28:14,124 "we won't know well enough where the object is 537 00:28:14,126 --> 00:28:17,261 to redirect the spacecraft to get there." 538 00:28:17,263 --> 00:28:19,963 NARRATOR: The clock is running out. 539 00:28:22,101 --> 00:28:25,803 It's time for the big guns. 540 00:28:25,805 --> 00:28:29,473 It's time for Hubble. 541 00:28:29,475 --> 00:28:32,843 From its vantage point far beyond the Earth's atmosphere, 542 00:28:32,845 --> 00:28:35,946 the Hubble space telescope has a better chance 543 00:28:35,948 --> 00:28:39,183 of spotting faint objects, 544 00:28:39,185 --> 00:28:42,152 and that makes all the difference. 545 00:28:42,154 --> 00:28:44,788 SPENCER: After a big effort with the Hubble telescope 546 00:28:44,790 --> 00:28:46,890 in the summer of 2014, 547 00:28:46,892 --> 00:28:49,893 we found an object. 548 00:28:49,895 --> 00:28:53,931 WEAVER: Wow, it was truly exhilarating. 549 00:28:53,933 --> 00:28:55,933 (laughing): Yay, we've done it! 550 00:28:58,104 --> 00:28:59,737 HOLDRIDGE: This is kind of a first, 551 00:28:59,739 --> 00:29:01,872 to discover an object while you're in flight, 552 00:29:01,874 --> 00:29:05,309 and then redirect the spacecraft to fly by it, 553 00:29:05,311 --> 00:29:08,545 and determine its orbit along the way. 554 00:29:10,483 --> 00:29:13,550 NARRATOR: Nailing down Ultima Thule's orbit 555 00:29:13,552 --> 00:29:16,720 is critical for the success of the mission. 556 00:29:16,722 --> 00:29:19,123 (gunshot echoes) 557 00:29:19,125 --> 00:29:21,959 Think of it like skeet shooting. 558 00:29:21,961 --> 00:29:25,028 You have to predict where your target will be... 559 00:29:25,030 --> 00:29:27,064 (gunshot echoes) ...in the future. 560 00:29:27,066 --> 00:29:30,367 So we do shooting and targeting in the outer solar system. 561 00:29:30,369 --> 00:29:31,769 You're going to tell me here 562 00:29:31,771 --> 00:29:34,671 how you do shooting and targeting on Earth. 563 00:29:34,673 --> 00:29:38,208 NARRATOR: New Horizons team member Anne Verbiscer 564 00:29:38,210 --> 00:29:40,344 and sharpshooter J.R. Pierce 565 00:29:40,346 --> 00:29:41,879 demonstrate. 566 00:29:41,881 --> 00:29:43,547 It's not a space vehicle, but... 567 00:29:43,549 --> 00:29:45,015 We'll get our point across here. 568 00:29:45,017 --> 00:29:46,917 ¶ ¶ 569 00:29:46,919 --> 00:29:47,985 PIERCE: Pull. 570 00:29:47,987 --> 00:29:50,053 (launcher rattles) 571 00:29:50,055 --> 00:29:52,990 NARRATOR: If J.R. aims directly at the target... 572 00:29:52,992 --> 00:29:54,024 (gunshot echoes) 573 00:29:54,026 --> 00:29:55,559 He's gonna miss. 574 00:29:55,561 --> 00:29:56,693 Launch. 575 00:29:56,695 --> 00:29:57,995 I'm initiating the launch sequence. 576 00:29:57,997 --> 00:29:59,463 Pull. 577 00:29:59,465 --> 00:30:01,398 NARRATOR: But if he aims ahead of the target... 578 00:30:01,400 --> 00:30:03,233 (gunshot echoes) It's a hit. 579 00:30:03,235 --> 00:30:06,837 (gunshots echo) Again and again. 580 00:30:06,839 --> 00:30:08,906 (laughing) 581 00:30:08,908 --> 00:30:10,874 (gunshot echoes) And again. 582 00:30:10,876 --> 00:30:13,710 You need to focus on where your target is going to be, 583 00:30:13,712 --> 00:30:16,046 not where your target is. 584 00:30:16,048 --> 00:30:17,815 (gunshot echoes) 585 00:30:17,817 --> 00:30:20,217 So this reminds me of when I was a child 586 00:30:20,219 --> 00:30:21,285 and watching the Apollo launches. 587 00:30:21,287 --> 00:30:22,653 MAN: All engines running. 588 00:30:22,655 --> 00:30:23,787 We have a lift-off. 589 00:30:23,789 --> 00:30:25,823 VERBISCER: It fascinated me 590 00:30:25,825 --> 00:30:29,960 that they were targeting where the moon was going to be 591 00:30:29,962 --> 00:30:32,563 three days after the launch happened, 592 00:30:32,565 --> 00:30:34,498 and that's when the astronauts would arrive 593 00:30:34,500 --> 00:30:37,100 to try and land on it. 594 00:30:37,102 --> 00:30:40,237 So for New Horizons, the concept is basically the same 595 00:30:40,239 --> 00:30:42,206 as it was for Apollo, 596 00:30:42,208 --> 00:30:45,175 but the distances are far greater. 597 00:30:47,379 --> 00:30:50,380 STERN: We have to intercept where it will be years down the road. 598 00:30:50,382 --> 00:30:51,849 So we have to calculate 599 00:30:51,851 --> 00:30:54,151 where it will end up on the exact day and hour 600 00:30:54,153 --> 00:30:56,320 and literally minute of the fly-by 601 00:30:56,322 --> 00:30:57,654 from years in advance. 602 00:30:59,258 --> 00:31:02,125 NARRATOR: Images taken by the Hubble space telescope 603 00:31:02,127 --> 00:31:06,196 help the team track Ultima Thule's orbit. 604 00:31:06,198 --> 00:31:08,599 But they still need to know more. 605 00:31:08,601 --> 00:31:13,437 They don't know how big it is, or even what shape it is. 606 00:31:13,439 --> 00:31:18,742 JOEL PARKER: Ultima Thule is a completely, almost unknown object. 607 00:31:18,744 --> 00:31:20,711 This is terra incognita. 608 00:31:20,713 --> 00:31:22,913 It's a new world. 609 00:31:22,915 --> 00:31:24,481 Details we don't know. 610 00:31:25,885 --> 00:31:28,552 NARRATOR: But there may be a way to find out more 611 00:31:28,554 --> 00:31:33,457 by observing a rare celestial event. 612 00:31:33,459 --> 00:31:35,726 An occultation in its simplest form 613 00:31:35,728 --> 00:31:38,562 is when something gets in front of something else. 614 00:31:38,564 --> 00:31:41,398 If you've ever been on a beach, 615 00:31:41,400 --> 00:31:44,167 and you're just enjoying a nice sunny day, 616 00:31:44,169 --> 00:31:47,604 and then all of a sudden the sun goes away 617 00:31:47,606 --> 00:31:51,341 because somebody just walked in between you and the sun, 618 00:31:51,343 --> 00:31:53,977 and there's that shadow passes across your face, 619 00:31:53,979 --> 00:31:56,246 the same exact thing is happening here, 620 00:31:56,248 --> 00:32:00,284 except instead of our sun, it's a star, 621 00:32:00,286 --> 00:32:04,488 and if the star is hidden from your view, 622 00:32:04,490 --> 00:32:06,089 you are in the shadow of the Kuiper Belt object. 623 00:32:06,091 --> 00:32:07,591 ¶ ¶ 624 00:32:07,593 --> 00:32:10,460 If you can measure the edge of that shadow, 625 00:32:10,462 --> 00:32:13,263 it shows the shape and size of the object. 626 00:32:14,800 --> 00:32:19,169 Suppose it's moving 20 miles per second across the sky, 627 00:32:19,171 --> 00:32:23,040 and the star disappears for one second, 628 00:32:23,042 --> 00:32:26,710 now you know that it's 20 miles across-- easy. 629 00:32:26,712 --> 00:32:29,680 You just have to be in the right place at the right time. 630 00:32:29,682 --> 00:32:31,648 NARRATOR: But how do you get 631 00:32:31,650 --> 00:32:36,186 to precisely the right place at the right time? 632 00:32:36,188 --> 00:32:38,789 BUIE: There's two pieces to this. 633 00:32:38,791 --> 00:32:40,757 You need to know where the object is, 634 00:32:40,759 --> 00:32:44,695 and that's what Hubble does for us, 635 00:32:44,697 --> 00:32:46,997 but you also need to know where the stars are. 636 00:32:46,999 --> 00:32:51,868 NARRATOR: And that's where the Gaia Mission comes in. 637 00:32:51,870 --> 00:32:54,705 The Gaia Space Observatory has been creating 638 00:32:54,707 --> 00:32:57,374 the most precise three-dimensional star map 639 00:32:57,376 --> 00:32:58,375 of our galaxy 640 00:32:58,377 --> 00:33:01,445 that has ever been made. 641 00:33:01,447 --> 00:33:04,281 BUIE: And we knew that when we had those star positions, 642 00:33:04,283 --> 00:33:07,084 we had a chance of actually predicting 643 00:33:07,086 --> 00:33:09,953 an occultation with M.U.69. 644 00:33:11,457 --> 00:33:13,256 NARRATOR: In the summer of 2017, 645 00:33:13,258 --> 00:33:17,127 the New Horizons team finds a match. 646 00:33:18,430 --> 00:33:21,932 The two best places to view this occultation-- 647 00:33:21,934 --> 00:33:25,302 where their telescopes can detect Ultima's shadow-- 648 00:33:25,304 --> 00:33:29,072 are in the mountains of Argentina 649 00:33:29,074 --> 00:33:32,442 and the countryside of South Africa. 650 00:33:32,444 --> 00:33:36,213 Much like the solar eclipse that many people saw in 2017, 651 00:33:36,215 --> 00:33:37,280 you have to be 652 00:33:37,282 --> 00:33:38,749 in the right place at the right time 653 00:33:38,751 --> 00:33:39,983 to be in the path of the shadow. 654 00:33:39,985 --> 00:33:40,917 So we're here. 655 00:33:43,422 --> 00:33:45,122 Let's hit that first. 656 00:33:45,124 --> 00:33:48,058 VERBISCER: 54 people going to two different continents 657 00:33:48,060 --> 00:33:53,497 to watch an event that takes two seconds to happen? 658 00:33:53,499 --> 00:33:54,798 Overwhelming. 659 00:33:54,800 --> 00:33:58,402 ¶ ¶ 660 00:33:58,404 --> 00:34:00,270 NARRATOR: The teams set up their telescopes 661 00:34:00,272 --> 00:34:02,572 in the middle of nowhere... 662 00:34:04,309 --> 00:34:06,843 And hope for clear skies. 663 00:34:09,915 --> 00:34:12,983 BUIE: We sent 13 telescopes to South Africa. 664 00:34:12,985 --> 00:34:15,485 12 telescopes to Mendoza, Argentina. 665 00:34:17,322 --> 00:34:19,656 NARRATOR: Searching for a blink 666 00:34:19,658 --> 00:34:22,092 four billion miles away. 667 00:34:25,431 --> 00:34:28,565 BUIE: And saw nothing. 668 00:34:28,567 --> 00:34:29,666 (sighs) 669 00:34:29,668 --> 00:34:32,803 All of that work and nothing. 670 00:34:32,805 --> 00:34:35,305 NARRATOR: It turns out 671 00:34:35,307 --> 00:34:37,107 that their estimations of Ultima Thule's orbit 672 00:34:37,109 --> 00:34:39,643 are off. 673 00:34:39,645 --> 00:34:43,747 The star that was supposed to blink continued to shine. 674 00:34:45,484 --> 00:34:48,618 BUIE: Everybody was a little depressed about that. 675 00:34:48,620 --> 00:34:52,322 ¶ ¶ 676 00:34:52,324 --> 00:34:55,525 NARRATOR: A month later, they get a second chance 677 00:34:55,527 --> 00:34:57,794 to find out whatever they can 678 00:34:57,796 --> 00:35:00,597 about Ultima Thule's size and shape, 679 00:35:00,599 --> 00:35:04,101 but to be in the right place at the right time 680 00:35:04,103 --> 00:35:06,937 is going to be even harder. 681 00:35:06,939 --> 00:35:10,807 On July 10, of 2017, there was another occultation 682 00:35:10,809 --> 00:35:14,211 observable only over the South Pacific Ocean, 683 00:35:14,213 --> 00:35:17,848 and really accessible only to the SOFIA aircraft. 684 00:35:19,685 --> 00:35:22,185 NARRATOR: The SOFIA Airborne Observatory 685 00:35:22,187 --> 00:35:25,188 is a specially modified Boeing 747, 686 00:35:25,190 --> 00:35:29,626 with a telescope on its side. 687 00:35:29,628 --> 00:35:31,228 What we're doing here with SOFIA 688 00:35:31,230 --> 00:35:33,897 is putting a very large telescope 689 00:35:33,899 --> 00:35:36,800 into the occultation path 690 00:35:36,802 --> 00:35:38,935 at just the time the shadow is there. 691 00:35:40,772 --> 00:35:43,874 BUIE: The reality is there are so many details, 692 00:35:43,876 --> 00:35:45,108 what are the winds doing, 693 00:35:45,110 --> 00:35:47,410 we had to worry about a turbulence zone 694 00:35:47,412 --> 00:35:50,614 that we might have to fly around. 695 00:35:50,616 --> 00:35:52,883 NARRATOR: The moment of truth arrives. 696 00:35:56,922 --> 00:35:59,156 They wait for the star to blink out. 697 00:36:01,693 --> 00:36:04,594 Are they in the right place at the right time? 698 00:36:06,965 --> 00:36:09,432 Again, they see nothing. 699 00:36:10,802 --> 00:36:12,636 So everybody is kind of depressed again. 700 00:36:12,638 --> 00:36:14,771 Okay, we've done it a second time and we've got nothing. 701 00:36:16,542 --> 00:36:20,443 NARRATOR: After two misses, reality sets in. 702 00:36:20,445 --> 00:36:22,078 BUIE: We thought we struck out twice. 703 00:36:22,080 --> 00:36:23,079 Okay. 704 00:36:23,081 --> 00:36:24,014 What's going to happen next? 705 00:36:26,118 --> 00:36:29,019 NARRATOR: But they get another chance. 706 00:36:29,021 --> 00:36:31,421 VERBISCER: The next occultation in Patagonia 707 00:36:31,423 --> 00:36:33,256 was only seven days later, on July 17. 708 00:36:37,062 --> 00:36:40,931 So really had to shift gears quickly and get ready 709 00:36:40,933 --> 00:36:44,634 to do this next ground-based effort. 710 00:36:44,636 --> 00:36:48,338 STERN: The stellar occultations that we have been attempting, 711 00:36:48,340 --> 00:36:50,240 are the most challenging stellar occultations 712 00:36:50,242 --> 00:36:52,542 ever attempted in history. 713 00:36:52,544 --> 00:36:54,177 Because Ultima is so much further away 714 00:36:54,179 --> 00:36:55,178 than anything else, 715 00:36:55,180 --> 00:36:56,913 and it's tiny. 716 00:37:00,018 --> 00:37:03,019 The night of the occultation, winds were, were pretty bad. 717 00:37:03,021 --> 00:37:04,955 (wind howling) 718 00:37:04,957 --> 00:37:07,524 These telescopes we use are really great 719 00:37:07,526 --> 00:37:09,526 however, they are very wind-sensitive. 720 00:37:09,528 --> 00:37:12,829 We wanted to shield that telescope 721 00:37:12,831 --> 00:37:16,366 from every possible vibration, and that meant we had to do 722 00:37:16,368 --> 00:37:17,734 whatever it took 723 00:37:17,736 --> 00:37:20,303 to get the data and observe the star 724 00:37:20,305 --> 00:37:22,505 without it jiggling around all over the place. 725 00:37:22,507 --> 00:37:24,407 (wind howling) 726 00:37:24,409 --> 00:37:29,012 NARRATOR: For that, they need a few volunteers. 727 00:37:29,014 --> 00:37:31,114 If you just started out with, "We're from NASA," 728 00:37:31,116 --> 00:37:34,217 people just come out of the woodwork. 729 00:37:34,219 --> 00:37:36,987 We had two people show up-- a father and his daughter. 730 00:37:36,989 --> 00:37:40,123 They brought a spare battery. 731 00:37:40,125 --> 00:37:41,791 Perfect, so we put them to work. 732 00:37:41,793 --> 00:37:43,260 ¶ ¶ 733 00:37:43,262 --> 00:37:45,662 NARRATOR: Together, for 45 minutes, 734 00:37:45,664 --> 00:37:49,933 they blocked the wind with a truck, some plywood, and a tarp. 735 00:37:52,738 --> 00:37:53,670 Did they catch it? 736 00:37:56,308 --> 00:37:59,409 We spent hours after people came back with the data 737 00:37:59,411 --> 00:38:03,246 to see whether we got it or not. 738 00:38:03,248 --> 00:38:05,982 (indistinct chatter) 739 00:38:05,984 --> 00:38:10,887 NARRATOR: Does the star blink or have they failed again? 740 00:38:10,889 --> 00:38:17,427 (cheering and applause) 741 00:38:17,429 --> 00:38:22,832 VERBISCER: We'd finally had success and saw the star blink out. 742 00:38:22,834 --> 00:38:24,234 This is what we came for. 743 00:38:24,236 --> 00:38:25,235 This is it. 744 00:38:25,237 --> 00:38:28,071 MAN: Oh, my God. 745 00:38:28,073 --> 00:38:29,172 That's what's it's all about. 746 00:38:29,174 --> 00:38:30,307 Six months worth of work. 747 00:38:30,309 --> 00:38:33,310 Just two frames and the star is gone. 748 00:38:33,312 --> 00:38:36,946 Unbelievable. 749 00:38:36,948 --> 00:38:40,650 NARRATOR: In fact, five telescopes capture the blink. 750 00:38:42,054 --> 00:38:45,422 Each from a different perspective. 751 00:38:45,424 --> 00:38:49,259 When pieced together, their data suggests that Ultima 752 00:38:49,261 --> 00:38:51,795 is about 20 miles long, 753 00:38:51,797 --> 00:38:55,665 but its shape is more complex than anyone expected. 754 00:38:56,968 --> 00:38:59,769 Immediately I could tell this is not just 755 00:38:59,771 --> 00:39:03,473 some simple spherical object that we're looking at. 756 00:39:03,475 --> 00:39:04,507 It's a much more complicated shape. 757 00:39:07,379 --> 00:39:09,546 NARRATOR: They come up with three possibilities. 758 00:39:11,883 --> 00:39:14,317 One is, you have two circular objects 759 00:39:14,319 --> 00:39:17,721 that are close to each other but they're orbiting each other. 760 00:39:19,958 --> 00:39:23,059 Or it could be just some lumpy potato-shaped thing. 761 00:39:23,061 --> 00:39:26,563 ¶ ¶ 762 00:39:26,565 --> 00:39:30,333 And then the third is what we call a contact binary-- 763 00:39:30,335 --> 00:39:31,901 two balls stuck together. 764 00:39:31,903 --> 00:39:33,970 ¶ ¶ 765 00:39:33,972 --> 00:39:36,873 And we think it could happen for Kuiper Belt objects. 766 00:39:36,875 --> 00:39:39,008 We don't know, we've never seen one of these things before. 767 00:39:40,846 --> 00:39:45,448 NARRATOR: But when New Horizons finally brings Ultima Thule into focus, 768 00:39:45,450 --> 00:39:47,984 the results could be profound. 769 00:39:49,488 --> 00:39:53,089 This elusive object could revolutionize our understanding 770 00:39:53,091 --> 00:39:57,794 of how the planets in our solar system formed. 771 00:39:57,796 --> 00:39:59,229 If the solar system is an intricate 772 00:39:59,231 --> 00:40:04,434 and complicated castle, then MU69 is a brick, 773 00:40:04,436 --> 00:40:07,804 and you don't know how this castle was made 774 00:40:07,806 --> 00:40:11,808 until you understand what the brick looks like. 775 00:40:16,047 --> 00:40:18,214 NARRATOR: Four and a half billion years ago, 776 00:40:18,216 --> 00:40:20,150 the planets in our solar system 777 00:40:20,152 --> 00:40:24,087 formed from a massive disk of gas and dust. 778 00:40:27,025 --> 00:40:30,360 Scientists have detected the beginning of this process 779 00:40:30,362 --> 00:40:34,297 in striking images of distant solar systems like this one 780 00:40:34,299 --> 00:40:37,033 known as HL Tauri, 781 00:40:37,035 --> 00:40:41,037 a young star about 450 light years from Earth. 782 00:40:43,241 --> 00:40:44,974 We have these beautiful observations 783 00:40:44,976 --> 00:40:46,376 of disks of gas and dust 784 00:40:46,378 --> 00:40:49,245 around other stars. 785 00:40:49,247 --> 00:40:53,883 So we know that planet formation starts from small dust grains. 786 00:40:53,885 --> 00:40:55,618 NARRATOR: In our own solar system, 787 00:40:55,620 --> 00:40:59,889 scientists theorize that through a process called accretion, 788 00:40:59,891 --> 00:41:04,360 gas and dust stuck together, 789 00:41:04,362 --> 00:41:06,729 a lot like those clumps of dust and dirt 790 00:41:06,731 --> 00:41:10,900 that collect under your bed. 791 00:41:10,902 --> 00:41:15,972 Dust bunnies, held together by a powerful force-- 792 00:41:15,974 --> 00:41:18,475 static electricity. 793 00:41:18,477 --> 00:41:19,642 SCHILICHTING: So you can think of 794 00:41:19,644 --> 00:41:21,077 planet formation, the initial stages, 795 00:41:21,079 --> 00:41:23,446 very similar to just letting your dust bunnies 796 00:41:23,448 --> 00:41:25,915 under your bed grow for millions of years 797 00:41:25,917 --> 00:41:27,217 into bigger and bigger objects. 798 00:41:29,054 --> 00:41:31,221 NARRATOR: If you don't vacuum, 799 00:41:31,223 --> 00:41:34,224 those dust bunnies will just keep getting bigger. 800 00:41:36,127 --> 00:41:39,062 But for the seeds of planets to grow, 801 00:41:39,064 --> 00:41:41,397 they need more. 802 00:41:41,399 --> 00:41:45,235 They need the power of gravity. 803 00:41:45,237 --> 00:41:46,736 (explosions) 804 00:41:46,738 --> 00:41:50,607 After objects reach a certain threshold in their mass, 805 00:41:52,210 --> 00:41:55,745 they can grow more rapidly than they could before, 806 00:41:55,747 --> 00:41:58,414 because they have substantial gravity. 807 00:41:58,416 --> 00:42:00,850 NARRATOR: But there's a catch: 808 00:42:00,852 --> 00:42:03,786 There's a gap between making something this big 809 00:42:03,788 --> 00:42:05,722 and making something the size of a planet. 810 00:42:07,559 --> 00:42:10,527 NARRATOR: How does an object grow from the size of a marble 811 00:42:10,529 --> 00:42:13,263 to the size of a planet? 812 00:42:14,599 --> 00:42:19,135 In the last decade a new theory has emerged. 813 00:42:19,137 --> 00:42:20,537 CAREY LISSE: A stream of marbles 814 00:42:20,539 --> 00:42:22,138 will come along 815 00:42:22,140 --> 00:42:25,208 and as it's moving around the sun and some of them will clump 816 00:42:25,210 --> 00:42:27,477 and you'll suddenly get a huge amount of clumping action 817 00:42:27,479 --> 00:42:28,945 and that's called pebble accretion. 818 00:42:30,549 --> 00:42:33,349 And one of the things we can do by looking at Ultima Thule 819 00:42:33,351 --> 00:42:37,020 is look to see whether it was formed by pebble accretion. 820 00:42:37,022 --> 00:42:39,989 If we see lots of BB- to marble-sized pieces 821 00:42:39,991 --> 00:42:41,491 on the surface of MU69, 822 00:42:41,493 --> 00:42:46,796 we're gonna go "A-ha, this is a loose collection of pebbles." 823 00:42:46,798 --> 00:42:49,098 And pebble accretion argues for things that are 824 00:42:49,100 --> 00:42:51,834 elongated or potato-shaped, which is what we seem to see 825 00:42:51,836 --> 00:42:53,836 for Ultima Thule from our ground base occultation. 826 00:42:55,640 --> 00:43:00,043 JOEL PARKER: We're interested scientifically how planets formed, 827 00:43:00,045 --> 00:43:05,548 although in our hearts we're also interested about 828 00:43:05,550 --> 00:43:08,685 where we came from, how we got here. 829 00:43:08,687 --> 00:43:11,321 What were the elements? 830 00:43:11,323 --> 00:43:15,325 And the outer solar system objects like Ultima Thule 831 00:43:15,327 --> 00:43:17,860 are the raw materials. 832 00:43:17,862 --> 00:43:19,929 And so we're getting a chance to look back 833 00:43:19,931 --> 00:43:23,566 at these well-preserved raw materials 834 00:43:23,568 --> 00:43:27,470 to see really what was the starting point, 835 00:43:27,472 --> 00:43:29,606 what were the ingredients 836 00:43:29,608 --> 00:43:34,544 that went in to the magic recipe that makes life. 837 00:43:39,150 --> 00:43:43,086 NARRATOR: October 4, 2018. 838 00:43:43,088 --> 00:43:45,989 89 days before fly-by, 839 00:43:45,991 --> 00:43:49,325 New Horizons is 30 million miles from Ultima Thule 840 00:43:49,327 --> 00:43:52,128 and closing. 841 00:43:52,130 --> 00:43:53,630 Fred Pelletier 842 00:43:53,632 --> 00:43:56,032 and a group of vigilant navigators 843 00:43:56,034 --> 00:43:59,068 are tracking Ultima's orbit to ensure their spacecraft 844 00:43:59,070 --> 00:44:02,639 won't miss the mark on New Year's Eve. 845 00:44:02,641 --> 00:44:06,609 They rely on images like this taken by New Horizons' 846 00:44:06,611 --> 00:44:09,779 long-range telescope, named Lorri. 847 00:44:09,781 --> 00:44:12,148 But at this distance, 848 00:44:12,150 --> 00:44:15,652 tracking tiny Ultima among a dense field of stars 849 00:44:15,654 --> 00:44:19,088 is no easy task. 850 00:44:19,090 --> 00:44:20,390 FRED PELLETIER: It's a very crowded 851 00:44:20,392 --> 00:44:22,058 star field-- these are all stars 852 00:44:22,060 --> 00:44:24,060 and Ultima is in the center right there. 853 00:44:24,062 --> 00:44:29,799 So what we do is we have a catalog of the starfield 854 00:44:29,801 --> 00:44:32,902 that we use to remove the stars. 855 00:44:32,904 --> 00:44:36,839 We end up with this image that highlights our target, 856 00:44:36,841 --> 00:44:39,108 Ultima Thule, here. 857 00:44:39,110 --> 00:44:42,278 NARRATOR: Next they zoom in to take a closer look 858 00:44:42,280 --> 00:44:47,483 and discover their estimate of Ultima Thule's orbit is off. 859 00:44:47,485 --> 00:44:50,553 PELLETIER: The yellow cross represents where we thought Ultima Thule 860 00:44:50,555 --> 00:44:53,423 would be before we took the picture, 861 00:44:53,425 --> 00:44:56,025 and the blue greenish one 862 00:44:56,027 --> 00:44:58,795 represents, well, where it actually is. 863 00:44:58,797 --> 00:45:02,198 So, as you can see, we're a little bit off. 864 00:45:02,200 --> 00:45:03,332 And the difference here 865 00:45:03,334 --> 00:45:04,901 doesn't seem too much on this scale, 866 00:45:04,903 --> 00:45:08,004 but it's actually 600 miles from the target. 867 00:45:10,041 --> 00:45:12,775 BOWMAN: Because this object is so very, very small, 868 00:45:12,777 --> 00:45:16,279 it's possible that if we are a little bit off, 869 00:45:16,281 --> 00:45:18,581 we could just miss seeing the object 870 00:45:18,583 --> 00:45:20,283 and we certainly don't want to do that. 871 00:45:21,453 --> 00:45:23,252 PELLETIER: There's only one shot 872 00:45:23,254 --> 00:45:26,589 and if you make a mistake, that could be it. 873 00:45:26,591 --> 00:45:28,458 NARRATOR: For the next few weeks, 874 00:45:28,460 --> 00:45:31,661 the navigators will carefully follow Ultima's path, 875 00:45:31,663 --> 00:45:35,998 examine every pixel of every frame 876 00:45:36,000 --> 00:45:39,869 to help guide New Horizons to its target on New Year's. 877 00:45:39,871 --> 00:45:43,005 If their calculations are right 878 00:45:43,007 --> 00:45:44,907 the spacecraft will fly 879 00:45:44,909 --> 00:45:50,279 just 2,200 miles above Ultima's surface. 880 00:45:50,281 --> 00:45:54,417 PELLETIER: This is a comparison of about 30 days out. 881 00:45:54,419 --> 00:45:55,618 What Pluto looked like 882 00:45:55,620 --> 00:45:58,788 and what Ultima Thule looks like right now. 883 00:45:58,790 --> 00:46:02,325 So you're asking me what the challenges are of this mission, 884 00:46:02,327 --> 00:46:06,162 this image is worth a thousand words. 885 00:46:06,164 --> 00:46:07,697 The size of Ultima Thule 886 00:46:07,699 --> 00:46:10,433 is a small dot still, and it will be the case 887 00:46:10,435 --> 00:46:14,103 until a few days before the fly-by. 888 00:46:14,105 --> 00:46:16,272 That makes it very different from Pluto. 889 00:46:18,076 --> 00:46:20,376 NARRATOR: As the weeks go by, 890 00:46:20,378 --> 00:46:25,481 New Horizons sends back more images of the distant dot. 891 00:46:25,483 --> 00:46:29,118 December 29, 2018. 892 00:46:29,120 --> 00:46:30,620 Three days away from the fly-by 893 00:46:30,622 --> 00:46:34,524 and the anticipation is certainly building. 894 00:46:34,526 --> 00:46:35,658 We thought we'd know a lot more by now. 895 00:46:38,696 --> 00:46:39,929 VERBISCER: I think everyone would have said, 896 00:46:39,931 --> 00:46:41,631 "You'll know how fast it's rotating, 897 00:46:41,633 --> 00:46:44,700 can get an idea of what the shape is like. 898 00:46:44,702 --> 00:46:49,772 NARRATOR: But so far, answers remain tantalizingly out of reach. 899 00:46:49,774 --> 00:46:52,475 VERBISCER: It s holding its secrets 900 00:46:52,477 --> 00:46:53,643 to the last possible minute. 901 00:46:53,645 --> 00:46:54,944 I mean we keep saying, 902 00:46:54,946 --> 00:46:57,213 "Well, we're gonna know eventually, right?" 903 00:46:57,215 --> 00:47:00,616 But right now, it's still a mystery. 904 00:47:01,820 --> 00:47:03,786 NARRATOR: As the fly-by approaches, 905 00:47:03,788 --> 00:47:07,924 preparations continue all night. 906 00:47:07,926 --> 00:47:09,859 This evening I'll be sleeping in my office, 907 00:47:09,861 --> 00:47:13,396 so I brought my little backpacking tent in. 908 00:47:13,398 --> 00:47:14,397 I'll have time for sleep later. 909 00:47:15,767 --> 00:47:18,467 BOWMAN: Things have been happening so fast. 910 00:47:18,469 --> 00:47:19,969 Don't ask us what day it is. (laughs) 911 00:47:19,971 --> 00:47:21,470 Most of us cannot remember 912 00:47:21,472 --> 00:47:22,839 whether it's Monday, Tuesday, or whatever. 913 00:47:22,841 --> 00:47:25,408 We know how many days it is to fly-by. 914 00:47:25,410 --> 00:47:27,043 CROWD: Ten... 915 00:47:27,045 --> 00:47:28,744 Nine... Eight... 916 00:47:28,746 --> 00:47:32,448 NARRATOR: January 1, 2019. 917 00:47:32,450 --> 00:47:34,050 12:33 AM. 918 00:47:34,052 --> 00:47:35,484 CROWD: One! 919 00:47:35,486 --> 00:47:37,820 Go New Horizons! 920 00:47:37,822 --> 00:47:40,756 NARRATOR: As the world brings in the new year, 921 00:47:40,758 --> 00:47:42,758 the New Horizons team celebrates the moment 922 00:47:42,760 --> 00:47:47,430 of the spacecraft's closest approach to Ultima Thule. 923 00:47:47,432 --> 00:47:52,235 But it will be hours before anyone knows 924 00:47:52,237 --> 00:47:54,604 if the fly-by is successful. 925 00:47:54,606 --> 00:47:57,340 PARKER: Ultima Thule is so far away 926 00:47:57,342 --> 00:47:59,408 that it takes six hours to send a signal 927 00:47:59,410 --> 00:48:02,979 from the spacecraft to Earth. 928 00:48:02,981 --> 00:48:06,015 Which is crazy, it's a really long time to wait. 929 00:48:07,418 --> 00:48:08,751 NARRATOR: Later that morning, 930 00:48:08,753 --> 00:48:11,621 team members, family, and friends 931 00:48:11,623 --> 00:48:14,824 wait anxiously for New Horizons' signal 932 00:48:14,826 --> 00:48:20,129 to finish crossing four billion miles of space and reach Earth. 933 00:48:20,131 --> 00:48:22,999 Go ahead, RF. 934 00:48:23,001 --> 00:48:24,300 MAN: What the green screens will tell you 935 00:48:24,302 --> 00:48:26,369 and RF is in fantastic shape. 936 00:48:26,371 --> 00:48:28,337 Copy that, RF is green. 937 00:48:28,339 --> 00:48:29,839 NARRATOR: The signal comes in. 938 00:48:29,841 --> 00:48:32,875 But Alice Bowman, New Horizons' MOM, 939 00:48:32,877 --> 00:48:34,710 waits for confirmation 940 00:48:34,712 --> 00:48:38,014 that each system on the spacecraft is working. 941 00:48:38,016 --> 00:48:39,815 Copy thermal is reporting green status. 942 00:48:39,817 --> 00:48:42,184 NARRATOR: Most crucially, she wants to hear 943 00:48:42,186 --> 00:48:45,955 if the digital recorders are full of precious data. 944 00:48:45,957 --> 00:48:47,356 Go ahead, CNDH. 945 00:48:47,358 --> 00:48:49,025 MAN: CNDH is nominal. 946 00:48:49,027 --> 00:48:51,727 Our SSR pointers are right where we predicted. 947 00:48:51,729 --> 00:48:53,529 (crowd cheering, applause) 948 00:48:53,531 --> 00:48:54,530 Copy that. 949 00:48:54,532 --> 00:48:56,699 Whoo! 950 00:48:56,701 --> 00:48:58,401 (applause) 951 00:48:58,403 --> 00:49:00,636 HOLDRIDGE: What that means is that the solid state recorder, 952 00:49:00,638 --> 00:49:02,171 the pointers are where they should be, 953 00:49:02,173 --> 00:49:04,740 that tells me that we observed something. 954 00:49:04,742 --> 00:49:06,342 Something filled that camera. 955 00:49:06,344 --> 00:49:08,210 (applause) 956 00:49:08,212 --> 00:49:10,112 We have a healthy spacecraft. 957 00:49:10,114 --> 00:49:13,349 We've just accomplished the most distant fly-by 958 00:49:13,351 --> 00:49:14,517 of our solar system. 959 00:49:14,519 --> 00:49:19,789 (applause) 960 00:49:24,262 --> 00:49:28,130 ¶ ¶ 961 00:49:28,132 --> 00:49:33,636 NARRATOR: The first close-up image of this distant object comes up. 962 00:49:33,638 --> 00:49:36,238 Well, what we saw today blows out of the water 963 00:49:36,240 --> 00:49:37,606 anything we've seen.