WEBVTT 1 00:00:03.439 --> 00:00:07.719 Welcome to Bedtime Astronomy. Explore the wonders of the cosmos 2 00:00:07.759 --> 00:00:12.279 with our soothing Bedtime Astronomie podcast. Each episode offers a 3 00:00:12.359 --> 00:00:16.320 gentle journey through the stars, planets, and beyond, perfect for 4 00:00:16.399 --> 00:00:20.239 unwinding after a long day. Let's travel through the mysteries 5 00:00:20.239 --> 00:00:22.440 of the universe as you drift off into a peaceful 6 00:00:22.480 --> 00:00:23.800 slumber under the night sky. 7 00:00:26.879 --> 00:00:28.600 I want you to close your eyes for a second, 8 00:00:28.640 --> 00:00:30.440 just for a moment. Forget about your to do list, 9 00:00:30.640 --> 00:00:33.640 forget about the emails pinging in your inbox. Instead, I 10 00:00:33.679 --> 00:00:35.000 want you to picture a heist. 11 00:00:35.320 --> 00:00:38.799 Not your typical heist though, No ski masks, no getaway cars, no, 12 00:00:39.039 --> 00:00:39.719 nothing like that. 13 00:00:40.359 --> 00:00:45.679 This is a heist happening, oh about two hundred million 14 00:00:45.719 --> 00:00:49.000 miles away from where you're sitting. Picture a robot, maybe 15 00:00:49.000 --> 00:00:51.840 the size of a large van, and it's just floating 16 00:00:51.880 --> 00:00:54.719 in the complete absolute silence of deep space. 17 00:00:55.000 --> 00:00:58.359 And its target is this mountain of rubble that's just 18 00:00:58.520 --> 00:00:59.600 tumbling through the dark. 19 00:00:59.679 --> 00:01:02.200 Exactly it's trying to I don't know, high five. This 20 00:01:02.960 --> 00:01:05.040 spinning pile of rocks and mountain. 21 00:01:04.719 --> 00:01:06.760 Of rubble is actually, you know, not far from the 22 00:01:06.760 --> 00:01:09.560 scientific term. We're talking about the asteroid Benu. It's what's 23 00:01:09.599 --> 00:01:12.480 called a rubble pile asteroid, which means it's basically a 24 00:01:12.560 --> 00:01:15.879 loose collection of rocks and dust all held together by well, 25 00:01:16.040 --> 00:01:18.400 not much more than its own weak gravity. 26 00:01:18.480 --> 00:01:22.560 It's it's fragile, right, And this Robi, which is Nanza's 27 00:01:22.799 --> 00:01:29.200 Osyrius for Rex spacecraft, had one job, just one incredibly delicate, 28 00:01:29.560 --> 00:01:32.760 high stakes job. Go to this asteroid, match its speed, 29 00:01:32.959 --> 00:01:36.000 match it spin, then reach out an arm, touch the 30 00:01:36.040 --> 00:01:38.280 surface for just a few seconds, grab a little souvenir, 31 00:01:38.799 --> 00:01:39.760 and then fly all the way home. 32 00:01:39.879 --> 00:01:41.640 It sounds so simple when you put it like that. 33 00:01:41.760 --> 00:01:44.359 It sounds simple when you say it fast. But it 34 00:01:44.400 --> 00:01:47.079 was anything but. I mean, the level precision is just 35 00:01:48.560 --> 00:01:49.680 it's mind boggling. 36 00:01:49.719 --> 00:01:51.400 And it was even harder than they planned when they 37 00:01:51.439 --> 00:01:54.280 actually made contact. This was back in twenty twenty. The 38 00:01:54.359 --> 00:01:58.359 surface was so much softer than their models predicted. 39 00:01:58.560 --> 00:01:58.879 Softer. 40 00:01:59.120 --> 00:02:03.000 Yeah, the collection arm it almost sank right into the astray. 41 00:02:03.040 --> 00:02:04.680 It was like trying to punch a ball pit. The 42 00:02:04.760 --> 00:02:06.000 surface just gave way. 43 00:02:06.079 --> 00:02:08.599 I remember seeing the video from the spacecraft's camera. Yes, 44 00:02:09.280 --> 00:02:12.680 it was terrifying to watch. Yeah, dust and pebbles flying everywhere. 45 00:02:12.800 --> 00:02:15.360 You realize, if that arm gets stuck, or if the 46 00:02:15.400 --> 00:02:18.560 thrusters fire at the wrong second, that's it. The whole 47 00:02:18.599 --> 00:02:19.400 mission is lost. 48 00:02:19.560 --> 00:02:23.039 Billions of dollars, decades of work just gone. But they 49 00:02:23.039 --> 00:02:25.319 pulled it off. They fired the thrusters, they backed away, 50 00:02:25.319 --> 00:02:28.639 and they had the goods. They sealed up the sample capsule. 51 00:02:28.479 --> 00:02:30.879 And then came the long trip home and finally, in 52 00:02:30.919 --> 00:02:34.319 twenty twenty three, that little capsule came blazing through our 53 00:02:34.360 --> 00:02:37.240 atmosphere and parachuted down into the Utah Desert. 54 00:02:37.400 --> 00:02:39.759 And that's another moment where you're holding your breath. I mean, 55 00:02:39.800 --> 00:02:42.520 if that parachute doesn't deploy correctly, if the capsule cracks 56 00:02:42.560 --> 00:02:43.639 open on impact. 57 00:02:43.439 --> 00:02:45.919 All that effort, all that distance, and you just end 58 00:02:46.000 --> 00:02:48.080 up with a very expensive crater in the sand exactly. 59 00:02:48.199 --> 00:02:51.120 But it worked. It stuck the landing, and inside, once 60 00:02:51.120 --> 00:02:54.240 they got it into a pristine, sterile clean room and 61 00:02:54.319 --> 00:02:58.599 carefully opened it up, they found dust, just a little 62 00:02:58.639 --> 00:03:02.080 cups worth of this very dark, very jagged dust. 63 00:03:02.400 --> 00:03:05.120 And that dust, specifically about a teaspoon of it is 64 00:03:05.159 --> 00:03:07.080 what we are here to talk about today, because this 65 00:03:07.159 --> 00:03:09.840 isn't just a story about an amazing engineering feat. Yeah, 66 00:03:10.199 --> 00:03:13.520 we were looking at a paper that was published literally yesterday, 67 00:03:13.680 --> 00:03:16.719 February ninth, twenty twenty six, in the Proceedings of the 68 00:03:16.800 --> 00:03:20.400 National Academy of Sciences. And it turns out that teaspoon 69 00:03:20.400 --> 00:03:23.520 of Dust contains a story that well, it completely rewrites 70 00:03:23.560 --> 00:03:25.680 what we thought we knew about the chemistry of life. 71 00:03:25.840 --> 00:03:27.840 It really does. It's one of those moments in science 72 00:03:27.840 --> 00:03:30.719 where you realize the recipe book you've been using might 73 00:03:30.759 --> 00:03:33.800 have been missing a critical chapter, or maybe we were 74 00:03:33.840 --> 00:03:35.319 just reading the wrong one entirely. 75 00:03:35.439 --> 00:03:36.400 That's a great way to put it. 76 00:03:36.439 --> 00:03:38.479 So let's set the stage here. The big headline is 77 00:03:38.520 --> 00:03:41.759 that researchers from Penn State found amino acids in this 78 00:03:42.039 --> 00:03:45.759 venue dust. But and I want to be really clear 79 00:03:45.800 --> 00:03:48.520 on this, because it confused me at first finding amino 80 00:03:48.599 --> 00:03:51.639 acids in space. That's not the new part, is it. 81 00:03:51.960 --> 00:03:54.400 No, And you are absolutely right to flag that that's 82 00:03:54.439 --> 00:03:57.840 the key nuance. If the headline was just scientists find 83 00:03:57.960 --> 00:04:00.759 organics on asteroid, we'd say, ok, add it to the 84 00:04:00.759 --> 00:04:01.439 growing list. 85 00:04:02.400 --> 00:04:05.919 We've known for decades, really that space rocks can carry 86 00:04:05.919 --> 00:04:07.159 these kinds of molecules. 87 00:04:07.240 --> 00:04:10.000 So what's the big deal. Why is this particular discovery 88 00:04:10.039 --> 00:04:10.919 causing such a stir. 89 00:04:11.599 --> 00:04:13.840 It's because of the how. It's not that they found 90 00:04:13.879 --> 00:04:17.560 amino acids. It's the story those amino acids have to tell. 91 00:04:17.800 --> 00:04:20.319 It's about their history. It's like finding a person in 92 00:04:20.360 --> 00:04:23.279 New York City. That's not a story, but finding out 93 00:04:23.360 --> 00:04:27.519 they got there by walking from Antarctica, that's a story. 94 00:04:27.639 --> 00:04:30.399 Okay, I like that. So we're looking at the molecule's journey. 95 00:04:30.519 --> 00:04:33.399 It's origin story we are, And for the last fifty 96 00:04:33.480 --> 00:04:36.839 years we had a pretty solid theory about that origin story. 97 00:04:36.879 --> 00:04:39.560 We thought the answer was always you know, warmth and water. 98 00:04:39.560 --> 00:04:42.160 The famous warm little pond that Darwin talked. 99 00:04:41.959 --> 00:04:45.759 About, the very same, the classic idea. But the samples 100 00:04:45.879 --> 00:04:49.279 from Benu they're telling us something completely different. They're saying 101 00:04:49.319 --> 00:04:53.639 the ingredients for life don't just form in cozy, warm ponds. 102 00:04:53.800 --> 00:04:54.839 They formed somewhere else. 103 00:04:54.920 --> 00:04:57.839 They can form in the deep freeze, in the pitch dark, 104 00:04:58.279 --> 00:05:01.720 in an environment that should be, by all accounts, completely 105 00:05:01.759 --> 00:05:04.319 hostile to creating these delicate molecules. 106 00:05:04.319 --> 00:05:06.720 We're talking about, what a radioactive environment. 107 00:05:06.800 --> 00:05:09.959 We're talking about frozen eyes being blasted by gamma rays, 108 00:05:10.399 --> 00:05:14.279 the harsh, unforgiving vacuum of the outer Solar system. 109 00:05:14.439 --> 00:05:17.439 Wow, that's well, it sounds more like the origin story 110 00:05:17.439 --> 00:05:21.079 for comic book Supervillain, not the origin story for life 111 00:05:21.160 --> 00:05:21.600 on Earth. 112 00:05:21.639 --> 00:05:25.360 And that's precisely why this is a revelation. The lead author, 113 00:05:25.519 --> 00:05:28.399 Alison Bozinski says, it flips the script on where we 114 00:05:28.399 --> 00:05:31.439 should be looking for life's ingredients and maybe even life itself. 115 00:05:31.680 --> 00:05:34.839 So our mission today for this deep dive seems pretty clear. 116 00:05:34.959 --> 00:05:37.480 We're going to unpack this brand new study. We're going 117 00:05:37.519 --> 00:05:39.839 to look at the incredible technology this team, led by 118 00:05:39.879 --> 00:05:43.639 Alison Bozinski and Elflee Macintosh used to basically read the 119 00:05:43.680 --> 00:05:47.319 atomic history of these molecules, and we're going to try 120 00:05:47.319 --> 00:05:51.360 to understand why a freezing radioactive void might actually be 121 00:05:51.399 --> 00:05:54.439 a better kitchen for creating life's building blocks than a 122 00:05:54.519 --> 00:05:55.079 warm bath. 123 00:05:55.319 --> 00:05:57.000 And beyond that, we have to talk about what this 124 00:05:57.079 --> 00:05:59.279 means for the rest of the universe, because if you 125 00:05:59.360 --> 00:06:03.120 don't need a special Goldilocks planet with warm oceans to 126 00:06:03.160 --> 00:06:05.240 make amino acids, if you can just make them in 127 00:06:05.319 --> 00:06:07.560 the cold darkness of space. 128 00:06:07.399 --> 00:06:10.399 Then the universe might be a lot more seeded with 129 00:06:10.480 --> 00:06:11.639 potential than we ever thought. 130 00:06:11.759 --> 00:06:14.360 Exactly the ingredients for the recipe it could be everywhere. 131 00:06:14.480 --> 00:06:16.800 Okay, I love this let's start with the sample itself, 132 00:06:16.879 --> 00:06:19.720 the Messenger from the Dawn of Time? Why this rock? 133 00:06:19.920 --> 00:06:23.519 Why Benu? What made NASA spend over a billion dollars 134 00:06:23.560 --> 00:06:25.560 to go to this specific pile of rubble. 135 00:06:26.199 --> 00:06:28.839 To really appreciate the science, you have to appreciate the sample. 136 00:06:29.000 --> 00:06:31.759 And as you mentioned, this material from Osiris Rex is 137 00:06:31.839 --> 00:06:35.639 special for one big reason. The word is pristine. 138 00:06:35.879 --> 00:06:39.199 Pristine meaning untouched. 139 00:06:38.800 --> 00:06:41.879 Completely untouched. See, most of the time when we study 140 00:06:41.920 --> 00:06:45.959 space rocks, we're studying meteorites, and meteorites are well, they're compromised, 141 00:06:45.959 --> 00:06:47.240 they've been through the Ringer, right. 142 00:06:47.360 --> 00:06:50.360 They didn't have a nice, gentle parachute landing in Utah, 143 00:06:50.560 --> 00:06:51.079 not at all. 144 00:06:51.199 --> 00:06:54.399 Think about the journey of a typical meteorite. It spends 145 00:06:55.319 --> 00:06:59.360 maybe millions, even billions of years floating through space, getting 146 00:06:59.399 --> 00:07:04.480 bombarded by radiation. Then it hits Earth's atmosphere at what 147 00:07:04.720 --> 00:07:06.000 thirty thousand miles an hour. 148 00:07:06.120 --> 00:07:08.000 It's a fireball. It literally burns up. 149 00:07:08.160 --> 00:07:11.920 It burns at thousands of degrees, the outer layers or vaporized. 150 00:07:11.959 --> 00:07:15.480 It often breaks apart. It's a profoundly traumatic entry. And 151 00:07:15.519 --> 00:07:18.839 then if a piece survives, it lands maybe in the 152 00:07:18.839 --> 00:07:21.480 Antarctic ice. If we're lucky, or maybe it lands in 153 00:07:21.519 --> 00:07:22.959 a field in Iowa. 154 00:07:22.759 --> 00:07:24.560 Or jungle or the ocean. 155 00:07:24.360 --> 00:07:26.519 Exactly, and it just sits there. It gets rained on. 156 00:07:26.839 --> 00:07:30.040 Microbes and bacteria from Earth's soil start to crawl all 157 00:07:30.040 --> 00:07:33.279 over it. It gets buried in mud. Humans eventually find it 158 00:07:33.319 --> 00:07:35.639 and touch it with their oily, greasy fingers. 159 00:07:35.800 --> 00:07:38.759 So it's contaminated from the second it enters our world. 160 00:07:38.879 --> 00:07:39.720 It's being altered. 161 00:07:40.000 --> 00:07:45.480 It is heavily, heavily contaminated. From a chemical analysis standpoint, 162 00:07:45.560 --> 00:07:48.600 It's like trying to read an ancient scroll that's been 163 00:07:48.680 --> 00:07:51.399 dropped in a puddle, then dried by a fire, and 164 00:07:51.439 --> 00:07:54.560 then scribbled on by a toddler. You can still make 165 00:07:54.600 --> 00:07:56.920 out some of the original text, but you're never one 166 00:07:57.000 --> 00:08:00.720 hundred percent sure what's original and what's just dirt from 167 00:08:00.720 --> 00:08:01.240 the journey. 168 00:08:01.519 --> 00:08:03.079 But the Benu sample is different. 169 00:08:03.199 --> 00:08:05.839 The Benu sample is a completely different ballgame. It was 170 00:08:05.879 --> 00:08:08.480 a grab and go mission. We flew to the source, 171 00:08:08.720 --> 00:08:11.680 We used a sterile robotic arm to grab the dust. 172 00:08:12.040 --> 00:08:14.800 We sealed it in a hermetically sealed capsule right then 173 00:08:14.839 --> 00:08:16.519 and there in space, and we brought it home. 174 00:08:16.879 --> 00:08:20.560 It never touched Earth's atmosphere. It never saw rain. It 175 00:08:20.680 --> 00:08:23.519 never encountered a single Earth bacterium. 176 00:08:22.959 --> 00:08:26.079 Until the moment it was opened in that NASA clean room. 177 00:08:26.680 --> 00:08:29.360 That dust was exactly as it had been for four 178 00:08:29.399 --> 00:08:32.120 point six billion years, floating out there in the void. 179 00:08:32.240 --> 00:08:34.399 So what this study is looking at is the real deal. 180 00:08:34.519 --> 00:08:35.799 This is unfiltered history. 181 00:08:35.960 --> 00:08:38.080 It is the closest thing we have to a perfect 182 00:08:38.080 --> 00:08:40.519 time capsule from the birth of our solar system, back 183 00:08:40.519 --> 00:08:44.120 before Earth even had oceans, before the first cell ever divided. 184 00:08:44.399 --> 00:08:47.080 This is a snapshot of the raw material that built everything. 185 00:08:47.360 --> 00:08:50.639 And what's just staggering to me is the amount of 186 00:08:50.759 --> 00:08:54.919 material they're working with. You said a teaspoon. The breakthrough 187 00:08:54.960 --> 00:08:58.240 came from a sample no bigger than a teaspoon of dust. 188 00:08:58.440 --> 00:09:00.360 It really is a testament to the lane level of 189 00:09:00.360 --> 00:09:03.200 technology we have now. The team at Penn State, the 190 00:09:03.279 --> 00:09:07.480 lead researchers Alison Basinski and Offley Macintosh, along with Christopher House, 191 00:09:07.559 --> 00:09:11.240 Catherine Freeman, and Mila Mattney, they weren't just putting this 192 00:09:11.480 --> 00:09:15.080 dust under a normal microscope. They were using instruments that 193 00:09:15.200 --> 00:09:18.240 tear molecules apart adam by adam and weigh them. 194 00:09:18.480 --> 00:09:20.600 Zuski had a quote in the press release about this, 195 00:09:20.639 --> 00:09:24.279 didn't she something like without these advances in technology. 196 00:09:23.759 --> 00:09:26.039 She said, we would never have made this discovery. And 197 00:09:26.080 --> 00:09:28.759 she's absolutely right, because they were looking for what she 198 00:09:28.840 --> 00:09:32.720 called really low abundances. These aren't huge, visible chunks of 199 00:09:32.799 --> 00:09:36.720 organic stuff. These are trace amounts parts per billion locked 200 00:09:36.759 --> 00:09:40.080 inside the mineral structure of the dust. You need instruments 201 00:09:40.120 --> 00:09:43.720 with incredible sensitivity to even see them, let alone analyze 202 00:09:43.720 --> 00:09:44.279 their history. 203 00:09:44.559 --> 00:09:47.320 Okay, so let's get into what they actually found. We 204 00:09:47.440 --> 00:09:51.279 keep using the term amino acids, and I feel like 205 00:09:51.360 --> 00:09:53.200 most of us have heard that term, maybe on a 206 00:09:53.279 --> 00:09:56.200 nutritional labels or in a biology class. But let's really 207 00:09:56.200 --> 00:09:59.360 define it for our context here. What exactly are we 208 00:09:59.440 --> 00:09:59.919 looking at. 209 00:10:00.200 --> 00:10:02.519 The best analogy, and it's one we use a lot 210 00:10:02.559 --> 00:10:04.960 in science communication is lego bricks. 211 00:10:05.120 --> 00:10:07.799 Legos. I can do legos. Everyone gets legos. 212 00:10:08.039 --> 00:10:11.440 Imagine you have a giant bin of mixed lego bricks. 213 00:10:11.799 --> 00:10:15.679 An individual brick, say a single red two by four piece, 214 00:10:15.919 --> 00:10:17.799 is just a piece of plastic. It doesn't do much 215 00:10:17.799 --> 00:10:20.519 on its own, but if you start snapping them together 216 00:10:20.519 --> 00:10:23.799 in a specific sequence, you can build anything. A house, 217 00:10:24.000 --> 00:10:27.399 a spaceship, a working model of a car engine. The 218 00:10:27.440 --> 00:10:30.679 complexity emerges from how you connect the simple pieces. 219 00:10:30.720 --> 00:10:32.600 So the power isn't in the brick, it's in the 220 00:10:32.639 --> 00:10:33.720 structure you build with it. 221 00:10:33.840 --> 00:10:36.799 Precisely, in the world of biology, amino acids are those 222 00:10:36.879 --> 00:10:39.240 lego bricks. You snap them together in long chains to 223 00:10:39.240 --> 00:10:42.639 build proteins, and proteins proteins are the machines that run 224 00:10:42.679 --> 00:10:44.799 the city of life. They do all the work, They 225 00:10:44.840 --> 00:10:47.919 do everything. They form the physical structure of your cells, 226 00:10:48.080 --> 00:10:50.720 like the steel beams and a skyscraper. They act as 227 00:10:50.879 --> 00:10:54.840 enzymes to catalyze chemical reactions like digesting your food. They 228 00:10:54.879 --> 00:10:58.799 carry oxygen in your blood. They fight off diseases as antibodies. 229 00:10:59.159 --> 00:11:03.080 Without protein, you can't replicate DNA, you can't have a metabolism. 230 00:11:03.440 --> 00:11:05.639 There is no life as we know it without them. 231 00:11:06.159 --> 00:11:09.240 So finding these fundamental lego bricks on an asteroid is 232 00:11:09.279 --> 00:11:12.399 a huge deal because it suggests the raw materials for 233 00:11:12.480 --> 00:11:15.399 life weren't invented here on Earth. Yeah, we didn't have 234 00:11:15.440 --> 00:11:18.240 to manufacture the plastic for the bricks ourselves. They were 235 00:11:18.240 --> 00:11:20.440 delivered to us pre made in the box. 236 00:11:20.679 --> 00:11:22.559 That is a perfect way to phrase it. And in 237 00:11:22.600 --> 00:11:25.360 this particular study from Penn State, they were focused on 238 00:11:25.360 --> 00:11:29.360 one specific very important amino acid glycine. 239 00:11:29.399 --> 00:11:31.440 Glycine, Why that one is it special? 240 00:11:31.840 --> 00:11:34.240 It's special because it's the simplest. If we're sticking with 241 00:11:34.279 --> 00:11:37.480 the Lego analogy, glycine is the most basic brick. It's 242 00:11:37.519 --> 00:11:40.480 the little two by two square. It's the smallest possible 243 00:11:40.519 --> 00:11:43.759 amino acid, just a tiny two carbon molecule. But because 244 00:11:43.759 --> 00:11:46.679 it's so simple and fundamental, it's found everywhere in biology. 245 00:11:46.879 --> 00:11:49.720 Okay, so they found glycine in the binu dust. But 246 00:11:49.799 --> 00:11:52.759 as we established earlier, we found glycine in space before 247 00:11:52.799 --> 00:11:54.679 we have Yes, So this is where we get to 248 00:11:54.679 --> 00:11:56.720 the script slip. You mentioned Lit's dig into the old 249 00:11:56.759 --> 00:11:59.320 theory before this paper dropped yesterday. If I were to 250 00:11:59.360 --> 00:12:04.039 ask you, how does glycine form in space? What would 251 00:12:04.039 --> 00:12:05.399 the textbook answer have been? 252 00:12:05.639 --> 00:12:08.240 The textbook answer for about half a century would have 253 00:12:08.240 --> 00:12:10.320 been a process called Strucker synthesis. 254 00:12:10.559 --> 00:12:13.639 Treker synthesis sounds like a villain's evil plan in a 255 00:12:13.679 --> 00:12:16.919 spy movie. We must initiate Operation Strecker. 256 00:12:17.120 --> 00:12:19.360 It does have that ring to it, doesn't it. But 257 00:12:19.759 --> 00:12:25.159 it's actually some pretty classic old school chemistry. It's named 258 00:12:25.200 --> 00:12:28.559 after Adolph Strecker, who figured this out all the way 259 00:12:28.559 --> 00:12:30.039 back in the eighteen fifties. 260 00:12:29.679 --> 00:12:33.080 The eighteen fifties, So this is really foundational chemistry. 261 00:12:32.720 --> 00:12:36.399 Very foundational, And for Streker synthesis, you need a few 262 00:12:36.519 --> 00:12:40.039 key ingredients. First, you need some kind of aldehyde or ketne. 263 00:12:40.039 --> 00:12:42.240 You can just think of that as your basic carbon 264 00:12:42.279 --> 00:12:45.679 containing molecule. Then you need ammonia. That's your source of nitrogen. 265 00:12:46.240 --> 00:12:48.120 And you need hydrogen cyanide. 266 00:12:48.240 --> 00:12:50.480 Hydrogen cyanide. Wait a second, isn't that Isn't that a 267 00:12:50.559 --> 00:12:52.080 lethal poison to us? 268 00:12:52.440 --> 00:12:57.279 Absolutely, it's incredibly toxic, But in the world of prebiotic chemistry, 269 00:12:57.360 --> 00:13:01.159 it's an essential ingredient. It's a very simple molecule containing 270 00:13:01.360 --> 00:13:04.000 carbon and nitrogen, and it's very very reactive. 271 00:13:04.240 --> 00:13:06.799 It's just so ironic that a key ingredient for life 272 00:13:06.840 --> 00:13:08.519 is something that's so deadly to life. 273 00:13:08.639 --> 00:13:11.120 Chemistry is full of these little ironies. But here's the 274 00:13:11.159 --> 00:13:13.519 crucial part of the recipe. If you just take those 275 00:13:13.519 --> 00:13:17.000 three ingredients, the aldehyde, the ammonia, the cyanide, and you 276 00:13:17.039 --> 00:13:19.159 put them in a jar and shake them up as gases, 277 00:13:19.320 --> 00:13:22.559 basically nothing happens. They just bounce off each other. They 278 00:13:22.600 --> 00:13:24.799 need a catalyst, a match. 279 00:13:24.559 --> 00:13:26.720 Maker, if you will, and the match maker is water. 280 00:13:27.039 --> 00:13:30.480 Liquid water. Absolutely, water acts as a solvent. It allows 281 00:13:30.519 --> 00:13:34.279 these molecules to dissolve, to move around freely, to exchange protons, 282 00:13:34.519 --> 00:13:37.000 and to actually interact and react with each other. But 283 00:13:37.039 --> 00:13:40.120 you need one more thing. You need energy. You need heat. Well, 284 00:13:40.159 --> 00:13:43.720 the heat, because molecules are fundamentally lazy, they're stable in 285 00:13:43.759 --> 00:13:46.720 the current forms. To get them to break their existing 286 00:13:46.759 --> 00:13:49.840 bonds and form new, more complex ones, to get them 287 00:13:49.840 --> 00:13:52.440 to rearrange themselves into an amino acid, you need to 288 00:13:52.440 --> 00:13:55.720 give them an energetic shove. Heat provides that shove. It's 289 00:13:55.799 --> 00:13:59.200 kinetic energy. It makes the molecules vibrate and smash into 290 00:13:59.279 --> 00:14:02.120 each other with enough force to trigger the reaction. 291 00:14:02.600 --> 00:14:05.720 So the warm little pond concept isn't just a nice 292 00:14:05.720 --> 00:14:09.759 poetic image. It's a literal chemical requirement. You need a 293 00:14:09.759 --> 00:14:12.320 liquid medium for the ingredients to mix, and you need 294 00:14:12.399 --> 00:14:14.799 warmth to make the reaction go precisely. 295 00:14:15.240 --> 00:14:18.840 So, for fifty years, whenever we found amino acids and meteorites, 296 00:14:18.879 --> 00:14:21.840 the assumption was always Okay, this rock must have, at 297 00:14:21.840 --> 00:14:24.080 some point in its history been part of a larger 298 00:14:24.120 --> 00:14:27.080 parent body that had liquid water and some source of 299 00:14:27.120 --> 00:14:27.840 internal heat. 300 00:14:27.919 --> 00:14:29.720 We just assumed it was cooked in some kind of 301 00:14:29.799 --> 00:14:33.759 cosmic crock pot, maybe inside a big asteroid with hydrothermal vents, 302 00:14:34.120 --> 00:14:36.759 or some surface ocean warmed by radioactive decay. 303 00:14:37.000 --> 00:14:40.240 Exactly. We were, in a way projecting our own planet 304 00:14:40.320 --> 00:14:43.120 story onto the rest of the Solar System. We see 305 00:14:43.159 --> 00:14:46.440 life thriving in water here, so we assumed life's ingredients 306 00:14:46.480 --> 00:14:47.840 must also need water there. 307 00:14:48.000 --> 00:14:49.679 But Benu is here to tell us that's not the 308 00:14:49.679 --> 00:14:50.120 only way. 309 00:14:50.279 --> 00:14:52.879 Benu is telling us something radically different. And this is 310 00:14:52.919 --> 00:14:56.200 where the real detective work gets incredibly cool. This is 311 00:14:56.200 --> 00:14:58.039 where we have to talk about isotopes. 312 00:14:58.159 --> 00:15:01.200 Lisotopes. Okay, I remember the term from high school chemistry, 313 00:15:01.480 --> 00:15:04.000 but let's do a quick refresher. How does weighing an 314 00:15:04.080 --> 00:15:06.440 atom tell you anything about its past. 315 00:15:06.720 --> 00:15:10.039 Think of atoms of a particular element like carbon, as 316 00:15:10.200 --> 00:15:12.120 all being part of the same family. They all have 317 00:15:12.200 --> 00:15:15.639 six protons. That's what makes them carbon. But some family 318 00:15:15.679 --> 00:15:18.000 members might weigh a little more than others. They might 319 00:15:18.039 --> 00:15:20.480 have an extra neutron or two in their nucleus. 320 00:15:20.639 --> 00:15:22.799 So it's the same element chemically, it just has a 321 00:15:22.799 --> 00:15:26.240 bit more mass. It's the chubby cousin of the family. 322 00:15:26.440 --> 00:15:29.039 That's a perfect analogy. It's a chubby atom had a 323 00:15:29.039 --> 00:15:33.240 little extra baggage. It's still carbon. It behaves light carbon. 324 00:15:33.240 --> 00:15:35.720 It forms bonds like carbon, but it's heavier. We call 325 00:15:35.799 --> 00:15:39.320 these heavier versions isotopes. Carbon twelve is the common one. 326 00:15:39.360 --> 00:15:42.399 Carbon thirteen is the heavier one. Now Here is the 327 00:15:42.440 --> 00:15:46.000 magic trick of this whole science. The ratio of the 328 00:15:46.039 --> 00:15:49.399 heavy atoms to the light atoms in a molecule acts 329 00:15:49.440 --> 00:15:52.159 like a passport stamp. It tells you where that molecule 330 00:15:52.279 --> 00:15:52.679 was born. 331 00:15:52.960 --> 00:15:56.960 Wait, how why would the environment affect how many chubby 332 00:15:57.000 --> 00:15:58.720 atoms get included in the molecule. 333 00:15:58.879 --> 00:16:01.919 It comes down to a principle called the kinetic isotope effect. 334 00:16:02.360 --> 00:16:04.559 Okay, but that sounds complicated, but break it down for us. 335 00:16:04.720 --> 00:16:07.600 It's actually just about that molecular laziness we talked about again. 336 00:16:08.399 --> 00:16:11.360 It turns out that chemical bonds involving the heavier isotope 337 00:16:11.360 --> 00:16:15.039 carbon thirteen are just a tiny bit stronger and more stable. 338 00:16:15.039 --> 00:16:17.519 They take a little more energy to break. So if 339 00:16:17.519 --> 00:16:20.440 you have a chemical reaction happening in that warm pond, 340 00:16:21.000 --> 00:16:25.080 a reaction that requires breaking bonds, it's slightly easier. It 341 00:16:25.120 --> 00:16:28.519 takes less energy to break the bond with the lighter 342 00:16:28.559 --> 00:16:30.120 carbon twelve atom, so. 343 00:16:30.120 --> 00:16:33.519 Nature takes the path of least resistance. The reaction prefers 344 00:16:33.559 --> 00:16:35.919 the lighter easier to work with atoms. You got it. 345 00:16:36.240 --> 00:16:40.240 So, generally speaking, chemical reactions driven by heat and happening 346 00:16:40.279 --> 00:16:42.480 in water will end up with a product that is 347 00:16:42.519 --> 00:16:46.200 depleted in the heavy isotope. They discriminate against the heavy stuff. 348 00:16:46.279 --> 00:16:48.720 So if I analyze the molecule made in a warm environment, 349 00:16:48.960 --> 00:16:52.480 it's isotopic fingerprint should show it's full of the light stuff. 350 00:16:52.559 --> 00:16:55.000 Relatively speaking, yes, it. 351 00:16:54.960 --> 00:16:59.000 Will have a very specific, predictable ratio of light versus 352 00:16:59.080 --> 00:17:03.279 heavy atoms. But here's the amazing part. At extremely cold 353 00:17:03.320 --> 00:17:07.240 temperatures we're talking deep space cold hundreds of degrees below zero, 354 00:17:07.759 --> 00:17:11.119 the rules of chemistry change. When you're not using heat 355 00:17:11.119 --> 00:17:14.519 to drive reactions, but you're using high energy radiation instead, 356 00:17:14.920 --> 00:17:16.319 that discrimination goes away. 357 00:17:16.559 --> 00:17:18.680 Radiation doesn't care if an atom is chevy or not. 358 00:17:19.160 --> 00:17:22.599 Radiation is like a sledgehammer. Heat is like a gentle push. 359 00:17:22.720 --> 00:17:25.160 The sledgehammer doesn't care if the one bond is slightly 360 00:17:25.200 --> 00:17:29.880 stronger than another. It just smashes everything. So reactions that 361 00:17:29.880 --> 00:17:33.160 are driven by radiation and frozen ice tend to incorporate 362 00:17:33.200 --> 00:17:35.880 the heavy and light isotopes in a different, more random 363 00:17:35.920 --> 00:17:38.519 seeming ratio. They don't show the same preference for the 364 00:17:38.599 --> 00:17:39.119 light stuff. 365 00:17:39.160 --> 00:17:41.200 I think I'm getting it. So the Penn State team, 366 00:17:41.279 --> 00:17:44.519 kachen Ski, Macintosh and the others, they take the glycine 367 00:17:44.519 --> 00:17:46.440 from the Beni sample. They put it in their super 368 00:17:46.440 --> 00:17:47.880 sensitive machine. 369 00:17:47.480 --> 00:17:50.480 A set of custom instruments, a mass spectrometer. 370 00:17:50.160 --> 00:17:51.960 And they literally just count the number of heavy carbon 371 00:17:52.000 --> 00:17:54.680 atoms versus light carbon atoms than nitrogen atoms too. 372 00:17:55.079 --> 00:17:58.279 That's essentially it. They measure that ratio with incredible precision, 373 00:17:58.640 --> 00:18:02.279 and the ratio they found it sacreamed coald. It screamed ice. 374 00:18:02.599 --> 00:18:05.319 It didn't look like the ratio from the Streker synthesis, 375 00:18:05.359 --> 00:18:06.559 the warm pond dress. 376 00:18:06.799 --> 00:18:10.160 It wasn't even in the same ballpark. The isotopic signature 377 00:18:10.240 --> 00:18:14.079 was completely inconsistent with formation in liquid water, but it 378 00:18:14.200 --> 00:18:17.599 perfectly matched the signature you'd expect from formation in solid 379 00:18:17.640 --> 00:18:21.400 frozen ice. Ice frozen solid, and not just ice sitting 380 00:18:21.400 --> 00:18:24.759 there peacefully, but ice being actively zapped by high energy 381 00:18:24.759 --> 00:18:26.359 cosmic rays and gamma rays. 382 00:18:26.480 --> 00:18:28.119 Okay, so let me see if I can picture this. 383 00:18:28.759 --> 00:18:31.640 The ingredients we talked about before, the ammonia, the cyani 384 00:18:31.759 --> 00:18:35.599 the simple carbon molecules. They're not dissolved in water. They're 385 00:18:35.640 --> 00:18:38.119 just trapped frozen solid inside. 386 00:18:37.839 --> 00:18:40.000 A block of ice exactly. They are suspended in the 387 00:18:40.039 --> 00:18:42.319 ice matrix like fruit in a jello mole and. 388 00:18:42.319 --> 00:18:46.160 Then over millions of years, radiation from space comes along 389 00:18:46.200 --> 00:18:49.839 and just zaps them, and that forces them to become 390 00:18:49.880 --> 00:18:50.720 amino acids. 391 00:18:51.079 --> 00:18:54.680 That's the idea. The process is called radiolysis. The high 392 00:18:54.759 --> 00:18:58.680 energy radiation particle smashes into a water molecule in the ice, 393 00:18:59.119 --> 00:19:04.039 shattering it and creating these incredibly reactive fragments called radicals. 394 00:19:04.279 --> 00:19:07.279 These radicals are like like chemical grenades. They are desperate 395 00:19:07.319 --> 00:19:10.759 to react with anything nearby, so they attack the frozen cyanide, 396 00:19:10.759 --> 00:19:13.559 they attack the ammonia, and they force them to combine 397 00:19:13.599 --> 00:19:14.240 in new ways. 398 00:19:14.359 --> 00:19:16.920 So the radiation is providing the energy that the heat 399 00:19:16.960 --> 00:19:18.720 would have provided in the warm pond. 400 00:19:18.559 --> 00:19:21.640 Precisely, but it's doing it without ever melting the ice. 401 00:19:21.759 --> 00:19:24.799