1 00:00:02,102 --> 00:00:07,239 Narrator:our solar system is the home of giants, 2 00:00:07,241 --> 00:00:12,044 gas giants Jupiter and Saturn seems to dominate, 3 00:00:12,046 --> 00:00:15,780 but two ice giants determine the fate of the rest - 4 00:00:15,782 --> 00:00:19,784 Neptune and Uranus,,, 5 00:00:19,786 --> 00:00:23,389 distant planets disconnected from us, 6 00:00:23,391 --> 00:00:26,258 or so we think, 7 00:00:26,260 --> 00:00:29,528 now we know the destination of the ice giants 8 00:00:29,530 --> 00:00:31,796 is intertwined with ours, 9 00:00:31,798 --> 00:00:34,866 they went from being these cold and boring worlds 10 00:00:34,868 --> 00:00:36,668 to really have in them the secret itself 11 00:00:36,670 --> 00:00:39,537 of why you and I exist, 12 00:00:39,539 --> 00:00:41,206 narrator:your story 13 00:00:41,208 --> 00:00:43,409 is an epic migration, 14 00:00:43,411 --> 00:00:45,544 brutal destruction,,, 15 00:00:45,546 --> 00:00:48,947 uranus got upset and then hit his side, 16 00:00:48,949 --> 00:00:53,551 Narrator:,,,of more worlds live more than anyone imagined, 17 00:00:53,553 --> 00:00:57,288 they hold the key to the story of the solar system 18 00:00:57,290 --> 00:01:01,626 and perhaps for life on Earth, 19 00:01:01,628 --> 00:01:02,494 [electric crackles] 20 00:01:02,496 --> 00:01:04,496 [rumbling] 21 00:01:04,498 --> 00:01:08,033 [explosion] 22 00:01:08,035 --> 00:01:10,969 - subtitles by vitac - www,vitac,com 23 00:01:10,971 --> 00:01:13,972 subtitles paid for discovery communications 24 00:01:18,245 --> 00:01:22,181 Narrator:uranus and neptune,,, 25 00:01:22,183 --> 00:01:23,449 mysterious giants 26 00:01:23,451 --> 00:01:27,385 lurking in the cold exterior solar system reaches,,, 27 00:01:27,387 --> 00:01:29,187 ♪♪ 28 00:01:29,189 --> 00:01:33,058 the most distant planets of the sun, 29 00:01:33,060 --> 00:01:35,060 braid:uranus and neptune are type of sentries 30 00:01:35,062 --> 00:01:36,528 from the outer solar system, 31 00:01:36,530 --> 00:01:38,930 they are out past Jupiter and Saturn 32 00:01:38,932 --> 00:01:42,935 as well as,2 billion, 3 billion miles from the sun, 33 00:01:42,937 --> 00:01:44,403 ♪♪ 34 00:01:44,405 --> 00:01:46,804 narrator: its size and location 35 00:01:46,806 --> 00:01:49,741 are a puzzle for planetary astronomers, 36 00:01:49,743 --> 00:01:52,811 uranus and neptune are a little of a mystery because, 37 00:01:52,813 --> 00:01:55,147 in a way, they shouldn't exist, 38 00:01:55,149 --> 00:01:58,816 or at least they shouldn't they exist where they are, 39 00:01:58,818 --> 00:02:01,019 narrator: Scientists can't understand 40 00:02:01,021 --> 00:02:06,091 how these giant planets grew as big as the sun, 41 00:02:06,093 --> 00:02:09,494 ♪♪ 42 00:02:09,496 --> 00:02:13,698 the mystery begins 4 1/2 billion years ago,,, 43 00:02:13,700 --> 00:02:15,167 ♪♪ 44 00:02:15,169 --> 00:02:17,302 ,,,with birth of the solar system, 45 00:02:17,304 --> 00:02:19,705 ♪♪ 46 00:02:19,707 --> 00:02:22,174 at the beginning, the sun lights up from a disk 47 00:02:22,176 --> 00:02:25,577 of gas and dust, 48 00:02:25,579 --> 00:02:30,983 the rocky cores of the first the planets begin to grow, 49 00:02:30,985 --> 00:02:34,986 they collide with the debris in the disk as they orbit the sun, 50 00:02:34,988 --> 00:02:37,121 ♪♪ 51 00:02:37,123 --> 00:02:40,858 but the inner planets has a size limit, 52 00:02:40,860 --> 00:02:44,596 to grow up on a giant planet, you need gas, 53 00:02:44,598 --> 00:02:46,732 ♪♪ 54 00:02:46,734 --> 00:02:51,135 heat from the infant sun's explosions these lighter gas molecules 55 00:02:51,137 --> 00:02:56,074 beyond a point of astronomers call the frost line, 56 00:02:56,076 --> 00:02:59,811 Out here, it's cool enough for gas molecules like hydrogen 57 00:02:59,813 --> 00:03:03,348 and helium to stabilize, 58 00:03:03,350 --> 00:03:08,219 Jupiter and Saturn take shape first,,, 59 00:03:08,221 --> 00:03:13,091 sweeping away the abundant gas and quickly becoming gas giants, 60 00:03:13,093 --> 00:03:16,494 ♪♪ 61 00:03:16,496 --> 00:03:20,365 but neptune and uranus are different, 62 00:03:20,367 --> 00:03:24,036 Jupiter and Saturn are about 90% hydrogen and helium, 63 00:03:24,038 --> 00:03:28,573 while neptune and uranus it's more like 20%, 64 00:03:28,575 --> 00:03:31,109 Narrator: So, what is this? gas difference tell us 65 00:03:31,111 --> 00:03:33,645 about your training? 66 00:03:33,647 --> 00:03:37,449 we suspect that uranus and Neptune arrived a little later 67 00:03:37,451 --> 00:03:41,253 when there was no so much gas to be swept up, 68 00:03:41,255 --> 00:03:42,721 ♪♪ 69 00:03:42,723 --> 00:03:45,991 Narrator:uranus and neptune have less time to suck 70 00:03:45,993 --> 00:03:50,795 both hydrogen and helium before these gases disappear, 71 00:03:50,797 --> 00:03:53,732 but they are also further away, 72 00:03:53,734 --> 00:03:58,337 where it's cold enough to other heavier gases to freeze, 73 00:03:58,339 --> 00:04:01,873 these are swept by the crescent outer planets, 74 00:04:05,079 --> 00:04:07,812 where uranus and neptune there are tons of ice, 75 00:04:07,814 --> 00:04:10,682 tons of frozen gases how can we think of them - 76 00:04:10,684 --> 00:04:12,283 methane, ammonia, water, 77 00:04:12,285 --> 00:04:16,288 and this is what makes up its composition predominantly, 78 00:04:16,290 --> 00:04:17,689 [thunder] 79 00:04:17,691 --> 00:04:20,225 Narrator: they could be smaller than Jupiter and Saturn, 80 00:04:20,227 --> 00:04:24,229 but these heavy ice creams means they grow dense, 81 00:04:24,231 --> 00:04:27,633 They become frost giants, 82 00:04:27,635 --> 00:04:29,701 but there is a problem, 83 00:04:29,703 --> 00:04:32,237 they are very big, 84 00:04:32,239 --> 00:04:35,373 the disk of gas and ice around a newborn star 85 00:04:35,375 --> 00:04:38,110 doesn't last forever 86 00:04:38,112 --> 00:04:39,845 and material within reach 87 00:04:39,847 --> 00:04:43,915 of the solar system is spread out, 88 00:04:43,917 --> 00:04:45,516 Walsh: as you walk away in the solar system, 89 00:04:45,518 --> 00:04:47,586 The time scale for two bodies 90 00:04:47,588 --> 00:04:50,655 to find each other and collide and accrete decreases 91 00:04:50,657 --> 00:04:52,791 because the periods around the sun is much longer 92 00:04:52,793 --> 00:04:55,393 and that just takes a very, very long time, 93 00:04:55,395 --> 00:04:59,931 Narrator:Neptune and Uranus orbit the sun incredibly slowly, 94 00:04:59,933 --> 00:05:03,602 too slowly to collide with lots of cold stuff 95 00:05:03,604 --> 00:05:06,872 to grow into giants we see today, 96 00:05:06,874 --> 00:05:10,542 so when we look at Neptune In this very distant orbit, 97 00:05:10,544 --> 00:05:12,744 we don't have enough time in the solar system 98 00:05:12,746 --> 00:05:14,279 to build a planet like Neptune, 99 00:05:14,281 --> 00:05:16,147 we just don't think we could build Neptune 100 00:05:16,149 --> 00:05:19,351 where we find it today, 101 00:05:19,353 --> 00:05:21,953 so what happened? 102 00:05:21,955 --> 00:05:24,622 it turns out, where do we see them now 103 00:05:24,624 --> 00:05:27,359 probably not where they started, 104 00:05:27,361 --> 00:05:29,227 [whooshing] 105 00:05:29,229 --> 00:05:31,096 oluseyl: one thing we learned about solar systems 106 00:05:31,098 --> 00:05:33,598 is that things are in a delicate balance, 107 00:05:33,600 --> 00:05:36,501 and the planets migrate, they move, 108 00:05:36,503 --> 00:05:39,437 they don't form in one place and stay there forever, 109 00:05:39,439 --> 00:05:42,240 narrator: So what has enough power 110 00:05:42,242 --> 00:05:45,910 to move a giant planet like Neptune? 111 00:05:45,912 --> 00:05:50,715 an even bigger one - Jupiter, 112 00:05:50,717 --> 00:05:52,584 a path for the planets to move 113 00:05:52,586 --> 00:05:55,052 is gravitationally interacting with each other, 114 00:05:55,054 --> 00:05:56,654 so they feel each other's gravity, 115 00:05:56,656 --> 00:06:00,258 they can pull, they can pull, and This effect can lead to planets 116 00:06:00,260 --> 00:06:04,729 migrating slowly in your planetary systems, 117 00:06:04,731 --> 00:06:08,533 Narrator: the two closest planets are, the greater the effect, 118 00:06:08,535 --> 00:06:10,802 and in the early days of the solar system, 119 00:06:10,804 --> 00:06:14,940 the giant planets are much closer, 120 00:06:14,942 --> 00:06:17,476 on top of that, they may have orbited 121 00:06:17,478 --> 00:06:20,745 in a different order of what we see today - 122 00:06:20,747 --> 00:06:26,017 Jupiter, Saturn Neptune and uranus, 123 00:06:26,019 --> 00:06:30,889 so what causes Neptune and uranus to exchange positions? 124 00:06:30,891 --> 00:06:34,292 the answer is with Jupiter and Saturn, 125 00:06:34,294 --> 00:06:39,631 the two biggest giants block in a gravitational dance, 126 00:06:39,633 --> 00:06:42,367 always exists interaction between them, 127 00:06:42,369 --> 00:06:47,105 think of capoeira dancers, balancing and moving together 128 00:06:47,107 --> 00:06:49,574 in a careful and orchestrated way, 129 00:06:49,576 --> 00:06:52,644 ♪♪ 130 00:06:52,646 --> 00:06:57,582 Narrator:more than millions of years, a rhythm slowly develops, 131 00:06:57,584 --> 00:07:00,184 these giants push and pull each other 132 00:07:00,186 --> 00:07:03,655 in more elliptical orbits, 133 00:07:03,657 --> 00:07:09,194 but the gravitational dance reaches its climax, 134 00:07:09,196 --> 00:07:12,464 the stretched orbits become unstable, 135 00:07:12,466 --> 00:07:16,601 The giants went off course, 136 00:07:16,603 --> 00:07:20,271 like saturn and jupiter twist out of the sun 137 00:07:20,273 --> 00:07:23,341 they fling Neptune besides uranus, 138 00:07:23,343 --> 00:07:25,610 ♪♪ 139 00:07:25,612 --> 00:07:28,613 as Neptune moves through the solar system 140 00:07:28,615 --> 00:07:32,083 This pushes the debris forward, 141 00:07:32,085 --> 00:07:36,621 These are the remaining ice creams fragments of the formation of the planet, 142 00:07:36,623 --> 00:07:40,224 Neptune Snowplows these bodies out, 143 00:07:40,226 --> 00:07:43,160 them because the kuiper belt, 144 00:07:43,162 --> 00:07:46,831 the band of thousands small bodies of ice and rock 145 00:07:46,833 --> 00:07:49,367 just beyond the orbit of Neptune, 146 00:07:49,369 --> 00:07:52,437 you can think about the structure from that kuiper belt like, like, 147 00:07:52,439 --> 00:07:54,906 blood splashes on the wall at a murder scene, 148 00:07:54,908 --> 00:07:58,376 It's the record of it Neptune's really violent 149 00:07:58,378 --> 00:08:01,646 migrating out through the solar system, 150 00:08:01,648 --> 00:08:04,649 Narrator: but the movement of Neptune not just fling 151 00:08:04,651 --> 00:08:08,119 these little bodies of ice in the kuiper belt, 152 00:08:08,121 --> 00:08:11,990 Also sends some of them falling towards the sun, 153 00:08:11,992 --> 00:08:15,393 some bomb the beginning of the earth, 154 00:08:15,395 --> 00:08:17,395 It's the most violent moment on our planet 155 00:08:17,397 --> 00:08:20,798 since the birth of the solar system itself, 156 00:08:20,800 --> 00:08:25,003 500 million years later The sun lit up life, 157 00:08:25,005 --> 00:08:28,406 is called the great late bombardment, 158 00:08:28,408 --> 00:08:29,941 during the heavy finale bombing, 159 00:08:29,943 --> 00:08:32,877 you had rocks literally falling descending from the sky constantly, 160 00:08:32,879 --> 00:08:35,746 that would have been a terrible moment in life, 161 00:08:35,748 --> 00:08:38,817 narrator: and yet, This cascade of icy bodies 162 00:08:38,819 --> 00:08:42,487 also brings something essential for life, 163 00:08:42,489 --> 00:08:43,822 [explosion] 164 00:08:43,824 --> 00:08:46,224 a feature of the exterior Solar system bodies 165 00:08:46,226 --> 00:08:48,760 is that we often find organic, 166 00:08:48,762 --> 00:08:50,295 ♪♪ 167 00:08:50,297 --> 00:08:52,831 narrator: organics provide the basis 168 00:08:52,833 --> 00:08:55,500 for all living organisms we found today, 169 00:08:55,502 --> 00:08:58,703 they are carbon-based molecules that form on the surface 170 00:08:58,705 --> 00:09:01,973 of dust grains in the early solar system, 171 00:09:01,975 --> 00:09:06,578 the rocky inner planets sweep these organics as they grow,,, 172 00:09:06,580 --> 00:09:10,782 [whoosh] 173 00:09:10,784 --> 00:09:13,919 but the burnt surfaces of young planets 174 00:09:13,921 --> 00:09:15,720 they are very inhospitable 175 00:09:15,722 --> 00:09:18,623 for many of these delicate molecules to survive, 176 00:09:20,860 --> 00:09:25,429 yet organic remains intact in small icy bodies 177 00:09:25,431 --> 00:09:27,332 of the outer solar system 178 00:09:27,334 --> 00:09:31,402 what neptune launches to the beginning of the Earth, 179 00:09:31,404 --> 00:09:37,208 Neptune was the solar system cosmic delivery service, 180 00:09:37,210 --> 00:09:39,410 as far as uranus and neptune are, 181 00:09:39,412 --> 00:09:42,213 the existence of ice giants in the outer solar system 182 00:09:42,215 --> 00:09:47,218 may have been fundamental to the existence of the Earth today, 183 00:09:47,220 --> 00:09:49,955 narrator: and the frost giants may have done 184 00:09:49,957 --> 00:09:52,690 more than giving life on earth a kickstart, 185 00:09:52,692 --> 00:09:54,892 they may have prevented Our planet 186 00:09:54,894 --> 00:09:58,830 to be completely destroyed, 187 00:09:58,832 --> 00:10:00,498 ♪♪ 188 00:10:06,907 --> 00:10:11,776 [explosion] 189 00:10:11,778 --> 00:10:15,246 Narrator: the frost giants - uranus and neptune, 190 00:10:15,248 --> 00:10:16,647 distant giant worlds 191 00:10:16,649 --> 00:10:20,451 that may have delivered the elements of life to the earth, 192 00:10:20,453 --> 00:10:25,189 Without them, our own planet may not exist at all, 193 00:10:25,191 --> 00:10:27,525 these ice giants are fascinating worlds, 194 00:10:27,527 --> 00:10:29,994 but they can be the same more important than that, 195 00:10:29,996 --> 00:10:33,398 they could be the reason was here, 196 00:10:33,400 --> 00:10:35,332 narrator: About 4 billion years ago, 197 00:10:35,334 --> 00:10:36,735 Newfoundland is under threat 198 00:10:36,737 --> 00:10:41,539 from the bully of our solar system, Jupiter, 199 00:10:41,541 --> 00:10:43,875 positioned between the inner rocky planets 200 00:10:43,877 --> 00:10:45,677 and the external giants, 201 00:10:45,679 --> 00:10:49,280 Jupiter dominates the solar system, 202 00:10:49,282 --> 00:10:52,216 when you have a behemoth like Jupiter in your solar system, 203 00:10:52,218 --> 00:10:57,555 What it does determines in part what everything does, 204 00:10:57,557 --> 00:10:59,757 narrator: like jupiter and saturn lock 205 00:10:59,759 --> 00:11:01,559 in your gravitational dance, 206 00:11:01,561 --> 00:11:06,164 they migrate out, away from the sun, 207 00:11:06,166 --> 00:11:09,033 Jupiter's immense gravity must pull the Earth 208 00:11:09,035 --> 00:11:13,138 and Venus along with him, 209 00:11:13,140 --> 00:11:16,173 orbits of earth and venus must stretch 210 00:11:16,175 --> 00:11:18,176 and overlap with each other, 211 00:11:21,248 --> 00:11:25,049 It's a collision waiting for it to happen,,, 212 00:11:25,051 --> 00:11:29,921 [explosion] 213 00:11:29,923 --> 00:11:32,524 ,,,except,,, 214 00:11:32,526 --> 00:11:33,925 it wasn't, 215 00:11:33,927 --> 00:11:36,193 Walsh: So because of the fact that we are talking about it here on earth 216 00:11:36,195 --> 00:11:37,595 suggests that earth and venus 217 00:11:37,597 --> 00:11:40,265 had no impact at the beginning of the solar system 218 00:11:40,267 --> 00:11:41,933 when jupiter and saturn were migrating, 219 00:11:41,935 --> 00:11:44,535 something appears to protect us, 220 00:11:44,537 --> 00:11:46,671 ♪♪ 221 00:11:46,673 --> 00:11:49,140 narrator: scientists think something pulled Jupiter 222 00:11:49,142 --> 00:11:52,410 in a different orbit before you have a chance to pull 223 00:11:52,412 --> 00:11:55,680 earth and venus on a collision course, 224 00:11:55,682 --> 00:11:58,483 but what could cause such a big leap 225 00:11:58,485 --> 00:12:01,686 in Jupiter's migration? 226 00:12:01,688 --> 00:12:06,290 This is where the frost giants enter the story, 227 00:12:06,292 --> 00:12:09,828 making jupiter to do a big leap in your migration 228 00:12:09,830 --> 00:12:11,095 it's not easy, 229 00:12:11,097 --> 00:12:13,765 and so the best way that the models achieved 230 00:12:13,767 --> 00:12:16,901 to actually recreate that jump is to have Jupiter 231 00:12:16,903 --> 00:12:19,237 actually eject something the size of Neptune 232 00:12:19,239 --> 00:12:21,139 outside the solar system entirely, 233 00:12:24,044 --> 00:12:26,377 braid: Jupiter has a lot of gravity, 234 00:12:26,379 --> 00:12:27,978 and if you get too close to it, 235 00:12:27,980 --> 00:12:30,782 you will be accelerated as you approach jupiter, 236 00:12:30,784 --> 00:12:33,518 and it is possible that you can expel a planet 237 00:12:33,520 --> 00:12:35,787 completely out of the solar system in this way, 238 00:12:35,789 --> 00:12:39,257 It's basically the slingshot, 239 00:12:39,259 --> 00:12:41,392 narrator: but a planet the size of Neptune 240 00:12:41,394 --> 00:12:43,727 It's heavy, even for Jupiter, 241 00:12:43,729 --> 00:12:46,731 and ruin it of the solar system 242 00:12:46,733 --> 00:12:49,267 gives Jupiter a setback, 243 00:12:49,269 --> 00:12:55,873 Jupiter is knocked out orbit and earth is saved, 244 00:12:55,875 --> 00:13:01,078 but which ice giant sacrificed himself for us? 245 00:13:01,080 --> 00:13:04,615 Neptune is still in the solar system, 246 00:13:04,617 --> 00:13:06,751 and it is also uranus, 247 00:13:06,753 --> 00:13:08,086 braid: if you use computer models 248 00:13:08,088 --> 00:13:11,289 practically predict the behavior of the planets, 249 00:13:11,291 --> 00:13:13,224 what did you think is that if you start with jupiter, 250 00:13:13,226 --> 00:13:16,294 Saturn, Uranus and Neptune, you can't save the Earth 251 00:13:16,296 --> 00:13:18,896 without ejecting or uranus or neptune, 252 00:13:18,898 --> 00:13:21,299 but they are there, so we know it's not right, 253 00:13:21,301 --> 00:13:23,234 however, if you add a third ice giant, 254 00:13:23,236 --> 00:13:25,637 a fifth giant planet out there, 255 00:13:25,639 --> 00:13:27,438 so, actually makes everything work, 256 00:13:27,440 --> 00:13:28,706 you can save the Earth, 257 00:13:28,708 --> 00:13:31,042 have the planets in your current configuration, 258 00:13:31,044 --> 00:13:35,246 and this ice giant is expelled of the solar system, 259 00:13:35,248 --> 00:13:36,981 narrator: imagine our solar system 260 00:13:36,983 --> 00:13:40,785 starting with three ice giants, 261 00:13:40,787 --> 00:13:43,988 one swings very close to Jupiter, 262 00:13:43,990 --> 00:13:46,657 the bully of our solar system casts its victim clean 263 00:13:46,659 --> 00:13:49,126 outside the playground, 264 00:13:49,128 --> 00:13:51,396 Jupiter is pushed in a new orbit 265 00:13:51,398 --> 00:13:53,998 by the gravity of the ice giant, 266 00:13:54,000 --> 00:13:59,604 Earth is saved from Jupiter's deadly gravitational pull 267 00:13:59,606 --> 00:14:02,072 and the solar system becomes safe 268 00:14:02,074 --> 00:14:05,809 and orderly place we see today, 269 00:14:05,811 --> 00:14:07,211 so we have a funny story here, 270 00:14:07,213 --> 00:14:10,147 this ice giant that may have existed billions of years ago 271 00:14:10,149 --> 00:14:12,550 pulled Jupiter back to the outer solar system, 272 00:14:12,552 --> 00:14:14,618 preventing this to destroy the earth, 273 00:14:14,620 --> 00:14:17,088 but in the meantime, sacrificed himself for us, 274 00:14:17,090 --> 00:14:18,956 being expelled from the solar system, 275 00:14:18,958 --> 00:14:20,625 we have to be grateful for our existence, 276 00:14:20,627 --> 00:14:24,028 but it's not there anymore, 277 00:14:24,030 --> 00:14:25,830 oluseil: we humans are really lucky, 278 00:14:25,832 --> 00:14:28,966 dinosaurs were not extinct, we wouldn't be here, 279 00:14:28,968 --> 00:14:31,903 If this planet hadn't been ejected of our solar system, 280 00:14:31,905 --> 00:14:33,837 we wouldn't be here, 281 00:14:33,839 --> 00:14:38,242 Narrator: So, where are you? That lost ice giant now? 282 00:14:38,244 --> 00:14:39,978 thaller: The answer is quite surprising, 283 00:14:39,980 --> 00:14:42,313 can be clear throughout the other side 284 00:14:42,315 --> 00:14:43,648 of the milky way galaxy, 285 00:14:43,650 --> 00:14:45,716 the sun moves around the Milky Way Galaxy 286 00:14:45,718 --> 00:14:48,052 in about half a million miles one hour, 287 00:14:48,054 --> 00:14:49,453 and in the history of the earth, 288 00:14:49,455 --> 00:14:50,921 we've been around about 20 times, 289 00:14:50,923 --> 00:14:54,658 we could have lost this planet anywhere in the milky way, 290 00:14:54,660 --> 00:14:56,994 ♪♪ 291 00:14:56,996 --> 00:15:00,265 narrator: but it's this third ice giant 292 00:15:00,267 --> 00:15:04,135 really lost or simply hidden? 293 00:15:04,137 --> 00:15:07,205 ♪♪ 294 00:15:07,207 --> 00:15:11,609 January 2016 - astronomers at caltech 295 00:15:11,611 --> 00:15:15,013 make an amazing advertisement, 296 00:15:15,015 --> 00:15:17,081 they claim to have evidence found 297 00:15:17,083 --> 00:15:21,885 of a mysterious nine planet disturbing the frozen bodies 298 00:15:21,887 --> 00:15:25,556 very far in the kuiper belt, 299 00:15:25,558 --> 00:15:29,827 simulations suggest that, if this the so-called planet nine exists, 300 00:15:29,829 --> 00:15:33,364 is of similar size Neptune and uranus, 301 00:15:33,366 --> 00:15:36,167 Could this be Earth's savior? 302 00:15:36,169 --> 00:15:39,303 could the solar system primary lack 303 00:15:39,305 --> 00:15:43,040 sacrificial ice giant be planet nine? 304 00:15:43,042 --> 00:15:45,443 [rumbling] 305 00:15:45,445 --> 00:15:46,644 yes, you could, 306 00:15:46,646 --> 00:15:48,980 narrator: maybe this third ice giant 307 00:15:48,982 --> 00:15:52,516 was not expelled from the solar system, after all, 308 00:15:52,518 --> 00:15:54,652 batygin:a type of ejection is where you simply take something 309 00:15:54,654 --> 00:15:56,454 and you throw it away of the solar system, 310 00:15:56,456 --> 00:15:57,789 but another kinder kind 311 00:15:57,791 --> 00:16:00,658 It's when you're not well go all out, 312 00:16:00,660 --> 00:16:04,328 and instead you carry on a very, very long orbit 313 00:16:04,330 --> 00:16:07,398 around the young solar system, 314 00:16:07,400 --> 00:16:10,268 Narrator:planet nine is thought to be so far away, 315 00:16:10,270 --> 00:16:15,206 takes 20 thousand years so that he travels around the sun, 316 00:16:15,208 --> 00:16:18,075 maybe you noticed the dramatic, 317 00:16:18,077 --> 00:16:19,811 dynamic evolution of the solar system 318 00:16:19,813 --> 00:16:26,216 Unfold from your frigid 20,000 year orbit, 319 00:16:26,218 --> 00:16:29,820 Narrator: if planet nine is it a long lost brother or not, 320 00:16:29,822 --> 00:16:33,891 ice giants played a huge role in taming Jupiter, 321 00:16:33,893 --> 00:16:39,497 they made our solar system paradise is today, 322 00:16:39,499 --> 00:16:43,634 but they are not peaceful places, 323 00:16:43,636 --> 00:16:45,837 Somehow, in the deep freeze, 324 00:16:45,839 --> 00:16:49,107 Neptune is tormented through the wild climate 325 00:16:49,109 --> 00:16:55,646 mysterious superstorms and maybe even the rain of diamonds, 326 00:17:02,188 --> 00:17:06,391 [explosion] 327 00:17:06,393 --> 00:17:07,991 ♪♪ 328 00:17:07,993 --> 00:17:11,529 Narrator:uranus and neptune - 329 00:17:11,531 --> 00:17:14,298 its location on the edge of our solar system 330 00:17:14,300 --> 00:17:17,068 makes them very difficult study, 331 00:17:17,070 --> 00:17:19,070 the ice giants uranus and Neptune 332 00:17:19,072 --> 00:17:20,738 are very mysterious to us, 333 00:17:20,740 --> 00:17:23,474 they are very far away, so they are difficult to observe 334 00:17:23,476 --> 00:17:27,478 with telescopes here on earth, 335 00:17:27,480 --> 00:17:28,879 Narrator: As a result, 336 00:17:28,881 --> 00:17:33,017 these planets have been neglected for a long time, 337 00:17:33,019 --> 00:17:37,221 the only time we glimpse these distant giants up close 338 00:17:37,223 --> 00:17:41,158 that was when voyager 2 They passed them in the 1980s, 339 00:17:41,160 --> 00:17:43,294 ♪♪ 340 00:17:43,296 --> 00:17:46,964 The results surprised Heidi Hammel, part of voyager 2 341 00:17:46,966 --> 00:17:50,101 image team at the time from Neptune Flyby, 342 00:17:50,103 --> 00:17:52,437 ♪♪ 343 00:17:52,439 --> 00:17:55,906 one of the most wonderful and frustrating things 344 00:17:55,908 --> 00:18:00,711 about planetary flyers is that you learned so much 345 00:18:00,713 --> 00:18:06,250 that you open a whole pandora's box of questions, 346 00:18:06,252 --> 00:18:10,788 Narrator: an observation curiously intrigued scientists, 347 00:18:10,790 --> 00:18:12,489 [whoosh] 348 00:18:12,491 --> 00:18:16,927 Neptune has the fastest winds in the solar system, 349 00:18:16,929 --> 00:18:18,462 [wind howling] 350 00:18:18,464 --> 00:18:20,864 here on earth, our winds are actually driven 351 00:18:20,866 --> 00:18:24,335 at different temperatures of sunlight, 352 00:18:24,337 --> 00:18:26,270 Neptune is so far away of the sun 353 00:18:26,272 --> 00:18:29,941 who receives almost without energy from our star, 354 00:18:29,943 --> 00:18:32,609 Neptune is 3 billion miles of the sun, 355 00:18:32,611 --> 00:18:37,948 It's really cold there, so why Do you have such fast winds? 356 00:18:37,950 --> 00:18:40,952 Narrator: less energy a planet receives from the sun 357 00:18:40,954 --> 00:18:44,021 quieter we hope It's the time to be,,, 358 00:18:44,023 --> 00:18:46,090 ♪♪ 359 00:18:46,092 --> 00:18:50,494 but neptune is not calm, 360 00:18:50,496 --> 00:18:55,032 is covered by massive violent storms, 361 00:18:55,034 --> 00:18:57,701 there are storms that rival 362 00:18:57,703 --> 00:19:00,637 the size of the inner planets, 363 00:19:00,639 --> 00:19:02,507 This is a big storm, 364 00:19:02,509 --> 00:19:05,242 Narrator: one of the greatest already recorded on Neptune 365 00:19:05,244 --> 00:19:09,847 is known as the 1989 big dark spot 366 00:19:09,849 --> 00:19:12,183 a single great storm, 367 00:19:12,185 --> 00:19:15,253 big enough to swallow the whole earth, 368 00:19:15,255 --> 00:19:19,256 riding in a jet stream with a sensible wind speed 369 00:19:19,258 --> 00:19:21,792 of 1,500 miles per hour, 370 00:19:21,794 --> 00:19:23,794 hands down, Neptune keeps the record 371 00:19:23,796 --> 00:19:27,198 for the fastest wind speeds in the solar system, 372 00:19:27,200 --> 00:19:30,000 Braid: the fastest tornado winds on earth 373 00:19:30,002 --> 00:19:32,069 are just a few one hundred miles per hour, 374 00:19:32,071 --> 00:19:34,538 and that does devastating destruction, 375 00:19:34,540 --> 00:19:38,075 so it's hard to imagine What would Neptune's winds do, 376 00:19:38,077 --> 00:19:41,345 Narrator: a probe that enters Neptune's upper atmosphere 377 00:19:41,347 --> 00:19:44,949 would record freezing temperatures 378 00:19:44,951 --> 00:19:47,884 minus 370 degrees Fahrenheit - 379 00:19:47,886 --> 00:19:51,689 Very cold to generate the wind we see, 380 00:19:51,691 --> 00:19:54,958 600 miles below, however, the probe is crushed 381 00:19:54,960 --> 00:19:58,963 by relentless Neptune jet stream winds, 382 00:19:58,965 --> 00:20:04,035 [winds howling] 383 00:20:04,037 --> 00:20:09,440 and the further you go, the hotter it becomes, 384 00:20:09,442 --> 00:20:11,709 Neptune is almost three times 385 00:20:11,711 --> 00:20:14,311 so much heat coming from your inside 386 00:20:14,313 --> 00:20:17,048 than you would expect of a ball of gas 387 00:20:17,050 --> 00:20:20,318 at the distance of Neptune, 388 00:20:20,320 --> 00:20:23,454 the strange thing about these high speed neptune winds 389 00:20:23,456 --> 00:20:26,857 is that they are not fed by the heat energy of the sun, 390 00:20:26,859 --> 00:20:29,259 in fact, they are fed by thermal energy 391 00:20:29,261 --> 00:20:31,996 from the very interior of Neptune, 392 00:20:31,998 --> 00:20:33,998 [blowing] 393 00:20:34,000 --> 00:20:38,402 Narrator: So, where is this? does the internal heat come from? 394 00:20:38,404 --> 00:20:42,205 when planets form, it is a violent event, very energetic, 395 00:20:42,207 --> 00:20:44,608 and the planets are really extremely hot, 396 00:20:44,610 --> 00:20:48,412 and it takes billions of years so that the heat escapes, 397 00:20:48,414 --> 00:20:49,880 so neptune, after all, 398 00:20:49,882 --> 00:20:52,616 probably still have one tremendous amount of this heat 399 00:20:52,618 --> 00:20:55,820 that is trapped inside it, and, as the bubbles bubble, 400 00:20:55,822 --> 00:20:57,688 is what it really is warming the atmosphere 401 00:20:57,690 --> 00:21:00,024 and directing it tremendous time, 402 00:21:00,026 --> 00:21:01,558 [whooshing] 403 00:21:01,560 --> 00:21:05,896 Narrator: then, like Neptune Keep so much heat? 404 00:21:05,898 --> 00:21:10,368 the secret is deep below the atmosphere, 405 00:21:10,370 --> 00:21:12,303 Kipping: how do you go down and down and down, 406 00:21:12,305 --> 00:21:14,305 you will find the pressure gets more and more intense 407 00:21:14,307 --> 00:21:17,375 until you are eventually essentially crushed, 408 00:21:17,377 --> 00:21:20,044 launch:this atmosphere will have thicker and thicker like a fog 409 00:21:20,046 --> 00:21:23,047 until suddenly you would realize that instead of an atmosphere, 410 00:21:23,049 --> 00:21:26,249 you are in an ocean, 411 00:21:26,251 --> 00:21:30,921 narrator:neptune has a super dense fluid mantle 412 00:21:30,923 --> 00:21:35,793 methane compound, ammonia and water, 413 00:21:35,795 --> 00:21:39,930 really, a frost giant is not a solid ball of ice, 414 00:21:39,932 --> 00:21:45,603 but rather an ocean in motion of liquid material rotating, 415 00:21:45,605 --> 00:21:48,739 Narrator: this swirling liquid traps heat, 416 00:21:48,741 --> 00:21:52,610 acting like a blanket, isolating the core, 417 00:21:52,612 --> 00:21:57,081 this is the secret to Neptune's wild time 418 00:21:57,083 --> 00:21:59,016 and the intense heat inside 419 00:21:59,018 --> 00:22:02,620 and pressure in Neptune's methane-rich mantle 420 00:22:02,622 --> 00:22:07,224 you can create another extraordinary effect, 421 00:22:07,226 --> 00:22:09,093 braid: the pressure is so intense 422 00:22:09,095 --> 00:22:10,627 that the methane breaks down, 423 00:22:10,629 --> 00:22:12,830 and methane is made carbon and hydrogen, 424 00:22:12,832 --> 00:22:16,032 So if you take carbon and you compress it too much, 425 00:22:16,034 --> 00:22:18,369 could you get diamond formation 426 00:22:18,371 --> 00:22:20,905 and it is perfectly possible 427 00:22:20,907 --> 00:22:24,307 what literal diamonds they are raining 428 00:22:24,309 --> 00:22:29,313 in this ocean of the mantle fluid in Neptune, 429 00:22:29,315 --> 00:22:31,782 [satellite survey] 430 00:22:31,784 --> 00:22:34,985 Narrator:from superstorms to diamond rain 431 00:22:34,987 --> 00:22:40,057 Neptune is weird dynamics beyond expectation, 432 00:22:40,059 --> 00:22:43,060 but uranus is the real mystery, 433 00:22:43,062 --> 00:22:47,130 victim of a cosmic punch of a year with seasons 434 00:22:47,132 --> 00:22:50,401 unlike anything else in the solar system, 435 00:22:58,677 --> 00:23:03,013 [explosion] 436 00:23:03,015 --> 00:23:05,215 ♪♪ 437 00:23:05,217 --> 00:23:09,353 narrator: January 1986 - 438 00:23:09,355 --> 00:23:14,692 Voyager 2 approaches Uranus at over 40,000 miles per hour, 439 00:23:14,694 --> 00:23:19,563 the astronomers waited for this moment 8 years ago, 440 00:23:19,565 --> 00:23:22,099 but upon the arrival of the traveler, 441 00:23:22,101 --> 00:23:26,903 all that is revealed is a soft, pale and blue ball, 442 00:23:26,905 --> 00:23:28,572 that was a little disappointing 443 00:23:28,574 --> 00:23:30,307 from my point of view 444 00:23:30,309 --> 00:23:34,512 as a scientist studying the planet's atmosphere, 445 00:23:34,514 --> 00:23:39,516 Narrator: 20 years later, everything changes, 446 00:23:39,518 --> 00:23:45,656 telescopes reveal big storms raging across the planet, 447 00:23:45,658 --> 00:23:47,858 Why the huge difference? 448 00:23:47,860 --> 00:23:53,597 the answer is on the planet extreme axial tilt, 449 00:23:53,599 --> 00:23:56,934 if neptune and uranus they are brothers, 450 00:23:56,936 --> 00:24:00,070 uranus is definitely the villainous brother, 451 00:24:00,072 --> 00:24:01,872 all planets are tilted with respect for the solar system, 452 00:24:01,874 --> 00:24:03,540 The earth is 23 degrees, 453 00:24:03,542 --> 00:24:05,475 Jupiter is just a handful of degrees, 454 00:24:05,477 --> 00:24:07,878 but uranus is actually on your side, 455 00:24:07,880 --> 00:24:11,081 is inclined 98 degrees, 456 00:24:11,083 --> 00:24:14,951 Narrator: the tilt of uranus is almost four times as extreme 457 00:24:14,953 --> 00:24:17,621 than any other planet in the system, 458 00:24:17,623 --> 00:24:21,024 You're lying like that, you poles are horizontal 459 00:24:21,026 --> 00:24:24,561 and its rings and moons are vertical relatives 460 00:24:24,563 --> 00:24:28,365 to the plane of the solar system, 461 00:24:28,367 --> 00:24:30,968 The Earth's tilt gives seasons, 462 00:24:30,970 --> 00:24:36,640 extreme tilt of uranus gives extreme seasons, 463 00:24:36,642 --> 00:24:40,110 twice a year, its poles are pointed directly in the direction 464 00:24:40,112 --> 00:24:43,513 or away from the sun, 465 00:24:43,515 --> 00:24:47,784 so that each pole has a very intense period of midnight sun 466 00:24:47,786 --> 00:24:51,789 and a dark, cold polar night, 467 00:24:51,791 --> 00:24:55,325 it takes Uranus 84 years to orbit the sun, 468 00:24:55,327 --> 00:24:58,862 so these seasons last for a long period of time, 469 00:24:58,864 --> 00:25:01,198 ♪♪ 470 00:25:01,200 --> 00:25:03,066 you start, like, 20 years of sunlight 471 00:25:03,068 --> 00:25:05,802 in the northern hemisphere like your going around the sun 472 00:25:05,804 --> 00:25:08,738 and 20 years of darkness in the southern hemisphere, 473 00:25:08,740 --> 00:25:13,811 ♪♪ 474 00:25:13,813 --> 00:25:15,946 Uranus is kind of like "Game of Thrones," 475 00:25:15,948 --> 00:25:18,282 you've been waiting ages for winter to come, 476 00:25:18,284 --> 00:25:20,750 and then the winter lasts 20 years, 477 00:25:20,752 --> 00:25:22,953 ♪♪ 478 00:25:22,955 --> 00:25:25,956 narrator: one winter night or a summer day 479 00:25:25,958 --> 00:25:27,558 that has lasted for decades, 480 00:25:27,560 --> 00:25:30,694 But what happens in the meantime? when the planet's orbit 481 00:25:30,696 --> 00:25:33,497 understand sunlight reaches its spinning equator 482 00:25:33,499 --> 00:25:36,166 instead of one of its poles? 483 00:25:36,168 --> 00:25:40,904 when it's to the side, the entire planet lit up, 484 00:25:40,906 --> 00:25:46,243 As it rotates, each piece of the planet is exposed to sunlight, 485 00:25:46,245 --> 00:25:49,113 narrator:sunlight hits the equator of the planet rotating, 486 00:25:49,115 --> 00:25:53,116 pumping energy to the surface, the warming of the atmosphere 487 00:25:53,118 --> 00:25:56,720 and direct air currents around the planet, 488 00:25:56,722 --> 00:26:02,258 the result -- spring and autumn storms, 489 00:26:02,260 --> 00:26:06,797 This extreme change in the way lots of sunlight is distributed 490 00:26:06,799 --> 00:26:09,199 through this planet's atmosphere 491 00:26:09,201 --> 00:26:12,269 probably plays an important role 492 00:26:12,271 --> 00:26:15,472 In driving it is remarkable seasonal change 493 00:26:15,474 --> 00:26:19,677 we see in the atmosphere of Uranus, 494 00:26:19,679 --> 00:26:22,746 narrator:unlike your ice giant brother, Neptune, 495 00:26:22,748 --> 00:26:28,018 Uranus has seasonal storms rather than the constants, 496 00:26:28,020 --> 00:26:31,154 so why Uranus roll around the sun 497 00:26:31,156 --> 00:26:34,891 while other planets rotate like tops? 498 00:26:34,893 --> 00:26:40,163 This goes against everything know about planetary formation, 499 00:26:40,165 --> 00:26:42,366 in some respects, forming new planets of the solar system 500 00:26:42,368 --> 00:26:45,369 it was very similar making cotton candy, 501 00:26:45,371 --> 00:26:49,105 there was a direction that everything was falling into place, 502 00:26:49,107 --> 00:26:50,907 if you put a stick down in it, 503 00:26:50,909 --> 00:26:52,575 the material would be accumulate around him 504 00:26:52,577 --> 00:26:55,245 in a certain direction, That's why all the planets 505 00:26:55,247 --> 00:26:57,914 have approximately the same orbital axes, 506 00:26:57,916 --> 00:27:00,784 ♪♪ 507 00:27:00,786 --> 00:27:04,521 narrator: if Uranus began with a vertical orbital axis, 508 00:27:04,523 --> 00:27:07,724 how do they end turned sideways? 509 00:27:07,726 --> 00:27:10,594 ♪♪ 510 00:27:10,596 --> 00:27:12,796 [Explosion] 511 00:27:12,798 --> 00:27:15,065 We know there were a lot of collisions between planets 512 00:27:15,067 --> 00:27:18,802 or planet-sized objects at the beginning of the Solar System, 513 00:27:18,804 --> 00:27:25,208 ♪♪ 514 00:27:25,210 --> 00:27:28,679 It's natural to assume that Uranus was probably hit 515 00:27:28,681 --> 00:27:31,281 as a grazing impact of another giant object, 516 00:27:31,283 --> 00:27:33,750 that tilted to the side, 517 00:27:33,752 --> 00:27:35,819 ♪♪ 518 00:27:35,821 --> 00:27:38,622 Narrator: but there's a problem With this assumption, 519 00:27:38,624 --> 00:27:41,291 if you hit uranus with a single impact to knock him down 520 00:27:41,293 --> 00:27:42,760 98 degrees, 521 00:27:42,762 --> 00:27:45,295 then actually what do you expect is that the rings are left over 522 00:27:45,297 --> 00:27:47,964 would be orbiting in the wrong direction 523 00:27:47,966 --> 00:27:50,434 relative to the planet's spin, 524 00:27:50,436 --> 00:27:54,237 ♪♪ 525 00:27:54,239 --> 00:27:56,306 narrator: the event could be powerful enough 526 00:27:56,308 --> 00:27:57,708 to turn a planet, 527 00:27:57,710 --> 00:28:02,112 but gentle enough to bring everything in orbit around him 528 00:28:02,114 --> 00:28:05,048 for the ride? 529 00:28:05,050 --> 00:28:07,250 a single big collision 530 00:28:07,252 --> 00:28:09,186 That's probably not what happened to Uranus 531 00:28:09,188 --> 00:28:11,521 because that would have been very disturbing, 532 00:28:11,523 --> 00:28:13,189 ♪♪ 533 00:28:13,191 --> 00:28:14,591 It's kind of like boxing, 534 00:28:14,593 --> 00:28:18,395 instead of a big knockout blow, it was the old one-two, 535 00:28:18,397 --> 00:28:20,731 ♪♪ 536 00:28:20,733 --> 00:28:22,800 narrator: one theory suggests that 537 00:28:22,802 --> 00:28:26,269 Newly formed Uranus is hit by a protoplanet 538 00:28:26,271 --> 00:28:27,538 the size of the earth, 539 00:28:27,540 --> 00:28:29,606 ♪♪ 540 00:28:29,608 --> 00:28:33,343 the scam is just looking, 541 00:28:33,345 --> 00:28:37,548 uranus is partially knocked down for your current inclination, 542 00:28:37,550 --> 00:28:40,083 your ring system survive the impact 543 00:28:40,085 --> 00:28:42,486 and remains in orbit around the equator, 544 00:28:42,488 --> 00:28:45,022 ♪♪ 545 00:28:45,024 --> 00:28:49,359 as the second object accesses, Uranus is knocked down all the way, 546 00:28:49,361 --> 00:28:52,229 and the rings follow, 547 00:28:52,231 --> 00:28:56,099 Uranus was speared and then hit him in the side, 548 00:28:56,101 --> 00:28:58,902 ♪♪ 549 00:28:58,904 --> 00:29:01,638 narrator:Uranus can orbit the sun sides, 550 00:29:01,640 --> 00:29:06,976 but Neptune's moon, Triton, has an even stranger trajectory, 551 00:29:06,978 --> 00:29:10,380 travels around Neptune on the contrary, 552 00:29:10,382 --> 00:29:14,651 but stranger than that, seems to be erupting, 553 00:29:14,653 --> 00:29:17,253 and could still harbor life, 554 00:29:17,255 --> 00:29:20,357 ♪♪ 555 00:29:26,932 --> 00:29:31,067 [Explosion] 556 00:29:31,069 --> 00:29:32,669 ♪♪ 557 00:29:32,671 --> 00:29:34,871 narrator: wherever we see planets, 558 00:29:34,873 --> 00:29:37,207 we hope to see moons, 559 00:29:37,209 --> 00:29:42,412 the planet seems to be bigger, The orbit of more moons around, 560 00:29:42,414 --> 00:29:46,550 ♪♪ 561 00:29:46,552 --> 00:29:51,054 Jupiter is 69, Saturn is 61, 562 00:29:53,425 --> 00:29:56,226 Then come the frost giants, 563 00:29:56,228 --> 00:30:00,630 astronomers have so far detected 27 moons around uranus 564 00:30:00,632 --> 00:30:02,566 and 13 around Neptune, 565 00:30:02,568 --> 00:30:04,500 ♪♪ 566 00:30:04,502 --> 00:30:09,039 but it stands out completely,,, 567 00:30:09,041 --> 00:30:12,175 Neptune's moon, Triton, 568 00:30:12,177 --> 00:30:14,044 ♪♪ 569 00:30:14,046 --> 00:30:15,445 Triton is a little strange 570 00:30:15,447 --> 00:30:17,981 because instead of in orbit Neptune in the same direction 571 00:30:17,983 --> 00:30:19,316 that Neptune rotates, 572 00:30:19,318 --> 00:30:21,317 the orbits in the opposite direction, 573 00:30:21,319 --> 00:30:24,922 what we call a retrograde orbit, 574 00:30:24,924 --> 00:30:27,524 narrator: a giant planet and its moons 575 00:30:27,526 --> 00:30:30,260 form the same round gas disc, 576 00:30:30,262 --> 00:30:33,664 dust and rocky material, 577 00:30:33,666 --> 00:30:36,532 the lighter gas falls in the center more easily, 578 00:30:36,534 --> 00:30:38,201 forming the planet, 579 00:30:38,203 --> 00:30:40,737 while some of the the heaviest rocky material 580 00:30:40,739 --> 00:30:44,474 is left on disk, forming the moons, 581 00:30:44,476 --> 00:30:46,409 ♪♪ 582 00:30:46,411 --> 00:30:48,946 Typically, the moon travels in the same direction 583 00:30:48,948 --> 00:30:50,614 that the planet is in orbit, 584 00:30:50,616 --> 00:30:52,816 but in case of triton and neptune, 585 00:30:52,818 --> 00:30:56,887 this is the complete Otherwise, 586 00:30:56,889 --> 00:30:58,488 thaller: We know it couldn't have formed 587 00:30:58,490 --> 00:30:59,690 in orbit around Neptune, 588 00:30:59,692 --> 00:31:01,825 had to come were Elsewhere, 589 00:31:01,827 --> 00:31:04,227 and a wonderful track where did it come from 590 00:31:04,229 --> 00:31:07,297 It's the next door neighbor, Pluto, 591 00:31:07,299 --> 00:31:09,566 narrator: Pluto is a dwarf planet 592 00:31:09,568 --> 00:31:11,367 in the next kuiper belt, 593 00:31:11,369 --> 00:31:14,571 It's only 200 miles smaller than Triton, 594 00:31:14,573 --> 00:31:18,975 but it's not just size that makes these two bodies similar, 595 00:31:18,977 --> 00:31:21,111 It's their composition, 596 00:31:21,113 --> 00:31:24,781 Spencer:Triton is actually more like Pluto, 597 00:31:24,783 --> 00:31:28,051 has a similar amount of stone inside, 598 00:31:28,053 --> 00:31:29,786 has a similar surface composition 599 00:31:29,788 --> 00:31:32,055 with a lot of nitrogen and methane, 600 00:31:32,057 --> 00:31:34,391 it really seems a world like Pluto, 601 00:31:34,393 --> 00:31:36,393 but it just happens be in orbit around a planet 602 00:31:36,395 --> 00:31:40,330 instead of orbiting the sun, 603 00:31:40,332 --> 00:31:42,599 narrator: if Triton is like Pluto, 604 00:31:42,601 --> 00:31:47,604 perhaps life also began on the kuiper belt, 605 00:31:47,606 --> 00:31:51,008 could have been captured by Neptune's gravity, 606 00:31:51,010 --> 00:31:54,210 pulled to the orbit of the gas giant? 607 00:31:54,212 --> 00:31:55,812 ♪♪ 608 00:31:55,814 --> 00:31:59,415 It's not easy to capture a moon in orbit around a planet, 609 00:31:59,417 --> 00:32:02,485 It's not natural for a body get closer to another world 610 00:32:02,487 --> 00:32:04,087 and just spiral, 611 00:32:04,089 --> 00:32:07,858 you somehow have to put the brakes when it is close, 612 00:32:09,694 --> 00:32:12,162 narrator: for neptune to capture triton, 613 00:32:12,164 --> 00:32:17,634 Triton had to be slowed down, but how? 614 00:32:17,636 --> 00:32:21,171 again, kuiper belt objects keep a track, 615 00:32:21,173 --> 00:32:24,240 many of the biggest are binary pairs 616 00:32:24,242 --> 00:32:26,376 two worlds orbiting each other, 617 00:32:26,378 --> 00:32:29,646 like pluto and its big moon charon, 618 00:32:29,648 --> 00:32:34,518 maybe Triton was one of a pair too, 619 00:32:34,520 --> 00:32:37,787 if Triton were in orbit with a partner 620 00:32:37,789 --> 00:32:41,324 each of the two travel at different speeds, 621 00:32:41,326 --> 00:32:44,928 This difference in speed is the key, 622 00:32:44,930 --> 00:32:47,530 Triton's speed is just a little slower, 623 00:32:47,532 --> 00:32:50,801 how your companion is orbiting, is slow enough 624 00:32:50,803 --> 00:32:53,003 that could really be captured by Neptune, 625 00:32:53,005 --> 00:32:56,673 while that other one would speed up throughout the solar system, 626 00:32:56,675 --> 00:33:00,744 ♪♪ 627 00:33:00,746 --> 00:33:03,479 narrator: Triton's original dance partner 628 00:33:03,481 --> 00:33:04,881 is tossed and thrown away, 629 00:33:04,883 --> 00:33:11,088 Triton has a new, very greater companion, Neptune, 630 00:33:11,090 --> 00:33:17,160 but these unlikely partners they are dancing out of sync, 631 00:33:17,162 --> 00:33:21,365 capture explains the orbit backwards, 632 00:33:21,367 --> 00:33:25,702 but there is a strange mystery to solve, 633 00:33:25,704 --> 00:33:27,170 on a moon like triton, 634 00:33:27,172 --> 00:33:30,173 we hope to see very cratered terrain, 635 00:33:30,175 --> 00:33:34,177 the registered trademark of geologically dead worlds, 636 00:33:34,179 --> 00:33:41,118 Instead,Voyager 2reveals a surprisingly alive world, 637 00:33:41,120 --> 00:33:42,853 I think one of the most incredible discoveries 638 00:33:42,855 --> 00:33:46,389 of the traveler's entire mission is that when we passed behind Triton, 639 00:33:46,391 --> 00:33:48,658 we saw these jets liquid nitrogen 640 00:33:48,660 --> 00:33:50,193 leaving the surface, 641 00:33:50,195 --> 00:33:53,397 We had no idea that this cold little world 642 00:33:53,399 --> 00:33:56,133 There would still be life there, 643 00:33:56,135 --> 00:33:59,936 Narrator:smooth, icy planes covers the surface, 644 00:33:59,938 --> 00:34:02,939 nitrogen geysers pierce the crust 645 00:34:02,941 --> 00:34:07,477 and scatters black dust 5 miles to the sky, 646 00:34:07,479 --> 00:34:11,748 we thought it was very far from The sun, very cold, very dead, 647 00:34:11,750 --> 00:34:13,884 was going to be an ice ball 648 00:34:13,886 --> 00:34:18,822 like all the other moons which had tended to be, but, no, 649 00:34:18,824 --> 00:34:21,691 It's a fresh new surface, 650 00:34:21,693 --> 00:34:24,828 ♪♪ 651 00:34:24,830 --> 00:34:26,496 Narrator: Triton's surface is 652 00:34:26,498 --> 00:34:29,232 a 200 degree ice cream below zero, 653 00:34:29,234 --> 00:34:31,368 ♪♪ 654 00:34:31,370 --> 00:34:36,506 where does the heat come from to generate these surface features? 655 00:34:36,508 --> 00:34:42,045 the answer is with Neptune's capture of Triton, 656 00:34:42,047 --> 00:34:46,783 Triton's orbit is circular, but it was once elliptical, 657 00:34:46,785 --> 00:34:50,053 ♪♪ 658 00:34:50,055 --> 00:34:53,389 as Triton approached and further, 659 00:34:53,391 --> 00:34:55,325 would have been repeatedly crushed 660 00:34:55,327 --> 00:34:58,394 and stretched by Neptune's gravity, 661 00:34:58,396 --> 00:35:00,463 This would generate enormous amounts of friction 662 00:35:00,465 --> 00:35:01,731 inside the triton, 663 00:35:01,733 --> 00:35:04,267 may well have completely melted newt 664 00:35:04,269 --> 00:35:05,668 Due to these forces, 665 00:35:05,670 --> 00:35:08,605 and how it happened, would have acted as a brake, 666 00:35:08,607 --> 00:35:12,475 everything that friction would have Triton's circular orbit 667 00:35:12,477 --> 00:35:14,611 and left it in orbit that we see today, 668 00:35:14,613 --> 00:35:16,812 ♪♪ 669 00:35:16,814 --> 00:35:21,884 Narrator:this change in orbit is what gives Triton its heat, 670 00:35:21,886 --> 00:35:24,087 the surface of triton froze, 671 00:35:24,089 --> 00:35:27,224 but the moon still holds back part of this heat 672 00:35:27,226 --> 00:35:29,692 deep beneath the icy shell, 673 00:35:29,694 --> 00:35:32,295 ♪♪ 674 00:35:32,297 --> 00:35:37,099 astronomers think there is enough heat to melt the ice in water, 675 00:35:37,101 --> 00:35:40,370 forming a meter liquid ocean 676 00:35:40,372 --> 00:35:44,241 in a world of 3 billion miles of the sun, 677 00:35:44,243 --> 00:35:48,844 liquid water,heat,,, there's just one question, 678 00:35:48,846 --> 00:35:52,048 and it is impossible not to ask for it, 679 00:35:52,050 --> 00:35:54,651 Could there be life? 680 00:35:54,653 --> 00:35:56,619 if there is a source of energy in the triton, 681 00:35:56,621 --> 00:35:59,655 so maybe there is a form of the life he discovered 682 00:35:59,657 --> 00:36:01,992 how to enjoy from that energy source, 683 00:36:01,994 --> 00:36:05,528 ♪♪ 684 00:36:05,530 --> 00:36:07,063 Narrator:an incredible thought, 685 00:36:07,065 --> 00:36:10,800 if life created a niche, this frozen ball 686 00:36:10,802 --> 00:36:14,737 could be the furthest habitable world of the sun, 687 00:36:14,739 --> 00:36:17,073 ♪♪ 688 00:36:17,075 --> 00:36:20,009 Neptune's moon, Triton, may be alive, 689 00:36:20,011 --> 00:36:23,346 but the moons of uranus are even stranger, 690 00:36:23,348 --> 00:36:27,416 they have a neat trick to cheat death entirely, 691 00:36:27,418 --> 00:36:31,922 ♪♪ 692 00:36:38,430 --> 00:36:40,096 [Explosion] 693 00:36:40,098 --> 00:36:45,501 narrator:uranus - a frost giant with beautiful, 694 00:36:45,503 --> 00:36:48,771 sparkling rings and 27 moons,,, 695 00:36:48,773 --> 00:36:51,041 ♪♪ 696 00:36:51,043 --> 00:36:54,777 and its position is a mystery, 697 00:36:54,779 --> 00:36:58,982 half exists inside a tightly packed orbit, 698 00:36:58,984 --> 00:37:01,450 shouldn't be possible for these many moons 699 00:37:01,452 --> 00:37:06,056 be so close proximity to each other, 700 00:37:06,058 --> 00:37:08,658 the environment around uranus is very busy, 701 00:37:08,660 --> 00:37:10,727 and the system seems unstable 702 00:37:10,729 --> 00:37:12,528 and the moons must be colliding 703 00:37:12,530 --> 00:37:15,532 but we still see it cool, well-formed moons, 704 00:37:15,534 --> 00:37:18,201 ♪♪ 705 00:37:18,203 --> 00:37:21,203 and what is even more surprising is that in 2003, 706 00:37:21,205 --> 00:37:23,073 hubble space telescope revealed 707 00:37:23,075 --> 00:37:26,542 two new rings and two new moons - 708 00:37:26,544 --> 00:37:29,879 cupid and mab, 709 00:37:29,881 --> 00:37:34,751 question is, where come these moons? 710 00:37:34,753 --> 00:37:39,823 a clue is in the rings of uranus, 711 00:37:39,825 --> 00:37:41,891 besides being very packed lunar system 712 00:37:41,893 --> 00:37:43,893 You also have rings around uranus, 713 00:37:43,895 --> 00:37:46,028 Which is also a little unexpected 714 00:37:46,030 --> 00:37:48,231 but these two unexpected qualities 715 00:37:48,233 --> 00:37:51,901 could really explain to each other, 716 00:37:51,903 --> 00:37:56,105 whenever you see a touch system, You are seeing part of a process, 717 00:37:56,107 --> 00:38:03,179 ♪♪ 718 00:38:03,181 --> 00:38:04,781 there was probably a time in the history of Earth 719 00:38:04,783 --> 00:38:08,384 when he had a ring, you know, when our moon was being formed, 720 00:38:08,386 --> 00:38:11,788 Narrator: it seems like the new the moons are made of material 721 00:38:11,790 --> 00:38:15,325 from a previous ring system, 722 00:38:15,327 --> 00:38:18,795 but when scientists model cupid future, 723 00:38:18,797 --> 00:38:24,667 they discover it is dangerously close to another moon, belinda, 724 00:38:24,669 --> 00:38:27,603 in a few thousand years, two of the moons in particular, 725 00:38:27,605 --> 00:38:30,540 cupid and belinda, are likely to collide together 726 00:38:30,542 --> 00:38:33,343 as their trajectories intersect, 727 00:38:33,345 --> 00:38:38,014 Narrator: and this collision will create a domino effect, 728 00:38:38,016 --> 00:38:39,349 when there is a moon collision, 729 00:38:39,351 --> 00:38:42,685 which creates a delicate gravitational balance 730 00:38:42,687 --> 00:38:44,621 and also creates lots of debris, 731 00:38:44,623 --> 00:38:48,891 then a collision triggers a series of collisions, 732 00:38:48,893 --> 00:38:51,361 narrator: we think cupid and belinda 733 00:38:51,363 --> 00:38:53,563 will destroy not just each other, 734 00:38:53,565 --> 00:38:56,566 but all the inner moons of uranus, 735 00:38:56,568 --> 00:39:03,106 an unbridled cascade of destruction Mole the moons of Uranus to pebbles, 736 00:39:03,108 --> 00:39:08,178 all this will happen in just a few thousand years, 737 00:39:08,180 --> 00:39:10,180 the fact that we are predicting have a collision 738 00:39:10,182 --> 00:39:12,582 within a few thousand years seems a bit contrary 739 00:39:12,584 --> 00:39:15,518 because this system was here for billions of years, 740 00:39:15,520 --> 00:39:18,521 so it seems a little lucky that we are looking at now, 741 00:39:18,523 --> 00:39:22,124 and we think there will be a collision in the near future, 742 00:39:22,126 --> 00:39:23,993 ♪♪ 743 00:39:23,995 --> 00:39:26,462 Narrator: what if this cycle of destruction 744 00:39:26,464 --> 00:39:31,000 is a case of Uruguay Groundhog Day? 745 00:39:31,002 --> 00:39:34,003 [clanking] 746 00:39:37,809 --> 00:39:39,875 when you look at the uranium system 747 00:39:39,877 --> 00:39:42,846 I like to think about this kind of like a violent hockey game, 748 00:39:46,684 --> 00:39:48,651 The guys are having big hits, 749 00:39:52,090 --> 00:39:54,023 they can't go on, So, what should you do? 750 00:39:54,025 --> 00:39:57,494 [men shout indistinctly] 751 00:39:57,496 --> 00:39:59,629 you have to subite them in and out, 752 00:39:59,631 --> 00:40:02,098 when you look at this game this is violent, 753 00:40:02,100 --> 00:40:04,167 you know the guys you see in the ice 754 00:40:04,169 --> 00:40:07,236 It's not the guys the game started, 755 00:40:07,238 --> 00:40:08,238 whoo! 756 00:40:08,240 --> 00:40:11,240 It's a new set of players, 757 00:40:11,242 --> 00:40:12,508 Narrator:like hockey subs, 758 00:40:12,510 --> 00:40:17,313 uranus keeps its moons Fresh recycling them, 759 00:40:17,315 --> 00:40:18,515 [buzzer] 760 00:40:18,517 --> 00:40:19,849 every time these moons collide, 761 00:40:19,851 --> 00:40:22,585 the forms of debris a ring system around uranus, 762 00:40:22,587 --> 00:40:23,786 and, over time, 763 00:40:23,788 --> 00:40:28,190 this ring system begins to generate new moons, 764 00:40:28,192 --> 00:40:30,260 narrator: Over time, the debris rings 765 00:40:30,262 --> 00:40:34,330 that surround uranus form in new moons 766 00:40:34,332 --> 00:40:39,401 which in turn collide and grind each other to dust, 767 00:40:39,403 --> 00:40:42,071 uranus, after all, In fact, it is very eco-conscious, 768 00:40:42,073 --> 00:40:43,339 your moons break, 769 00:40:43,341 --> 00:40:45,741 they beat each other, form all these remains, 770 00:40:45,743 --> 00:40:48,745 and then the reformation of the moons from this material, 771 00:40:48,747 --> 00:40:52,081 and then the whole pattern, The whole cycle starts again, 772 00:40:52,083 --> 00:40:56,619 and the moons crash, break and new moons form again, 773 00:40:56,621 --> 00:40:59,489 ultimately, this eternal cycle of life and death 774 00:40:59,491 --> 00:41:01,624 that we see with these moons could be a story 775 00:41:01,626 --> 00:41:04,694 this is actually somewhat true of many things in the universe, 776 00:41:04,696 --> 00:41:06,496 When it comes to stars, planets, 777 00:41:06,498 --> 00:41:10,433 and maybe even the universe itself, 778 00:41:10,435 --> 00:41:13,837 Narrator:uranus and neptune, 779 00:41:13,839 --> 00:41:17,707 outposts no longer forgotten of the solar system, 780 00:41:17,709 --> 00:41:23,847 suddenly, these planets are revealed to you as worlds, 781 00:41:23,849 --> 00:41:27,383 it's breathtaking, It's - it's inspiring, 782 00:41:27,385 --> 00:41:31,521 It's humiliating, and you are proud 783 00:41:31,523 --> 00:41:33,055 that you are part of a species 784 00:41:33,057 --> 00:41:34,924 this could really do it, 785 00:41:34,926 --> 00:41:38,661 to leave and to see these places, 786 00:41:38,663 --> 00:41:40,930 narrator: dynamic worlds with dramatic, 787 00:41:40,932 --> 00:41:45,734 often violent stories, stolen moons 788 00:41:45,736 --> 00:41:48,338 giants cast into the cold, 789 00:41:48,340 --> 00:41:52,675 saving the Earth of destruction, 790 00:41:52,677 --> 00:41:55,811 uranus and neptune are enigmas parts in the solar system, 791 00:41:55,813 --> 00:41:59,015 they are giant planets, 792 00:41:59,017 --> 00:42:02,352 they have a lot to tell us, not just about themselves 793 00:42:02,354 --> 00:42:04,220 but about everything in our solar system, 794 00:42:04,222 --> 00:42:07,222 including our own planet, the earth, 795 00:42:07,224 --> 00:42:09,692 somewhere in history of the ice giants 796 00:42:09,694 --> 00:42:11,427 is the reason why you and me are really here 797 00:42:11,429 --> 00:42:12,762 to talk about it, 798 00:42:12,764 --> 00:42:15,298 the reason for the earth capable of forming and stabilizing 799 00:42:15,300 --> 00:42:17,499 and become a environment for life, 800 00:42:17,501 --> 00:42:19,835 wouldn't be an exaggeration to say 801 00:42:19,837 --> 00:42:22,037 that the ice giants are the coolest planets 802 00:42:22,039 --> 00:42:23,973 in the solar system, 803 00:42:23,975 --> 00:42:28,611 ♪♪