1 00:00:01,070 --> 00:00:03,244 Viewers like you make this program possible. 2 00:00:03,244 --> 00:00:05,350 Support your local PBS station. 3 00:00:13,289 --> 00:00:15,705 NARRATOR: Across the solar system, 4 00:00:15,705 --> 00:00:20,020 spectacular storms are raging. 5 00:00:20,020 --> 00:00:22,539 JAMES DOTTIN: What we've learned about weather on other planets 6 00:00:22,539 --> 00:00:25,611 has rewritten the rulebook on what we thought was possible. 7 00:00:25,611 --> 00:00:28,925 NARRATOR: From corrosive clouds... 8 00:00:28,925 --> 00:00:32,342 GEORGE DRANSFIELD: If you were to go skydiving through the clouds of Venus, 9 00:00:32,342 --> 00:00:35,104 there wouldn't be a lot of you left at the end. 10 00:00:35,104 --> 00:00:37,865 NARRATOR: ...to global dust storms. 11 00:00:37,865 --> 00:00:41,455 DAVID GRINSPOON: On Mars, the whole atmosphere basically freaks out, 12 00:00:41,455 --> 00:00:44,734 and the storm grows to the point 13 00:00:44,734 --> 00:00:46,356 where it engulfs the entire planet. 14 00:00:46,356 --> 00:00:48,082 We don't have anything like that on Earth. 15 00:00:48,082 --> 00:00:52,017 NARRATOR: Storms found in unexpected places... 16 00:00:52,017 --> 00:00:55,710 DERRICK PITTS: It's a moon that looks like this! 17 00:00:55,710 --> 00:00:58,713 How do you have these features on the moon of a planet? 18 00:00:58,713 --> 00:01:03,477 NARRATOR: ...and made of bizarre materials. 19 00:01:03,477 --> 00:01:05,375 SHANNON MACKENZIE: Buckets and buckets of rain 20 00:01:05,375 --> 00:01:07,412 are falling on the surface, and yet, 21 00:01:07,412 --> 00:01:09,690 it's not water raining out of the atmosphere, 22 00:01:09,690 --> 00:01:10,725 but liquid methane. 23 00:01:10,725 --> 00:01:13,280 NARRATOR: Extra-terrestrial weather 24 00:01:13,280 --> 00:01:15,454 makes exploration challenging. 25 00:01:17,663 --> 00:01:20,183 ABIGAIL FRAEMAN: Seeing the skies get darker and darker and darker, 26 00:01:20,183 --> 00:01:21,633 we started to realize that, 27 00:01:21,633 --> 00:01:24,429 "Oh, this is actually, this is a really bad one." 28 00:01:24,429 --> 00:01:28,295 NARRATOR: But can teach us so much. 29 00:01:28,295 --> 00:01:31,815 PETER GAO: It opens up the possibilities of, "What is weather?" 30 00:01:34,163 --> 00:01:40,134 NARRATOR: What drives these exotic storms raging across the solar system? 31 00:01:40,134 --> 00:01:44,345 And how do they shape a planet's destiny? 32 00:01:44,345 --> 00:01:47,866 "Solar System: Storm Worlds." 33 00:01:47,866 --> 00:01:51,559 Right now, on "NOVA." 34 00:01:51,559 --> 00:01:57,910 ♪ 35 00:02:09,094 --> 00:02:11,165 NARRATOR: It's midsummer. 36 00:02:11,165 --> 00:02:17,585 ♪ 37 00:02:17,585 --> 00:02:20,416 A storm is brewing. 38 00:02:24,765 --> 00:02:29,494 ♪ 39 00:02:29,494 --> 00:02:32,945 It unleashes torrents of rain... 40 00:02:37,778 --> 00:02:42,507 ...forming floods that drain into rushing rivers... 41 00:02:42,507 --> 00:02:48,271 ♪ 42 00:02:48,271 --> 00:02:51,274 ...and giant lakes. 43 00:02:51,274 --> 00:02:55,071 ♪ 44 00:02:55,071 --> 00:02:59,938 This is the only world in our solar system 45 00:02:59,938 --> 00:03:03,942 where rainstorms pummel the surface. 46 00:03:03,942 --> 00:03:08,188 ♪ 47 00:03:08,188 --> 00:03:11,708 The only world other than Earth. 48 00:03:16,368 --> 00:03:21,028 Here, more than 800 million miles from the sun... 49 00:03:23,133 --> 00:03:26,516 ...orbits the largest of Saturn's moons. 50 00:03:30,279 --> 00:03:32,833 In some ways, Titan is more similar to Earth 51 00:03:32,833 --> 00:03:35,663 than any other place in the solar system. 52 00:03:35,663 --> 00:03:37,631 But upon closer inspection, 53 00:03:37,631 --> 00:03:40,116 you will find that it's actually exceptionally alien. 54 00:03:40,116 --> 00:03:43,292 The surface temperature of Titan 55 00:03:43,292 --> 00:03:46,571 is around - 300 degrees Fahrenheit. 56 00:03:46,571 --> 00:03:50,195 NARRATOR: Far too cold for liquid water. 57 00:03:52,197 --> 00:03:53,957 DOTTIN: What's fascinating is that 58 00:03:53,957 --> 00:03:56,236 the rain that's falling out of the sky on Titan 59 00:03:56,236 --> 00:03:57,547 and filling up the lakes 60 00:03:57,547 --> 00:04:00,964 is usually found on Earth as a flammable gas. 61 00:04:04,623 --> 00:04:05,866 NARRATOR: Methane. 62 00:04:05,866 --> 00:04:09,732 Titan is a world shaped by alien storms, 63 00:04:09,732 --> 00:04:12,597 and it is not alone. 64 00:04:12,597 --> 00:04:14,426 MACKENZIE: It's pretty mind-blowing 65 00:04:14,426 --> 00:04:17,291 that as we look elsewhere in the solar system, 66 00:04:17,291 --> 00:04:18,706 we see these weather patterns 67 00:04:18,706 --> 00:04:22,227 that look very familiar to us, 68 00:04:22,227 --> 00:04:25,541 and yet there are also these wild extremes. 69 00:04:25,541 --> 00:04:27,646 ♪ 70 00:04:27,646 --> 00:04:29,234 DRANSFIELD: Some of the storms we're seeing 71 00:04:29,234 --> 00:04:30,718 are like supersized versions 72 00:04:30,718 --> 00:04:32,513 of the storms that we see here on Earth. 73 00:04:32,513 --> 00:04:34,653 ♪ 74 00:04:34,653 --> 00:04:37,622 NARRATOR: And the more we explore, 75 00:04:37,622 --> 00:04:40,590 the more weird and wonderful weather we're finding. 76 00:04:40,590 --> 00:04:43,317 GRINSPOON: Pretty much every planet with weather 77 00:04:43,317 --> 00:04:47,183 has some oddity to it that's surprised us. 78 00:04:48,633 --> 00:04:52,015 NARRATOR: So what creates the wild diversity in weather 79 00:04:52,015 --> 00:04:54,294 across the solar system? 80 00:04:55,674 --> 00:04:58,988 GAO: We're so used to dealing with our specific brand of weather. 81 00:04:58,988 --> 00:05:00,645 But there's just so much more out there, 82 00:05:00,645 --> 00:05:02,509 if you look at these stormy worlds. 83 00:05:02,509 --> 00:05:07,583 ♪ 84 00:05:22,494 --> 00:05:26,878 ♪ 85 00:05:26,878 --> 00:05:28,914 ALEJANDRO SOTO: When I hear the word "weather," 86 00:05:28,914 --> 00:05:32,539 I get a memory 87 00:05:32,539 --> 00:05:36,266 of when I was a kid, standing out in a field... 88 00:05:36,266 --> 00:05:38,510 ♪ 89 00:05:38,510 --> 00:05:41,375 ...when the wind would pick up, the sky would darken a bit, 90 00:05:41,375 --> 00:05:43,170 and you knew it was about to rain. 91 00:05:43,170 --> 00:05:46,311 [wind gusting] 92 00:05:46,311 --> 00:05:49,314 And yet it would also be the best. 93 00:05:51,627 --> 00:05:54,768 NARRATOR: From towering thunderstorms 94 00:05:54,768 --> 00:05:59,220 to howling blizzards 95 00:05:59,220 --> 00:06:04,502 to choking dust storms, 96 00:06:04,502 --> 00:06:08,091 our atmosphere is a restless place. 97 00:06:10,818 --> 00:06:15,651 But what causes all this chaos? 98 00:06:15,651 --> 00:06:17,998 JEN GUPTA: Earth, like all the planets, 99 00:06:17,998 --> 00:06:21,139 is essentially a big ball floating in space 100 00:06:21,139 --> 00:06:24,280 being heated by the sun. 101 00:06:24,280 --> 00:06:26,109 It's pretty simple, really. 102 00:06:26,109 --> 00:06:28,146 But because of the shape of a planet, 103 00:06:28,146 --> 00:06:31,425 its spherical geometry, 104 00:06:31,425 --> 00:06:34,048 it's actually really hard to heat the planet evenly. 105 00:06:34,048 --> 00:06:35,429 For a start, 106 00:06:35,429 --> 00:06:37,224 there's always a side of the Earth 107 00:06:37,224 --> 00:06:40,434 in darkness, the night side of the planet. 108 00:06:40,434 --> 00:06:41,539 DOTTIN: And some parts, 109 00:06:41,539 --> 00:06:42,954 like the Equator, 110 00:06:42,954 --> 00:06:44,714 receive more sunlight 111 00:06:44,714 --> 00:06:46,095 than others, like the poles, 112 00:06:46,095 --> 00:06:50,133 and that creates an energy imbalance. 113 00:06:50,133 --> 00:06:53,999 But because the Earth is surrounded by this atmosphere, 114 00:06:53,999 --> 00:06:57,175 this envelope of gas that's free to move around, 115 00:06:57,175 --> 00:07:00,868 it can carry the heat from the hot places to the cold 116 00:07:00,868 --> 00:07:04,285 in an attempt to equalize this imbalance. 117 00:07:04,285 --> 00:07:08,255 LEIGH FLETCHER: And without that conveyor belt of energy motion, 118 00:07:08,255 --> 00:07:09,946 we wouldn't have 119 00:07:09,946 --> 00:07:11,396 the incredible diversity ofweather 120 00:07:11,396 --> 00:07:12,984 that we can see around us today. 121 00:07:12,984 --> 00:07:17,298 ♪ 122 00:07:17,298 --> 00:07:20,716 NARRATOR: Wind, rain, and lightning are all side effects 123 00:07:20,716 --> 00:07:24,616 as our atmosphere balances hot and cold. 124 00:07:24,616 --> 00:07:27,654 ♪ 125 00:07:27,654 --> 00:07:33,142 And what applies here applies elsewhere, too. 126 00:07:33,142 --> 00:07:35,662 CLARA SOUSA-SILVA: In our solar system, wherever there's an atmosphere, 127 00:07:35,662 --> 00:07:38,527 there's weather, no matter how different 128 00:07:38,527 --> 00:07:40,494 an atmosphere from Earth's. 129 00:07:40,494 --> 00:07:42,634 FRAEMAN: Some are thicker, some are thinner, 130 00:07:42,634 --> 00:07:45,326 sometimes they're made of different things. 131 00:07:45,326 --> 00:07:46,673 And all of these combine 132 00:07:46,673 --> 00:07:50,124 to give these crazy cool weathersystems 133 00:07:50,124 --> 00:07:51,540 that are all so different 134 00:07:51,540 --> 00:07:52,955 across the solar system. 135 00:07:52,955 --> 00:07:57,062 ♪ 136 00:08:00,238 --> 00:08:02,827 NARRATOR: To see this alien weather in action 137 00:08:02,827 --> 00:08:06,658 across our vast solar system, 138 00:08:06,658 --> 00:08:09,765 we head away from our shared star... 139 00:08:09,765 --> 00:08:14,079 ♪ 140 00:08:14,079 --> 00:08:17,220 ...passing a planet so small and close to the sun 141 00:08:17,220 --> 00:08:21,155 that it has no atmosphere, 142 00:08:21,155 --> 00:08:24,365 to encounter a planet 143 00:08:24,365 --> 00:08:28,093 smothered by one. 144 00:08:34,686 --> 00:08:39,001 PITTS: Venus looks so beautiful in the evening sky. 145 00:08:39,001 --> 00:08:41,624 Brilliant, clear, white, 146 00:08:41,624 --> 00:08:44,558 just stunningly lovely to see, 147 00:08:44,558 --> 00:08:48,942 yet it's such a horribly nasty environment. 148 00:08:50,633 --> 00:08:52,773 NARRATOR: Looking down from orbit, 149 00:08:52,773 --> 00:08:58,020 we can't actually see Venus's surface at all. 150 00:08:59,953 --> 00:09:05,890 Instead, all we see are endless, thick, churning clouds 151 00:09:05,890 --> 00:09:09,583 that completely conceal the rest of the planet. 152 00:09:09,583 --> 00:09:13,656 ♪ 153 00:09:13,656 --> 00:09:16,659 GRINSPOON: Historically, we thought, "Oh, Venus has clouds. 154 00:09:16,659 --> 00:09:18,419 "They're probably made out of water. 155 00:09:18,419 --> 00:09:19,697 It might be sort of nice there." 156 00:09:19,697 --> 00:09:21,250 [laughing]: But then, 157 00:09:21,250 --> 00:09:25,461 when we started to actually get data from spacecraft, 158 00:09:25,461 --> 00:09:27,463 we discovered, no, they're not water. 159 00:09:27,463 --> 00:09:28,637 In fact, they're battery acid. 160 00:09:28,637 --> 00:09:32,468 ♪ 161 00:09:32,468 --> 00:09:33,952 SOUSA-SILVA: The clouds on Venus are 162 00:09:33,952 --> 00:09:36,990 made up of extremely concentrated sulfuric acid, 163 00:09:36,990 --> 00:09:39,751 one of the most corrosive substances we know of. 164 00:09:39,751 --> 00:09:41,477 If you were to go skydiving 165 00:09:41,477 --> 00:09:43,134 through the clouds of Venus, 166 00:09:43,134 --> 00:09:45,826 there wouldn't be a lot of you left at the end. 167 00:09:49,278 --> 00:09:53,213 NARRATOR: But if we could withstand the acid 168 00:09:53,213 --> 00:09:56,596 and took the plunge down through Venus's clouds... 169 00:09:59,909 --> 00:10:03,672 ...we'd reach a landscape that is eerily calm... 170 00:10:05,708 --> 00:10:09,194 ...but with air pressure more than 90 times greater 171 00:10:09,194 --> 00:10:11,645 than at Earth's surface. 172 00:10:11,645 --> 00:10:13,405 GAO: Even though we don't realize it, 173 00:10:13,405 --> 00:10:14,717 air has weight. 174 00:10:14,717 --> 00:10:16,201 It's being pulled down bygravity, 175 00:10:16,201 --> 00:10:17,444 just like the rest of us. 176 00:10:17,444 --> 00:10:19,239 And so, on Venus, where the atmosphere 177 00:10:19,239 --> 00:10:21,310 is so thick and so massive, 178 00:10:21,310 --> 00:10:23,036 all that air is being pulled down, 179 00:10:23,036 --> 00:10:24,762 and if we're on the bottom of it, 180 00:10:24,762 --> 00:10:26,660 then we'll feel all that pressure. 181 00:10:26,660 --> 00:10:29,352 SOUSA-SILVA: If you find yourself on the surface of Venus, 182 00:10:29,352 --> 00:10:32,493 you would almost immediately be crushed. 183 00:10:32,493 --> 00:10:34,737 But if somehow you survived 184 00:10:34,737 --> 00:10:37,913 and tried to go for a stroll, it would be exhausting. 185 00:10:37,913 --> 00:10:39,639 The atmosphere is so thick, 186 00:10:39,639 --> 00:10:41,744 it would be like walking through molasses. 187 00:10:43,643 --> 00:10:45,472 NARRATOR: The surface of Venus 188 00:10:45,472 --> 00:10:48,475 is comparable to the bottom of Earth's oceans, 189 00:10:48,475 --> 00:10:50,995 but with a key difference. 190 00:10:52,513 --> 00:10:55,102 At about 900 degrees Fahrenheit, 191 00:10:55,102 --> 00:10:59,037 this is the hottest planetary surface in the solar system. 192 00:11:01,005 --> 00:11:05,630 And again, Venus's extreme atmosphere is responsible. 193 00:11:05,630 --> 00:11:08,081 SOUSA-SILVA: Carbon dioxide and other molecules 194 00:11:08,081 --> 00:11:10,290 are able to absorb and radiate heat, 195 00:11:10,290 --> 00:11:12,430 and so, in large enough quantities, 196 00:11:12,430 --> 00:11:14,156 they can act like a planetary blanket 197 00:11:14,156 --> 00:11:15,813 that traps that heat in a planet. 198 00:11:15,813 --> 00:11:18,678 That's what we call the greenhouse effect. 199 00:11:20,714 --> 00:11:23,234 NARRATOR: And Venus's incredibly dense atmosphere 200 00:11:23,234 --> 00:11:27,238 is 96.5% carbon dioxide. 201 00:11:27,238 --> 00:11:29,930 ♪ 202 00:11:29,930 --> 00:11:33,175 Even 0.04% CO2 in our atmosphere 203 00:11:33,175 --> 00:11:35,591 is enough to initiate a climate crisis 204 00:11:35,591 --> 00:11:37,697 in our world right now. 205 00:11:37,697 --> 00:11:40,147 So you can imagine how bad it is on Venus. 206 00:11:43,668 --> 00:11:46,050 NARRATOR: Venus's extreme greenhouse effect 207 00:11:46,050 --> 00:11:49,709 means it's even hotter than Mercury. 208 00:11:52,263 --> 00:11:54,368 Which is why what we would find there 209 00:11:54,368 --> 00:11:56,750 is so extraordinary. 210 00:11:56,750 --> 00:11:59,822 ♪ 211 00:11:59,822 --> 00:12:02,583 What look like snow-capped mountains 212 00:12:02,583 --> 00:12:06,726 towering over the scalding surface. 213 00:12:12,662 --> 00:12:15,527 For generations, we could only guess 214 00:12:15,527 --> 00:12:18,116 at what lay beneath Venus's clouds. 215 00:12:19,428 --> 00:12:22,534 But, thanks to radar images 216 00:12:22,534 --> 00:12:25,710 beamed back by NASA's Magellan orbiter, 217 00:12:25,710 --> 00:12:30,680 we now have detailed maps of the planet's surface. 218 00:12:30,680 --> 00:12:32,855 So, here we have an image taken by Magellan, 219 00:12:32,855 --> 00:12:33,891 and what we're looking at 220 00:12:33,891 --> 00:12:36,031 is actually Maxwell Montes. 221 00:12:36,031 --> 00:12:37,032 Maxwell Montes here 222 00:12:37,032 --> 00:12:39,586 is the highest region on Venus. 223 00:12:39,586 --> 00:12:43,590 And what you'll notice is that around this image, 224 00:12:43,590 --> 00:12:45,730 the surface looks dark. 225 00:12:45,730 --> 00:12:48,422 But in the center, where Maxwell Montes is, 226 00:12:48,422 --> 00:12:50,839 it's much brighter-- it almost looks white. 227 00:12:50,839 --> 00:12:52,564 We weren't expecting 228 00:12:52,564 --> 00:12:54,774 to have such radar-bright regions 229 00:12:54,774 --> 00:12:57,431 on the highlands, in the mountaintops of Venus. 230 00:12:57,431 --> 00:13:01,056 ♪ 231 00:13:01,056 --> 00:13:04,369 GUPTA: When you see those radar images of Maxwell Montes, 232 00:13:04,369 --> 00:13:07,579 it's hard not to imagine snow-capped mountains. 233 00:13:07,579 --> 00:13:10,824 ♪ 234 00:13:10,824 --> 00:13:13,620 NARRATOR: But given the conditions on Venus, 235 00:13:13,620 --> 00:13:17,693 snow as we know it is impossible. 236 00:13:17,693 --> 00:13:20,696 ♪ 237 00:13:20,696 --> 00:13:23,043 In places, it's so hot, 238 00:13:23,043 --> 00:13:25,770 the ground actually glows, 239 00:13:25,770 --> 00:13:29,705 like metal coming out of a forge. 240 00:13:29,705 --> 00:13:31,431 GRINSPOON: On Earth, you can imagine 241 00:13:31,431 --> 00:13:33,226 waiting till nighttime to cool off. 242 00:13:33,226 --> 00:13:34,779 That wouldn't work on Venus. 243 00:13:34,779 --> 00:13:37,678 There's no relief at night on Venus from the temperature. 244 00:13:37,678 --> 00:13:39,957 And in fact, if you go from the equator to the pole, 245 00:13:39,957 --> 00:13:42,925 it doesn't get any cooler, for the same reason-- 246 00:13:42,925 --> 00:13:44,996 that thick atmosphere is very efficient 247 00:13:44,996 --> 00:13:47,274 at redistributing the heat. 248 00:13:49,656 --> 00:13:54,523 NARRATOR: It is a world where there is no place for snow to hide. 249 00:13:54,523 --> 00:13:56,007 But there's one way to cool off on Venus, 250 00:13:56,007 --> 00:13:57,526 and that's to go up a mountain. 251 00:13:57,526 --> 00:14:03,463 ♪ 252 00:14:08,675 --> 00:14:12,990 NARRATOR: A phenomenon that we here on Earth can also relate to. 253 00:14:12,990 --> 00:14:18,685 ♪ 254 00:14:18,685 --> 00:14:21,170 PORT: Everyone knows when you go up a mountain, 255 00:14:21,170 --> 00:14:24,173 you should always pack a jacket. 256 00:14:24,173 --> 00:14:25,968 And the reason for that is because it's much colder. 257 00:14:25,968 --> 00:14:27,245 But why is it colder? 258 00:14:27,245 --> 00:14:29,765 Well, when you go up a mountain, there's less air, 259 00:14:29,765 --> 00:14:31,525 and that means there's less pressure. 260 00:14:31,525 --> 00:14:34,183 ♪ 261 00:14:34,183 --> 00:14:36,841 NARRATOR: And as the pressure decreases, 262 00:14:36,841 --> 00:14:39,430 so does the temperature. 263 00:14:41,570 --> 00:14:43,503 PORT: So, as we go up in elevation, 264 00:14:43,503 --> 00:14:45,056 we cross a threshold 265 00:14:45,056 --> 00:14:47,507 where the temperature drops low enough 266 00:14:47,507 --> 00:14:51,028 that water can be a solid. 267 00:14:51,028 --> 00:14:54,824 And this is what we call the snow line. 268 00:14:56,654 --> 00:14:58,759 NARRATOR: Venus's snow line suggests 269 00:14:58,759 --> 00:15:01,452 something may be freezing up there. 270 00:15:01,452 --> 00:15:04,213 But even its highest peaks 271 00:15:04,213 --> 00:15:07,837 are far too hot for that something to be water. 272 00:15:07,837 --> 00:15:10,944 And that points us to substances 273 00:15:10,944 --> 00:15:15,707 that solidify at much higher temperatures. 274 00:15:15,707 --> 00:15:17,399 PORT: So, instead of water, 275 00:15:17,399 --> 00:15:20,505 it actually could be something like this. 276 00:15:20,505 --> 00:15:22,852 So this is a piece of galena, 277 00:15:22,852 --> 00:15:24,716 also known as a lead sulfide. 278 00:15:24,716 --> 00:15:26,442 On Earth, it's present as a solid, 279 00:15:26,442 --> 00:15:28,030 as you can see here. 280 00:15:28,030 --> 00:15:29,411 But on Venus, 281 00:15:29,411 --> 00:15:32,690 it may only be a solid in the highlands. 282 00:15:32,690 --> 00:15:35,072 NARRATOR: Deep in Venus's lowlands, 283 00:15:35,072 --> 00:15:38,144 like valleys, 284 00:15:38,144 --> 00:15:41,181 it's hot enough for compounds like lead sulfide 285 00:15:41,181 --> 00:15:44,391 to vaporize, 286 00:15:44,391 --> 00:15:47,498 drift on the wind, 287 00:15:47,498 --> 00:15:49,396 and, as the winds flow up 288 00:15:49,396 --> 00:15:51,571 into the mountains of Maxwell Montes... 289 00:15:55,678 --> 00:15:59,199 ...the temperature drops just enough for the compounds 290 00:15:59,199 --> 00:16:02,444 to freeze out of the air. 291 00:16:06,068 --> 00:16:10,762 At 820 degrees Fahrenheit, 292 00:16:10,762 --> 00:16:13,834 Venus's atmosphere may coat its mountaintops 293 00:16:13,834 --> 00:16:15,284 not in snow, 294 00:16:15,284 --> 00:16:19,012 but in a metallic frost. 295 00:16:27,745 --> 00:16:29,540 PORT: We still don't know for sure 296 00:16:29,540 --> 00:16:32,025 if metal frost can explain the bright regions 297 00:16:32,025 --> 00:16:34,027 that we're seeing on the mountaintops. 298 00:16:34,027 --> 00:16:36,236 There's still a lot that we don't know about Venus, 299 00:16:36,236 --> 00:16:38,273 and that's because we haven't even sent a lander 300 00:16:38,273 --> 00:16:40,171 to the surface of Venus since the 1980s. 301 00:16:40,171 --> 00:16:42,035 But it's amazing to think 302 00:16:42,035 --> 00:16:44,037 that something like this could be condensing 303 00:16:44,037 --> 00:16:46,108 on the mountaintops of Venus. 304 00:16:50,043 --> 00:16:53,322 When we think of the possibility of metallic frost on Venus, 305 00:16:53,322 --> 00:16:56,774 it sounds crazy, but that's only crazy for us Earthlings. 306 00:16:56,774 --> 00:16:59,087 If you have a different atmosphere, 307 00:16:59,087 --> 00:17:03,229 you get different weather, different phenomena playing out. 308 00:17:03,229 --> 00:17:07,267 ♪ 309 00:17:09,649 --> 00:17:13,032 NARRATOR: Leaving this crushing world behind... 310 00:17:16,414 --> 00:17:18,382 ...we head out in search of an atmosphere 311 00:17:18,382 --> 00:17:23,214 that could almost be Venus's opposite. 312 00:17:25,734 --> 00:17:29,600 To reach it, we bypass our own planet. 313 00:17:36,745 --> 00:17:40,128 Passing two potato-shaped moons 314 00:17:40,128 --> 00:17:43,614 orbiting our other next-door neighbor, 315 00:17:43,614 --> 00:17:46,065 we encounter an atmosphere 316 00:17:46,065 --> 00:17:49,896 more than 10,000 times thinner than Venus's. 317 00:17:54,659 --> 00:17:57,524 With little in the way of cloud cover, 318 00:17:57,524 --> 00:18:02,219 we don't need radar to get a look at the Martian surface. 319 00:18:04,600 --> 00:18:07,224 Yet, images sent back by our orbiters 320 00:18:07,224 --> 00:18:11,883 suggest rain may have once fallen here. 321 00:18:14,196 --> 00:18:17,717 These pictures show that Mars is covered in features 322 00:18:17,717 --> 00:18:22,687 which appear to have been created by flowing water. 323 00:18:22,687 --> 00:18:24,482 DOTTIN: With such a thin atmosphere, 324 00:18:24,482 --> 00:18:26,105 it's really difficult 325 00:18:26,105 --> 00:18:28,210 to retain heat, and certainly 326 00:18:28,210 --> 00:18:29,591 not enough heat to have 327 00:18:29,591 --> 00:18:31,110 liquid water on the surface. 328 00:18:32,732 --> 00:18:36,805 NARRATOR: So if Mars was once home to lakes and rivers, 329 00:18:36,805 --> 00:18:40,291 it must have had a much thicker atmosphere in the past. 330 00:18:42,673 --> 00:18:44,295 FRAEMAN: In the early 2000s, 331 00:18:44,295 --> 00:18:46,539 we'd seen that there were hints 332 00:18:46,539 --> 00:18:47,885 that liquid water had once been 333 00:18:47,885 --> 00:18:48,955 on the Martian surface 334 00:18:48,955 --> 00:18:50,232 from our orbiters, 335 00:18:50,232 --> 00:18:51,785 but we didn't have definitive proof 336 00:18:51,785 --> 00:18:53,546 from the surface. 337 00:18:53,546 --> 00:18:55,996 So the goal of the Mars Exploration Rover mission 338 00:18:55,996 --> 00:18:58,137 was to follow the water. 339 00:18:58,137 --> 00:19:02,520 MAN: T minus five, four, three, 340 00:19:02,520 --> 00:19:05,005 two, main engine start, 341 00:19:05,005 --> 00:19:07,560 zero, and liftoff 342 00:19:07,560 --> 00:19:10,183 of the Delta rocket with Opportunity, 343 00:19:10,183 --> 00:19:11,840 a chance to explore 344 00:19:11,840 --> 00:19:15,844 and unlock the secrets of our neighboring planet. 345 00:19:15,844 --> 00:19:18,433 FRAEMAN: I was 16 years old when Spirit and Opportunity 346 00:19:18,433 --> 00:19:20,193 launched and landed on Mars. 347 00:19:20,193 --> 00:19:22,920 But I had the amazing opportunity 348 00:19:22,920 --> 00:19:25,888 through an outreach program to actually go to be at NASA, 349 00:19:25,888 --> 00:19:27,649 at the Jet Propulsion Laboratory, 350 00:19:27,649 --> 00:19:28,960 when the rovers landed. 351 00:19:28,960 --> 00:19:31,204 MAN: Getting a bounce to signal. 352 00:19:31,204 --> 00:19:33,241 [cheering] 353 00:19:33,241 --> 00:19:35,450 FRAEMAN: And I was in the room with the science team 354 00:19:35,450 --> 00:19:36,865 when Opportunity landed on Mars, 355 00:19:36,865 --> 00:19:40,213 and it was the most amazing experience. 356 00:19:40,213 --> 00:19:42,008 [cheering and applauding] 357 00:19:42,008 --> 00:19:44,528 NARRATOR: Two rovers named Spirit and Opportunity 358 00:19:44,528 --> 00:19:47,047 were sent to opposite sides of the Red Planet 359 00:19:47,047 --> 00:19:50,085 to search for definitive proof 360 00:19:50,085 --> 00:19:53,226 that Mars's dry landscape 361 00:19:53,226 --> 00:19:54,883 was once a water world. 362 00:19:58,749 --> 00:20:02,235 At first glance, modern Mars doesn't appear 363 00:20:02,235 --> 00:20:05,721 to be a very dynamic place. 364 00:20:05,721 --> 00:20:07,482 With an average surface temperature 365 00:20:07,482 --> 00:20:10,416 of about - 80 degrees Fahrenheit 366 00:20:10,416 --> 00:20:14,005 and an atmosphere just one percent as thick as Earth's, 367 00:20:14,005 --> 00:20:16,491 it is a freezing desert. 368 00:20:18,803 --> 00:20:23,187 Typically, we think of Mars as this dead world. 369 00:20:23,187 --> 00:20:26,742 But we do see changes on the surface over time. 370 00:20:29,538 --> 00:20:33,887 NARRATOR: Strange, overlapping lines, 371 00:20:33,887 --> 00:20:37,650 often dozens of feet wide, 372 00:20:37,650 --> 00:20:41,274 can stretch for miles. 373 00:20:45,658 --> 00:20:48,661 Unlike many of Mars's features, 374 00:20:48,661 --> 00:20:53,113 these are not relics. 375 00:20:53,113 --> 00:20:57,532 We see them appear and disappear. 376 00:21:02,675 --> 00:21:05,850 What are these bizarre, shape-shifting patterns? 377 00:21:05,850 --> 00:21:09,268 ♪ 378 00:21:13,133 --> 00:21:16,930 In January 2004, Spirit and Opportunity 379 00:21:16,930 --> 00:21:20,313 began to investigate Mars. 380 00:21:20,313 --> 00:21:25,698 ♪ 381 00:21:25,698 --> 00:21:30,323 But their mission wasn't expected to last very long. 382 00:21:30,323 --> 00:21:32,325 GUPTA: Mars is covered in dust. 383 00:21:32,325 --> 00:21:34,223 It gets everywhere, 384 00:21:34,223 --> 00:21:37,123 including on the solar panels of Mars rovers. 385 00:21:37,123 --> 00:21:40,678 As the solar panels got dustier and dustier, 386 00:21:40,678 --> 00:21:42,370 the power levels that the rover would have 387 00:21:42,370 --> 00:21:44,233 would get lower and lower and lower, 388 00:21:44,233 --> 00:21:46,546 and eventually, they would just stop working. 389 00:21:48,237 --> 00:21:50,067 NARRATOR: The team hoped the rovers 390 00:21:50,067 --> 00:21:51,896 would last at least three months, 391 00:21:51,896 --> 00:21:55,659 a feat they surpassed. 392 00:21:57,661 --> 00:22:00,353 But, as the months wore on, 393 00:22:00,353 --> 00:22:03,908 the power levels continued to drop. 394 00:22:05,531 --> 00:22:07,256 What was really exciting 395 00:22:07,256 --> 00:22:08,672 was, at one point in the mission, 396 00:22:08,672 --> 00:22:10,846 as we were seeing the power levels 397 00:22:10,846 --> 00:22:13,228 getting lower and lower and lower, 398 00:22:13,228 --> 00:22:15,886 all of a sudden, the power levels were 399 00:22:15,886 --> 00:22:17,577 back up high again. 400 00:22:17,577 --> 00:22:22,237 ♪ 401 00:22:22,237 --> 00:22:25,171 Almost as high as they were when the rovers had landed. 402 00:22:26,724 --> 00:22:29,934 And you can take a look at the before and after pictures, 403 00:22:29,934 --> 00:22:32,420 and you can see that it looks like the solar panels 404 00:22:32,420 --> 00:22:35,802 have just been wiped clean. 405 00:22:35,802 --> 00:22:37,942 You could call up AAA and send them to Mars 406 00:22:37,942 --> 00:22:39,772 with the rag to clean everything off. 407 00:22:39,772 --> 00:22:41,463 They couldn't have done a better job. 408 00:22:44,673 --> 00:22:47,849 NARRATOR: Finally, a clue to what might be happening 409 00:22:47,849 --> 00:22:50,921 was spotted by Spirit's Navcam. 410 00:22:56,478 --> 00:23:00,620 ♪ 411 00:23:00,620 --> 00:23:02,933 In the mid-afternoon sun... 412 00:23:02,933 --> 00:23:04,417 ♪ 413 00:23:04,417 --> 00:23:06,350 ...heating of the Martian surface 414 00:23:06,350 --> 00:23:10,527 creates towering vortices, 415 00:23:10,527 --> 00:23:14,013 which can grow miles high. 416 00:23:17,775 --> 00:23:20,709 Dust devils. 417 00:23:20,709 --> 00:23:23,298 GUPTA: I imagine it would be absolutely terrifying 418 00:23:23,298 --> 00:23:25,887 to be standing on the surface of Mars 419 00:23:25,887 --> 00:23:28,683 and see one of these dust devils coming straight at you. 420 00:23:30,719 --> 00:23:32,825 FRAEMAN: You might think that there was this 421 00:23:32,825 --> 00:23:36,104 tornado-force wind coming towards the rover, 422 00:23:36,104 --> 00:23:38,900 and it might pick the rover up and spin them around 423 00:23:38,900 --> 00:23:40,522 and do all sorts of horrible things. 424 00:23:40,522 --> 00:23:42,248 But in reality, 425 00:23:42,248 --> 00:23:45,044 the Martian atmosphere is actually very, very thin, 426 00:23:45,044 --> 00:23:47,667 and so you can have a dust devil pass over you 427 00:23:47,667 --> 00:23:49,531 and, and you would barely even notice it. 428 00:23:49,531 --> 00:23:51,706 But even though a Martian dust devil 429 00:23:51,706 --> 00:23:53,432 might not be able to pick you up, 430 00:23:53,432 --> 00:23:55,537 it can certainly pick dust up. 431 00:23:57,677 --> 00:23:59,403 NARRATOR: It's thought that 432 00:23:59,403 --> 00:24:02,855 as these whirlwinds traveled over the rovers, 433 00:24:02,855 --> 00:24:05,374 they sucked dust off the solar panels, 434 00:24:05,374 --> 00:24:08,308 like a vacuum. 435 00:24:08,308 --> 00:24:12,623 So a mission expected to last just a few months 436 00:24:12,623 --> 00:24:15,454 was extended again, 437 00:24:15,454 --> 00:24:19,665 and again, 438 00:24:19,665 --> 00:24:22,012 and again. 439 00:24:23,738 --> 00:24:25,636 But the cleaning power of the dust devils 440 00:24:25,636 --> 00:24:28,397 doesn't just work on rovers. 441 00:24:28,397 --> 00:24:32,436 [wind roaring] 442 00:24:32,436 --> 00:24:36,267 ♪ 443 00:24:36,267 --> 00:24:38,684 As they travel, 444 00:24:38,684 --> 00:24:39,995 these huge vortices 445 00:24:39,995 --> 00:24:43,171 suck up dust from Mars's surface, 446 00:24:43,171 --> 00:24:47,037 exposing the darker bedrock beneath. 447 00:24:49,660 --> 00:24:53,008 Leaving trails so large, 448 00:24:53,008 --> 00:24:56,184 we can see them clearly from space. 449 00:24:56,184 --> 00:24:59,636 ♪ 450 00:24:59,636 --> 00:25:03,156 There are no Martians creating the lines. 451 00:25:05,400 --> 00:25:10,405 The culprit is the Martian atmosphere. 452 00:25:12,649 --> 00:25:16,445 Dust devils might create the tracks, 453 00:25:16,445 --> 00:25:21,209 but something else wipes them away. 454 00:25:21,209 --> 00:25:23,694 ♪ 455 00:25:23,694 --> 00:25:25,489 Just like Earth, 456 00:25:25,489 --> 00:25:29,735 Mars has a tilt that gives it seasons. 457 00:25:29,735 --> 00:25:33,739 Summer in one hemisphere means winter in the other. 458 00:25:37,743 --> 00:25:40,021 And with no oceans or thick atmosphere 459 00:25:40,021 --> 00:25:42,541 to help spread heat around the globe, 460 00:25:42,541 --> 00:25:45,923 an extreme temperature difference. 461 00:25:48,374 --> 00:25:51,757 So here, dust helps drive the action. 462 00:25:53,206 --> 00:25:57,625 ♪ 463 00:25:57,625 --> 00:26:01,145 As summer arrives in the southern hemisphere, 464 00:26:01,145 --> 00:26:04,217 warmer temperatures drive stronger winds, 465 00:26:04,217 --> 00:26:07,600 which kick dust up into the air. 466 00:26:09,326 --> 00:26:13,572 The dust absorbs sunlight and heats the air around it... 467 00:26:16,644 --> 00:26:18,266 ...further strengthening the winds, 468 00:26:18,266 --> 00:26:22,822 which lift even more dust... 469 00:26:27,758 --> 00:26:32,280 ...until a storm forms... 470 00:26:34,834 --> 00:26:39,908 ...wiping away dust devil trails. 471 00:26:39,908 --> 00:26:44,188 And these storms can combine and grow so large... 472 00:26:47,951 --> 00:26:52,438 ...that they engulf the entire planet, 473 00:26:52,438 --> 00:26:56,649 sometimes blocking more than 99% of the incoming sunlight 474 00:26:56,649 --> 00:26:59,997 from reaching the surface... 475 00:27:01,758 --> 00:27:06,072 ...and the solar panels of Mars rovers. 476 00:27:08,799 --> 00:27:14,011 In May 2018, with Opportunity still active on the surface, 477 00:27:14,011 --> 00:27:17,497 a storm began to build. 478 00:27:17,497 --> 00:27:18,913 FRAEMAN: It only took a couple of days 479 00:27:18,913 --> 00:27:22,571 of seeing the skies get darker and darker and darker 480 00:27:22,571 --> 00:27:24,263 before we started to realize that, 481 00:27:24,263 --> 00:27:26,817 "Oh, this is actually, this is a really bad one." 482 00:27:26,817 --> 00:27:29,130 Um, and by the end of the week, 483 00:27:29,130 --> 00:27:31,857 we knew that this was the worst dust storm 484 00:27:31,857 --> 00:27:33,790 that we were ever gonna have to survive. 485 00:27:33,790 --> 00:27:37,103 We knew we were probably gonna lose communication with Oppy. 486 00:27:37,103 --> 00:27:40,279 So we let her go dark 487 00:27:40,279 --> 00:27:44,214 and we just waited and waited. 488 00:27:44,214 --> 00:27:47,631 NARRATOR: Mars's low gravity means the dust in the air 489 00:27:47,631 --> 00:27:51,704 can remain there for months. 490 00:27:51,704 --> 00:27:54,500 ♪ 491 00:27:54,500 --> 00:27:56,640 Eventually, with so little sunlight 492 00:27:56,640 --> 00:27:59,781 reaching the Martian surface, 493 00:27:59,781 --> 00:28:02,404 the temperature differences which fueled the storm 494 00:28:02,404 --> 00:28:05,235 are dampened, 495 00:28:05,235 --> 00:28:07,962 cutting off its own energy supply, 496 00:28:07,962 --> 00:28:12,691 and the dust finally settles. 497 00:28:12,691 --> 00:28:15,694 But by the end of 2018, 498 00:28:15,694 --> 00:28:19,111 even after the Martian skies had cleared, 499 00:28:19,111 --> 00:28:22,701 there was no signal from Opportunity. 500 00:28:22,701 --> 00:28:24,633 And with winter looming, 501 00:28:24,633 --> 00:28:27,050 it was unlikely the rover's electronics 502 00:28:27,050 --> 00:28:29,017 would survive the cold. 503 00:28:30,985 --> 00:28:33,608 ♪ 504 00:28:33,608 --> 00:28:35,990 On February 13, 2019, 505 00:28:35,990 --> 00:28:40,649 NASA declared its mission complete. 506 00:28:40,649 --> 00:28:42,582 FRAEMAN: I know it sounds weird, 507 00:28:42,582 --> 00:28:44,653 'cause it's a robot... [laughs] 508 00:28:44,653 --> 00:28:46,345 ...but it's sort of the same feeling you have 509 00:28:46,345 --> 00:28:48,105 when you might lose a loved one 510 00:28:48,105 --> 00:28:50,383 who's lived a very full life. 511 00:28:50,383 --> 00:28:53,352 I was a high school student when they landed. 512 00:28:53,352 --> 00:28:55,492 By the time Opportunity's mission ended, 513 00:28:55,492 --> 00:28:58,460 I had gone to college, I had gotten a Ph.D., 514 00:28:58,460 --> 00:28:59,910 I had done a post-doc, 515 00:28:59,910 --> 00:29:02,223 and then I had been hired by NASA 516 00:29:02,223 --> 00:29:05,640 to work on this very same Opportunity rover 517 00:29:05,640 --> 00:29:07,815 that had inspired me when I was a high school student. 518 00:29:10,231 --> 00:29:14,269 NARRATOR: Sent to Mars to hunt for ancient evidence of water, 519 00:29:14,269 --> 00:29:19,723 Opportunity not only succeeded, but exceeded expectations, 520 00:29:19,723 --> 00:29:24,107 lasting over 14 years thanks to the Martian weather. 521 00:29:27,144 --> 00:29:32,460 ♪ 522 00:29:32,460 --> 00:29:34,255 Despite their differences, 523 00:29:34,255 --> 00:29:40,192 Venus and Mars have one thing in common. 524 00:29:40,192 --> 00:29:43,574 Their weather is powered by solar energy. 525 00:29:47,268 --> 00:29:49,201 But beyond the asteroid belt... 526 00:29:52,514 --> 00:29:57,243 ...ruled by the dwarf planet Ceres, 527 00:29:57,243 --> 00:30:00,419 the sun's influence wanes. 528 00:30:02,593 --> 00:30:06,218 And yet, the next planet we encounter 529 00:30:06,218 --> 00:30:07,978 is a storm world... 530 00:30:10,187 --> 00:30:13,225 ...on the grandest scale. 531 00:30:23,752 --> 00:30:26,928 PITTS: If you were just arriving at Jupiter in a spacecraft, 532 00:30:26,928 --> 00:30:29,275 you would be stunned by what you see. 533 00:30:29,275 --> 00:30:30,898 First of all, there's the size. 534 00:30:32,140 --> 00:30:37,905 You can fit 1,300 planet Earths inside Jupiter. 535 00:30:37,905 --> 00:30:39,285 In fact, you could fit all of the planets 536 00:30:39,285 --> 00:30:41,046 in the solar system insideJupiter 537 00:30:41,046 --> 00:30:42,599 and still have room to spare. 538 00:30:45,498 --> 00:30:49,917 NARRATOR: Jupiter is a gas giant 539 00:30:49,917 --> 00:30:53,852 on which storms can grow bigger than Earth itself. 540 00:30:56,993 --> 00:31:00,962 Since 2016, NASA's Juno spacecraft 541 00:31:00,962 --> 00:31:05,449 has been exploring this gargantuan planet 542 00:31:05,449 --> 00:31:08,901 and found its weather is anything but subtle. 543 00:31:08,901 --> 00:31:14,079 [thunder rumbling] 544 00:31:14,079 --> 00:31:17,634 Jupiter's thunderstorms can produce lightning bolts 545 00:31:17,634 --> 00:31:21,569 ten times more energetic than anything recorded on Earth. 546 00:31:21,569 --> 00:31:24,261 [thunder rumbling, lightning crackling] 547 00:31:24,261 --> 00:31:28,645 Most of the flashes lie beneath thick ammonia ice clouds. 548 00:31:31,027 --> 00:31:34,651 But the most powerful storms break free, 549 00:31:34,651 --> 00:31:38,551 soaring to the edge of space. 550 00:31:38,551 --> 00:31:42,038 [thunder booming, lightning crackling] 551 00:31:42,038 --> 00:31:46,732 The scale of Jupiter's storms may be hard to comprehend. 552 00:31:48,630 --> 00:31:50,770 But Juno found that the frequency 553 00:31:50,770 --> 00:31:53,704 of its lightning strikes is remarkably similar 554 00:31:53,704 --> 00:31:57,363 to Earth's thunderclouds. 555 00:32:00,746 --> 00:32:03,024 DRANSFIELD: It's odd that lightning is such a common occurrence 556 00:32:03,024 --> 00:32:04,025 here on Earth, 557 00:32:04,025 --> 00:32:05,371 but it's taken us centuries 558 00:32:05,371 --> 00:32:07,615 to really understand how itworks. 559 00:32:07,615 --> 00:32:10,859 [thunder claps, lightning crackles] 560 00:32:10,859 --> 00:32:12,827 NARRATOR: The substance responsible 561 00:32:12,827 --> 00:32:18,177 for our planet's thunderstorms is water. 562 00:32:18,177 --> 00:32:19,316 The way that lightning getsformed 563 00:32:19,316 --> 00:32:21,353 is that it relies on collisions 564 00:32:21,353 --> 00:32:25,288 between icy particles and watery droplets. 565 00:32:25,288 --> 00:32:29,395 And as the watery droplets are moving upwards and colliding 566 00:32:29,395 --> 00:32:31,501 with the icy particles that are falling downwards, 567 00:32:31,501 --> 00:32:36,678 they're exchanging charge with each other. 568 00:32:36,678 --> 00:32:39,267 So you get a separation of charge 569 00:32:39,267 --> 00:32:41,960 from the top of a cloud to the bottom of the cloud. 570 00:32:43,375 --> 00:32:45,101 And as that separation of charge 571 00:32:45,101 --> 00:32:47,241 becomes bigger and bigger and bigger, 572 00:32:47,241 --> 00:32:49,588 eventually, the atmosphere can't cope anymore. 573 00:32:49,588 --> 00:32:51,210 PITTS: And when that occurs, 574 00:32:51,210 --> 00:32:53,661 now a flow of electricity can happen. 575 00:32:53,661 --> 00:32:58,217 [lightning crackling] 576 00:32:58,217 --> 00:33:02,221 NARRATOR: A single bolt of lightning is so powerful, 577 00:33:02,221 --> 00:33:05,121 it can heat the surrounding air 578 00:33:05,121 --> 00:33:08,883 to temperatures greater than the surface of the sun. 579 00:33:08,883 --> 00:33:13,992 ♪ 580 00:33:17,996 --> 00:33:23,242 So how can clouds produce so much energy? 581 00:33:23,242 --> 00:33:26,314 HEIDI BECKER: For all of our history, lightning has been 582 00:33:26,314 --> 00:33:29,007 something that humans have feared. 583 00:33:29,007 --> 00:33:33,011 But what's driving it really is the water cycle. 584 00:33:33,011 --> 00:33:35,151 The sun heats the water, 585 00:33:35,151 --> 00:33:37,808 it evaporates, becomes water vapor, 586 00:33:37,808 --> 00:33:39,810 rises up into the atmosphere, 587 00:33:39,810 --> 00:33:42,261 cools, and eventually becomes 588 00:33:42,261 --> 00:33:44,298 water droplets in clouds. 589 00:33:44,298 --> 00:33:46,610 And intuitively, as humans, 590 00:33:46,610 --> 00:33:49,234 we actually understand what's happening very well. 591 00:33:49,234 --> 00:33:51,960 We wet our hand, 592 00:33:51,960 --> 00:33:53,755 and it feels cold because 593 00:33:53,755 --> 00:33:57,069 the water is stealing energy from our hand, 594 00:33:57,069 --> 00:33:59,071 breaking up the water molecules, 595 00:33:59,071 --> 00:34:00,417 turning them into water vapor 596 00:34:00,417 --> 00:34:01,418 so that they can 597 00:34:01,418 --> 00:34:02,695 rise up intothe sky. 598 00:34:04,249 --> 00:34:07,252 NARRATOR: Water evaporation requires energy, 599 00:34:07,252 --> 00:34:12,291 whether it's from our body heat or the sun. 600 00:34:12,291 --> 00:34:17,365 As water turns from a liquid to a gas, it stores this energy. 601 00:34:18,815 --> 00:34:23,026 And when it turns back into a liquid, in the form of clouds, 602 00:34:23,026 --> 00:34:27,755 it releases this energy back into the atmosphere. 603 00:34:27,755 --> 00:34:29,584 What's kind of incredible to believe 604 00:34:29,584 --> 00:34:33,278 is that a, a small little cumulus cloud that you might see 605 00:34:33,278 --> 00:34:36,281 floating in the sky, looking so graceful and peaceful, 606 00:34:36,281 --> 00:34:38,179 is actually the result 607 00:34:38,179 --> 00:34:40,837 of an enormous amount of energy being released. 608 00:34:40,837 --> 00:34:44,461 It's the same as hundreds of tons of TNT. 609 00:34:46,187 --> 00:34:48,155 NARRATOR: And for an average thunderstorm, 610 00:34:48,155 --> 00:34:52,297 the energy released is equivalent to a nuclear blast. 611 00:34:54,402 --> 00:34:57,716 It's this huge release of heat 612 00:34:57,716 --> 00:35:01,133 that makes thunderclouds so turbulent, 613 00:35:01,133 --> 00:35:04,240 causing the countless icy collisions... 614 00:35:04,240 --> 00:35:06,656 [thunder rumbling, lightning crackling] 615 00:35:09,141 --> 00:35:11,592 ...which power Earth's lightning. 616 00:35:15,527 --> 00:35:18,426 Several missions to Jupiter have detected water 617 00:35:18,426 --> 00:35:20,877 in its atmosphere. 618 00:35:22,396 --> 00:35:25,709 But the planet receives just four percent of the sunlight 619 00:35:25,709 --> 00:35:29,127 that reaches Earth, 620 00:35:29,127 --> 00:35:33,510 too little energy to account for its ferocious lightning storms. 621 00:35:35,547 --> 00:35:39,067 ♪ 622 00:35:39,067 --> 00:35:43,210 But looking at the planet in infrared 623 00:35:43,210 --> 00:35:46,454 reveals a different source of energy. 624 00:35:46,454 --> 00:35:49,250 Jupiter is radiating heat, 625 00:35:49,250 --> 00:35:53,668 almost twice the energy it receives from the sun. 626 00:35:56,361 --> 00:35:59,536 FLETCHER: So, Jupiter itself is slowly cooling, 627 00:35:59,536 --> 00:36:02,574 and has been over the entire age of the solar system. 628 00:36:02,574 --> 00:36:07,130 And as it's cooling, the entire gas giant is slowly shrinking. 629 00:36:07,130 --> 00:36:10,409 And as it shrinks, it's relinquishing that energy 630 00:36:10,409 --> 00:36:13,723 that was left over from when Jupiter was born. 631 00:36:13,723 --> 00:36:15,173 That's enough to power 632 00:36:15,173 --> 00:36:17,209 the gargantuan storms that we see. 633 00:36:17,209 --> 00:36:21,282 [crackling] 634 00:36:21,282 --> 00:36:23,802 NARRATOR: This internal heat means water. 635 00:36:23,802 --> 00:36:29,014 The chemical powering Earth's storms 636 00:36:29,014 --> 00:36:32,190 also powers storms on Jupiter. 637 00:36:34,985 --> 00:36:38,161 In vapor form, water rises, 638 00:36:38,161 --> 00:36:41,578 carrying heat energy from deep inside the planet... 639 00:36:44,236 --> 00:36:49,345 ...until it reaches a place under the ammonia ice clouds... 640 00:36:51,001 --> 00:36:52,520 [thunder crashes] 641 00:36:52,520 --> 00:36:53,797 ...where it's cool enough 642 00:36:53,797 --> 00:36:56,490 to condense into liquid water droplets 643 00:36:56,490 --> 00:36:59,562 and ice crystals. 644 00:37:01,322 --> 00:37:04,808 The energy released by this condensing water 645 00:37:04,808 --> 00:37:08,467 powers the growth of violent thunderstorms. 646 00:37:12,230 --> 00:37:15,094 But because Jupiter has so much internal heat 647 00:37:15,094 --> 00:37:18,166 that's trying to escape, 648 00:37:18,166 --> 00:37:22,654 in some places, enough energy is released by condensing water... 649 00:37:24,483 --> 00:37:29,247 ...that ice crystals are swept up into the ice clouds above. 650 00:37:34,493 --> 00:37:39,636 Here, ammonia acts as an antifreeze... 651 00:37:41,328 --> 00:37:43,433 ...allowing thunderclouds to grow 652 00:37:43,433 --> 00:37:47,472 to more than 35 miles tall 653 00:37:47,472 --> 00:37:51,924 and lightning to strike at minus 150 degrees Fahrenheit. 654 00:37:53,616 --> 00:38:00,864 ♪ 655 00:38:00,864 --> 00:38:03,902 Jupiter and Earth may be worlds apart, 656 00:38:03,902 --> 00:38:07,319 but both play host to lightning storms 657 00:38:07,319 --> 00:38:12,082 which are driven by water. 658 00:38:14,568 --> 00:38:16,155 I just find it wicked cool that on a planet 659 00:38:16,155 --> 00:38:17,674 as different as Jupiter, 660 00:38:17,674 --> 00:38:20,643 the weather is being formed in much the same way 661 00:38:20,643 --> 00:38:21,816 as it is here on Earth. 662 00:38:26,787 --> 00:38:30,480 NARRATOR: However, there is one more place in the solar system 663 00:38:30,480 --> 00:38:35,382 with even more Earth-like weather. 664 00:38:35,382 --> 00:38:37,867 PITTS: But what's really interesting and exciting is, 665 00:38:37,867 --> 00:38:40,352 the liquid that's being shiftedaround 666 00:38:40,352 --> 00:38:41,664 isn't water. 667 00:38:43,390 --> 00:38:46,876 NARRATOR: To find it, we travel 400 million miles farther 668 00:38:46,876 --> 00:38:49,361 from the sun 669 00:38:49,361 --> 00:38:54,608 and encounter another gas giant. 670 00:38:54,608 --> 00:38:57,404 But this isn't our destination. 671 00:38:57,404 --> 00:39:00,648 ♪ 672 00:39:00,648 --> 00:39:06,136 Saturn is orbited by an amazing variety of moons, 673 00:39:06,136 --> 00:39:10,417 so many that it can be hard to keep track of them all. 674 00:39:14,006 --> 00:39:15,905 Iapetus, Rhea, 675 00:39:15,905 --> 00:39:17,527 Enceladus... 676 00:39:17,527 --> 00:39:20,634 GAO: Tethys, Mimas, Epimethys. 677 00:39:20,634 --> 00:39:25,639 Helene, Prometheus, uh, Calypso. 678 00:39:25,639 --> 00:39:27,468 Shoot, there's that really funny one. 679 00:39:27,468 --> 00:39:28,573 Phoebe. 680 00:39:28,573 --> 00:39:30,437 There's Pan, which is really cool 681 00:39:30,437 --> 00:39:32,059 because it looks like a ravioli. 682 00:39:32,059 --> 00:39:34,372 GRINSPOON [laughing]: I didn't cram for this. 683 00:39:34,372 --> 00:39:35,787 Did I mention Mimas? 684 00:39:35,787 --> 00:39:37,409 GRINSPOON: What's the little, really weird... 685 00:39:37,409 --> 00:39:38,617 Hyperion. 686 00:39:38,617 --> 00:39:40,412 Uh... [chuckles] 687 00:39:40,412 --> 00:39:41,586 Um... 688 00:39:41,586 --> 00:39:43,553 Um, uh, let's see. 689 00:39:43,553 --> 00:39:46,245 And a bunch more. [laughs] 690 00:39:47,246 --> 00:39:50,077 NARRATOR: But one is special. 691 00:39:50,077 --> 00:39:53,874 More than 20 times the mass of all the others combined. 692 00:39:56,221 --> 00:40:00,570 It's the only moon in the solar system with a thick atmosphere. 693 00:40:10,269 --> 00:40:14,998 In November 1980, NASA's Voyager 1 spacecraft 694 00:40:14,998 --> 00:40:17,760 revealed Saturn and its many moons 695 00:40:17,760 --> 00:40:21,315 in greater detail than ever before. 696 00:40:21,315 --> 00:40:24,732 PITTS: When the Voyager 1 spacecraft flew by Titan, 697 00:40:24,732 --> 00:40:26,527 we could see that it had an atmosphere, 698 00:40:26,527 --> 00:40:28,011 and a thick atmosphere, 699 00:40:28,011 --> 00:40:32,499 but this was only a tantalizing view. 700 00:40:32,499 --> 00:40:34,466 SOTO: The images from Voyager of Titan 701 00:40:34,466 --> 00:40:37,745 were exciting but also, in a way, 702 00:40:37,745 --> 00:40:39,298 infuriating, right? 703 00:40:39,298 --> 00:40:43,371 It confirmed everything that we had thought about Titan, 704 00:40:43,371 --> 00:40:45,615 but it didn't allow us to see down to the surface. 705 00:40:45,615 --> 00:40:48,031 With Voyager, we could do some remote sensing 706 00:40:48,031 --> 00:40:52,208 and start to tell that the surface was, was very cold, 707 00:40:52,208 --> 00:40:54,175 but in the right temperature range 708 00:40:54,175 --> 00:40:57,040 so that you might actually have liquid methane on the surface. 709 00:40:57,040 --> 00:40:59,180 And so we, we just knew that we had to go back 710 00:40:59,180 --> 00:41:02,839 and, and learn more. 711 00:41:02,839 --> 00:41:08,155 MAN: Five, four, three, two, one, 712 00:41:08,155 --> 00:41:11,296 and liftoff of the Cassini spacecraft 713 00:41:11,296 --> 00:41:14,506 on a billion-mile trek to Saturn. 714 00:41:14,506 --> 00:41:16,888 NARRATOR: The legendary Cassini-Huygens mission 715 00:41:16,888 --> 00:41:20,443 took almost seven years to reach Saturn 716 00:41:20,443 --> 00:41:22,514 and spent over a decade 717 00:41:22,514 --> 00:41:26,035 exploring the planet and its moons. 718 00:41:26,035 --> 00:41:29,417 And on December 25, 2004, 719 00:41:29,417 --> 00:41:33,111 nearly a quarter of a century after Voyager 1's flyby... 720 00:41:34,975 --> 00:41:40,187 ...the Huygens probe detached from Cassini 721 00:41:40,187 --> 00:41:44,087 in a bid to become the first probe ever to land on a body 722 00:41:44,087 --> 00:41:47,090 in the outer solar system. 723 00:41:47,090 --> 00:41:49,403 ♪ 724 00:41:49,403 --> 00:41:51,543 You know, there was so much anticipation 725 00:41:51,543 --> 00:41:53,649 of what that surface might be like. 726 00:41:53,649 --> 00:41:56,790 But I think in none of our wildest dreams 727 00:41:56,790 --> 00:42:00,518 was the surface of Titan as interesting and beautiful 728 00:42:00,518 --> 00:42:04,073 and exotic and exciting as it turns out to actually be. 729 00:42:12,737 --> 00:42:16,844 NARRATOR: During its two-and-a-half-hour descent to Titan, 730 00:42:16,844 --> 00:42:20,917 Huygens captured images of intricate ridges, 731 00:42:20,917 --> 00:42:23,644 deep gullies, 732 00:42:23,644 --> 00:42:27,924 and, perhaps most strikingly, river channels. 733 00:42:31,894 --> 00:42:35,345 GRINSPOON: It was truly like a dream, but there they are. 734 00:42:35,345 --> 00:42:36,450 These are real pictures coming 735 00:42:36,450 --> 00:42:38,486 from our first-ever descent to Titan. 736 00:42:38,486 --> 00:42:41,559 And, uh, it's unmistakable what we're seeing. 737 00:42:41,559 --> 00:42:43,561 And I'll, I'll just never forget that moment. 738 00:42:44,907 --> 00:42:46,356 PITTS: It's a moon! 739 00:42:46,356 --> 00:42:48,911 It's a moon that looks like this! 740 00:42:48,911 --> 00:42:51,430 Not a planet. 741 00:42:51,430 --> 00:42:55,642 How do you, how do you have these fluvial erosional features 742 00:42:55,642 --> 00:42:57,678 on the moon of a planet? 743 00:42:57,678 --> 00:43:00,508 ♪ 744 00:43:00,508 --> 00:43:06,204 NARRATOR: The team had designed Huygens to float, 745 00:43:06,204 --> 00:43:11,692 but it landed in what appeared to be an empty riverbed. 746 00:43:11,692 --> 00:43:16,179 And the river channels it imaged during its descent were dry. 747 00:43:18,803 --> 00:43:21,012 The probe continued to transmit data 748 00:43:21,012 --> 00:43:24,015 from Titan's surface for more than an hour 749 00:43:24,015 --> 00:43:29,020 before its breathtaking mission came to an end. 750 00:43:29,020 --> 00:43:33,403 But Cassini continued to explore the surface from afar. 751 00:43:35,889 --> 00:43:40,652 ♪ 752 00:43:40,652 --> 00:43:44,656 It saw a landscape of rolling dune fields, 753 00:43:44,656 --> 00:43:48,349 vast plains, 754 00:43:48,349 --> 00:43:52,043 and more dried-up rivers. 755 00:43:52,043 --> 00:43:54,977 It seemed Titan was a desert world. 756 00:43:57,945 --> 00:44:03,641 But in 2006, after many months of searching... 757 00:44:06,264 --> 00:44:08,680 ...Cassini's radar instrument found 758 00:44:08,680 --> 00:44:14,306 what everyone had been waiting for: 759 00:44:14,306 --> 00:44:18,172 lakes and seas of liquid methane at the north pole. 760 00:44:20,140 --> 00:44:23,868 Titan's equatorial region may be a desert, 761 00:44:23,868 --> 00:44:29,977 but Cassini had proved that its poles were anything but. 762 00:44:29,977 --> 00:44:31,358 FLETCHER: So that difference we could see 763 00:44:31,358 --> 00:44:33,084 between the deserts 764 00:44:33,084 --> 00:44:34,741 down around the equatorialregion 765 00:44:34,741 --> 00:44:36,087 and the seas that were present 766 00:44:36,087 --> 00:44:37,709 up at high latitudes 767 00:44:37,709 --> 00:44:39,366 had us scratching our heads. 768 00:44:40,988 --> 00:44:42,714 NARRATOR: What could be carving channels 769 00:44:42,714 --> 00:44:48,030 over a thousand miles away from the poles? 770 00:44:55,002 --> 00:44:57,591 MACKENZIE: We think about deserts as dry places, 771 00:44:57,591 --> 00:45:00,732 and most of the time they are, but they're carved, 772 00:45:00,732 --> 00:45:04,563 they're shaped, they're defined by these seasonal rainstorms 773 00:45:04,563 --> 00:45:07,118 that may happen only once or twice a year. 774 00:45:08,326 --> 00:45:12,986 The question is, could something similar be happening on Titan? 775 00:45:12,986 --> 00:45:14,781 Saturn happens to be tilted 776 00:45:14,781 --> 00:45:17,369 at about the same angle that the Earth is. 777 00:45:17,369 --> 00:45:18,923 So as it's going around the sun, 778 00:45:18,923 --> 00:45:22,581 it experiences seasons much like we do here on the Earth. 779 00:45:22,581 --> 00:45:25,067 But it takes Saturn and Titan a lot longer 780 00:45:25,067 --> 00:45:27,138 to go around the sun than we do. 781 00:45:27,138 --> 00:45:29,865 It takes 29-and-a-half years. 782 00:45:29,865 --> 00:45:32,695 Titan shares the same orbital plane as Saturn. 783 00:45:32,695 --> 00:45:34,939 And so it also experiences seasons 784 00:45:34,939 --> 00:45:37,562 as it's going around the sun. 785 00:45:37,562 --> 00:45:39,633 If we take the southern hemisphere, for example, 786 00:45:39,633 --> 00:45:42,256 there are seven years of summer 787 00:45:42,256 --> 00:45:44,776 where the southern hemisphere is pointed 788 00:45:44,776 --> 00:45:47,537 towards the sun and receiving more energy. 789 00:45:47,537 --> 00:45:49,091 That extra bit of energy, 790 00:45:49,091 --> 00:45:51,265 even though it's only a 100th 791 00:45:51,265 --> 00:45:53,371 of what we experience here on the Earth, 792 00:45:53,371 --> 00:45:56,754 is enough to pump the atmosphere full of methane, 793 00:45:56,754 --> 00:45:58,031 thanks to evaporation 794 00:45:58,031 --> 00:45:59,964 from the lakes in the south pole. 795 00:45:59,964 --> 00:46:04,658 ♪ 796 00:46:04,658 --> 00:46:07,972 NARRATOR: Cassini saw this happening. 797 00:46:07,972 --> 00:46:11,596 It flew by Titan during the southern summer... 798 00:46:14,392 --> 00:46:20,363 ...and saw methane clouds swirling around the south pole. 799 00:46:21,502 --> 00:46:24,540 But the clouds didn't stay there. 800 00:46:28,268 --> 00:46:31,443 MACKENZIE: In 2010, there was a giant cloud 801 00:46:31,443 --> 00:46:34,999 that formed over the equatorial region in the shape of an arrow. 802 00:46:34,999 --> 00:46:37,104 And as it moved across the surface of Titan, 803 00:46:37,104 --> 00:46:40,625 we saw that land that was bright before 804 00:46:40,625 --> 00:46:43,835 darkened, uh, after the cloud passed over. 805 00:46:43,835 --> 00:46:45,457 And the area that darkened 806 00:46:45,457 --> 00:46:49,461 is equivalent to about Utah and Arizona put together. 807 00:46:49,461 --> 00:46:51,498 So how did that happen? 808 00:46:51,498 --> 00:46:52,879 What is responsible for that? 809 00:46:52,879 --> 00:46:54,570 Well, we think the best explanation 810 00:46:54,570 --> 00:46:57,642 is a giant rainstorm. 811 00:46:57,642 --> 00:47:03,234 ♪ 812 00:47:03,234 --> 00:47:09,067 NARRATOR: In Titan's deserts, autumn brings change to the air. 813 00:47:09,067 --> 00:47:11,898 Monsoons arrive from the south... 814 00:47:16,212 --> 00:47:20,872 ...unleashing torrents of methane rain. 815 00:47:20,872 --> 00:47:25,704 But because of Titan's low gravity and dense atmosphere, 816 00:47:25,704 --> 00:47:29,847 the raindrops fall about six times slower than on Earth. 817 00:47:33,954 --> 00:47:37,855 These storms dump enough liquid methane onto the surface... 818 00:47:40,961 --> 00:47:43,308 ...to create flash floods... 819 00:47:46,622 --> 00:47:49,659 ...which drain into dry riverbeds... 820 00:47:53,940 --> 00:47:56,701 ...carving into the landscape... 821 00:48:06,918 --> 00:48:12,544 ...before spilling out onto vast floodplains. 822 00:48:17,929 --> 00:48:20,173 MACKENZIE: So, thanks to Cassini, we know 823 00:48:20,173 --> 00:48:22,382 that massive floods are happening on Titan. 824 00:48:22,382 --> 00:48:24,487 And just a few months later, 825 00:48:24,487 --> 00:48:28,043 which is only, like, five Titan days, that same land 826 00:48:28,043 --> 00:48:31,080 reverted to what it looked like before, it brightened. 827 00:48:31,080 --> 00:48:32,564 And the clouds themselves 828 00:48:32,564 --> 00:48:36,120 that were responsible for that rain had already moved on. 829 00:48:36,120 --> 00:48:41,884 ♪ 830 00:48:41,884 --> 00:48:47,579 NARRATOR: In 2022, five years after the Cassini mission ended, 831 00:48:47,579 --> 00:48:49,857 the James Webb Space Telescope 832 00:48:49,857 --> 00:48:55,622 turned its infrared gaze towards Saturn's largest moon. 833 00:48:56,692 --> 00:49:00,489 By now it was late summer in Titan's northern hemisphere, 834 00:49:00,489 --> 00:49:06,253 and the telescope spotted something remarkable: 835 00:49:06,253 --> 00:49:10,292 huge clouds over the north pole. 836 00:49:10,292 --> 00:49:15,814 The traveling storms had reached their destination. 837 00:49:16,850 --> 00:49:19,853 It is now believed Titan's storm belt 838 00:49:19,853 --> 00:49:24,996 goes on an epic 29-and-a-half-year journey 839 00:49:24,996 --> 00:49:30,105 from one pole to the other and back again. 840 00:49:30,105 --> 00:49:32,210 Slow-motion seasons 841 00:49:32,210 --> 00:49:36,732 unleashing massive, slow-motion storms, 842 00:49:36,732 --> 00:49:41,944 creating seasonal rivers of methane, 843 00:49:41,944 --> 00:49:46,535 in a desert on one of Saturn's moons. 844 00:49:46,535 --> 00:49:49,987 ♪ 845 00:49:55,509 --> 00:49:58,857 MACKENZIE: It's pretty incredible to be standing here 846 00:49:58,857 --> 00:50:01,791 in a desert landscape on the Earth 847 00:50:01,791 --> 00:50:04,415 and think about how similar that is 848 00:50:04,415 --> 00:50:06,865 to a landscape a billion miles away 849 00:50:06,865 --> 00:50:08,902 elsewhere in the solar system, 850 00:50:08,902 --> 00:50:12,457 the same processes, the same desert monsoon systems 851 00:50:12,457 --> 00:50:14,390 we think are at work on Titan, 852 00:50:14,390 --> 00:50:18,153 creating vistas much like this one that we see here. 853 00:50:18,153 --> 00:50:21,397 And yet the compounds, the materials 854 00:50:21,397 --> 00:50:24,538 that are involved in that process are totally different, 855 00:50:24,538 --> 00:50:26,540 and the temperature's totally different, 856 00:50:26,540 --> 00:50:28,439 and the timescales are totally different. 857 00:50:28,439 --> 00:50:31,476 And they're leading to a phenomenal landscape 858 00:50:31,476 --> 00:50:34,479 like the one that we see here. 859 00:50:34,479 --> 00:50:36,861 ♪ 860 00:50:43,178 --> 00:50:46,077 SOUSA-SILVA: On all these worlds, all this complexity, 861 00:50:46,077 --> 00:50:47,596 all these storms 862 00:50:47,596 --> 00:50:50,254 ultimately come from one fundamental law of nature. 863 00:50:50,254 --> 00:50:52,911 FLETCHER: That need to move energy 864 00:50:52,911 --> 00:50:55,673 from where it's plentiful to where it's scarce. 865 00:51:01,230 --> 00:51:03,474 DOTTIN: What makes these worlds so different 866 00:51:03,474 --> 00:51:05,200 are the unique conditions 867 00:51:05,200 --> 00:51:07,029 that are found in their atmospheres. 868 00:51:07,029 --> 00:51:08,962 [thunder rumbling] 869 00:51:08,962 --> 00:51:11,344 GUPTA: Because that determines the chemistry 870 00:51:11,344 --> 00:51:14,692 that drives their storms and shapes their surfaces. 871 00:51:14,692 --> 00:51:17,729 [thunder rumbling] 872 00:51:17,729 --> 00:51:20,042 GRINSPOON: You know, it's a pretty amazing time to be alive 873 00:51:20,042 --> 00:51:22,493 in, in that we have the ability 874 00:51:22,493 --> 00:51:26,013 to be monitoring weather on other planets. 875 00:51:26,013 --> 00:51:28,533 And yet I feel like we're in our early stages 876 00:51:28,533 --> 00:51:31,018 of understanding weather beyond Earth. 877 00:51:32,572 --> 00:51:34,505 DRANSFIELD: There are hundreds of billions of stars 878 00:51:34,505 --> 00:51:36,093 out there in the galaxy. 879 00:51:36,093 --> 00:51:40,269 And we now know that planets around stars is the norm. 880 00:51:40,269 --> 00:51:43,030 GAO: So that's potentially billions and billions 881 00:51:43,030 --> 00:51:44,687 of planets orbiting out there, 882 00:51:44,687 --> 00:51:46,448 all each with their own weather systems and storms. 883 00:51:47,690 --> 00:51:49,382 FRAEMAN: And I think there are things that are happening 884 00:51:49,382 --> 00:51:52,523 on these planets that we haven't even begun to imagine, 885 00:51:52,523 --> 00:51:54,249 because they're gonna be so different 886 00:51:54,249 --> 00:51:56,147 from anything else that we've been able 887 00:51:56,147 --> 00:51:59,150 to experience in our own solar system. 888 00:52:00,324 --> 00:52:02,395 GAO: And so that just makes me think of, 889 00:52:02,395 --> 00:52:04,638 what possibilities exist out there? 890 00:52:05,639 --> 00:52:09,298 What have we not thought of? 891 00:52:09,298 --> 00:52:13,333 ♪