WEBVTT 1 00:00:03.399 --> 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 00:00:26.960 --> 00:00:29.120 I want you to imagine, just for a second, that 8 00:00:29.199 --> 00:00:33.479 you are standing in a dry, freezing, just incredibly dusty 9 00:00:33.560 --> 00:00:34.799 crater on another planet. 10 00:00:34.880 --> 00:00:36.600 Yeah, an absolutely brutal environment. 11 00:00:36.799 --> 00:00:40.320 Exactly. The sky above you isn't blue. It's this hazy 12 00:00:41.479 --> 00:00:45.079 butterscotch color tinted by all that iron oxide dust just 13 00:00:45.079 --> 00:00:48.240 suspended in the thin air, right, And the atmosphere is 14 00:00:48.280 --> 00:00:50.960 so wispy, I mean, it's mostly carbon dioxide, less than 15 00:00:51.039 --> 00:00:53.520 one percent the density of Earth's You couldn't breathe it 16 00:00:53.600 --> 00:00:56.159 even if it magically filled with oxygen right then and there. 17 00:00:56.240 --> 00:00:58.600 No, you'd suffocate immediately and freeze. 18 00:00:58.679 --> 00:01:02.640 Yeah, freeze. Because the temperature is hovering somewhere around eighty 19 00:01:02.679 --> 00:01:06.560 degrees below zero. There is no sound but this thin wind. 20 00:01:06.680 --> 00:01:10.000 It is utterly barren, like a sterile desert, right, but 21 00:01:10.120 --> 00:01:13.239 then you kneel down, you brush away that rusty red 22 00:01:13.280 --> 00:01:16.480 top layer of dirt you screep just I don't know, 23 00:01:16.519 --> 00:01:19.000 a couple of inches into the rock beneath and staring 24 00:01:19.079 --> 00:01:22.920 back at you are the very chemical building blocks of DNA. 25 00:01:23.200 --> 00:01:24.799 I mean, it sounds like the opening scene of a 26 00:01:24.840 --> 00:01:28.719 science fiction novel right where the protagonist makes this impossible discovery. 27 00:01:28.799 --> 00:01:29.359 It really does. 28 00:01:29.519 --> 00:01:32.640 But we are looking at hard, peer reviewed reality today, 29 00:01:32.760 --> 00:01:36.640 and it's a reality that completely shatters our previous assumptions 30 00:01:36.920 --> 00:01:38.599 about the chemistry of our solar. 31 00:01:38.359 --> 00:01:41.599 System because the surf on is basically a death zone exactly. 32 00:01:41.719 --> 00:01:44.680 We already know the Martian surface is essentially a sterilization 33 00:01:44.760 --> 00:01:50.040 engine unshielded UV radiation, and these highly reactive chemicals in 34 00:01:50.079 --> 00:01:54.439 the soil called perchlorates, well, they usually tear organic bonds 35 00:01:54.439 --> 00:01:57.599 apart in a matter of months, let alone millennia, which. 36 00:01:57.400 --> 00:02:00.480 Makes this monumental. And that's our mission today to really 37 00:02:00.519 --> 00:02:05.120 explore this. We are talking about NASA's Curiosity Mars rover, right, 38 00:02:05.760 --> 00:02:09.960 this car sized nuclear powered laboratory that has managed to 39 00:02:10.000 --> 00:02:13.479 pull off something planetary scientists have dreamed of for decades. 40 00:02:13.520 --> 00:02:15.280 It's an incredible engineering feature. 41 00:02:15.039 --> 00:02:17.400 In a specific spot on the Martian surface. This rover 42 00:02:17.560 --> 00:02:21.120 has successfully uncovered a diverse mix of never before seen 43 00:02:21.280 --> 00:02:25.439 organic molecules and yes, that includes the literal precursors to DNA. 44 00:02:25.639 --> 00:02:25.879 Yeah. 45 00:02:25.879 --> 00:02:28.680 I mean, it is impossible to overstate how thrilling this is. 46 00:02:28.840 --> 00:02:31.719 We are looking at the potential seeds of life sitting 47 00:02:31.840 --> 00:02:33.719 right there in the dirt of our neighboring planet. 48 00:02:33.840 --> 00:02:34.360 It really is. 49 00:02:34.599 --> 00:02:36.840 It's the kind of discovery that forces you to look 50 00:02:36.919 --> 00:02:39.280 up at the night sky and just realize how incredibly 51 00:02:39.319 --> 00:02:40.879 dynamic our universe actually is. 52 00:02:41.199 --> 00:02:44.240 The thrill is absolutely justified. I agree, though, you know, 53 00:02:44.280 --> 00:02:46.080 I think we have to tamper that excitement just a 54 00:02:46.080 --> 00:02:49.280 bit by grounding ourselves in the sheer, staggering time scale 55 00:02:49.680 --> 00:02:51.840 of what we are analyzing. 56 00:02:51.240 --> 00:02:54.319 Here, right, the three point five billion years part. 57 00:02:54.520 --> 00:02:58.039 Exactly. The true marvel here isn't just the inventory of 58 00:02:58.039 --> 00:03:01.120 what the rover found, is the fact that these complex 59 00:03:01.240 --> 00:03:04.159 molecular structures survived at. 60 00:03:03.960 --> 00:03:06.879 All because Mars doesn't have a magnetic field like we do. 61 00:03:07.120 --> 00:03:11.400 Right. Mars is a giant, unshielded radiation chamber. It lacks 62 00:03:11.400 --> 00:03:15.080 a global magnetic field to deflect galactic cosmic rays and 63 00:03:15.199 --> 00:03:19.680 solar energetic particles. Just relentlessly bombard the surface. Wow, Ionizing 64 00:03:19.759 --> 00:03:24.199 radiation functions like a like a microscopic wrecking ball, systematically 65 00:03:24.240 --> 00:03:28.120 smashing into complex molecules and breaking their delicate carbon bonds 66 00:03:28.120 --> 00:03:28.919 over deep time. 67 00:03:28.919 --> 00:03:30.280 Just constantly chipping away at them. 68 00:03:30.360 --> 00:03:34.639 Yeah, exactly so. Finding intact macromolecules that endure this bootle 69 00:03:34.719 --> 00:03:39.120 environment for billions of years completely redefines our baseline understanding 70 00:03:39.120 --> 00:03:40.800 of planetary preservation models. 71 00:03:41.080 --> 00:03:43.520 Well, let me stop you there, because that immediately raises 72 00:03:43.520 --> 00:03:47.199 a massive question. Sure, if the surface is a sterilization 73 00:03:47.400 --> 00:03:51.719 engine and cosmic rays are acting like microscopic wrecking balls 74 00:03:51.759 --> 00:03:54.879 for three and a half billion years, how on Earth, 75 00:03:55.159 --> 00:03:57.280 or rather how on Mars did anything survive? 76 00:03:57.439 --> 00:03:58.639 Right? It seems impossible. 77 00:03:58.680 --> 00:04:01.360 It defies logic, which means we have to look at 78 00:04:01.360 --> 00:04:06.080 the exact spot where the rover parked. Right. Curiosity didn't just, 79 00:04:06.199 --> 00:04:09.919 you know, stumble upon these fragile molecules randomly while rolling 80 00:04:09.960 --> 00:04:10.759 across the dunes. 81 00:04:10.879 --> 00:04:13.800 No, not at all. Survival in that kind of environment 82 00:04:13.879 --> 00:04:17.480 is never random. If Curiosity had parked a few miles away, 83 00:04:17.519 --> 00:04:19.399 we wouldn't be having this conversation right now. 84 00:04:19.439 --> 00:04:21.360 Wait, really, just a few miles. 85 00:04:20.959 --> 00:04:23.439 Just a few miles the rover had to find a 86 00:04:23.680 --> 00:04:28.360 very specific geologic vault. Curiosity landed in Gale Crater back 87 00:04:28.399 --> 00:04:31.720 in August of twenty twelve. And Gale Crater is this 88 00:04:31.920 --> 00:04:34.879 massive impact basin formed billions of years ago. 89 00:04:34.920 --> 00:04:36.439 And it used to be a lake, right. 90 00:04:36.439 --> 00:04:39.279 Yes, we are fairly certain it hosted an ancient, long 91 00:04:39.319 --> 00:04:42.519 lived lake system. But the specific samples we were dissecting 92 00:04:42.519 --> 00:04:44.120 today weren't taken in twenty twelve. 93 00:04:44.120 --> 00:04:44.759 Well they weren't. 94 00:04:45.199 --> 00:04:48.639 No, they weren't taken in twenty fourteen or twenty sixteen either. 95 00:04:49.519 --> 00:04:52.920 The rover had to meticulously climb the foothills of the 96 00:04:52.959 --> 00:04:56.920 crater's central peak, Mount Sharp. It took it till twenty nineteen, 97 00:04:57.199 --> 00:05:00.519 when it finally drove into a highly specialized region called 98 00:05:00.600 --> 00:05:01.480 Glenn Torden. 99 00:05:01.680 --> 00:05:05.040 Okay, let's unpack this. Glenn Torden isn't just another patch 100 00:05:05.079 --> 00:05:06.879 of rusty terrain, is it not? 101 00:05:06.959 --> 00:05:10.959 At all? The rover specifically targeted a clay bearing unit 102 00:05:11.040 --> 00:05:15.560 within this region, which the science team nicknamed Mary anning Ah. 103 00:05:15.319 --> 00:05:19.279 After the nineteenth century English palaeontologists who discovered Jurassic marine 104 00:05:19.319 --> 00:05:20.079 fossil beds. 105 00:05:20.360 --> 00:05:23.279 Exactly, and calling it a clay bearing unit is the 106 00:05:23.319 --> 00:05:26.160 absolute crux of this entire story, because. 107 00:05:25.839 --> 00:05:28.000 Clay is special. I like to think of this specific 108 00:05:28.040 --> 00:05:30.560 Martian clay as like cosmic tupperware. 109 00:05:30.680 --> 00:05:31.879 Cosmic tupperware. I like that. 110 00:05:32.120 --> 00:05:35.680 Yeah, it's a geologic container ceiling in the chemical freshness 111 00:05:35.680 --> 00:05:37.920 of Mars from three and a half billion years ago, 112 00:05:38.040 --> 00:05:42.199 just completely locking out the destructive, irradiated environment of the surface. 113 00:05:42.399 --> 00:05:46.839 That analogy holds up surprisingly well under microscopic scrutiny. Actually, yeah, 114 00:05:46.839 --> 00:05:49.279 when we talk about clay implanetary science, we aren't just 115 00:05:49.319 --> 00:05:54.000 talking about you know, wet mud. We are talking about phylicilicates, 116 00:05:54.639 --> 00:05:57.279 smecktight clays, specifically. 117 00:05:56.759 --> 00:05:59.600 Smack tighte clays. Okay, what makes them so good at 118 00:05:59.600 --> 00:06:00.800 being tupperware? 119 00:06:01.199 --> 00:06:05.160 Well, on a molecular level, these clays are structured in 120 00:06:05.160 --> 00:06:09.800 incredibly tight microscopic layers, almost like the pages of a 121 00:06:09.839 --> 00:06:10.720 tightly bound book. 122 00:06:11.000 --> 00:06:11.759 Oh. Interesting. 123 00:06:11.839 --> 00:06:15.120 When liquid water flows through volcanic rock over long periods 124 00:06:15.120 --> 00:06:19.040 of time, it chemically alters the primary minerals like olivine 125 00:06:19.079 --> 00:06:21.639 and pyroxene into these layered silicates. 126 00:06:22.279 --> 00:06:23.879 Okay, So the water changes the. 127 00:06:23.879 --> 00:06:27.800 Rock, right, and when that alteration happens, organic chemicals flowing 128 00:06:27.800 --> 00:06:30.639 in that water can essentially get trapped right between these 129 00:06:30.680 --> 00:06:31.720 microscopic sheets. 130 00:06:31.879 --> 00:06:34.839 So the clay physically swallows the organics like it just 131 00:06:34.879 --> 00:06:36.879 traps them inside the pages of the book. 132 00:06:36.920 --> 00:06:39.519 It traps them, yes, but it also chemically binds them. 133 00:06:39.759 --> 00:06:43.000 The surfaces of these clay layers have slight electrical charges 134 00:06:43.079 --> 00:06:44.959 that hold onto organic molecules. 135 00:06:45.000 --> 00:06:46.800 Oh wow, so it's not just a physical box. It's 136 00:06:46.800 --> 00:06:48.360 grabbing onto them exactly. 137 00:06:49.000 --> 00:06:52.879 The clay minerals act as heavy duty protective vaults. They 138 00:06:52.920 --> 00:06:56.600 physically shield the trapped organics from the ionizing radiation raining 139 00:06:56.639 --> 00:06:59.639 down from space, and they protect them from the chemical 140 00:06:59.680 --> 00:07:02.120 oxide driven by the perchlorids on the surface. 141 00:07:02.240 --> 00:07:03.240 That makes total sense. 142 00:07:03.279 --> 00:07:05.639 If you want to find preserved organics on a dead world, 143 00:07:05.920 --> 00:07:09.680 you follow the clay. This actually circles directly back to 144 00:07:09.759 --> 00:07:12.040 Curiosity's original mission. 145 00:07:11.720 --> 00:07:14.959 Mandate, right, because people forget that goal wasn't to find 146 00:07:15.000 --> 00:07:15.800 little green men. 147 00:07:16.199 --> 00:07:19.560 No, when the rover launched in twenty eleven, its primary 148 00:07:19.560 --> 00:07:22.800 goal wasn't to find living microbes. The goal was to 149 00:07:22.800 --> 00:07:27.040 find evidence that ancient Mars had the specific environmental conditions 150 00:07:27.040 --> 00:07:29.720 that could have supported microbial life billions of years. 151 00:07:29.600 --> 00:07:32.839 Ago, right, the habitability factor. But I'm looking at this 152 00:07:32.920 --> 00:07:35.879 finding and my immediate thought is, Okay, we know Gale 153 00:07:35.879 --> 00:07:38.839 Crater was a massive lake. Yes, we know glenn Torden 154 00:07:39.040 --> 00:07:42.120 is full of clay formed by water interacting with rock. 155 00:07:42.439 --> 00:07:45.399 So water was clearly present for a massive stretch of 156 00:07:45.439 --> 00:07:50.120 time denied. But does water automatically equal a habitable environment? 157 00:07:50.399 --> 00:07:52.879 Because you know we have places on Earth like certain 158 00:07:53.000 --> 00:07:57.160 ultra acidic volcanic lakes or highly irradiated zones that have 159 00:07:57.279 --> 00:07:59.480 water but are completely devoid of life. 160 00:08:00.079 --> 00:08:03.920 You're hitting on the critical distinction that drives astrobiology. Water 161 00:08:04.160 --> 00:08:06.720 is the solvent necessary for life as we know it, 162 00:08:07.079 --> 00:08:09.720 but it is entirely insufficient on its own right. 163 00:08:10.240 --> 00:08:12.160 Just having a glass of water doesn't mean something can 164 00:08:12.160 --> 00:08:13.480 live in it exactly. 165 00:08:13.560 --> 00:08:17.199 To declare an environment truly habitable, you need a confluence 166 00:08:17.240 --> 00:08:18.680 of three major pillars. 167 00:08:18.800 --> 00:08:19.920 Okay, what are the three? 168 00:08:20.160 --> 00:08:23.600 First, you need that liquid water solvent. Second, you need 169 00:08:23.639 --> 00:08:28.639 an energy source to drive metabolism like sunlight sunlight for photosynthesis, 170 00:08:28.680 --> 00:08:32.600 sure or chemical gradients and geothermal heat for chemosynthesis like 171 00:08:32.639 --> 00:08:35.240 we see in deep ocean hydrothermal vents here on Earth. 172 00:08:35.360 --> 00:08:37.200 Okay, so water and energy, what's a third? 173 00:08:37.320 --> 00:08:40.000 And third? You need the elemental building blocks of life which, 174 00:08:40.080 --> 00:08:43.759 as scientists often abbreviate as hnopshnops. 175 00:08:43.759 --> 00:08:47.039 That's carbon, hydrogen, nitrogen, oxygen, phosphorus and sulfur. 176 00:08:47.159 --> 00:08:51.399 Right, you got it. The clay in Gale Crater proved 177 00:08:51.440 --> 00:08:55.279 the long standing water pillar, but to prove full habitability, 178 00:08:55.559 --> 00:09:00.919 Curiosity had to definitively find those complex Organicsware is useless 179 00:09:00.960 --> 00:09:02.720 to our search for life if we open it up 180 00:09:02.799 --> 00:09:04.200 and find it completely empty. 181 00:09:04.240 --> 00:09:09.720 Wow. Yeah, which brings us to an absolutely massive engineering nightmare. Oh, 182 00:09:09.759 --> 00:09:13.159 it was a nightmare, because finding the ultimate cosmic tupperware 183 00:09:13.240 --> 00:09:16.279 is a triumph in itself. We sent a robot tens 184 00:09:16.320 --> 00:09:18.919 of millions of miles, landed it via a sky crane, 185 00:09:18.919 --> 00:09:21.559 which is still insane to me, and drove it for 186 00:09:21.679 --> 00:09:24.399 seven years to find this specific mudstone. 187 00:09:24.440 --> 00:09:25.200 It's incredible. 188 00:09:25.240 --> 00:09:27.279 But figuring out how to pop the lid open right 189 00:09:27.600 --> 00:09:30.120 to crack into those microscopic clay vaults and read the 190 00:09:30.200 --> 00:09:33.200 chemical signatures inside that required one of the most high 191 00:09:33.279 --> 00:09:37.279 stakes limited resource experiments in the entire history of space exploration. 192 00:09:37.480 --> 00:09:40.720 The sheer audacity the engineering required to achieve this is 193 00:09:40.840 --> 00:09:44.200 just staggering. To pop that lid, The rover utilized an 194 00:09:44.200 --> 00:09:46.639 onboard instrument suite called SAM. 195 00:09:46.440 --> 00:09:48.600 SAM that stands for Sample Analysis of Mars. 196 00:09:48.440 --> 00:09:52.279 Right exactly, and this particular highly specialized experiment was led 197 00:09:52.320 --> 00:09:57.039 in part by astrobiologist Jennifer Eigenbrode at NASA's Goddard Space 198 00:09:57.120 --> 00:10:00.600 Flight Center. Okay, now SAM isn't just a single it's 199 00:10:00.600 --> 00:10:04.720 effectively a miniaturized analytical chemistry lab tucked right inside the 200 00:10:04.720 --> 00:10:05.639 belly of the rover. 201 00:10:05.639 --> 00:10:07.279 Like a full lab shrunked down. 202 00:10:07.360 --> 00:10:11.120 Yeah, it contains a gas chromatograph, a quadrupole mass s pectrometer, 203 00:10:11.440 --> 00:10:13.080 and a tunable laser spectrometer. 204 00:10:13.200 --> 00:10:15.919 That is a lot of fancy equipment in a small box, 205 00:10:16.039 --> 00:10:16.360 it is. 206 00:10:16.759 --> 00:10:20.240 But this specific dig at mary Anning wasn't a standard 207 00:10:20.399 --> 00:10:23.879 run of the mill SAM test. To coax these complex 208 00:10:24.000 --> 00:10:26.720 organics out of their clay vaults without destroying them in 209 00:10:26.759 --> 00:10:29.919 the process, the team had to use a highly specialized 210 00:10:30.000 --> 00:10:32.639 chemical region called TMAH. 211 00:10:32.720 --> 00:10:38.000 Okay TMAH tetra misleamonium hydroxide for the organic chemists listening 212 00:10:38.000 --> 00:10:40.320 who love a mouthful of syllables, that's the one. 213 00:10:40.440 --> 00:10:43.039 And to understand why TMAH is so crucial, you have 214 00:10:43.080 --> 00:10:45.559 to understand how SAM normally operates. 215 00:10:45.159 --> 00:10:46.679 Right, how does it normally check the dirt. 216 00:10:46.960 --> 00:10:50.159 Usually the rover's robotic arm drills into a rock, collects 217 00:10:50.200 --> 00:10:52.720 a powdered sample, and drops it into a tiny quartz 218 00:10:52.759 --> 00:10:53.600 cup inside SAM. 219 00:10:53.639 --> 00:10:54.480 Okay, it makes sense. 220 00:10:54.759 --> 00:10:57.840 The instrument then heats that dirt up to roughly eight 221 00:10:57.960 --> 00:11:01.399 hundred degrees celsius, process called pyrolysis. 222 00:11:01.600 --> 00:11:02.639 Eight hundred degrees. 223 00:11:02.840 --> 00:11:07.080 Yeah. As the dirt bakes, gases boil off, and the 224 00:11:07.120 --> 00:11:10.399 mass spectrometer basically sniffs those gases to see what they 225 00:11:10.440 --> 00:11:10.720 made of. 226 00:11:10.879 --> 00:11:13.639 Okay, I have to interject here because heating Martian dirt 227 00:11:13.679 --> 00:11:16.840 to eight hundred degrees seems like a massive design flaw 228 00:11:17.279 --> 00:11:20.080 if you are looking for fragile, three and a half 229 00:11:20.080 --> 00:11:22.360 billion year old organic molecules. 230 00:11:22.519 --> 00:11:24.039 It sounds counterintuitive. I know. 231 00:11:24.279 --> 00:11:27.480 If I take a complex organic structure, like I don't 232 00:11:27.519 --> 00:11:29.799 know a sugar or an amino acid, and I've glassed 233 00:11:29.840 --> 00:11:32.519 it with eight hundred degrees of heat, I don't get gas. 234 00:11:32.639 --> 00:11:36.080 I get a burnt, carbonized mess. I'm essentially making charcoal. 235 00:11:36.200 --> 00:11:39.600 Right. It's not a flaw, but it is the fundamental 236 00:11:39.639 --> 00:11:43.200 constraint of the technology available when SAM was designed in 237 00:11:43.240 --> 00:11:46.240 the early two thousands. Okay, and you are entirely correct 238 00:11:46.240 --> 00:11:50.519 about the chemistry. Large complex organic molecules, especially ones that 239 00:11:50.519 --> 00:11:54.399 have already been battered by cosmic radiation. They do not easily. 240 00:11:54.159 --> 00:11:58.080 Volatilize, meaning they don't turn into gas neatly exactly. 241 00:11:58.120 --> 00:12:00.679 They degrade, they fracture, They turn it into a morphous 242 00:12:00.679 --> 00:12:05.120 carbon or char. When Sam bakes them, normally, the mass 243 00:12:05.120 --> 00:12:08.440 spectrometer often just sees carbon dioxide, water vapor coming. 244 00:12:08.200 --> 00:12:09.159 Off, just the smoke. 245 00:12:09.279 --> 00:12:12.960 Basically yeah, yeah, the ghostly combusted remains of what used 246 00:12:13.000 --> 00:12:16.600 to be a complex organic molecule. The instrument knows something 247 00:12:16.720 --> 00:12:20.120 organic was there, but the original structure is completely lost 248 00:12:20.120 --> 00:12:21.039 to the fire. 249 00:12:20.879 --> 00:12:24.240 Which is exactly why they needed TMAH. So how does 250 00:12:24.279 --> 00:12:28.120 this chemical stop the organics from burning into useless ash? 251 00:12:28.480 --> 00:12:32.360 Well, TMAH performs a brilliant chemical trick called thermochemolysis. 252 00:12:32.440 --> 00:12:33.759 Okay, break that down for us. 253 00:12:33.919 --> 00:12:37.440 Thermo for heat, chemo for chemical, and lysis for breaking. 254 00:12:37.720 --> 00:12:40.360 When TMH is missed with the Martian dirt and heated, 255 00:12:40.600 --> 00:12:44.120 it doesn't just passively watch the molecules burn. It actively 256 00:12:44.159 --> 00:12:44.799 attacks them. 257 00:12:44.840 --> 00:12:46.000 Oh, it goes on the offensive. 258 00:12:46.120 --> 00:12:50.399 Yeah. TMAH is a strong base and it chemically fragments larger, 259 00:12:50.480 --> 00:12:55.279 stubborn organic macromolecules. Into smaller manageable pieces. But crucial to 260 00:12:55.320 --> 00:12:59.320 this process, it performs something called methylation. As it breaks 261 00:12:59.360 --> 00:13:04.000 the molecules part the TMAH donates methyl groups. That's one 262 00:13:04.080 --> 00:13:07.559 carbon atom attached to three hydrogen atoms and attaches them 263 00:13:07.559 --> 00:13:11.080 to the broken highly reactive ends of the organic. 264 00:13:10.720 --> 00:13:12.919 Fragments, so it caps them off so they don't burn. 265 00:13:13.000 --> 00:13:16.960 Precisely, it protects them, allowing them to volatilize into gas 266 00:13:17.200 --> 00:13:18.559 without turning into charcoal. 267 00:13:19.000 --> 00:13:21.919 That is genius. But here's the part that stresses me 268 00:13:21.960 --> 00:13:25.879 out just thinking about it. Imagine packing for a decade long, 269 00:13:26.159 --> 00:13:30.360 multi million mile road trip across a hostile desert. Right, sure, 270 00:13:30.360 --> 00:13:33.759 but you're only allowed to bring exactly two fluid ounces 271 00:13:33.799 --> 00:13:35.879 of engine coolant for the entire journey. 272 00:13:35.960 --> 00:13:36.840 That's a good way to put it. 273 00:13:36.879 --> 00:13:39.360 Because you have a car sized robot roaming an entire 274 00:13:39.440 --> 00:13:42.360 planet and it only had two tiny cups of this 275 00:13:42.440 --> 00:13:45.960 liquid tma H chemical on board, two cups, two cups 276 00:13:45.960 --> 00:13:48.399 for the entire multi year life span of the mission. 277 00:13:48.440 --> 00:13:50.919 It's like reaching the final most difficult puzzle of a 278 00:13:51.039 --> 00:13:53.720 vastly complex video game and realizing you only have a 279 00:13:53.759 --> 00:13:56.399 single lock pick to open the most important safe on Earth. 280 00:13:56.480 --> 00:13:58.360 And if you turn it too hard it snaps. 281 00:13:58.639 --> 00:14:02.200 Yeah, and the physical constraints of spaceflight force these kinds 282 00:14:02.200 --> 00:14:05.399 of impossible bottlenecks. When you're launching a payload to Mars, 283 00:14:05.879 --> 00:14:08.159 every single gram is negotiated. 284 00:14:08.240 --> 00:14:09.840 Everything costs fuel. 285 00:14:09.840 --> 00:14:13.320 Right, and liquids are exceptionally difficult to fly with. They 286 00:14:13.360 --> 00:14:17.879 require sealed, pressurized containment systems that have to survive the violent, 287 00:14:18.200 --> 00:14:22.039 bone rattling vibrations of launch, plus the cold, oh yeah, 288 00:14:22.080 --> 00:14:25.879 the freezing vacuum of interplanetary transit, and then the fiery 289 00:14:25.960 --> 00:14:29.200 deceleration of entering the Martian atmosphere. So yes, they only 290 00:14:29.200 --> 00:14:32.519 had two cups. And because of that terrifying scarcity, the 291 00:14:32.559 --> 00:14:35.159 patients required by the science team was just immense. 292 00:14:35.320 --> 00:14:38.000 I just can't imagine the tension you land in twenty twelve. 293 00:14:38.039 --> 00:14:41.000 You know, you have this incredibly powerful chemical lock pick 294 00:14:41.200 --> 00:14:42.440 in the rover's belly. 295 00:14:42.639 --> 00:14:43.360 You just have to wait. 296 00:14:43.639 --> 00:14:47.840 Yeah, How do planetary scientists handle the psychological pressure of 297 00:14:47.960 --> 00:14:51.240 knowing that one wrong scoop of dirt wastes a decade 298 00:14:51.240 --> 00:14:53.720 of waiting and searching a lot of pressure Because if 299 00:14:53.720 --> 00:14:56.279 they drill a rock mix in the TMAH and it 300 00:14:56.320 --> 00:14:58.600 turns out that specific rock was I don't know, too 301 00:14:58.720 --> 00:15:02.240 highly oxidized or lacked the right smectite clays, or had 302 00:15:02.279 --> 00:15:04.200 too much perchlorate. That's it. 303 00:15:04.519 --> 00:15:06.399 That's game over for the lock pick. 304 00:15:06.679 --> 00:15:09.720 You press enter on the code sending the command to Mars, 305 00:15:10.240 --> 00:15:12.440 and then you just sit in a control room on Earth, 306 00:15:12.840 --> 00:15:16.440 agonizing for the fourteen minute communication delay, waiting to see 307 00:15:16.440 --> 00:15:18.000 if you blew your one and only chance. 308 00:15:18.799 --> 00:15:24.000 They mitigate that pressure through a deeply exhausting, meticulous process 309 00:15:24.039 --> 00:15:25.960 of elimination. They didn't just. 310 00:15:26.039 --> 00:15:28.120 Guess, they couldn't afford to exactly. 311 00:15:28.720 --> 00:15:32.480 From twenty twelve to twenty nineteen, as Curiosity traversed from 312 00:15:32.480 --> 00:15:35.679 the Breadbury landing site through Yellowknife Bay and up the 313 00:15:35.720 --> 00:15:39.840 slopes of Mount Sharp, the team continuously analyzed the mineralogy 314 00:15:39.919 --> 00:15:40.879 of everything. 315 00:15:40.480 --> 00:15:42.879 They passed, using the other tools. 316 00:15:42.519 --> 00:15:45.039 Right, using the rovers, other instruments like chimin, which is 317 00:15:45.039 --> 00:15:48.240 the chemistry of mineralogy X ray diffraction instrument. They were 318 00:15:48.320 --> 00:15:52.399 constantly building a geological map, waiting for the absolute perfect, 319 00:15:52.559 --> 00:15:53.759 most favorable location. 320 00:15:53.919 --> 00:15:56.600 So they were passing up decent spots because they weren't perfect. 321 00:15:56.679 --> 00:15:59.200 Oh, they pass up dozens of interesting sites. They're doing 322 00:15:59.200 --> 00:16:01.639 sure the sample wasn't to acidic that the clay was 323 00:16:02.200 --> 00:16:04.399 authogenic ophogenic. 324 00:16:04.440 --> 00:16:05.080 What does that mean? 325 00:16:05.399 --> 00:16:07.799 It means it formed in place in the lake, rather 326 00:16:07.840 --> 00:16:10.039 than just being blown in by the wind from somewhere else. 327 00:16:10.159 --> 00:16:12.279 Oh okay, And they got to make sure that the 328 00:16:12.360 --> 00:16:16.360 radiation exposure was as low as possible. What's fascinating here 329 00:16:16.600 --> 00:16:19.039 is that the legacy of the SAM instrument is really 330 00:16:19.039 --> 00:16:22.000 built on this kind of disciplined precision. 331 00:16:22.159 --> 00:16:23.440 They really knew what they were doing. 332 00:16:23.600 --> 00:16:27.600 Yeah. Even before this specific TMH experiment, SAM had already 333 00:16:27.600 --> 00:16:32.200 revolutionized our understanding of Mars, quantifying the planet's atmospheric loss 334 00:16:32.440 --> 00:16:35.159 and detecting the seasonal spikes of background methane. 335 00:16:35.240 --> 00:16:39.120 But this was the main event. Mixing liquids with pulverized 336 00:16:39.159 --> 00:16:44.279 extraterrestrial rock, heating it precisely to trigger methylation without causing combustion, 337 00:16:44.960 --> 00:16:48.399 and analyzing the vaders at a molecular level, all happening 338 00:16:48.440 --> 00:16:52.039 autonomously inside a robot millions of miles away. It's a 339 00:16:52.080 --> 00:16:56.000 symphony of engineering, and the craziest part, it worked, It 340 00:16:56.080 --> 00:16:59.279 actually worked. The team took their shot. In twenty twenty, 341 00:16:59.480 --> 00:17:02.720 they finally authorized the use of their precious TMAH on 342 00:17:02.759 --> 00:17:05.440 the dirt pulled from the Marianning site in Glenn Torridon. 343 00:17:05.920 --> 00:17:09.480 They baked it, the TMAH chemically capped the fragments, and 344 00:17:09.559 --> 00:17:13.279 the mass spectrometer readouts that beamed back to Earth exceeded 345 00:17:13.279 --> 00:17:15.000 their wildest expectations. 346 00:17:15.319 --> 00:17:19.160 It was a watershed moment for astrobiology. The data analysis 347 00:17:19.160 --> 00:17:22.119 of this specific experiment was led by Amy Williams, a 348 00:17:22.160 --> 00:17:25.240 professor of geological sciences at the University of Florida, and 349 00:17:25.319 --> 00:17:28.279 her team published the findings in Nature Communications, and they 350 00:17:28.319 --> 00:17:30.839 found a lot. They didn't just find a faint whisper 351 00:17:30.880 --> 00:17:36.400 of carbon. The TMAH test revealed over twenty distinct complex 352 00:17:36.599 --> 00:17:38.599 organic chemical compound. 353 00:17:38.400 --> 00:17:41.559 Why ded That is a massive chemical hall huge. 354 00:17:41.799 --> 00:17:44.799 But among those twenty, there are two specific structural findings 355 00:17:44.839 --> 00:17:47.480 that genuinely altered the landscape of planetary science. 356 00:17:47.519 --> 00:17:48.400 Okay, let's hear them. 357 00:17:48.480 --> 00:17:51.599 First, they identified a nitrogen bearing molecule with a structure 358 00:17:51.640 --> 00:17:54.559 fundamentally similar to the nucleobases that formed the precursors of 359 00:17:54.640 --> 00:17:58.880 DNA wow. And second, they found a significant presence of benzothiophine, 360 00:17:58.960 --> 00:18:01.920 which is a large, double ringed sulfur based chemical. 361 00:18:02.200 --> 00:18:04.599 Okay, So if you were to look at the mass 362 00:18:04.599 --> 00:18:09.720 spectrometer readouts right now. You wouldn't see the letters DNA 363 00:18:10.200 --> 00:18:11.160 flashing on a screen. 364 00:18:11.400 --> 00:18:12.400 No, definitely not. 365 00:18:12.640 --> 00:18:15.680 You'd see a spike in mass to charge ratios, indicating 366 00:18:15.880 --> 00:18:19.880 a very specific heavy nitrogen bearing ring. You have to 367 00:18:19.920 --> 00:18:23.319 basically play detective to reconstruct what that ring used to 368 00:18:23.319 --> 00:18:26.200 be before three and a half billion years of radiation 369 00:18:26.279 --> 00:18:26.720 got to it. 370 00:18:26.839 --> 00:18:28.759 Right, you're looking at the fragments. 371 00:18:28.319 --> 00:18:30.200 But the conclusion is that we are looking at a 372 00:18:30.279 --> 00:18:35.440 DNA precursor, the literal structural foundation of genetic information as 373 00:18:35.480 --> 00:18:38.319 we understand it, just sitting there, frozen in a Martian 374 00:18:38.400 --> 00:18:41.559 lake bed exactly. And here's where it gets really interesting. 375 00:18:41.599 --> 00:18:43.799 And I have to push back on the scientific communities 376 00:18:43.839 --> 00:18:44.440 messaging here. 377 00:18:44.559 --> 00:18:45.400 Okay, lay it on me. 378 00:18:45.680 --> 00:18:48.839 We found the building blocks of DNA on Mars. Why 379 00:18:48.920 --> 00:18:52.240 isn't this front page above the fold news everywhere declaring 380 00:18:52.279 --> 00:18:56.559 we found aliens. It feels like scientists are deliberately downplaying this, 381 00:18:56.759 --> 00:19:00.440 framing it merely as chemistry rather than definitively by alogy. 382 00:19:00.720 --> 00:19:03.000 It is the most natural reaction to have, believe me, 383 00:19:03.559 --> 00:19:05.599 and it gets to the very heart of the rigor 384 00:19:05.680 --> 00:19:07.400 required by the scientific. 385 00:19:06.960 --> 00:19:09.200 Method, because it's not proof yet, right. 386 00:19:09.400 --> 00:19:13.599 The boundary between a biological building block, and actual functioning 387 00:19:13.640 --> 00:19:18.119 biological activity is a vast complicated gulf. How so, well, 388 00:19:18.240 --> 00:19:21.440 think of finding a nuclear base a DNA precursor like 389 00:19:21.480 --> 00:19:25.839 finding a single perfectly formed clay brick. A brick is 390 00:19:25.920 --> 00:19:29.519 incredibly useful. It is the fundamental unit you need if 391 00:19:29.559 --> 00:19:32.319 you want to build a complex house. But finding a 392 00:19:32.319 --> 00:19:35.039 single brick lying in an empty field does not prove 393 00:19:35.079 --> 00:19:37.599 that a house was ever actually built there, let alone 394 00:19:37.599 --> 00:19:38.559 that someone lived in it. 395 00:19:38.680 --> 00:19:39.920 Oh, that makes a lot of sense. 396 00:19:40.319 --> 00:19:42.960 Biology is not just a collection of chemicals. It's a 397 00:19:43.079 --> 00:19:47.880 highly organized, selective, energy consuming system. And the universe, it 398 00:19:47.920 --> 00:19:50.960 turns out, is remarkably good at forging the basic chemical 399 00:19:50.960 --> 00:19:52.920 bricks of life entirely on its own. 400 00:19:52.960 --> 00:19:55.400 Without life being involved at all, exactly. 401 00:19:55.160 --> 00:19:58.799