Solar.System.2024.S01E04.1080p.BluRay.x264-DRCOX_track3_[eng] Movie Subtitles

1 00:00:06,80 --> 00:00:08,80 (WIND WHISTLES) 2 00:00:26,560 --> 00:00:29,880 If | asked you, "What is a planet made of?" 3 00:00:30,00 --> 00:00:34,280 then you'd probably say, "Well, rocks and iron." 4 00:00:37,840 --> 00:00:39,760 And for the planets of the inner solar system, 5 00:00:39,880 --> 00:00:44,80 like Earth, close to the heat of the sun, you'd be right. 6 00:00:48,400 --> 00:00:51,360 But if you head out into the frozen outer reaches 7 00:00:51,480 --> 00:00:52,720 of the solar system, 8 00:00:52,840 --> 00:00:56,40 then even the gases that make up our atmosphere, 9 00:00:56,160 --> 00:01:00,40 so nitrogen and carbon dioxide and, of course, water 10 00:01:00,160 --> 00:01:01,720 are all frozen solid. 11 00:01:03,840 --> 00:01:06,160 And the planets and moons out there, 12 00:01:06,280 --> 00:01:08,240 the mountains and glaciers, 13 00:01:08,360 --> 00:01:11,760 and even the crust of the worlds themselves, 14 00:01:11,880 --> 00:01:13,680 are made of that - 15 00:01:13,800 --> 00:01:17,760 solid, frozen, pristine ice. 16 00:01:19,480 --> 00:01:21,840 Ice that, in the extreme conditions 17 00:01:21,960 --> 00:01:23,720 we find beyond Earth, 18 00:01:23,840 --> 00:01:27,320 behaves in ways we never imagined possible. 19 00:01:33,880 --> 00:01:36,160 As we've explored the solar system, 20 00:01:36,280 --> 00:01:40,00 our spacecraft have encountered moons torn apart... 21 00:01:41,720 --> 00:01:45,280 ...by great canyons of shifting ice... 22 00:01:49,440 --> 00:01:52,880 ... dwarf planets where mountains of solid ice 23 00:01:53,00 --> 00:01:54,640 float across the surface... 24 00:01:58,200 --> 00:02:01,280 ...worlds where ice appears to cover one face... 25 00:02:03,360 --> 00:02:05,800 ...but leaves the other entirely alone. 26 00:02:11,600 --> 00:02:15,360 And elsewhere, alien aurora hang above the clouds, 27 00:02:15,480 --> 00:02:19,960 all thanks to a strange, newly discovered form of ice. 28 00:02:25,520 --> 00:02:27,520 Even here, on Earth, 29 00:02:27,640 --> 00:02:32,240 the behaviour of something as simple as ice has had, 30 00:02:32,360 --> 00:02:34,560 we think, profound consequences. 31 00:02:34,680 --> 00:02:38,720 Because without ice's counterintuitive behaviour, 32 00:02:38,840 --> 00:02:42,800 life on our planet may not have survived. 33 00:03:11,640 --> 00:03:14,320 We begin our journey to the ice worlds 34 00:03:14,440 --> 00:03:17,480 at the freezing edge of the solar system. 35 00:03:34,600 --> 00:03:38,160 Out here, the sun Is so far away, 36 00:03:38,280 --> 00:03:40,760 it resembles just another star. 37 00:03:47,40 --> 00:03:48,480 Pluto is so remote 38 00:03:48,600 --> 00:03:51,360 that it was only in July 2015 39 00:03:51,480 --> 00:03:55,240 that we had our first and, to date, only close encounter. 40 00:04:01,280 --> 00:04:03,880 As it flew by, the New Horizons spacecraft 41 00:04:04,00 --> 00:04:06,400 sent back the first close-up images 42 00:04:06,520 --> 00:04:08,880 of this mysterious frozen world. 43 00:04:17,800 --> 00:04:20,320 It discovered a great heart-shaped plain 44 00:04:20,440 --> 00:04:22,480 1,000km across 45 00:04:22,600 --> 00:04:24,720 that dominates one face. 46 00:04:36,560 --> 00:04:38,320 Around the edge of this plain, 47 00:04:38,440 --> 00:04:43,400 mountains made of solid ice tower over Pluto's surface. 48 00:04:52,120 --> 00:04:54,520 And amongst its rugged uplands, 49 00:04:54,640 --> 00:04:56,640 ice was detected in a form 50 00:04:56,760 --> 00:04:59,840 no-one ever expected to see on Pluto. 51 00:05:05,40 --> 00:05:06,400 Glaciers. 52 00:05:08,480 --> 00:05:12,120 Flowing rivers of ice on a world so far away, 53 00:05:12,240 --> 00:05:15,00 we expected nothing would be moving. 54 00:05:17,440 --> 00:05:19,520 That's because the temperature here 55 00:05:19,640 --> 00:05:24,400 is only 40 degrees Celsius or so away from absolute zero... 56 00:05:25,920 --> 00:05:28,880 ...a temperature at which nothing should move. 57 00:05:33,80 --> 00:05:36,320 And yet New Horizons discovered regions of Pluto 58 00:05:36,440 --> 00:05:38,120 that for all the world 59 00:05:38,240 --> 00:05:41,360 look like the frozen reaches of our planet. 60 00:06:05,520 --> 00:06:07,440 So when you fly here over the years, 61 00:06:07,560 --> 00:06:08,960 how much does it change? 62 00:06:09,80 --> 00:06:10,120 It changes every day. 63 00:06:10,240 --> 00:06:11,360 - Yeah? - Yeah. 64 00:06:13,520 --> 00:06:15,680 The shape of the glaciers change. 65 00:06:16,920 --> 00:06:18,400 It's never the same. 66 00:06:21,480 --> 00:06:24,240 I'm just imagining flying over Pluto, actually... 67 00:06:24,360 --> 00:06:25,440 (CHUCKLES) 68 00:06:25,560 --> 00:06:27,840 ...beCause it looks remarkably similar. 69 00:06:27,960 --> 00:06:29,00 Really? 70 00:06:31,120 --> 00:06:34,120 - What is the topography like? - It's like this. 71 00:06:34,240 --> 00:06:36,760 Same topography, same mountain heights. 72 00:06:36,880 --> 00:06:38,320 LEIGHAN: That's incredible! 73 00:06:46,640 --> 00:06:49,880 PROF COX: The discovery of Pluto's dynamic icy landscapes 74 00:06:50,00 --> 00:06:51,800 came as a huge shock. 75 00:06:54,480 --> 00:06:57,120 It forced us to rethink our understanding 76 00:06:57,240 --> 00:06:59,280 of this so-called dwarf planet. 77 00:07:00,960 --> 00:07:02,360 LEIGHAN: We're coming in for landing, 78 00:07:02,480 --> 00:07:05,240 so I'll just be talking to the airplane and not you. 79 00:07:05,360 --> 00:07:06,800 PROF COxX: | respect that choice. 80 00:07:06,920 --> 00:07:07,840 (LEIGHAN LAUGHS) 81 00:07:07,960 --> 00:07:11,40 I've had a lot of landings, but none quite like this. 82 00:07:12,120 --> 00:07:13,760 In fact, none like this at all. 83 00:07:14,880 --> 00:07:18,280 It's the world's most beautiful runway! 84 00:07:24,480 --> 00:07:27,480 LEIGHAN: Welcome to the glacier, you guys! 85 00:07:27,600 --> 00:07:29,840 (PROPELLER SLOWS) 86 00:07:29,960 --> 00:07:31,760 (WIND WHISTLES) 87 00:07:38,200 --> 00:07:39,320 Wow! 88 00:07:41,560 --> 00:07:43,640 You know, when we arrived, 89 00:07:43,760 --> 00:07:45,680 they said, "Oh, it's zero degrees," 90 00:07:45,800 --> 00:07:49,80 and | thought, "That's great. Zero degrees, it's warm." 91 00:07:49,200 --> 00:07:51,880 Fahrenheit. Zero degrees Fahrenheit. 92 00:07:52,00 --> 00:07:54,40 It's about minus 20 up here. 93 00:07:54,160 --> 00:07:55,320 It's just... 94 00:07:55,440 --> 00:07:57,920 And you g***t a real sense actually, coming in, 95 00:07:58,40 --> 00:08:00,200 of...it looks frigid and frozen, 96 00:08:00,320 --> 00:08:03,40 you know, unmoving, unchanging, 97 00:08:03,160 --> 00:08:04,640 but it's so dynamic. 98 00:08:04,760 --> 00:08:07,240 You can feel it in the wind as you land. 99 00:08:07,360 --> 00:08:09,600 And then, you know, you can see... 100 00:08:09,720 --> 00:08:12,320 ...you can see the way that everything flows. 101 00:08:19,240 --> 00:08:21,40 Just look at that glacier. 102 00:08:22,360 --> 00:08:26,40 You can almost feel or see it moving. 103 00:08:26,160 --> 00:08:29,40 It looks like a slow-motion river, 104 00:08:29,160 --> 00:08:31,00 and indeed it is moving. 105 00:08:31,120 --> 00:08:33,480 It does flow very, very slowly. 106 00:08:35,680 --> 00:08:36,720 And the reason 107 00:08:36,840 --> 00:08:39,520 this great mass can grind its way down the valley 108 00:08:39,640 --> 00:08:42,720 is because of the unique properties of the ice 109 00:08:42,840 --> 00:08:44,880 from which it's made. 110 00:08:48,960 --> 00:08:52,520 That bright-blue ice certainly looks solid. 111 00:08:52,640 --> 00:08:54,40 Immovable. 112 00:08:54,160 --> 00:08:56,560 It's formed by pressure. 113 00:08:56,680 --> 00:08:59,160 So these snowflakes are falling down 114 00:08:59,280 --> 00:09:02,200 onto the top of the glacier, and over time they build up, 115 00:09:02,320 --> 00:09:04,00 and their weight presses down, 116 00:09:04,120 --> 00:09:05,720 increasing the pressure, 117 00:09:05,840 --> 00:09:09,320 and you get that particular crystalline structure of ice, 118 00:09:09,440 --> 00:09:12,200 which looks transparent and blue. 119 00:09:13,440 --> 00:09:15,400 But actually, at those pressures and temperatures, 120 00:09:15,520 --> 00:09:17,40 it's not completely solid. 121 00:09:17,160 --> 00:09:19,800 The crystals are sort of arranged in planes, 122 00:09:19,920 --> 00:09:22,40 a little bit like a deck of cards. 123 00:09:22,160 --> 00:09:24,600 And that means that as gravity is acting, 124 00:09:24,720 --> 00:09:26,640 trying to slide this whole thing 125 00:09:26,760 --> 00:09:28,80 down the valley. 126 00:09:28,200 --> 00:09:32,00 those planes can slip and slide over each other, 127 00:09:32,120 --> 00:09:35,280 and that allows the whole glacier to move. 128 00:09:35,400 --> 00:09:38,280 You can also get liquid water between the rock and the ice, 129 00:09:38,400 --> 00:09:40,320 and that sort of lubricates the glacier, 130 00:09:40,440 --> 00:09:42,320 and that allows it to slip as well. 131 00:09:42,440 --> 00:09:45,760 So although this looks fixed and immovable, 132 00:09:45,880 --> 00:09:48,360 at the conditions we find on Earth, 133 00:09:48,480 --> 00:09:52,200 this can almost behave like a...like a fluid, 134 00:09:52,320 --> 00:09:57,640 sort of sliding very slowly and deforming down the valley. 135 00:10:07,00 --> 00:10:11,200 Glaciers were the last things we expected to see on Pluto. 136 00:10:11,320 --> 00:10:14,360 It's so cold here that we'd expect 137 00:10:14,480 --> 00:10:17,80 the ice crystals to be too brittle to flow. 138 00:10:20,600 --> 00:10:24,00 Nothing should slip, nothing should slide. 139 00:10:29,360 --> 00:10:32,520 Yet that's precisely what these glaciers are doing. 140 00:10:37,520 --> 00:10:40,200 So if they can't be made of water ice, 141 00:10:40,320 --> 00:10:42,480 what are they made of? 142 00:10:54,200 --> 00:10:56,640 As New...