1 00:00:01,768 --> 00:00:03,603 >> Announcer: NASA's Jet Propulsion Laboratory 2 00:00:03,603 --> 00:00:06,906 presents the von Karman Lecture. 3 00:00:06,906 --> 00:00:09,743 A series of talks by scientists and engineers 4 00:00:09,743 --> 00:00:13,313 who are exploring our planet, our solar system, 5 00:00:13,313 --> 00:00:14,914 and all that lies beyond. 6 00:00:22,055 --> 00:00:23,890 >> Good evening everybody. 7 00:00:23,890 --> 00:00:25,325 I'm Brian White from JPL's 8 00:00:25,325 --> 00:00:27,394 Office of Communications and Education. 9 00:00:27,394 --> 00:00:29,863 Welcome to the von Karman series. 10 00:00:29,863 --> 00:00:31,431 Before we get started, I want to talk about 11 00:00:31,431 --> 00:00:33,800 a teacher I had in college who on the very first, 12 00:00:33,800 --> 00:00:36,669 great teacher, on the very first day of class, 13 00:00:36,669 --> 00:00:39,939 he drew this itty-bitty tiny little circle on the board, 14 00:00:39,939 --> 00:00:42,776 and he said "this is everything you know." 15 00:00:42,776 --> 00:00:44,244 [laughter] 16 00:00:44,244 --> 00:00:45,345 Exactly that's what we thought as college students. 17 00:00:45,345 --> 00:00:46,880 We thought we knew everything. 18 00:00:46,880 --> 00:00:48,281 We thought we knew more than a tiny little circle. 19 00:00:48,281 --> 00:00:49,783 He says "it's fine because everything 20 00:00:49,783 --> 00:00:52,018 "that circle is touching, is everything 21 00:00:52,018 --> 00:00:54,120 "you now know you don't know." 22 00:00:55,722 --> 00:00:57,223 He said "by the end of the class," 23 00:00:57,223 --> 00:00:59,259 and drew this much bigger circle all the way around it, 24 00:00:59,259 --> 00:01:00,627 and he said "I hope this is you, 25 00:01:00,627 --> 00:01:02,529 "and I hope it's a lot scarier, 26 00:01:02,529 --> 00:01:05,298 "because everything that circle is touching 27 00:01:05,298 --> 00:01:09,169 "is everything you now know you don't know." 28 00:01:09,169 --> 00:01:10,503 [laughter] 29 00:01:10,503 --> 00:01:13,206 Ocean worlds are a rich and vibrant part 30 00:01:13,206 --> 00:01:15,308 of our solar system that intrigue both scientists 31 00:01:15,308 --> 00:01:16,643 and the public alike. 32 00:01:16,643 --> 00:01:18,478 Obviously you're all here tonight. 33 00:01:18,478 --> 00:01:21,014 But what exactly are we looking for, 34 00:01:21,014 --> 00:01:25,485 and how will we know we've found it, whatever it is? 35 00:01:25,485 --> 00:01:26,986 Tonight we'll take a look at some things 36 00:01:26,986 --> 00:01:29,923 that we know we don't know and how we go about figuring out 37 00:01:29,923 --> 00:01:31,858 which questions to ask. 38 00:01:31,858 --> 00:01:33,827 Now this evening's speaker, Doctor Morgan Cable 39 00:01:33,827 --> 00:01:36,129 is a research scientist here at JPL. 40 00:01:36,129 --> 00:01:39,265 While earning her PhD in chemistry at Caltech, 41 00:01:39,265 --> 00:01:41,367 she designed receptor sites for the detection 42 00:01:41,367 --> 00:01:44,504 of bacterial spores, the toughest form of life. 43 00:01:44,504 --> 00:01:46,940 She and colleagues were the first to discover a cocrystal, 44 00:01:46,940 --> 00:01:49,909 the equivalent of hydrated mineral made exclusively 45 00:01:49,909 --> 00:01:52,912 of organics that may exist on Titan's surface. 46 00:01:52,912 --> 00:01:55,181 This work has led to the inception of a new field, 47 00:01:55,181 --> 00:01:57,150 Titan petrology, and she can correct me 48 00:01:57,150 --> 00:01:59,385 if I screwed that one up. 49 00:01:59,385 --> 00:02:01,955 She conducts fieldwork in extreme environments on Earth, 50 00:02:01,955 --> 00:02:05,625 searching for life in places such as the Atacama Desert, 51 00:02:05,625 --> 00:02:06,926 the summit of Mount Kilimanjaro 52 00:02:06,926 --> 00:02:08,661 and the lava fields of Iceland. 53 00:02:08,661 --> 00:02:11,030 She is an extreme unicyclist. 54 00:02:12,499 --> 00:02:15,301 She's a surfer who worked on the Cassini mission as 55 00:02:15,301 --> 00:02:19,172 a project science systems engineer, 56 00:02:19,172 --> 00:02:20,607 is currently a co-investigator on 57 00:02:20,607 --> 00:02:22,342 the Dragonfly mission to Titan, 58 00:02:22,342 --> 00:02:24,344 and a member of the project science team 59 00:02:24,344 --> 00:02:25,678 for the Europa lander. 60 00:02:25,678 --> 00:02:28,214 Ladies and gentlemen, Doctor Morgan Cable. 61 00:02:28,214 --> 00:02:30,450 [applause] 62 00:02:34,554 --> 00:02:36,089 >> Thank you. 63 00:02:36,089 --> 00:02:38,491 Can you all hear me all right? 64 00:02:38,491 --> 00:02:39,993 All right. 65 00:02:39,993 --> 00:02:42,328 Thanks so much for coming, for braving the coronavirus. 66 00:02:42,328 --> 00:02:44,564 Make sure you're all washing your hands. 67 00:02:44,564 --> 00:02:46,232 We've been doing the chemistry hi-five, 68 00:02:46,232 --> 00:02:47,467 which is with the elbow. 69 00:02:47,467 --> 00:02:49,202 I've also seen some with the foot, you know, 70 00:02:49,202 --> 00:02:51,304 instead of shaking hands. 71 00:02:51,304 --> 00:02:53,406 It's such a pleasure to be here tonight. 72 00:02:53,406 --> 00:02:55,808 I'm so excited to tell you a bit about 73 00:02:55,808 --> 00:02:58,444 the work that we're doing here at JPL 74 00:02:58,444 --> 00:03:00,680 and other NASA centers to explore 75 00:03:00,680 --> 00:03:03,583 this ultimate question, are we alone. 76 00:03:03,583 --> 00:03:05,285 So before we get started, 77 00:03:05,285 --> 00:03:07,554 I'd like you all to do a little exercise. 78 00:03:07,554 --> 00:03:09,756 Now it's kind of late here, 7 p.m. 79 00:03:09,756 --> 00:03:10,990 For those of you watching online, 80 00:03:10,990 --> 00:03:12,091 it might be a little bit later, 81 00:03:12,091 --> 00:03:14,060 but I'd like you to take a minute 82 00:03:14,060 --> 00:03:17,931 to take a breath and close your eyes. 83 00:03:17,931 --> 00:03:20,133 And I want you to picture yourself, 84 00:03:20,133 --> 00:03:24,103 in your mind's eye, standing on an alien world. 85 00:03:24,103 --> 00:03:26,105 All right, picture it. 86 00:03:26,105 --> 00:03:29,175 Look up into the sky. 87 00:03:29,175 --> 00:03:31,144 How many suns are there? 88 00:03:31,144 --> 00:03:33,446 Is there a single star like we have here, 89 00:03:33,446 --> 00:03:35,715 or is it more like Tatooine? 90 00:03:35,715 --> 00:03:38,685 Binary star systems are actually pretty common. 91 00:03:38,685 --> 00:03:40,320 Maybe it's night time. 92 00:03:40,320 --> 00:03:43,456 Do you see different constellations in the sky? 93 00:03:43,456 --> 00:03:44,390 Look down. 94 00:03:44,390 --> 00:03:45,992 What are you standing on? 95 00:03:45,992 --> 00:03:47,527 Is it rock? 96 00:03:47,527 --> 00:03:49,028 Is it ice? 97 00:03:49,028 --> 00:03:50,430 Sand? 98 00:03:50,430 --> 00:03:51,798 Maybe you're floating. 99 00:03:51,798 --> 00:03:54,000 Maybe it's a boat in your own liquid. 100 00:03:54,000 --> 00:03:57,537 Is that liquid water or is it something else? 101 00:03:57,537 --> 00:04:00,840 Picture yourself there on your alien world. 102 00:04:00,840 --> 00:04:02,675 Is there a lot of gravity? 103 00:04:02,675 --> 00:04:06,246 Is it larger than Earth and so it's pulling you down, 104 00:04:06,246 --> 00:04:07,747 or are you kind of floating? 105 00:04:07,747 --> 00:04:10,883 Would you skip around like the astronauts did on the moon? 106 00:04:10,883 --> 00:04:12,685 Think about this place. 107 00:04:12,685 --> 00:04:14,687 And now I'm going to give you a mission. 108 00:04:14,687 --> 00:04:17,490 Your mission, if you choose to accept it, 109 00:04:17,490 --> 00:04:19,092 is to collect one sample. 110 00:04:19,092 --> 00:04:20,260 Well, not even one. 111 00:04:20,260 --> 00:04:22,795 Anything that your arms can carry to prove 112 00:04:22,795 --> 00:04:26,332 that there is life on your alien world. 113 00:04:26,332 --> 00:04:27,934 Think about what you might grab. 114 00:04:29,135 --> 00:04:31,604 Okay and now I'd like you to open your eyes. 115 00:04:33,039 --> 00:04:37,644 This is our only example of a place that has life, right? 116 00:04:38,244 --> 00:04:39,045 Our home planet. 117 00:04:39,045 --> 00:04:40,280 Our pale blue dot. 118 00:04:40,280 --> 00:04:41,814 The Earth. 119 00:04:41,814 --> 00:04:45,518 And you may think that in a world teeming with life, 120 00:04:45,518 --> 00:04:47,553 doing that exercise that I just asked 121 00:04:47,553 --> 00:04:49,589 of you would be easy, right? 122 00:04:49,589 --> 00:04:51,624 This would be super simple. 123 00:04:51,624 --> 00:04:52,959 But is it? 124 00:04:52,959 --> 00:04:55,128 Well it depends on where you land. 125 00:04:55,128 --> 00:04:57,430 If you land here, super easy. 126 00:04:57,430 --> 00:04:59,432 This is the Amazon rainforest, right? 127 00:04:59,432 --> 00:05:01,301 You could just go grab a leaf, 128 00:05:01,301 --> 00:05:02,735 maybe a monkey if you're quick enough. 129 00:05:02,735 --> 00:05:04,003 You know, you could get something 130 00:05:04,003 --> 00:05:07,040 really easy and obvious that there's life there. 131 00:05:07,040 --> 00:05:08,408 Okay that's great. 132 00:05:08,408 --> 00:05:10,276 But if I were an engineer trying to design 133 00:05:10,276 --> 00:05:14,580 a spacecraft to land here, do you see a safe place to land? 134 00:05:14,580 --> 00:05:16,082 Not so much. 135 00:05:16,082 --> 00:05:18,918 Chances are I would want to land in a nice flat place. 136 00:05:18,918 --> 00:05:22,322 This is the Atacama Desert in northern Chile. 137 00:05:22,322 --> 00:05:24,290 It's one of the driest deserts in the world, 138 00:05:24,290 --> 00:05:26,959 and we actually love this here at NASA, 139 00:05:26,959 --> 00:05:29,295 because this makes an excellent analog for Mars. 140 00:05:29,295 --> 00:05:31,331 A lot of the salts, the water activity, 141 00:05:31,331 --> 00:05:32,965 other things about this environment 142 00:05:32,965 --> 00:05:35,702 make it a good analog for Mars. 143 00:05:35,702 --> 00:05:38,037 But if you were to try to look for life here, 144 00:05:38,037 --> 00:05:41,708 there is life here, but it's not quite as easy to find. 145 00:05:41,708 --> 00:05:43,976 You might need a microscope for example. 146 00:05:43,976 --> 00:05:47,246 You might need a tool to dig down underneath 147 00:05:47,246 --> 00:05:50,016 the surface a little bit to find that life. 148 00:05:51,184 --> 00:05:53,820 Now what if you went to a place like here. 149 00:05:53,820 --> 00:05:55,621 Does anyone recognize the skyline? 150 00:05:55,621 --> 00:05:58,124 Yeah, this is Los Angeles. 151 00:05:58,124 --> 00:06:00,827 Now this gets into a different kind of bio-signature, 152 00:06:00,827 --> 00:06:02,895 something that we call a techno-signature, 153 00:06:02,895 --> 00:06:05,965 and we're going to save that discussion for another time. 154 00:06:05,965 --> 00:06:07,767 That would be amazing, and if we find something 155 00:06:07,767 --> 00:06:09,302 like this somewhere checking 156 00:06:09,302 --> 00:06:11,838 that life box would be pretty easy. 157 00:06:11,838 --> 00:06:15,641 But chances are if we were to land anywhere here on Earth, 158 00:06:15,641 --> 00:06:17,877 we would land here, right? 159 00:06:17,877 --> 00:06:21,914 About 70% of Earth's surface is covered in water. 160 00:06:21,914 --> 00:06:26,853 And if you were to design a container to collect life 161 00:06:26,853 --> 00:06:29,655 to bring back, you would design it differently 162 00:06:29,655 --> 00:06:32,692 if you were going to land someplace like an ocean 163 00:06:32,692 --> 00:06:34,093 then you would if you were landing in 164 00:06:34,093 --> 00:06:36,662 a desert or in a rainforest, 165 00:06:36,662 --> 00:06:40,333 and so depending on where you go 166 00:06:40,333 --> 00:06:43,870 and what you're looking for, may define the type 167 00:06:43,870 --> 00:06:48,641 of things that you would bring with you to your alien world. 168 00:06:48,641 --> 00:06:51,210 And it's appropriate that we end on water, 169 00:06:51,210 --> 00:06:54,280 because for NASA this is one of the key ingredients 170 00:06:54,280 --> 00:06:56,416 that we look for when we're searching for life. 171 00:06:56,416 --> 00:06:57,917 It's not the only thing. 172 00:06:57,917 --> 00:07:01,387 Of course there could be life that is not aqueous based, 173 00:07:01,387 --> 00:07:03,356 that's not based on liquid water. 174 00:07:03,356 --> 00:07:05,958 But this is our sample size, right? 175 00:07:05,958 --> 00:07:06,959 Sample size of one. 176 00:07:06,959 --> 00:07:09,629 One world and here we find 177 00:07:09,629 --> 00:07:13,032 that life needs three key ingredients. 178 00:07:13,032 --> 00:07:15,234 One of them is liquid water. 179 00:07:15,234 --> 00:07:18,638 Liquid helps you transport nutrients in, 180 00:07:18,638 --> 00:07:20,440 transport waste out. 181 00:07:20,440 --> 00:07:22,208 It gives, it sort of greases 182 00:07:22,208 --> 00:07:26,045 the molecular machinery of life it lubricates it. 183 00:07:26,045 --> 00:07:28,815 So we know that life needs water. 184 00:07:28,815 --> 00:07:31,717 We also know that it needs what I call chemistry. 185 00:07:31,717 --> 00:07:32,952 Basically building blocks. 186 00:07:32,952 --> 00:07:35,688 You need something to make those molecules 187 00:07:35,688 --> 00:07:37,623 that you are made up of. 188 00:07:37,623 --> 00:07:39,392 You need something to make those out of, 189 00:07:39,392 --> 00:07:42,395 and that can be carbon, hydrogen, nitrogen, 190 00:07:42,395 --> 00:07:44,096 like we have here abundantly. 191 00:07:44,096 --> 00:07:46,132 Typically it'll be something that's pretty common. 192 00:07:46,132 --> 00:07:50,403 If we were all based on, I don't know, titanium or iridium, 193 00:07:50,403 --> 00:07:51,971 there's not a lot of that around, 194 00:07:51,971 --> 00:07:53,739 so there wouldn't be very many of us. 195 00:07:53,739 --> 00:07:55,208 Which I guess means we wouldn't have 196 00:07:55,208 --> 00:07:58,311 as many coronavirus distributor, which would be good. 197 00:07:58,311 --> 00:08:03,115 But you typically use building blocks that are common. 198 00:08:03,115 --> 00:08:04,317 So that's the second thing. 199 00:08:04,317 --> 00:08:05,985 We need the building blocks of life. 200 00:08:05,985 --> 00:08:08,788 And the third thing we need is energy. 201 00:08:08,788 --> 00:08:10,556 Something to metabolize. 202 00:08:10,556 --> 00:08:12,925 Something to drive the chemical reactions, 203 00:08:12,925 --> 00:08:16,128 the biochemical reactions that keep us alive. 204 00:08:16,128 --> 00:08:18,264 And so any place on Earth where we find 205 00:08:18,264 --> 00:08:21,133 those three things, we find life. 206 00:08:21,133 --> 00:08:22,568 Every time. 207 00:08:22,568 --> 00:08:25,004 And so these are the things that we will look for 208 00:08:25,004 --> 00:08:28,040 when we try to explore our solar system and beyond 209 00:08:28,040 --> 00:08:29,609 and search for life there. 210 00:08:31,310 --> 00:08:34,180 So let's go a little bit further out from Earth, 211 00:08:34,180 --> 00:08:38,718 we're going to go about 480 million miles to Jupiter. 212 00:08:38,718 --> 00:08:41,854 Jupiter's our largest planet in our solar system, right? 213 00:08:41,854 --> 00:08:43,122 It's kind of the bouncer. 214 00:08:43,122 --> 00:08:46,125 It sorta kept a lot of major meteoritic events 215 00:08:46,125 --> 00:08:47,994 from happening here on Earth, at least not too many. 216 00:08:47,994 --> 00:08:50,530 So we're 65 million years and counting since the last one. 217 00:08:50,530 --> 00:08:51,931 That's great. 218 00:08:51,931 --> 00:08:53,466 Jupiter is amazing. 219 00:08:53,466 --> 00:08:55,301 It's beautiful and I love it. 220 00:08:55,301 --> 00:08:57,603 But I love its moons even more. 221 00:08:57,603 --> 00:09:00,606 Jupiter has four what we call Galilean moons, 222 00:09:00,606 --> 00:09:02,441 'cause Galileo discovered them, 223 00:09:02,441 --> 00:09:03,876 should get some credit. 224 00:09:03,876 --> 00:09:06,679 And three of them are locked 225 00:09:06,679 --> 00:09:09,282 in what's called the tidal resonance. 226 00:09:09,282 --> 00:09:13,152 And this one, Europa, is in the middle. 227 00:09:13,152 --> 00:09:17,456 So in between Europa and Jupiter is a world called Io. 228 00:09:17,456 --> 00:09:20,860 It's the most volcanically active body in the solar system. 229 00:09:20,860 --> 00:09:24,030 It's a really cool place and it's really hot because 230 00:09:24,030 --> 00:09:27,433 of its interaction with Europa and also with 231 00:09:27,433 --> 00:09:30,603 the third moon out which is called Ganymede. 232 00:09:30,603 --> 00:09:33,973 So it goes Io, Europa, Ganymede. 233 00:09:33,973 --> 00:09:38,978 And for every one orbit Europa does, Io does two. 234 00:09:40,313 --> 00:09:43,449 For every orbit that Ganymede does, Europa does two. 235 00:09:43,449 --> 00:09:45,585 And so what happens is, it's kind of like, 236 00:09:45,585 --> 00:09:47,286 you remember on the playground when you were a kid, 237 00:09:47,286 --> 00:09:49,956 if you pushed your friend or maybe your sister, 238 00:09:49,956 --> 00:09:51,357 brother on the swing set, 239 00:09:51,357 --> 00:09:52,925 and you wanted them to go really high, 240 00:09:52,925 --> 00:09:55,628 you had to time that pushes just right, you know, 241 00:09:55,628 --> 00:09:57,997 and if you did that you could get them go maybe higher 242 00:09:57,997 --> 00:10:00,166 than your parents thought was safe. 243 00:10:00,166 --> 00:10:02,902 That's what's happening here with these worlds. 244 00:10:02,902 --> 00:10:05,371 So they're locked in this gravitational tug-of-war 245 00:10:05,371 --> 00:10:07,306 and because of this resonance, 246 00:10:07,306 --> 00:10:08,708 every time they orbit around they give 247 00:10:08,708 --> 00:10:10,743 each other this energetic kick. 248 00:10:10,743 --> 00:10:13,546 And here that kick turns into this friction that causes 249 00:10:13,546 --> 00:10:16,616 the worlds to move like this. 250 00:10:16,616 --> 00:10:19,619 And so that flexing we call tidal flexing, 251 00:10:19,619 --> 00:10:21,020 that generates heat. 252 00:10:21,020 --> 00:10:23,656 And that's why Europa has a lot 253 00:10:23,656 --> 00:10:26,525 of liquid underneath this icy shell. 254 00:10:26,525 --> 00:10:28,628 And it's why it's one of my favorite places 255 00:10:28,628 --> 00:10:30,262 in the entire solar system. 256 00:10:30,262 --> 00:10:34,767 Europa actually has two to three times the volume of all 257 00:10:34,767 --> 00:10:38,204 of Earth's oceans combined in liquid water. 258 00:10:38,204 --> 00:10:39,672 That's a lot of water. 259 00:10:39,672 --> 00:10:42,208 Now it's under a shell of ice. 260 00:10:42,208 --> 00:10:45,945 But it's really interesting because you can learn 261 00:10:45,945 --> 00:10:48,280 a lot about this world, we think, 262 00:10:48,280 --> 00:10:50,483 from studying Europa's surface. 263 00:10:50,483 --> 00:10:53,953 Now you may notice that it's got some cracks 264 00:10:53,953 --> 00:10:57,089 and some grooves and they seem to be a darker color. 265 00:10:57,089 --> 00:10:59,125 We're not sure exactly what that dark color is, 266 00:10:59,125 --> 00:11:01,961 we think it could either be salts or organic molecules, 267 00:11:01,961 --> 00:11:03,863 maybe a little bit of both. 268 00:11:03,863 --> 00:11:07,033 But one thing is kind of missing from this. 269 00:11:07,033 --> 00:11:08,534 Does anyone know? 270 00:11:08,534 --> 00:11:10,169 I'll give you a hint, our moon has a lot of these. 271 00:11:10,169 --> 00:11:11,003 Yes. 272 00:11:11,003 --> 00:11:12,204 Craters. 273 00:11:12,204 --> 00:11:14,040 Turns out Europa only has this many. 274 00:11:14,040 --> 00:11:16,509 It's got about seven big craters. 275 00:11:16,509 --> 00:11:17,710 You know that's important, 276 00:11:17,710 --> 00:11:19,912 because this is how we date objects 277 00:11:19,912 --> 00:11:22,148 in our solar system, by crater counting. 278 00:11:22,148 --> 00:11:23,582 And this tells us that the surface 279 00:11:23,582 --> 00:11:26,485 of Europa is relatively young. 280 00:11:26,485 --> 00:11:27,420 Now this is cool. 281 00:11:27,420 --> 00:11:29,655 It's about 50 million years. 282 00:11:29,655 --> 00:11:31,857 So even younger than the dinosaurs, 283 00:11:31,857 --> 00:11:35,528 which means something must be refreshing it somehow. 284 00:11:35,528 --> 00:11:39,331 We think that there could be some activity from the ocean, 285 00:11:39,331 --> 00:11:41,067 maybe some localized heating. 286 00:11:41,067 --> 00:11:43,135 We see these things called lenticulae, 287 00:11:43,135 --> 00:11:45,337 which is Greek or Latin for freckles. 288 00:11:45,337 --> 00:11:47,907 Some places where it looks like there're little hot spots. 289 00:11:47,907 --> 00:11:51,310 We see these smooth bands where it looks like some of 290 00:11:51,310 --> 00:11:55,915 the surface has split open and water has been sucked up 291 00:11:55,915 --> 00:11:58,551 or ice has been sucked up and filled in the gaps. 292 00:11:58,551 --> 00:12:00,519 And so we see these places on the surface 293 00:12:00,519 --> 00:12:02,755 where it looks like there's a lot of activity, 294 00:12:02,755 --> 00:12:04,390 and that gets us really excited, 295 00:12:04,390 --> 00:12:06,025 because we would want, 296 00:12:06,025 --> 00:12:08,594 if we send something to explore this place, 297 00:12:08,594 --> 00:12:11,630 to search those fresher regions. 298 00:12:11,630 --> 00:12:14,066 Those may have more organics in them, 299 00:12:14,066 --> 00:12:15,868 they may have better evidence 300 00:12:15,868 --> 00:12:19,038 of what's in that ocean underneath. 301 00:12:19,038 --> 00:12:21,941 And boy, wouldn't it be great to send a spacecraft here 302 00:12:21,941 --> 00:12:26,045 and look for life or look for evidence of habitability? 303 00:12:26,045 --> 00:12:26,979 Yes it would. 304 00:12:26,979 --> 00:12:28,214 And we're going to do that. 305 00:12:29,682 --> 00:12:32,551 Europa is incredible, right? 306 00:12:32,551 --> 00:12:35,121 We think that underneath this ice shell, 307 00:12:35,121 --> 00:12:37,356 we know that it has a liquid water ocean, 308 00:12:37,356 --> 00:12:39,425 we're not sure exactly how deep it is. 309 00:12:39,425 --> 00:12:40,626 That's one of the things 310 00:12:40,626 --> 00:12:43,129 that our next mission is going to study. 311 00:12:43,129 --> 00:12:44,363 But we do know that there's 312 00:12:44,363 --> 00:12:46,832 a lot of radiation at the surface. 313 00:12:46,832 --> 00:12:49,535 This is because Jupiter is really big. 314 00:12:49,535 --> 00:12:51,771 It acts as the bouncer for the rest of our solar system, 315 00:12:51,771 --> 00:12:55,174 which is great, but it also has some negative effects 316 00:12:55,174 --> 00:12:56,475 for some of the moons around it. 317 00:12:56,475 --> 00:12:58,544 Because it's so large it sucks in a lot of 318 00:12:58,544 --> 00:13:01,080 the charged particles from the solar winds 319 00:13:01,080 --> 00:13:02,314 and it whips them around with 320 00:13:02,314 --> 00:13:03,883 its really strong magnetic field, 321 00:13:03,883 --> 00:13:05,918 and it slams them into Europa. 322 00:13:05,918 --> 00:13:07,686 Now Europa doesn't have an atmosphere, 323 00:13:07,686 --> 00:13:10,289 and so these things will interact directly 324 00:13:10,289 --> 00:13:12,358 with that water ice on the surface. 325 00:13:12,358 --> 00:13:14,293 And water ice is H2O right? 326 00:13:14,293 --> 00:13:15,294 That's water. 327 00:13:15,294 --> 00:13:16,428 It'll break that up. 328 00:13:16,428 --> 00:13:17,897 It'll kick off the hydrogens 329 00:13:17,897 --> 00:13:19,498 and since they're super light they float away, 330 00:13:19,498 --> 00:13:21,734 and so you'll end up with this tenuous oxygen, 331 00:13:21,734 --> 00:13:23,936 we don't even call it an atmosphere. 332 00:13:23,936 --> 00:13:26,572 We call it in exosphere 'cause it's so thin. 333 00:13:26,572 --> 00:13:30,309 And that oxygen is really rich in electrons. 334 00:13:30,309 --> 00:13:33,312 Now down at the seafloor where we think 335 00:13:33,312 --> 00:13:36,415 there could be hydrothermal activity, heating, 336 00:13:36,415 --> 00:13:38,617 geothermal activity, things like that, 337 00:13:38,617 --> 00:13:41,487 we are pretty sure based on examples here on Earth 338 00:13:41,487 --> 00:13:43,656 that that place is electron poor. 339 00:13:43,656 --> 00:13:45,925 So if you've got a lot of electrons in one place, 340 00:13:45,925 --> 00:13:49,562 a few electrons in another place, you know what that is? 341 00:13:49,562 --> 00:13:51,997 That's a battery, basically right? 342 00:13:51,997 --> 00:13:54,967 You just need to connect the two and there's a lot of types 343 00:13:54,967 --> 00:13:58,671 of life here on Earth that we call a chemotroph. 344 00:13:58,671 --> 00:13:59,572 Chemoautotrophs. 345 00:13:59,572 --> 00:14:01,006 Chemo- means chemistry, 346 00:14:01,006 --> 00:14:02,775 auto means it does it by itself, it doesn't need help, 347 00:14:02,775 --> 00:14:05,377 and it uses those types of energy sources, 348 00:14:05,377 --> 00:14:07,279 just shuttling the electrons around. 349 00:14:07,279 --> 00:14:09,815 Takes a little tax, a little bit off the top, 350 00:14:09,815 --> 00:14:12,151 and that's what it uses to be alive. 351 00:14:12,151 --> 00:14:13,853 And so there are all sorts of organisms 352 00:14:13,853 --> 00:14:16,088 that could exist in environments like this. 353 00:14:16,088 --> 00:14:19,859 And the Europa Clipper Mission is going to study this world. 354 00:14:19,859 --> 00:14:21,460 So Europa Clipper is a mission 355 00:14:21,460 --> 00:14:23,963 that NASA's building right now. 356 00:14:23,963 --> 00:14:27,633 It's going to have nine different instruments 357 00:14:27,633 --> 00:14:30,202 that will be able to study Europa, 358 00:14:30,202 --> 00:14:32,204 its surface, its interior, 359 00:14:32,204 --> 00:14:34,907 and all of these properties to help us understand 360 00:14:34,907 --> 00:14:37,209 whether or not it's habitable and whether or not 361 00:14:37,209 --> 00:14:40,679 there could be life there today, or maybe in the past. 362 00:14:40,679 --> 00:14:43,282 Europa Clipper is going to be ready 363 00:14:43,282 --> 00:14:46,485 for launch in about 2025, as I said we're building it now. 364 00:14:46,485 --> 00:14:48,354 And depending on which rocket we go on, 365 00:14:48,354 --> 00:14:52,291 we'll reach the Jupiter system maybe sixish years later, 366 00:14:52,291 --> 00:14:55,895 and we'll bring all of these instruments to bear. 367 00:14:55,895 --> 00:14:58,530 We're going to have some very sensitive cameras 368 00:14:58,530 --> 00:15:00,132 that will be able to take incredibly 369 00:15:00,132 --> 00:15:03,269 high resolution images of Europa's surface. 370 00:15:03,269 --> 00:15:05,771 We will have basically a fancy compass, 371 00:15:05,771 --> 00:15:08,807 magnetometer that can tell us by studying 372 00:15:08,807 --> 00:15:13,379 the magnetic field properties of that ocean and its depth. 373 00:15:13,379 --> 00:15:16,015 We'll have a radar sounder that could do 374 00:15:16,015 --> 00:15:18,083 the same thing we do here when we fly radar 375 00:15:18,083 --> 00:15:20,452 over Antarctica to get at the thickness of the ice 376 00:15:20,452 --> 00:15:23,522 and if there are any pockets of water in there. 377 00:15:23,522 --> 00:15:27,860 It will also have an instrument called a mass spectrometer. 378 00:15:27,860 --> 00:15:29,895 And we actually have two different kinds. 379 00:15:29,895 --> 00:15:31,196 One that can get at the gas. 380 00:15:31,196 --> 00:15:32,531 It's sort of like your nose. 381 00:15:32,531 --> 00:15:33,999 It'll sniff what's there. 382 00:15:33,999 --> 00:15:35,467 Things that are coming off the surface, 383 00:15:35,467 --> 00:15:37,903 to tell us if there are any interesting gases 384 00:15:37,903 --> 00:15:39,805 like hydrogen or methane, 385 00:15:39,805 --> 00:15:41,006 things that we could tie 386 00:15:41,006 --> 00:15:43,509 to some sort of geothermal activity. 387 00:15:43,509 --> 00:15:45,778 And we'll also have one that it's kind 388 00:15:45,778 --> 00:15:48,981 of like sticking out your tongue and tasting snowflakes, 389 00:15:48,981 --> 00:15:51,817 except doing it, you know, five kilometers a second. 390 00:15:51,817 --> 00:15:53,585 Would not recommend doing that with your tongue, 391 00:15:53,585 --> 00:15:56,422 but with the instrument aboard that's a dust detector, 392 00:15:56,422 --> 00:16:00,125 that is actually the perfect speed to pick up dust grains, 393 00:16:00,125 --> 00:16:03,195 ice grains, you smash them open and you can determine 394 00:16:03,195 --> 00:16:05,731 what kind of organic molecules are present. 395 00:16:05,731 --> 00:16:08,300 And so we can do that for bits of ice 396 00:16:08,300 --> 00:16:09,768 that are sputtered off the surface 397 00:16:09,768 --> 00:16:12,838 from micrometeoroid impacts and things like that, 398 00:16:12,838 --> 00:16:15,808 and get an idea what that surface composition is, 399 00:16:15,808 --> 00:16:17,309 even without landing. 400 00:16:17,309 --> 00:16:19,878 So the Europa Clipper Mission is going to be in 401 00:16:19,878 --> 00:16:21,680 the Jupiter system for several years, 402 00:16:21,680 --> 00:16:24,783 but we decided to not have it orbit Europa 403 00:16:24,783 --> 00:16:26,618 because of the intense radiation. 404 00:16:26,618 --> 00:16:29,188 It's not so good for us if we were standing on 405 00:16:29,188 --> 00:16:30,723 the surface of Europa, you probably get 406 00:16:30,723 --> 00:16:33,258 a lethal dose of radiation in a few hours, 407 00:16:33,258 --> 00:16:34,660 it's not good for spacecraft either. 408 00:16:34,660 --> 00:16:37,830 It can cause things like single-event upsets 409 00:16:37,830 --> 00:16:40,499 in your electronics and make them function, 410 00:16:40,499 --> 00:16:42,935 turn on and off in ways that you don't expect. 411 00:16:42,935 --> 00:16:44,737 And so what Europa Clipper's going to do 412 00:16:44,737 --> 00:16:46,238 is it's going to get close to Europa, 413 00:16:46,238 --> 00:16:48,474 take lots of data and then come back out, 414 00:16:48,474 --> 00:16:51,310 cool off, send the data back give us some time 415 00:16:51,310 --> 00:16:53,445 to interpret it, think about it before 416 00:16:53,445 --> 00:16:56,015 it goes back in again for its next pass. 417 00:16:56,015 --> 00:16:59,084 And this is something that we're really excited about, 418 00:16:59,084 --> 00:17:01,453 because we'll be able to get images that 419 00:17:01,453 --> 00:17:05,591 every time we send a powerful spacecraft somewhere, 420 00:17:05,591 --> 00:17:07,826 and we bring advanced instruments like cameras, 421 00:17:07,826 --> 00:17:12,398 detectors, the electronic tongue I was talking about, 422 00:17:12,398 --> 00:17:14,466 we always find things that surprise us. 423 00:17:14,466 --> 00:17:17,169 And I can't imagine the things that we will find here 424 00:17:17,169 --> 00:17:19,204 that will surprise us. 425 00:17:19,204 --> 00:17:22,107 Now when NASA does missions, typically we like to send 426 00:17:22,107 --> 00:17:25,377 an orbiter or a flyby mission first. 427 00:17:25,377 --> 00:17:26,779 Now there's some reasons for that. 428 00:17:26,779 --> 00:17:28,847 This can give us a lot of great images 429 00:17:28,847 --> 00:17:30,582 and maps of the surface. 430 00:17:30,582 --> 00:17:32,217 One of the other instruments aboard Clipper 431 00:17:32,217 --> 00:17:34,420 is basically like a really fancy camera. 432 00:17:34,420 --> 00:17:37,556 For every picture that it takes, each pixel 433 00:17:37,556 --> 00:17:40,092 of that image will actually be a spectrum. 434 00:17:40,092 --> 00:17:41,693 That will give us information about 435 00:17:41,693 --> 00:17:43,462 what the surface is made of. 436 00:17:43,462 --> 00:17:45,397 Those kinds of details are really important, 437 00:17:45,397 --> 00:17:47,499 'cause ultimately if we want to answer 438 00:17:47,499 --> 00:17:50,202 the life question, we need to land, 439 00:17:50,202 --> 00:17:53,172 and we're working right now on a concept. 440 00:17:53,172 --> 00:17:55,174 This is called the Europa Lander. 441 00:17:55,174 --> 00:17:58,077 This is something that would come after Clipper 442 00:17:58,077 --> 00:18:00,245 and be able to take all of that information 443 00:18:00,245 --> 00:18:03,649 to help us pick just the right spot to land, right? 444 00:18:03,649 --> 00:18:06,685 We want to go to a safe place but an interesting place 445 00:18:06,685 --> 00:18:09,755 that could potentially have signatures of life. 446 00:18:09,755 --> 00:18:12,257 It will have the ability to communicate directly 447 00:18:12,257 --> 00:18:15,627 with Earth through its high gain antenna, 448 00:18:15,627 --> 00:18:18,063 and it will have an arm, it would, 449 00:18:18,063 --> 00:18:21,166 that would be able to cut into the surface. 450 00:18:21,166 --> 00:18:24,636 Now the surface of Europa is pretty cold. 451 00:18:24,636 --> 00:18:27,673 It's about a hundred and fifty Kelvin. 452 00:18:27,673 --> 00:18:31,276 Which, let's see in celsius that's what -130 degrees C. 453 00:18:31,276 --> 00:18:33,345 I don't know what it is in fahrenheit I'm a scientist. 454 00:18:33,345 --> 00:18:34,713 We don't work in fahrenheit. 455 00:18:34,713 --> 00:18:36,748 But it's really cold. 456 00:18:36,748 --> 00:18:39,718 And it turns out that ice at those temperatures 457 00:18:39,718 --> 00:18:43,188 has a lot of similar properties to rock, like granite. 458 00:18:43,188 --> 00:18:45,157 And some of our engineers here at JPL 459 00:18:45,157 --> 00:18:47,893 who are designing types of cutting tools to be able 460 00:18:47,893 --> 00:18:51,363 to slice into that really hard ice, 461 00:18:51,363 --> 00:18:53,065 boy they are really interesting. 462 00:18:53,065 --> 00:18:54,233 One of the guys was telling me 463 00:18:54,233 --> 00:18:55,701 "yeah I was on my treadmill this morning, 464 00:18:55,701 --> 00:18:57,870 "I was thinking about what is the toughest sample 465 00:18:57,870 --> 00:18:59,404 "that we could come up with." 466 00:18:59,404 --> 00:19:01,373 And he ended up, this was really mean. 467 00:19:01,373 --> 00:19:04,209 He took cotton, and he stretched out the cotton balls 468 00:19:04,209 --> 00:19:06,879 until you get like that really fibrous kind of stuff, 469 00:19:06,879 --> 00:19:08,947 and then he put that in water ice, 470 00:19:08,947 --> 00:19:10,749 and then dunked that and liquid nitrogen. 471 00:19:10,749 --> 00:19:13,619 And he said that broke about half of their prototypes, 472 00:19:13,619 --> 00:19:17,122 because of the fibers, you know, tripped up all the blades. 473 00:19:17,122 --> 00:19:20,159 But the reason that we do that is because we want to be sure 474 00:19:20,159 --> 00:19:22,528 that we have over-engineered everything, 475 00:19:22,528 --> 00:19:24,396 such that even if the surface is something 476 00:19:24,396 --> 00:19:26,798 we wouldn't necessarily expect, 477 00:19:26,798 --> 00:19:29,234 we can still do our science. 478 00:19:29,234 --> 00:19:32,037 Even if we land in a place where there's something, 479 00:19:32,037 --> 00:19:34,506 there're bigger rocks than we expected, 480 00:19:34,506 --> 00:19:35,707 there might be some weird fibrous things, 481 00:19:35,707 --> 00:19:37,843 that we could still cut some of that sample, 482 00:19:37,843 --> 00:19:40,746 hopefully not destroy some really sensitive organism, 483 00:19:40,746 --> 00:19:44,316 and bring it in and look at it with our instruments. 484 00:19:44,316 --> 00:19:46,685 And so that's what this type of mission concept 485 00:19:46,685 --> 00:19:48,120 would be able to do. 486 00:19:48,120 --> 00:19:50,789 So Europa is a fascinating place. 487 00:19:50,789 --> 00:19:52,424 But it's not the only place. 488 00:19:52,424 --> 00:19:53,592 There are a few other worlds I'd like 489 00:19:53,592 --> 00:19:55,460 to tell you about tonight. 490 00:19:55,460 --> 00:19:56,962 So let's go a little bit further, 491 00:19:56,962 --> 00:19:59,865 actually a lot further, out further away from the sun. 492 00:19:59,865 --> 00:20:02,734 So you know how you've got those like nice diagrams 493 00:20:02,734 --> 00:20:05,070 of the solar system and it shows like the sun and then 494 00:20:05,070 --> 00:20:08,307 Mercury, Venus and they're all kind of evenly spaced out. 495 00:20:08,307 --> 00:20:10,409 You know they're not actually like that, right? 496 00:20:10,409 --> 00:20:13,412 Like the distance from the sun to Jupiter, 497 00:20:13,412 --> 00:20:16,081 you've got to do that again to get to Saturn. 498 00:20:16,081 --> 00:20:17,516 Space is big, okay. 499 00:20:17,516 --> 00:20:20,953 So if you're here at Saturn now, the sun is, 500 00:20:20,953 --> 00:20:23,722 it's not 10 times dimmer. 501 00:20:23,722 --> 00:20:25,257 The distance is 10 times, 502 00:20:25,257 --> 00:20:26,925 but the light intensity varies, 503 00:20:26,925 --> 00:20:28,827 do you guys remember this from from high school? 504 00:20:28,827 --> 00:20:29,895 One over R squared. 505 00:20:29,895 --> 00:20:32,164 100 times dimmer, right? 506 00:20:32,164 --> 00:20:33,398 Because it's 10 squared. 507 00:20:33,398 --> 00:20:36,068 So things are very different around Saturn. 508 00:20:36,068 --> 00:20:39,471 We were fortunate to have a spacecraft in 509 00:20:39,471 --> 00:20:41,473 the Saturn system called Cassini, 510 00:20:41,473 --> 00:20:42,708 which if you're here in the room 511 00:20:42,708 --> 00:20:45,544 is right over there, the scale model. 512 00:20:45,544 --> 00:20:48,547 Cassini launched in, let's see, '97, 513 00:20:48,547 --> 00:20:51,817 it arrived in the Saturn system in 2004. 514 00:20:51,817 --> 00:20:53,085 Space is big. 515 00:20:53,085 --> 00:20:55,053 And was there for about 13 years. 516 00:20:55,053 --> 00:20:57,489 And I was lucky enough to be involved in 517 00:20:57,489 --> 00:20:59,791 the Cassini mission right near the end 518 00:20:59,791 --> 00:21:02,027 of its time in the Saturn system. 519 00:21:02,027 --> 00:21:06,698 We learned so much about Saturn, its rings, and its moons. 520 00:21:06,698 --> 00:21:11,370 And one of the ones that surprised us the most was this one. 521 00:21:11,370 --> 00:21:12,838 This is one of my favorite places. 522 00:21:12,838 --> 00:21:14,273 This is Enceladus. 523 00:21:14,273 --> 00:21:16,441 Small things can be mighty, I know. 524 00:21:16,441 --> 00:21:18,477 Enceladus is relatively small. 525 00:21:18,477 --> 00:21:20,545 It's about the size of Arizona. 526 00:21:20,545 --> 00:21:23,849 But really amazing things are packed in this tiny package. 527 00:21:23,849 --> 00:21:28,854 It is the whitest and brightest body in the solar system, 528 00:21:29,721 --> 00:21:31,156 which tells us that the surface 529 00:21:31,156 --> 00:21:33,992 is mostly just really reflective snow, water ice. 530 00:21:33,992 --> 00:21:38,163 And you see that cool thing spewing out of the south pole? 531 00:21:38,163 --> 00:21:41,967 Yes, that is a plume and that surprised all of us. 532 00:21:41,967 --> 00:21:44,436 When we built Cassini, we didn't think there 533 00:21:44,436 --> 00:21:46,371 was liquid water out this far. 534 00:21:46,371 --> 00:21:48,940 So we cleaned it but we didn't sterilize it. 535 00:21:48,940 --> 00:21:51,109 That's actually why Cassini ended up doing 536 00:21:51,109 --> 00:21:54,713 its swan dive into Saturn when we reached 537 00:21:54,713 --> 00:21:56,181 the end of the spacecraft's life, 538 00:21:56,181 --> 00:21:59,084 'cause we didn't want to contaminate places like this. 539 00:21:59,084 --> 00:22:03,822 Enceladus, in its south pole, has these four big cracks. 540 00:22:03,822 --> 00:22:05,324 They're called tiger stripes, 541 00:22:05,324 --> 00:22:08,093 'cause it looks like a giant tiger just went like that. 542 00:22:08,093 --> 00:22:09,628 But these are really big, it'd have to be 543 00:22:09,628 --> 00:22:11,863 a very large tiger there about, 544 00:22:11,863 --> 00:22:13,031 let's see, three marathons long. 545 00:22:13,031 --> 00:22:15,634 A marathon's what's 42 kilometers? 546 00:22:15,634 --> 00:22:17,302 42, answer to everything. 547 00:22:17,302 --> 00:22:18,470 Yes. 548 00:22:18,470 --> 00:22:20,072 And they're a little bit less than 549 00:22:20,072 --> 00:22:22,207 a marathon in between each of them. 550 00:22:22,207 --> 00:22:24,509 So these are really large cracks, 551 00:22:24,509 --> 00:22:28,013 and coming out from them is a lot of water. 552 00:22:28,013 --> 00:22:29,781 It starts out as liquid, this has 553 00:22:29,781 --> 00:22:32,517 a liquid water ocean just like Europa, 554 00:22:32,517 --> 00:22:35,020 and when that water comes out into space it freezes, 555 00:22:35,020 --> 00:22:37,122 and then it can reflect light beautifully 556 00:22:37,122 --> 00:22:38,523 from the sun which are what 557 00:22:38,523 --> 00:22:41,593 some of these gorgeous back-lit or front-lit images are. 558 00:22:41,593 --> 00:22:45,597 And it's spewing out tons of just free sample 559 00:22:45,597 --> 00:22:46,832 from its ocean into space. 560 00:22:46,832 --> 00:22:48,367 No need to dig or drill, 561 00:22:48,367 --> 00:22:50,135 just like "NASA, you want to find life somewhere? 562 00:22:50,135 --> 00:22:54,106 "Come on down, get your free sample right here." 563 00:22:54,106 --> 00:22:56,341 Now when we built Cassini, we didn't think there 564 00:22:56,341 --> 00:22:57,576 was liquid water out this far, 565 00:22:57,576 --> 00:22:59,277 and we sure didn't think that there could 566 00:22:59,277 --> 00:23:01,113 be life this far out, 567 00:23:01,113 --> 00:23:04,649 and so Cassini did not have life detection instruments 568 00:23:04,649 --> 00:23:08,387 on board, but it was still able to fly through 569 00:23:08,387 --> 00:23:11,256 this plume multiple times and use its instruments 570 00:23:11,256 --> 00:23:14,493 to give us some hints of what we think is there. 571 00:23:14,493 --> 00:23:18,430 Just like Europa Clipper, Cassini also had that tongue 572 00:23:18,430 --> 00:23:20,632 that could stick out and collect some ice grains 573 00:23:20,632 --> 00:23:22,601 and figure out if there are organic molecules there, 574 00:23:22,601 --> 00:23:24,069 and it found some. 575 00:23:24,069 --> 00:23:26,938 It had a sniffing instrument so we could sniff gases, 576 00:23:26,938 --> 00:23:29,107 and it found hydrogen and methane, 577 00:23:29,107 --> 00:23:32,077 two things that we know organisms either eat or poop out. 578 00:23:32,077 --> 00:23:34,379 Either way it's exciting that they're there, 579 00:23:34,379 --> 00:23:38,583 and it also found evidence of hydrothermal vents, 580 00:23:38,583 --> 00:23:40,952 like we think are also present on Europa. 581 00:23:40,952 --> 00:23:43,054 We found three separate lines of evidence 582 00:23:43,054 --> 00:23:46,858 that tell us there could be places at the seafloor 583 00:23:46,858 --> 00:23:49,394 where water from the ocean goes underneath, 584 00:23:49,394 --> 00:23:52,130 gets heated up and then comes back out. 585 00:23:52,130 --> 00:23:55,133 Now this is a video of a hydrothermal vent here on Earth. 586 00:23:55,133 --> 00:23:57,035 I would love if this was taken at Enceladus, 587 00:23:57,035 --> 00:23:59,404 we're not quite there yet but we're working on it. 588 00:23:59,404 --> 00:24:04,042 These places are very rich ecosystems of life. 589 00:24:04,042 --> 00:24:08,180 Not just bacteria, but crabs octopus, 590 00:24:08,180 --> 00:24:11,616 octopods I think is a plural officially of octopus, 591 00:24:11,616 --> 00:24:15,053 we see tubeworms, all sorts of advanced organisms. 592 00:24:15,053 --> 00:24:17,389 And their living as far removed from sunlight 593 00:24:17,389 --> 00:24:20,125 as you can get here on Earth. 594 00:24:20,125 --> 00:24:21,626 Now this is important, right? 595 00:24:21,626 --> 00:24:23,962 'Cause all of these ocean worlds I'm showing you have 596 00:24:23,962 --> 00:24:26,698 a thick layer of ice that's shielding 597 00:24:26,698 --> 00:24:28,467 that ocean from sunlight. 598 00:24:28,467 --> 00:24:31,303 Almost all life here on Earth needs sunlight, 599 00:24:31,303 --> 00:24:32,871 directly or indirectly. 600 00:24:32,871 --> 00:24:34,906 If you are a plant, it's direct. 601 00:24:34,906 --> 00:24:36,408 If you eat a plant, it's indirect. 602 00:24:36,408 --> 00:24:41,279 And so we seek evidence in communities like this, 603 00:24:42,647 --> 00:24:45,617 these rare places where sunlight doesn't seem to be needed, 604 00:24:45,617 --> 00:24:49,855 to give us clues to what we might look for in these worlds. 605 00:24:49,855 --> 00:24:52,324 And so a lot of NASA scientists will study 606 00:24:52,324 --> 00:24:54,526 these hydrothermal systems here on Earth, 607 00:24:54,526 --> 00:24:57,762 or ask our oceanographer buddies to give us some hints 608 00:24:57,762 --> 00:24:59,498 and some clues as to what we might look for 609 00:24:59,498 --> 00:25:02,467 and where we might get tripped up 610 00:25:02,467 --> 00:25:05,937 if we're trying to design an experiment to look for life. 611 00:25:05,937 --> 00:25:08,540 So Enceladus is another fascinating place. 612 00:25:08,540 --> 00:25:10,542 But I want to tell you about one more. 613 00:25:10,542 --> 00:25:13,311 This is one of the bigger moons in our solar system. 614 00:25:13,311 --> 00:25:14,779 It looks tiny next to Saturn, 615 00:25:14,779 --> 00:25:17,349 you see that little sorta golden dot. 616 00:25:17,349 --> 00:25:19,484 That's Titan. 617 00:25:19,484 --> 00:25:22,888 Titan is the second largest moon in our solar system. 618 00:25:22,888 --> 00:25:25,790 If you count its atmosphere, it's actually the biggest. 619 00:25:25,790 --> 00:25:27,259 But we'll give Ganymede a win, 620 00:25:27,259 --> 00:25:29,594 'cause otherwise it's not quite as fascinating. 621 00:25:29,594 --> 00:25:31,496 Titan has an atmosphere, 622 00:25:31,496 --> 00:25:34,332 an atmosphere that's actually thicker than Earth's. 623 00:25:34,332 --> 00:25:36,868 And thanks to a collaboration between NASA 624 00:25:36,868 --> 00:25:39,638 and the European Space Agency, the ESA, 625 00:25:39,638 --> 00:25:42,607 we were able to land the Huygens probe on 626 00:25:42,607 --> 00:25:46,411 the surface of Titan, and this is the image that it took. 627 00:25:46,411 --> 00:25:48,480 Now it kind of looks like Earth, right? 628 00:25:48,480 --> 00:25:49,915 You see some dirt there, 629 00:25:49,915 --> 00:25:52,083 it's probably a really hazy day here in LA, right? 630 00:25:52,083 --> 00:25:53,952 It's kinda yellowish brown. 631 00:25:53,952 --> 00:25:56,788 And you see some pebbles there, some rocks. 632 00:25:56,788 --> 00:25:58,623 Those are not rocks as we know it. 633 00:25:58,623 --> 00:26:01,359 Those we think are made out of water ice, 634 00:26:01,359 --> 00:26:04,863 and that brown stuff we think is a mixture 635 00:26:04,863 --> 00:26:06,765 of complex organic molecules 636 00:26:06,765 --> 00:26:08,833 that are made in the atmosphere. 637 00:26:08,833 --> 00:26:10,335 Actually similar to smog. 638 00:26:10,335 --> 00:26:11,603 We think it's photochemistry, 639 00:26:11,603 --> 00:26:13,271 it's the same way smog is made. 640 00:26:13,271 --> 00:26:15,473 So light interacts with some gases, 641 00:26:15,473 --> 00:26:17,676 those gases start to link their atoms together 642 00:26:17,676 --> 00:26:19,878 to make bigger molecules, and those continue, 643 00:26:19,878 --> 00:26:21,646 those reactions continue to happen 644 00:26:21,646 --> 00:26:23,548 and you get bigger and bigger aerosols 645 00:26:23,548 --> 00:26:25,016 that eventually get big enough 646 00:26:25,016 --> 00:26:27,819 that they rain down or snow down on the surface. 647 00:26:27,819 --> 00:26:29,788 We think that's what's happening. 648 00:26:29,788 --> 00:26:34,459 But there's still a lot of unanswered questions about Titan. 649 00:26:34,459 --> 00:26:37,395 One of the coolest things about Titan 650 00:26:37,395 --> 00:26:40,031 is that it's not just rocks, it's not just, you know, 651 00:26:40,031 --> 00:26:42,667 it has clouds, it has an atmosphere, 652 00:26:42,667 --> 00:26:45,570 but it also has liquid on its surface. 653 00:26:45,570 --> 00:26:47,572 Titan is even colder than Europa though. 654 00:26:47,572 --> 00:26:51,076 Its -183 degrees C, which is 90 kelvin 655 00:26:51,076 --> 00:26:52,477 and I don't know what that is in fahrenheit, 656 00:26:52,477 --> 00:26:53,979 but it's even colder. 657 00:26:53,979 --> 00:26:56,915 However if you were standing on the surface of Titan, 658 00:26:56,915 --> 00:26:58,183 you would not actually need 659 00:26:58,183 --> 00:27:00,085 a spacesuit because of that atmosphere. 660 00:27:00,085 --> 00:27:01,319 You'd need a heck of a parka. 661 00:27:01,319 --> 00:27:02,587 Like a really thick one. 662 00:27:02,587 --> 00:27:04,089 You know frostbite would be a thing. 663 00:27:04,089 --> 00:27:07,292 But you could walk around without 664 00:27:07,292 --> 00:27:09,127 that pressurized spacesuit. 665 00:27:09,127 --> 00:27:11,196 This is, the pressure is about one and a half times 666 00:27:11,196 --> 00:27:16,034 our pressure here on Earth at sea level. 667 00:27:16,034 --> 00:27:17,669 And so because of that, 668 00:27:17,669 --> 00:27:20,805 a lot of really cool things are possible. 669 00:27:20,805 --> 00:27:25,210 We also see rain happening on Titan, 670 00:27:25,210 --> 00:27:27,612 but because it's so cold it's not liquid water. 671 00:27:27,612 --> 00:27:29,247 Water is frozen solid. 672 00:27:29,247 --> 00:27:32,517 We see lakes that are made out of liquid hydrocarbons. 673 00:27:32,517 --> 00:27:33,985 Methane and ethane. 674 00:27:33,985 --> 00:27:35,453 When I give talks to kids, 675 00:27:35,453 --> 00:27:37,088 I say liquid farts and they all get really excited. 676 00:27:37,088 --> 00:27:38,456 Sometimes adults do too. 677 00:27:38,456 --> 00:27:40,091 [laughter] 678 00:27:40,091 --> 00:27:40,925 I love it. 679 00:27:40,925 --> 00:27:42,027 It's great. 680 00:27:42,027 --> 00:27:43,395 But this is fascinating, right? 681 00:27:43,395 --> 00:27:46,364 Because if you remember from like maybe 682 00:27:46,364 --> 00:27:48,033 middle or high school chemistry, 683 00:27:48,033 --> 00:27:50,769 water is a polar solvent, right? 684 00:27:50,769 --> 00:27:53,405 Methane and ethane are the opposite. 685 00:27:53,405 --> 00:27:55,106 They are nonpolar. 686 00:27:55,106 --> 00:27:57,709 And you may recall like dissolves like. 687 00:27:57,709 --> 00:28:00,545 Anything that dissolves in liquid water is not going to 688 00:28:00,545 --> 00:28:04,416 in these liquid hydrocarbons, and vice versa. 689 00:28:04,416 --> 00:28:07,285 And so we have these huge seas, they're as big as 690 00:28:07,285 --> 00:28:08,820 the Great Lakes, and bigger, 691 00:28:08,820 --> 00:28:12,657 that are filled with this liquid that couldn't be, 692 00:28:12,657 --> 00:28:17,095 it could not grease the machinery of life as we know it. 693 00:28:17,095 --> 00:28:18,730 But it could potentially do that 694 00:28:18,730 --> 00:28:22,467 for some other weird alien chemistry that would have to be 695 00:28:22,467 --> 00:28:26,404 by definition very different from any biochemistry here 696 00:28:26,404 --> 00:28:28,973 on Earth just to be able to stay dissolved 697 00:28:28,973 --> 00:28:31,076 and work in a liquid like this. 698 00:28:31,076 --> 00:28:32,977 So just in our own cosmic backyard, 699 00:28:32,977 --> 00:28:35,814 we have this wild example of something that 700 00:28:35,814 --> 00:28:37,982 boy would be really nice if we could go here 701 00:28:37,982 --> 00:28:39,684 and study this world more. 702 00:28:39,684 --> 00:28:42,087 So it's got this cool stuff on its surface, 703 00:28:42,087 --> 00:28:45,490 but people always forget this Titan also has 704 00:28:45,490 --> 00:28:47,025 a liquid water ocean underneath all 705 00:28:47,025 --> 00:28:49,260 of the cool stuff happening on the surface. 706 00:28:49,260 --> 00:28:51,663 You got those liquid hydrocarbon lakes, 707 00:28:51,663 --> 00:28:54,165 that cool organicy stuff that we don't know what it is, 708 00:28:54,165 --> 00:28:57,635 and then you go down through the ice, which is the shell, 709 00:28:57,635 --> 00:28:59,771 and you hit liquid water also. 710 00:28:59,771 --> 00:29:02,173 Now this is really exciting to me, 711 00:29:02,173 --> 00:29:04,142 for someone who is a chemist by training, 712 00:29:04,142 --> 00:29:07,445 I study organic chemistry because we've tried 713 00:29:07,445 --> 00:29:11,483 to replicate some places in Titans environment, 714 00:29:11,483 --> 00:29:13,151 here in the laboratory. 715 00:29:13,151 --> 00:29:15,019 We can do that same photochemistry 716 00:29:15,019 --> 00:29:17,489 that makes that gunk in the atmosphere. 717 00:29:17,489 --> 00:29:19,257 Carl Sagan was actually one of the first people 718 00:29:19,257 --> 00:29:22,060 to do this in the lab and he named that stuff, 719 00:29:22,060 --> 00:29:25,964 he called it tholin, which is from the Greek word tholos, 720 00:29:25,964 --> 00:29:28,266 which means muddy or not clear. 721 00:29:28,266 --> 00:29:29,768 Which is really great it's a double meaning. 722 00:29:29,768 --> 00:29:31,002 Because the stuff, when you make it, 723 00:29:31,002 --> 00:29:32,871 it's like that brownish orangeish color, 724 00:29:32,871 --> 00:29:34,139 so it's sort of mud colored. 725 00:29:34,139 --> 00:29:36,074 And we also don't know what it's made of. 726 00:29:36,074 --> 00:29:37,776 'Cause you stick it into an instrument, 727 00:29:37,776 --> 00:29:39,410 and you get this forest of peaks. 728 00:29:39,410 --> 00:29:41,212 It's like anything that you can think of 729 00:29:41,212 --> 00:29:44,048 that's made out of carbon, hydrogen and nitrogen. 730 00:29:44,048 --> 00:29:46,618 Those three elements, you mix 'em together whatever way, 731 00:29:46,618 --> 00:29:48,486 do you have your chemistry set at home, anybody? 732 00:29:48,486 --> 00:29:49,420 I do. 733 00:29:49,420 --> 00:29:51,156 No, you don't do that for fun? 734 00:29:51,156 --> 00:29:54,058 But you can make small things, big things, every, 735 00:29:54,058 --> 00:29:56,194 it's all in there, in the tholin, 736 00:29:56,194 --> 00:29:59,230 and the really cool thing is if you take that tholin 737 00:29:59,230 --> 00:30:01,132 and you dissolve it in liquid water, 738 00:30:01,132 --> 00:30:04,169 you make amino acids, like that. 739 00:30:04,169 --> 00:30:08,473 So if any of that organicy goopy stuff that's made on, 740 00:30:08,473 --> 00:30:10,208 in the atmosphere that stuck on the surface, 741 00:30:10,208 --> 00:30:11,342 if any of that gets pulled down 742 00:30:11,342 --> 00:30:13,444 into that liquid water ocean, 743 00:30:13,444 --> 00:30:16,181 boy you've got a lot of interesting molecules now 744 00:30:16,181 --> 00:30:18,750 that life could use potentially. 745 00:30:18,750 --> 00:30:20,718 And so this is why I think Titan is 746 00:30:20,718 --> 00:30:23,788 a really fascinating world, worthy of study. 747 00:30:23,788 --> 00:30:25,256 Boy, wouldn't it be great if we were working on 748 00:30:25,256 --> 00:30:27,025 a mission to go there? 749 00:30:27,025 --> 00:30:28,259 We are. 750 00:30:28,259 --> 00:30:30,261 This is Dragonfly. 751 00:30:30,261 --> 00:30:32,997 This is a brand new mission, 752 00:30:32,997 --> 00:30:37,168 it was just selected in July of last year, and it is big. 753 00:30:37,168 --> 00:30:41,706 This is eight-bladed rotorcraft that can move, 754 00:30:41,706 --> 00:30:43,408 remember I said the atmosphere is thick? 755 00:30:43,408 --> 00:30:45,743 The gravity on Titan is a lot less. 756 00:30:45,743 --> 00:30:48,613 It turns out it's more efficient to fly around 757 00:30:48,613 --> 00:30:50,081 than it would be to drive, 758 00:30:50,081 --> 00:30:52,617 like our typical rovers do on Mars. 759 00:30:52,617 --> 00:30:53,852 And this thing is large. 760 00:30:53,852 --> 00:30:55,620 Like our first science team meeting, 761 00:30:55,620 --> 00:30:57,689 they had the VR headset so we can see how big it is, 762 00:30:57,689 --> 00:30:59,724 and like okay, I'm not normal-sized human, 763 00:30:59,724 --> 00:31:00,892 so picture little bit bigger than me, 764 00:31:00,892 --> 00:31:02,594 but it's like I put out my arms 765 00:31:02,594 --> 00:31:04,329 and I can't quite reach as wide. 766 00:31:04,329 --> 00:31:05,597 Like it's big. 767 00:31:05,597 --> 00:31:07,765 That antenna, the direct to Earth antenna, 768 00:31:07,765 --> 00:31:10,034 that thing that folds up in back, is like taller than me, 769 00:31:10,034 --> 00:31:11,336 I was looking up at it. 770 00:31:11,336 --> 00:31:12,904 This thing is big. 771 00:31:12,904 --> 00:31:14,672 But because of all the advancements 772 00:31:14,672 --> 00:31:18,877 in rotorcraft technology, in autonomous navigation, 773 00:31:18,877 --> 00:31:21,479 this type of thing is possible to do now, 774 00:31:21,479 --> 00:31:23,147 which is super exciting, 775 00:31:23,147 --> 00:31:25,416 'cause this means we can land in one spot, 776 00:31:25,416 --> 00:31:27,452 study that place and then pick up 777 00:31:27,452 --> 00:31:29,053 and go somewhere else interesting. 778 00:31:29,053 --> 00:31:32,123 So we can study these dunes that we see in 779 00:31:32,123 --> 00:31:33,591 the equatorial region of Titan, 780 00:31:33,591 --> 00:31:34,759 that's where we're going to start. 781 00:31:34,759 --> 00:31:36,261 We're going to start near a crater. 782 00:31:36,261 --> 00:31:38,296 Titan also doesn't have very many craters, 783 00:31:38,296 --> 00:31:39,530 but it's got a few, 784 00:31:39,530 --> 00:31:40,999 and it's a great place 'cause it looks like 785 00:31:40,999 --> 00:31:43,468 that impact excavated some stuff out and some of 786 00:31:43,468 --> 00:31:45,470 the water ice may be really accessible, 787 00:31:45,470 --> 00:31:46,971 and so we're gonna go there too, 788 00:31:46,971 --> 00:31:48,940 and we're going to just hop around for a few years. 789 00:31:48,940 --> 00:31:51,776 This is going to launch we hope in 2026, 790 00:31:51,776 --> 00:31:54,178 land on Titan in 2034. 791 00:31:54,178 --> 00:31:55,413 Space is big. 792 00:31:55,413 --> 00:31:56,648 And don't count how old you will be, 793 00:31:56,648 --> 00:31:58,116 because you might get depressed, 794 00:31:58,116 --> 00:32:01,786 but I'm really excited about this mission. 795 00:32:01,786 --> 00:32:05,657 So the future is really bright when it comes to 796 00:32:05,657 --> 00:32:07,926 the types of missions that we're working on, 797 00:32:07,926 --> 00:32:09,894 that we're building to answer some of 798 00:32:09,894 --> 00:32:12,697 these critical questions about ocean worlds 799 00:32:12,697 --> 00:32:14,265 and whether or not we're alone. 800 00:32:14,265 --> 00:32:17,402 But this is just in our own cosmic backyard. 801 00:32:17,402 --> 00:32:19,270 What about further than that? 802 00:32:19,270 --> 00:32:22,407 I'd like to introduce you to the TRAPPIST system. 803 00:32:22,407 --> 00:32:24,976 So this is about 12 parsecs out in 804 00:32:24,976 --> 00:32:27,111 the Aquarius constellation, so if you're 805 00:32:27,111 --> 00:32:28,513 a really good pilot like Han Solo, 806 00:32:28,513 --> 00:32:30,548 this is one Kessel Run away. 807 00:32:30,548 --> 00:32:31,783 [laughter] 808 00:32:31,783 --> 00:32:33,418 I'm glad you went with me on that one. 809 00:32:33,418 --> 00:32:36,020 It's got about seven planets 810 00:32:36,020 --> 00:32:38,456 in orbit around a red dwarf star. 811 00:32:38,456 --> 00:32:41,726 Now this is a place that we are just starting to study, 812 00:32:41,726 --> 00:32:45,263 but there are a handful of worlds even in this system 813 00:32:45,263 --> 00:32:47,999 that are in what we call the habitable zone. 814 00:32:47,999 --> 00:32:49,033 Now what is that? 815 00:32:49,033 --> 00:32:50,301 Well that's where Earth is. 816 00:32:50,301 --> 00:32:52,070 If you're too close to your host star, 817 00:32:52,070 --> 00:32:54,572 things get a little bit hot and liquid water 818 00:32:54,572 --> 00:32:57,241 is not stable at the surface, it would all boil away. 819 00:32:57,241 --> 00:32:59,477 If you're too far you end up with 820 00:32:59,477 --> 00:33:00,645 the opposite problem, right? 821 00:33:00,645 --> 00:33:02,080 Things get frozen solid. 822 00:33:02,080 --> 00:33:05,149 Earth is in just that right happy place, 823 00:33:05,149 --> 00:33:07,452 where liquid water can be stable on the surface, 824 00:33:07,452 --> 00:33:09,387 and when we look at exoplanets, 825 00:33:09,387 --> 00:33:10,888 that's what we call these planets 826 00:33:10,888 --> 00:33:12,757 in orbit around other stars, 827 00:33:12,757 --> 00:33:15,994 We start off looking in that habitable zone, 828 00:33:15,994 --> 00:33:19,964 because those worlds may be similar to Earth. 829 00:33:19,964 --> 00:33:22,433 And we've started a catalog and just in 830 00:33:22,433 --> 00:33:25,003 a few years of looking we've already found a bunch. 831 00:33:25,003 --> 00:33:26,838 You can see some that say TRAPPIST-1, 832 00:33:26,838 --> 00:33:28,506 whatever there's a letter at the end, 833 00:33:28,506 --> 00:33:30,475 that's typically how we name exoplanets. 834 00:33:30,475 --> 00:33:32,310 We start with the telescope that found them, 835 00:33:32,310 --> 00:33:35,513 so the TRAPPIST, or the mission that found them is first, 836 00:33:35,513 --> 00:33:37,982 then we give it a number for the star that we observed, 837 00:33:37,982 --> 00:33:41,219 and then the planets all get letters, so A-B-C-D-E, 838 00:33:41,219 --> 00:33:42,954 so you can figure out where it is, 839 00:33:42,954 --> 00:33:44,922 how close it is to its host star. 840 00:33:44,922 --> 00:33:48,393 And so you can see TRAPPIST D, E and F and G 841 00:33:48,393 --> 00:33:51,329 all seem to be in that habitable zone, 842 00:33:51,329 --> 00:33:53,331 and that's just around one star, 843 00:33:53,331 --> 00:33:54,832 and we've just started looking. 844 00:33:54,832 --> 00:33:56,367 This thing is probably already out of date, 845 00:33:56,367 --> 00:33:57,635 it's from September of last year 846 00:33:57,635 --> 00:33:59,037 but I'm sure we found a few more. 847 00:33:59,037 --> 00:34:02,440 And this just blows your mind, right? 848 00:34:02,440 --> 00:34:04,876 These are just the ones in the habitable system. 849 00:34:04,876 --> 00:34:07,478 We haven't even started looking for exo-Europas 850 00:34:07,478 --> 00:34:10,515 and exo-Titans and exo-Enceladi? 851 00:34:10,515 --> 00:34:11,349 Enceladi. 852 00:34:12,750 --> 00:34:16,854 Now we know that liquid water can exist even further out 853 00:34:16,854 --> 00:34:19,957 than this habitable zone that Earth resides in. 854 00:34:19,957 --> 00:34:22,293 It's an incredibly exciting time to be 855 00:34:22,293 --> 00:34:25,930 a planetary scientist, to be studying these worlds. 856 00:34:25,930 --> 00:34:28,099 But looking for life on a place 857 00:34:28,099 --> 00:34:30,701 this far away is challenging, right? 858 00:34:30,701 --> 00:34:33,638 If we wanted to send a spacecraft there, 859 00:34:33,638 --> 00:34:35,606 it would take a very long time. 860 00:34:35,606 --> 00:34:37,075 We're working on concepts like that. 861 00:34:37,075 --> 00:34:39,510 There's some spacecraft that we're working 862 00:34:39,510 --> 00:34:42,413 on using things like solar electric propulsion 863 00:34:42,413 --> 00:34:44,315 or even lasers to accelerate them to 864 00:34:44,315 --> 00:34:46,751 a significant percentage of the speed of light, 865 00:34:46,751 --> 00:34:48,953 which is nuts, 'cause then how do you slow down. 866 00:34:48,953 --> 00:34:50,588 But we're working on that, too. 867 00:34:50,588 --> 00:34:52,957 And to get to these world so that we can study them. 868 00:34:52,957 --> 00:34:54,492 We can still do a lot 869 00:34:54,492 --> 00:34:57,161 with powerful telescopes here on Earth. 870 00:34:57,161 --> 00:34:59,330 One of the nice things we can do is if some of 871 00:34:59,330 --> 00:35:01,332 these worlds are just the right angle 872 00:35:01,332 --> 00:35:04,635 where they pass between us and their host star, 873 00:35:04,635 --> 00:35:06,404 we can do spectroscopy. 874 00:35:06,404 --> 00:35:11,409 Spectro- is lights, -scopy is study, 875 00:35:12,577 --> 00:35:13,811 so we're studying light, spectroscopy. 876 00:35:13,811 --> 00:35:16,080 So we can break that down into the rainbow 877 00:35:16,080 --> 00:35:18,182 and look at what wavelengths are missing, 878 00:35:18,182 --> 00:35:21,185 and by doing that we can tell what kind of gases are in 879 00:35:21,185 --> 00:35:23,254 the atmospheres of some of these worlds, 880 00:35:23,254 --> 00:35:25,056 which is pretty amazing. 881 00:35:25,056 --> 00:35:29,160 But the search for life can have challenges, right? 882 00:35:29,160 --> 00:35:30,495 It can be tough. 883 00:35:30,495 --> 00:35:32,096 Who recognizes this image? 884 00:35:33,464 --> 00:35:35,800 Yeah, this is, does anyone know the name of the meteorite? 885 00:35:35,800 --> 00:35:39,070 Very good, it's ALH84001. 886 00:35:39,070 --> 00:35:41,205 Which do you want to know how meteorites are named? 887 00:35:41,205 --> 00:35:42,073 I'm going to tell you. 888 00:35:42,073 --> 00:35:43,574 Guess what. 889 00:35:43,574 --> 00:35:46,010 All right so this was a Mars meteorite that was discovered 890 00:35:46,010 --> 00:35:49,647 in Allan Hills Antarctica, that's where the ALH comes for, 891 00:35:49,647 --> 00:35:52,750 the 84 is from 1984, 'cause that was the year 892 00:35:52,750 --> 00:35:55,553 that it was discovered, and then the 001 is it was 893 00:35:55,553 --> 00:35:58,523 the first meteorite that was found that year in this place. 894 00:35:58,523 --> 00:35:59,957 They leave a couple extra digits, 895 00:35:59,957 --> 00:36:01,659 'cause I guess they're hoping they'll find, you know, 896 00:36:01,659 --> 00:36:03,628 maybe 100 or more, that would be great. 897 00:36:03,628 --> 00:36:05,997 We haven't found that many Mars meteorites though. 898 00:36:05,997 --> 00:36:08,065 We found about 30 so far, 899 00:36:08,065 --> 00:36:10,601 and most of them we do find in Antarctica, 900 00:36:10,601 --> 00:36:12,270 because it's nice and white, 901 00:36:12,270 --> 00:36:14,805 there's not a lot of snow or anything else happening, 902 00:36:14,805 --> 00:36:18,075 and so these black meteorites show up brilliantly. 903 00:36:18,075 --> 00:36:20,444 They're very easy to find. 904 00:36:20,444 --> 00:36:23,981 So this one ALH84001 is 905 00:36:23,981 --> 00:36:27,151 the oldest Mars meteorite that we've found. 906 00:36:27,151 --> 00:36:29,887 We think that it's from a time in Mars's history 907 00:36:29,887 --> 00:36:31,756 when it was much warmer and wetter. 908 00:36:31,756 --> 00:36:33,591 Now the reason we know it's from Mars is because 909 00:36:33,591 --> 00:36:35,793 there were some trapped gases inside 910 00:36:35,793 --> 00:36:37,728 that we were able to sample, and those gases are 911 00:36:37,728 --> 00:36:40,565 the same as in Mars's atmosphere. 912 00:36:40,565 --> 00:36:42,700 We also some other evidence to show us, 913 00:36:42,700 --> 00:36:45,670 to prove to ourselves as scientists that this is from Mars. 914 00:36:45,670 --> 00:36:48,105 And when we sliced it open and looked at it under 915 00:36:48,105 --> 00:36:51,175 a scanning electron microscope, this is what we saw. 916 00:36:51,175 --> 00:36:54,679 And of course we all immediately got very excited, right? 917 00:36:54,679 --> 00:36:56,814 Because that thing looks like a worm. 918 00:36:56,814 --> 00:36:58,449 Well it's not. 919 00:36:58,449 --> 00:37:01,285 It's about 1/100 the width of a human hair, 920 00:37:01,285 --> 00:37:02,853 which is incredibly small, 921 00:37:02,853 --> 00:37:04,655 very few cells are even that small, 922 00:37:04,655 --> 00:37:07,959 much less a multicellular organism like this. 923 00:37:07,959 --> 00:37:12,964 But it gives us some lessons as to when life can, 924 00:37:14,398 --> 00:37:18,469 or when evidence that we think as biased humans 925 00:37:18,469 --> 00:37:20,438 that we see looks like life, 926 00:37:20,438 --> 00:37:23,007 whether or not it is actually life or not. 927 00:37:23,007 --> 00:37:25,243 So we study the chemical signatures that were in 928 00:37:25,243 --> 00:37:28,512 this meteorite and there is still to this day, 929 00:37:28,512 --> 00:37:31,182 some scientists, a small subset of the community 930 00:37:31,182 --> 00:37:34,285 that are convinced that this is actually evidence of life. 931 00:37:34,285 --> 00:37:37,622 But the problem is it's hard to convince the rest of us, 932 00:37:37,622 --> 00:37:39,457 and the reason for that is because there 933 00:37:39,457 --> 00:37:42,493 are abiotic explanations for all of 934 00:37:42,493 --> 00:37:43,894 the things that we see here. 935 00:37:43,894 --> 00:37:46,297 We see some carbonate globules. 936 00:37:46,297 --> 00:37:49,467 Carbonate typically is associated with life, 937 00:37:49,467 --> 00:37:51,869 especially fossilized life, 938 00:37:51,869 --> 00:37:54,605 but you can also make it without life, too. 939 00:37:54,605 --> 00:37:57,742 We see magnetite crystals inside of this meteorite. 940 00:37:57,742 --> 00:38:00,578 Now some bacteria will actually use magnetite, 941 00:38:00,578 --> 00:38:02,613 kind of like little compasses to sort of navigate around, 942 00:38:02,613 --> 00:38:05,283 but the amount of magnetite that we saw 943 00:38:05,283 --> 00:38:07,351 was inconsistent with what 944 00:38:07,351 --> 00:38:09,320 we would expect for most organisms. 945 00:38:09,320 --> 00:38:11,222 The amount that we saw would have meant 946 00:38:11,222 --> 00:38:13,891 that Mars's magnetic field would be super strong, 947 00:38:13,891 --> 00:38:15,393 like way stronger than Earth's, 948 00:38:15,393 --> 00:38:17,161 and that's doesn't make sense 'cause it's smaller, 949 00:38:17,161 --> 00:38:18,996 how could it, that doesn't make sense. 950 00:38:18,996 --> 00:38:22,800 And you can also deposit that abiotically, too. 951 00:38:22,800 --> 00:38:25,436 So Carl Sagan said once that 952 00:38:25,436 --> 00:38:29,106 "life has to be the hypothesis of last resort." 953 00:38:29,106 --> 00:38:32,476 You must have eliminated all other possible explanations, 954 00:38:32,476 --> 00:38:34,779 and if you can do that and the only thing you're left with 955 00:38:34,779 --> 00:38:37,248 is life then you can be convinced. 956 00:38:37,248 --> 00:38:40,217 And the problem with this meteorite is there are still 957 00:38:40,217 --> 00:38:43,387 enough abiotic explanations for this 958 00:38:43,387 --> 00:38:46,991 that all of us can't be convinced. 959 00:38:46,991 --> 00:38:49,126 And this is something that we have here, on Earth. 960 00:38:49,126 --> 00:38:50,394 So we can bring to bear all 961 00:38:50,394 --> 00:38:52,129 of our most sensitive instruments, 962 00:38:52,129 --> 00:38:54,265 some of the microscopes and spectrometers 963 00:38:54,265 --> 00:38:56,567 that fill a room, right? 964 00:38:56,567 --> 00:38:59,370 What if you want to take that and now put it on 965 00:38:59,370 --> 00:39:00,838 a spacecraft, miniaturize it 966 00:39:00,838 --> 00:39:02,807 and then send it somewhere else? 967 00:39:04,275 --> 00:39:07,044 Some of the instrumentation, it gets challenging, right? 968 00:39:07,044 --> 00:39:09,547 You may not be able to be as sensitive, 969 00:39:09,547 --> 00:39:13,684 but now you can be sure that you know exactly what happened 970 00:39:13,684 --> 00:39:16,087 to your sample in between when it was there on Mars, 971 00:39:16,087 --> 00:39:18,122 for example like with Viking, 972 00:39:18,122 --> 00:39:19,724 and when you reached out your robotic arm 973 00:39:19,724 --> 00:39:22,093 and grabbed it and then looked at what was inside. 974 00:39:22,093 --> 00:39:25,329 With meteorites we can guess at when they formed, 975 00:39:25,329 --> 00:39:27,231 that meteorite that I was showing you, 976 00:39:27,231 --> 00:39:29,800 it probably was ejected from Mars millions, 977 00:39:29,800 --> 00:39:32,703 maybe billions of years ago, when it was warmer and wetter, 978 00:39:32,703 --> 00:39:34,605 and then it just kind of circled around in space for 979 00:39:34,605 --> 00:39:38,042 a while we think until about 16,000 years ago. 980 00:39:38,042 --> 00:39:40,311 And that's when it crashed here on Earth. 981 00:39:40,311 --> 00:39:42,546 We don't really know what was happening to it during 982 00:39:42,546 --> 00:39:46,217 that time and that uncertainty can lead us 983 00:39:46,217 --> 00:39:48,919 to question anything we might find inside it. 984 00:39:48,919 --> 00:39:51,689 That's why we want to go and land on these places, 985 00:39:51,689 --> 00:39:53,491 where we have a better understanding 986 00:39:53,491 --> 00:39:56,360 of what we call the provenance of that sample, 987 00:39:56,360 --> 00:39:59,563 the history, where it's been, how it got there, 988 00:39:59,563 --> 00:40:01,365 so that if we find a signature in it 989 00:40:01,365 --> 00:40:04,101 we can say for sure that came from this place, 990 00:40:04,101 --> 00:40:05,336 it's not contamination. 991 00:40:05,336 --> 00:40:07,505 It's not something it picked up later. 992 00:40:07,505 --> 00:40:09,540 That's really important for being sure 993 00:40:09,540 --> 00:40:13,144 when we finally answer this key question are we alone, 994 00:40:13,144 --> 00:40:14,712 we can be sure of our answer. 995 00:40:16,247 --> 00:40:17,515 So the Viking landers, 996 00:40:17,515 --> 00:40:19,183 there were two of them in the 1970s. 997 00:40:19,183 --> 00:40:21,218 These landed on the surface of Mars, 998 00:40:21,218 --> 00:40:24,255 and this was the first mission that explicitly had 999 00:40:24,255 --> 00:40:27,625 the goal of looking for life somewhere else. 1000 00:40:27,625 --> 00:40:29,360 On Mars in this case. 1001 00:40:29,360 --> 00:40:32,196 The Viking landers, they had identical instruments 1002 00:40:32,196 --> 00:40:35,232 and they went to two different places on Mars's surface, 1003 00:40:35,232 --> 00:40:39,970 and they had three biology detection instruments. 1004 00:40:39,970 --> 00:40:41,739 They also had a chemical analyzer called 1005 00:40:41,739 --> 00:40:43,374 a mass spectrometer, remember the tongue, 1006 00:40:43,374 --> 00:40:45,376 it's like similar to that. 1007 00:40:45,376 --> 00:40:48,312 Of the three biology experiments, 1008 00:40:48,312 --> 00:40:50,915 one gave a positive result for life, 1009 00:40:50,915 --> 00:40:53,784 one was negative and one was ambiguous. 1010 00:40:53,784 --> 00:40:57,521 Now this isn't because the scientists did a poor job, 1011 00:40:57,521 --> 00:41:00,090 they did the best job that they could designing 1012 00:41:00,090 --> 00:41:01,759 an experiment that they thought would give them 1013 00:41:01,759 --> 00:41:04,628 that absolute yes or no answer. 1014 00:41:04,628 --> 00:41:06,130 But all three of these techniques 1015 00:41:06,130 --> 00:41:08,866 were based off of metabolic assays. 1016 00:41:08,866 --> 00:41:11,502 Basically what they did is they scooped up some Mars soil, 1017 00:41:11,502 --> 00:41:13,938 some Mars regolith, they put it in a bin 1018 00:41:13,938 --> 00:41:17,074 and then they dropped either water or liquid water 1019 00:41:17,074 --> 00:41:20,277 or some nutrients on it or both and sealed it up 1020 00:41:20,277 --> 00:41:23,180 and they looked at the gases that came off or they looked 1021 00:41:23,180 --> 00:41:25,883 at whether or not it could take some of the nutrients 1022 00:41:25,883 --> 00:41:30,387 that it was given and be able to turn that into 1023 00:41:30,387 --> 00:41:33,824 other molecules that could give us evidence of life. 1024 00:41:33,824 --> 00:41:37,194 So these tests were based off of them going 1025 00:41:37,194 --> 00:41:38,429 to different places here on Earth 1026 00:41:38,429 --> 00:41:40,130 and trying those same experiments, 1027 00:41:40,130 --> 00:41:42,233 and they thought that they were very confident that 1028 00:41:42,233 --> 00:41:44,435 these types of things could give us 1029 00:41:44,435 --> 00:41:47,238 an absolute yes or no answer, are we alone. 1030 00:41:47,238 --> 00:41:50,975 Well it turns out that we didn't have as deep of 1031 00:41:50,975 --> 00:41:54,879 a knowledge of the surface chemistry of Mars at that time. 1032 00:41:54,879 --> 00:41:56,380 Since then we've discovered that there 1033 00:41:56,380 --> 00:41:59,617 are things like perchlorates, very reactive salts, 1034 00:41:59,617 --> 00:42:02,286 that can give the same types of answers. 1035 00:42:02,286 --> 00:42:04,555 It turns out that a scientist recently was able 1036 00:42:04,555 --> 00:42:07,858 to replicate very well, not perfectly, 1037 00:42:07,858 --> 00:42:11,195 but really closely those same false positives, 1038 00:42:11,195 --> 00:42:13,030 what we call it, when you see something 1039 00:42:13,030 --> 00:42:14,798 that you think is real but its not. 1040 00:42:14,798 --> 00:42:16,967 Those false positive measurements, 1041 00:42:16,967 --> 00:42:18,836 if you take perchlorate and you sort of give it 1042 00:42:18,836 --> 00:42:20,304 a light dusting of gamma rays, 1043 00:42:20,304 --> 00:42:21,605 and then you do that same 1044 00:42:21,605 --> 00:42:22,873 sort of life detection measurement, 1045 00:42:22,873 --> 00:42:24,508 you dump some water and some nutrients on it, 1046 00:42:24,508 --> 00:42:26,677 you'd get the same gases off. 1047 00:42:26,677 --> 00:42:29,980 And so, as Carl said, life has to be 1048 00:42:29,980 --> 00:42:32,149 that hypothesis of last resort, 1049 00:42:32,149 --> 00:42:34,351 and in the case of the Viking experiments, 1050 00:42:34,351 --> 00:42:38,923 we still have abiotic explanations that could explain 1051 00:42:38,923 --> 00:42:40,925 the data that we see. 1052 00:42:40,925 --> 00:42:42,626 But we have learned a lot since then. 1053 00:42:42,626 --> 00:42:45,496 When we were building and launching the Viking landers, 1054 00:42:45,496 --> 00:42:47,865 we didn't know about the third branch of life. 1055 00:42:47,865 --> 00:42:50,167 We knew about bacteria and fungi, 1056 00:42:52,269 --> 00:42:53,671 but we didn't know about archaea. 1057 00:42:53,671 --> 00:42:55,706 That haven't been discovered yet. 1058 00:42:55,706 --> 00:42:58,142 We know a lot more now than we did then. 1059 00:42:58,142 --> 00:43:00,945 It doesn't mean though that we won't make new mistakes 1060 00:43:00,945 --> 00:43:03,180 whenever we search for life elsewhere. 1061 00:43:03,180 --> 00:43:04,982 And that's something that as scientists 1062 00:43:04,982 --> 00:43:06,350 we always need to keep in mind. 1063 00:43:06,350 --> 00:43:08,986 We will do our best to design 1064 00:43:08,986 --> 00:43:10,754 the most foolproof experiments. 1065 00:43:10,754 --> 00:43:13,691 But we have to prepare ourselves for the fact 1066 00:43:13,691 --> 00:43:16,093 that we will likely make new and different mistakes. 1067 00:43:16,093 --> 00:43:18,996 We'll still learn something, and we still have to go. 1068 00:43:18,996 --> 00:43:20,898 Because we need to know. 1069 00:43:20,898 --> 00:43:25,369 But we need to make sure that we're prepared for an answer. 1070 00:43:25,369 --> 00:43:27,571 And so that's something that I always try 1071 00:43:27,571 --> 00:43:29,073 to keep in mind when we're having 1072 00:43:29,073 --> 00:43:31,609 these endless discussions about what experiments 1073 00:43:31,609 --> 00:43:33,477 we should do, how sure we can be, 1074 00:43:33,477 --> 00:43:36,313 how many tests we can do here to be positive 1075 00:43:36,313 --> 00:43:38,382 that we're spending our taxpayer dollars, 1076 00:43:38,382 --> 00:43:40,184 your dollars, as well as we can, right? 1077 00:43:40,184 --> 00:43:42,519 Because that's what NASA does. 1078 00:43:42,519 --> 00:43:44,855 And we can take a lot of lessons from 1079 00:43:44,855 --> 00:43:47,524 the types of life that we have here on Earth. 1080 00:43:47,524 --> 00:43:50,661 Does anyone recognize this little guy? 1081 00:43:50,661 --> 00:43:51,495 The tardigrade. 1082 00:43:51,495 --> 00:43:52,696 The water bear. 1083 00:43:52,696 --> 00:43:54,398 This little guy can survive in space, right? 1084 00:43:54,398 --> 00:43:55,833 I think he's super cute. 1085 00:43:55,833 --> 00:43:58,035 One of my friends said "boy, it would be terrifying 1086 00:43:58,035 --> 00:43:59,870 "if that was like large enough to ride." 1087 00:43:59,870 --> 00:44:01,105 I think that'd be amazing. 1088 00:44:01,105 --> 00:44:02,272 Could you imagine like riding around. 1089 00:44:02,272 --> 00:44:03,974 It's be awesome. 1090 00:44:03,974 --> 00:44:05,576 So we have examples of life 1091 00:44:05,576 --> 00:44:07,778 that can survive really extreme conditions. 1092 00:44:07,778 --> 00:44:10,114 How would you look for a tardigrade? 1093 00:44:10,114 --> 00:44:11,515 Would a microscope be enough? 1094 00:44:11,515 --> 00:44:14,885 That would just be a morphology type of measurement. 1095 00:44:14,885 --> 00:44:15,919 What if you saw it move? 1096 00:44:15,919 --> 00:44:17,254 That would be better. 1097 00:44:17,254 --> 00:44:19,823 Maybe if you also were able to study some of 1098 00:44:19,823 --> 00:44:22,960 the molecules that the tardigrade is consuming or producing, 1099 00:44:22,960 --> 00:44:25,829 or maybe sad to say, maybe just take 1100 00:44:25,829 --> 00:44:27,297 the tardigrade itself and stick it into 1101 00:44:27,297 --> 00:44:29,199 an instrument and see what it's made of. 1102 00:44:29,199 --> 00:44:31,468 These are types of things that we could do 1103 00:44:31,468 --> 00:44:32,903 if we expect this kind of life. 1104 00:44:32,903 --> 00:44:35,172 But we see some other weird things too. 1105 00:44:35,172 --> 00:44:37,408 This kind of organism, I can't remember its name, 1106 00:44:37,408 --> 00:44:39,209 but it doesn't need oxygen. 1107 00:44:39,209 --> 00:44:41,445 It's one of the few animals, even though it's microscopic, 1108 00:44:41,445 --> 00:44:44,515 it's an animal that doesn't need oxygen to be alive. 1109 00:44:44,515 --> 00:44:46,750 This is a brand-new sea slug that's new to science, 1110 00:44:46,750 --> 00:44:48,285 discovered just last year. 1111 00:44:48,285 --> 00:44:50,821 So we're still finding even on our own planet all sorts 1112 00:44:50,821 --> 00:44:54,692 of wacky and wild forms of what look like alien life, 1113 00:44:54,692 --> 00:44:56,393 and this guy, this is something we call 1114 00:44:56,393 --> 00:44:57,661 the immortal jellyfish. 1115 00:44:57,661 --> 00:44:59,530 It's about the size of your pinky nail, 1116 00:44:59,530 --> 00:45:00,998 and it does this weird thing. 1117 00:45:00,998 --> 00:45:03,300 When conditions get bad, it reverts back to its sort 1118 00:45:03,300 --> 00:45:06,403 of primordial polyp form and it just kind of chills out, 1119 00:45:06,403 --> 00:45:07,671 and then again when conditions get good again, 1120 00:45:07,671 --> 00:45:10,207 it makes itself back into a jellyfish. 1121 00:45:10,207 --> 00:45:12,376 So we think this thing could potentially live for 1122 00:45:12,376 --> 00:45:14,011 a really long time, maybe forever. 1123 00:45:14,011 --> 00:45:16,313 Forever is a long time, but at least for a very long time. 1124 00:45:16,313 --> 00:45:19,883 So we try to take lessons from the extreme forms 1125 00:45:19,883 --> 00:45:23,687 of life that we see here to help inform those tests 1126 00:45:23,687 --> 00:45:25,956 that we might perform somewhere else, 1127 00:45:25,956 --> 00:45:28,092 to answer that pivotal question. 1128 00:45:28,092 --> 00:45:30,394 'Cause this is what we're going for, right? 1129 00:45:30,394 --> 00:45:32,062 At least, you know, it'd be great, 1130 00:45:32,062 --> 00:45:34,898 to write my speech, to go in and collect the Nobel Prize 1131 00:45:34,898 --> 00:45:38,769 for finding life for the first time in human history. 1132 00:45:38,769 --> 00:45:42,706 This is something we call civilization level science. 1133 00:45:42,706 --> 00:45:44,408 You only get to make this discovery once, 1134 00:45:44,408 --> 00:45:48,412 and it would revolutionize, I think, 1135 00:45:48,412 --> 00:45:52,049 our opinion of who we are as a species. 1136 00:45:52,049 --> 00:45:54,151 Whether or not we're alone. 1137 00:45:54,151 --> 00:45:57,888 Is the Earth just this this precious terribly alone ball, 1138 00:45:57,888 --> 00:46:01,058 or is it one of millions and billions that are out there, 1139 00:46:01,058 --> 00:46:03,927 that could potentially all have different various forms 1140 00:46:03,927 --> 00:46:06,497 of life that we couldn't even imagine? 1141 00:46:06,497 --> 00:46:09,032 This kind, we have the technology to answer 1142 00:46:09,032 --> 00:46:12,302 this question now, and we're building missions 1143 00:46:12,302 --> 00:46:13,904 to go and find these answers. 1144 00:46:13,904 --> 00:46:17,441 It's an incredibly exciting time to work for NASA, 1145 00:46:17,441 --> 00:46:21,278 to be a planetary scientist, and I don't even need that. 1146 00:46:21,278 --> 00:46:24,882 I would just be so happy to be part of this question, 1147 00:46:24,882 --> 00:46:26,483 of trying to find the answer. 1148 00:46:27,651 --> 00:46:29,753 But there is that other potential, 1149 00:46:29,753 --> 00:46:31,789 that maybe we search for life here 1150 00:46:31,789 --> 00:46:34,057 in our own cosmic backyard and elsewhere 1151 00:46:34,057 --> 00:46:35,492 and we come up empty. 1152 00:46:35,492 --> 00:46:37,194 Do you recognize this image? 1153 00:46:37,194 --> 00:46:39,029 This is the 30-year anniversary, actually, 1154 00:46:39,029 --> 00:46:40,998 of the pale blue dot, 1155 00:46:40,998 --> 00:46:43,100 which was taken by Voyager One spacecraft, 1156 00:46:43,100 --> 00:46:44,868 the last von Karman lecture I believe 1157 00:46:44,868 --> 00:46:46,804 focused heavily on this. 1158 00:46:46,804 --> 00:46:49,606 What if this is all there is? 1159 00:46:49,606 --> 00:46:52,409 I find that terrifying, but in a way it could also 1160 00:46:52,409 --> 00:46:55,445 be really gratifying to think that we are this precious. 1161 00:46:55,445 --> 00:46:57,948 That this world just happened to be 1162 00:46:57,948 --> 00:47:00,551 the magical place where life can happen, 1163 00:47:00,551 --> 00:47:02,519 and boy it really makes you think about 1164 00:47:02,519 --> 00:47:07,524 how we want to preserve that and keep it going, 1165 00:47:08,959 --> 00:47:10,194 maybe go over to Mars and you know, set up a colony there, 1166 00:47:10,194 --> 00:47:13,096 just in case the next 65 million year meteor. 1167 00:47:13,096 --> 00:47:15,766 We don't want that to happen. 1168 00:47:15,766 --> 00:47:19,036 But that would be a revolutionary discovery, too. 1169 00:47:19,036 --> 00:47:22,105 And either way as a scientist, I want to know. 1170 00:47:22,105 --> 00:47:23,707 I want to ask the question. 1171 00:47:23,707 --> 00:47:26,610 I want to design that experiment or help to design 1172 00:47:26,610 --> 00:47:28,579 that experiment where we end up with 1173 00:47:28,579 --> 00:47:31,281 that single hypothesis of last resort, 1174 00:47:31,281 --> 00:47:33,851 that the only explanation could be life. 1175 00:47:33,851 --> 00:47:36,186 it could not be made abiotically. 1176 00:47:36,186 --> 00:47:39,022 And then I want to go and figure out what that life is. 1177 00:47:39,022 --> 00:47:42,826 Right now we only have a sample size of one. 1178 00:47:42,826 --> 00:47:44,828 That's it, right? 1179 00:47:44,828 --> 00:47:46,496 This could be all there is, 1180 00:47:46,496 --> 00:47:48,899 or it could be one small grain of sand in 1181 00:47:48,899 --> 00:47:52,202 an immense universe of worlds 1182 00:47:52,202 --> 00:47:55,038 that could all have life of their own. 1183 00:47:55,038 --> 00:47:58,041 I want to be part of finding that answer. 1184 00:47:59,576 --> 00:48:01,178 So I want you to go back now, close your eyes again. 1185 00:48:01,178 --> 00:48:03,847 I know it's like 45 minutes later, but you can do it. 1186 00:48:03,847 --> 00:48:05,315 I believe in you. 1187 00:48:05,315 --> 00:48:07,951 I haven't heard any snoring yet, you guys have done so well. 1188 00:48:07,951 --> 00:48:11,088 And go back to that alien world again. 1189 00:48:11,088 --> 00:48:14,057 Except this time it's not you standing there, 1190 00:48:14,057 --> 00:48:15,959 it's a robotic version of you. 1191 00:48:15,959 --> 00:48:18,562 It's a robotic exploration spacecraft. 1192 00:48:18,562 --> 00:48:21,465 So now when you look up at that sun or those suns in 1193 00:48:21,465 --> 00:48:24,401 the sky, it's not just a light that you see now you have 1194 00:48:24,401 --> 00:48:27,271 a spectrometer, and you can break down that light 1195 00:48:27,271 --> 00:48:29,706 and figure out what that energy profile is 1196 00:48:29,706 --> 00:48:32,242 and how that light might be utilized 1197 00:48:32,242 --> 00:48:33,977 by life that's on your world. 1198 00:48:33,977 --> 00:48:35,479 Now whenever you look down, 1199 00:48:35,479 --> 00:48:38,548 you can figure out what the rock distribution is, 1200 00:48:38,548 --> 00:48:40,517 and which one is most likely to have maybe 1201 00:48:40,517 --> 00:48:42,552 a microbe hiding underneath it. 1202 00:48:42,552 --> 00:48:45,255 Now you have instruments inside of you and your belly 1203 00:48:45,255 --> 00:48:47,457 that when you take a sample and you put it in there, 1204 00:48:47,457 --> 00:48:51,161 you can be sure that that has the signatures of life. 1205 00:48:52,329 --> 00:48:53,130 For the first time in human history of 1206 00:48:53,130 --> 00:48:55,132 an alien somewhere else. 1207 00:48:55,132 --> 00:48:57,301 That's what we do at NASA. 1208 00:48:57,301 --> 00:49:00,337 That's what I'm helping to work on with my colleagues, 1209 00:49:00,337 --> 00:49:04,341 is to be able to extend our senses further out into 1210 00:49:04,341 --> 00:49:06,276 the solar system and beyond. 1211 00:49:06,276 --> 00:49:08,779 I want to be able to take that circle 1212 00:49:08,779 --> 00:49:11,949 and expand it out further than I can possibly imagine, 1213 00:49:11,949 --> 00:49:14,117 to stretch it out as far as I can 1214 00:49:14,117 --> 00:49:16,253 during my time here as a human 1215 00:49:16,253 --> 00:49:21,258 and that's just why I love terribly what I do. 1216 00:49:21,992 --> 00:49:23,560 Thank you very much. 1217 00:49:23,560 --> 00:49:25,796 [applause] 1218 00:49:36,406 --> 00:49:37,374 >> Folks, we are going to open up 1219 00:49:37,374 --> 00:49:39,309 for some questions right now. 1220 00:49:39,309 --> 00:49:40,911 If you are in the house and you've got a question, 1221 00:49:40,911 --> 00:49:41,979 you're going to line up right behind 1222 00:49:41,979 --> 00:49:42,980 that microphone over there. 1223 00:49:42,980 --> 00:49:44,281 We also have some questions from 1224 00:49:44,281 --> 00:49:46,817 our online audience as well. 1225 00:49:46,817 --> 00:49:48,885 So while you're all thinking about maybe 1226 00:49:48,885 --> 00:49:49,820 a question you're going to ask, 1227 00:49:49,820 --> 00:49:51,254 I'm going to go online here to 1228 00:49:51,254 --> 00:49:53,657 the great Mosasaur from YouTube asks 1229 00:49:53,657 --> 00:49:56,927 "although there isn't a concrete answer for this, 1230 00:49:56,927 --> 00:49:59,997 "in your opinion, your opinion, 1231 00:49:59,997 --> 00:50:02,132 "do you think we can find life on these worlds? 1232 00:50:02,132 --> 00:50:04,968 "Can we expect to see it in our lifetime?" 1233 00:50:06,169 --> 00:50:07,437 >> I think so, otherwise I would 1234 00:50:07,437 --> 00:50:09,506 be spending my energy doing something else. 1235 00:50:09,506 --> 00:50:13,643 Again with just the sample size of one, 1236 00:50:13,643 --> 00:50:15,278 we have some guesstimates of 1237 00:50:15,278 --> 00:50:16,780 the types of life we would find, 1238 00:50:16,780 --> 00:50:19,750 chances are they're going to be small microorganisms, 1239 00:50:19,750 --> 00:50:21,918 just based on the energy that's there, 1240 00:50:21,918 --> 00:50:23,387 and we have some estimates of 1241 00:50:23,387 --> 00:50:26,590 how many organisms we might expect in some of these oceans. 1242 00:50:26,590 --> 00:50:29,026 So we have some idea of the types of life 1243 00:50:29,026 --> 00:50:31,261 and the amounts of life we might find, 1244 00:50:31,261 --> 00:50:33,497 and some of the instruments that we are working 1245 00:50:33,497 --> 00:50:36,867 on miniaturizing and sticking on spacecraft right now 1246 00:50:36,867 --> 00:50:39,069 have limits of detection that are sensitive enough 1247 00:50:39,069 --> 00:50:40,771 that they could find those things. 1248 00:50:40,771 --> 00:50:42,806 That's why I think that we have the ability 1249 00:50:42,806 --> 00:50:44,174 to answer this question now. 1250 00:50:45,675 --> 00:50:48,912 >> Another one from online, from Space Debris 1251 00:50:48,912 --> 00:50:52,382 on YouTube, it's kind of similar 1252 00:50:52,382 --> 00:50:53,917 to what you were just answering 1253 00:50:53,917 --> 00:50:54,985 and what the last part of what you were talking about, 1254 00:50:54,985 --> 00:50:57,154 "besides knowing we're not alone, 1255 00:50:57,154 --> 00:50:58,722 "what is the best value for humans 1256 00:50:58,722 --> 00:51:00,657 "in finding life on another world?" 1257 00:51:01,825 --> 00:51:05,228 >> For me it's knowing that there are 1258 00:51:05,228 --> 00:51:07,798 so many other possibilities out there. 1259 00:51:07,798 --> 00:51:11,268 I mean if we're not asking these big questions, 1260 00:51:11,268 --> 00:51:16,006 the things that when we were much earlier on in our history 1261 00:51:16,006 --> 00:51:18,475 of just starting to be humans and we looked up from 1262 00:51:18,475 --> 00:51:20,610 that campfire up into the stars at night 1263 00:51:20,610 --> 00:51:22,145 and wondered about them. 1264 00:51:22,145 --> 00:51:23,947 That's what sets us apart, right? 1265 00:51:23,947 --> 00:51:25,415 Otherwise we're just what, 1266 00:51:25,415 --> 00:51:28,452 like eat, sleep, reproduce and die and that's it? 1267 00:51:28,452 --> 00:51:29,686 You know? 1268 00:51:29,686 --> 00:51:31,354 This is the thing that drives us, 1269 00:51:31,354 --> 00:51:34,758 that makes us human is to ask these questions why, 1270 00:51:34,758 --> 00:51:37,828 and because of that we want to strive to know the answers. 1271 00:51:37,828 --> 00:51:39,830 And as soon as we know the answer to that question, 1272 00:51:39,830 --> 00:51:41,498 we're going to have so many more. 1273 00:51:41,498 --> 00:51:44,000 It's going to be this amazing beautiful cycle 1274 00:51:44,000 --> 00:51:46,136 and I want to kick off some more of that. 1275 00:51:47,904 --> 00:51:50,807 >> I think we've got a question here in the house. 1276 00:51:52,876 --> 00:51:54,711 >> This is a very very interesting lecture. 1277 00:51:54,711 --> 00:51:55,645 I really like it. 1278 00:51:57,147 --> 00:52:02,052 So you talked about the the nonpolar versus the polar 1279 00:52:04,254 --> 00:52:09,025 and how if those mix I guess it was on Europa? 1280 00:52:09,025 --> 00:52:09,960 >> Titan. 1281 00:52:09,960 --> 00:52:11,595 >> It was on Titan that we mix. 1282 00:52:11,595 --> 00:52:14,731 Because there's what is actually water 1283 00:52:14,731 --> 00:52:16,299 under Titan even though. 1284 00:52:16,299 --> 00:52:21,304 So my question is, so you have all this carbon on Titan, 1285 00:52:24,641 --> 00:52:28,245 why, do we have any idea why we have a planet, 1286 00:52:28,245 --> 00:52:33,083 satellite at Saturn that's heavily carbon, 1287 00:52:33,083 --> 00:52:36,720 and then we have Io at Jupiter that's heavily sulfur. 1288 00:52:36,720 --> 00:52:41,658 Why do we have, why don't we have one of each on both, 1289 00:52:41,658 --> 00:52:44,027 circling both Jupiter and Saturn? 1290 00:52:44,027 --> 00:52:45,228 >> That's a great question. 1291 00:52:45,228 --> 00:52:46,463 Well a lot of these worlds probably 1292 00:52:46,463 --> 00:52:47,764 do have a lot of carbon and sulfur, 1293 00:52:47,764 --> 00:52:49,733 but it may be in different forms 1294 00:52:49,733 --> 00:52:54,571 where it's trapped in the crust or underneath the ice shell. 1295 00:52:54,571 --> 00:52:57,774 Titan we're lucky, because of its atmosphere. 1296 00:52:57,774 --> 00:53:00,810 It's outgassing methane from its interior. 1297 00:53:00,810 --> 00:53:03,580 We're actually not sure why it's still doing that, 1298 00:53:03,580 --> 00:53:04,981 because if you look at the amount 1299 00:53:04,981 --> 00:53:06,216 of methane that should be there, 1300 00:53:06,216 --> 00:53:07,617 it should have run out in oh, you know, 1301 00:53:07,617 --> 00:53:09,119 a hundred million years. 1302 00:53:09,119 --> 00:53:11,087 So there's probably some funky cycle that's going on 1303 00:53:11,087 --> 00:53:12,923 and we're catching it at a good time. 1304 00:53:12,923 --> 00:53:16,293 But that methane is what's broken up by light. 1305 00:53:16,293 --> 00:53:17,260 Methane and nitrogen. 1306 00:53:17,260 --> 00:53:19,229 So we've got CH4 and N2, 1307 00:53:19,229 --> 00:53:20,964 and you break those apart and you make all sorts 1308 00:53:20,964 --> 00:53:23,300 of other different C, H, N things, 1309 00:53:23,300 --> 00:53:25,936 and that's what the photo chemistry is making 1310 00:53:25,936 --> 00:53:28,271 that's depositing on the surface. 1311 00:53:28,271 --> 00:53:31,408 There are other worlds where you still have reservoirs 1312 00:53:31,408 --> 00:53:33,743 of carbon maybe as methane ice, 1313 00:53:33,743 --> 00:53:36,479 like Pluto is very rich in methane ice for an example. 1314 00:53:36,479 --> 00:53:39,716 As you step further into the solar system, 1315 00:53:39,716 --> 00:53:42,419 closer to the sun you don't have as many volatiles. 1316 00:53:42,419 --> 00:53:45,355 Those, the things that are gases here 1317 00:53:45,355 --> 00:53:47,824 freeze out as ices further out, 1318 00:53:47,824 --> 00:53:49,993 but you have other complex organic molecules. 1319 00:53:49,993 --> 00:53:51,294 Like we have here on Earth. 1320 00:53:51,294 --> 00:53:53,330 A lot of the organics that are here probably 1321 00:53:53,330 --> 00:53:55,699 were deposited by comets 1322 00:53:55,699 --> 00:53:58,535 and meteoritic impacts over a millennia, 1323 00:53:58,535 --> 00:54:00,770 and so that's another great source of carbon. 1324 00:54:01,972 --> 00:54:03,473 >> Audience Member: Thank you. 1325 00:54:03,473 --> 00:54:05,442 >> All right and this will be our last question in the house. 1326 00:54:05,442 --> 00:54:08,111 If we don't get a chance to ask your question, 1327 00:54:08,111 --> 00:54:10,547 Morgan is going to stick around for awhile, 1328 00:54:10,547 --> 00:54:13,283 answer, she said she'll answer everything 1329 00:54:13,283 --> 00:54:14,117 that comes up here. 1330 00:54:14,117 --> 00:54:15,819 So good luck to that. 1331 00:54:15,819 --> 00:54:17,454 But our last question in here. 1332 00:54:17,454 --> 00:54:18,922 >> Yes. 1333 00:54:18,922 --> 00:54:20,924 What promising technologies do we have at this point 1334 00:54:20,924 --> 00:54:23,526 for getting through the layers of ice into 1335 00:54:23,526 --> 00:54:26,930 the oceans of these water worlds? 1336 00:54:26,930 --> 00:54:28,098 >> Okay. 1337 00:54:28,098 --> 00:54:29,833 I could do a whole other talk just on that. 1338 00:54:29,833 --> 00:54:32,002 So there are a few different architectures 1339 00:54:32,002 --> 00:54:34,804 that NASA scientists and a bunch of engineers both 1340 00:54:34,804 --> 00:54:37,040 at NASA centers and universities 1341 00:54:37,040 --> 00:54:39,509 and other companies are working on. 1342 00:54:39,509 --> 00:54:42,279 There's one that we call it a melt probe, 1343 00:54:42,279 --> 00:54:44,381 it's something that would have a heated tip, 1344 00:54:44,381 --> 00:54:46,349 there are a bunch of different ways you can do that, 1345 00:54:46,349 --> 00:54:48,084 that would slowly melt away 1346 00:54:48,084 --> 00:54:50,053 or sublime if you're in a vacuum, right? 1347 00:54:50,053 --> 00:54:52,789 The solid would just turn into water vapor and go away. 1348 00:54:52,789 --> 00:54:54,491 You can use that to get down. 1349 00:54:54,491 --> 00:54:56,860 There are also some robotic techniques. 1350 00:54:56,860 --> 00:55:00,096 There's a concept that I'm working on with 1351 00:55:00,096 --> 00:55:02,499 some colleagues here at JPL called EELS, 1352 00:55:02,499 --> 00:55:04,234 Enceladus Extant Life Surveyor, 1353 00:55:04,234 --> 00:55:06,569 it also is like snake like, so eels, get it. 1354 00:55:06,569 --> 00:55:08,772 We love acronyms if you haven't noticed. 1355 00:55:08,772 --> 00:55:12,876 That could maneuver down through those open tiger stripes 1356 00:55:12,876 --> 00:55:15,679 on Enceladus, and potentially reach the ocean that way, 1357 00:55:15,679 --> 00:55:17,113 and so there are a bunch of different things 1358 00:55:17,113 --> 00:55:19,582 we're working on, 'cause getting to that ocean would be 1359 00:55:19,582 --> 00:55:22,619 the ideal place to look for life, 1360 00:55:22,619 --> 00:55:24,087 'cause then you could take in your sensor 1361 00:55:24,087 --> 00:55:26,256 and you could just filter water for as long 1362 00:55:26,256 --> 00:55:29,159 as you wanted until you got the concentrations high enough 1363 00:55:29,159 --> 00:55:32,429 to be sure that if there was even one cell in like, 1364 00:55:32,429 --> 00:55:34,230 you know, gallons and gallons of water, 1365 00:55:34,230 --> 00:55:36,132 that you would find it. 1366 00:55:36,132 --> 00:55:37,767 >> And how would we get the information back from the probe? 1367 00:55:37,767 --> 00:55:39,436 >> How would we get the information back? 1368 00:55:39,436 --> 00:55:40,770 So there are some theories about that. 1369 00:55:40,770 --> 00:55:42,372 You could have a tether, 1370 00:55:42,372 --> 00:55:47,377 but if there are some geophysical tidal flexing things 1371 00:55:48,778 --> 00:55:50,013 that could break the tether you could deposit pucks 1372 00:55:50,013 --> 00:55:51,614 that could communicate, that would have their 1373 00:55:51,614 --> 00:55:54,084 own little power supplies that you could connect. 1374 00:55:54,084 --> 00:55:56,052 So there are a bunch of different ways that we're looking 1375 00:55:56,052 --> 00:55:58,154 to try to answer that question, 1376 00:55:58,154 --> 00:56:00,123 because that kind of engineering is super fun, 1377 00:56:00,123 --> 00:56:02,058 the really challenging things. 1378 00:56:02,058 --> 00:56:03,960 >> Do we know enough about the cracks on Europa 1379 00:56:03,960 --> 00:56:08,264 to know if a similar type of eel like device 1380 00:56:08,264 --> 00:56:09,899 could get through the cracks there? 1381 00:56:09,899 --> 00:56:11,301 >> That's a good question. 1382 00:56:11,301 --> 00:56:12,902 There is some preliminary evidence 1383 00:56:12,902 --> 00:56:15,905 that Europa may have a plume as well. 1384 00:56:15,905 --> 00:56:17,440 It hasn't been verified yet. 1385 00:56:17,440 --> 00:56:19,442 We've seen some funky things with 1386 00:56:19,442 --> 00:56:20,910 the Hubble Space Telescope. 1387 00:56:20,910 --> 00:56:23,179 We've seen some, it looks like water vapor 1388 00:56:23,179 --> 00:56:24,581 in places it shouldn't be, 1389 00:56:24,581 --> 00:56:26,683 and we, some scientists went back 1390 00:56:26,683 --> 00:56:28,585 and looked at the Galileo data. 1391 00:56:28,585 --> 00:56:31,988 Galileo was a spacecraft that went to the Jupiter system in 1392 00:56:31,988 --> 00:56:35,492 the '90s and early 2000s, and the magnetometer, 1393 00:56:35,492 --> 00:56:37,560 that fancy compass, found some weird readings 1394 00:56:37,560 --> 00:56:40,597 that might be consistent with a plume of water vapor. 1395 00:56:40,597 --> 00:56:42,932 But my understanding of talking to the geologists 1396 00:56:42,932 --> 00:56:45,335 and the geophysicists is that a crack, 1397 00:56:45,335 --> 00:56:47,771 since Europe is bigger and its ice shell is thicker, 1398 00:56:47,771 --> 00:56:50,273 might not propagate all the way to the ocean, 1399 00:56:50,273 --> 00:56:52,509 instead if there is a plume, which Clipper, 1400 00:56:52,509 --> 00:56:54,811 Europa Clipper would confirm, 1401 00:56:54,811 --> 00:56:56,446 if there is one it's probably from 1402 00:56:56,446 --> 00:56:57,847 a near surface reservoir. 1403 00:56:57,847 --> 00:57:01,151 And if that's true, well could life get up there, 1404 00:57:01,151 --> 00:57:03,019 if it could would it still be alive? 1405 00:57:03,019 --> 00:57:04,821 Chances are it might be very salty. 1406 00:57:04,821 --> 00:57:06,256 Will that affect things? 1407 00:57:06,256 --> 00:57:07,690 There are a bunch of things that we would need 1408 00:57:07,690 --> 00:57:09,959 to think about to understand the provenance, right? 1409 00:57:09,959 --> 00:57:12,228 The history of that sample. 1410 00:57:12,228 --> 00:57:13,696 >> Thank you. 1411 00:57:13,696 --> 00:57:15,465 >> That's all the time that we have for tonight. 1412 00:57:15,465 --> 00:57:17,967 Real quick, join us next month, April 16th and 17th, 1413 00:57:17,967 --> 00:57:20,837 where we kind of what we're looking at right here, 1414 00:57:20,837 --> 00:57:24,073 how NASA observe Earth from air and orbit. 1415 00:57:24,073 --> 00:57:25,642 But before we go, let's give our speaker 1416 00:57:25,642 --> 00:57:27,110 another great big round of applause. 1417 00:57:27,110 --> 00:57:29,379 [applause] 1418 00:57:34,317 --> 00:57:35,752 Thank you for joining us this evening.