1 00:00:00,040 --> 00:00:04,440 Speaker 1: All right, so let's try and unpack this. There's this feeling, 2 00:00:04,799 --> 00:00:09,519 you know, the one you get when a rule you 3 00:00:09,599 --> 00:00:13,480 thought was totally fixed, a law of nature almost just 4 00:00:13,480 --> 00:00:14,960 gets shattered right in front of you. 5 00:00:15,199 --> 00:00:19,359 Speaker 2: Yeah, that sense of cosmic displacement. I know exactly what 6 00:00:19,399 --> 00:00:19,679 you mean. 7 00:00:19,760 --> 00:00:22,160 Speaker 1: I had this happen to me once. I was driving 8 00:00:22,199 --> 00:00:24,039 really late at night, way out in the middle nowhere, 9 00:00:24,359 --> 00:00:27,920 and I saw this this thing on a side road, 10 00:00:28,120 --> 00:00:30,440 just a blur, a blur. Yeah, it was moving so 11 00:00:30,640 --> 00:00:32,799 fast that it just didn't make sense for the environment. 12 00:00:32,799 --> 00:00:34,840 It wasn't just a car speeding. It felt like it wasn't, 13 00:00:34,960 --> 00:00:37,399 i don't know, operating by the same rules of physics 14 00:00:37,439 --> 00:00:38,159 as everything else. 15 00:00:38,399 --> 00:00:41,719 Speaker 2: That's a perfect analogy, actually, because that feeling is exactly 16 00:00:41,799 --> 00:00:44,880 what we're talking about today, just on an astronomical scale. Okay, 17 00:00:45,039 --> 00:00:47,479 we're talking about object that show up in our solar system, 18 00:00:47,960 --> 00:00:53,039 not from around the block, cosmically speaking, but from completely 19 00:00:53,079 --> 00:00:56,039 outside the Sun's entire sphere of influence. 20 00:00:56,119 --> 00:00:57,799 Speaker 1: So they're not just running a stop sign. 21 00:00:57,840 --> 00:01:00,759 Speaker 2: Moving so fast. Yeah, the stop sign. The whole town 22 00:01:00,799 --> 00:01:02,520 doesn't even have the gravity to slow them down. 23 00:01:02,759 --> 00:01:06,079 Speaker 1: And that's the key, that distinction. We've always had theories. 24 00:01:06,120 --> 00:01:07,840 I mean, it makes sense that stuff from the void 25 00:01:07,840 --> 00:01:08,480 would pass. 26 00:01:08,319 --> 00:01:10,239 Speaker 2: Through, right, is a statistical certainty. 27 00:01:10,359 --> 00:01:13,640 Speaker 1: But to actually see one, to confirm it, and then 28 00:01:13,680 --> 00:01:16,959 to see more, that just rewrites the rule book for 29 00:01:17,040 --> 00:01:18,640 our entire cosmic neighborhood. 30 00:01:18,680 --> 00:01:20,680 Speaker 2: It does, and that's what this deep dive is all about. 31 00:01:20,959 --> 00:01:24,920 We're looking at the discovery of these interstellar visitors. We've 32 00:01:24,920 --> 00:01:27,680 got two main players on the board. It's the first messenger, 33 00:01:27,760 --> 00:01:31,519 the first confirmed messenger. Yeah, a really peculiar high speed mystery. 34 00:01:32,159 --> 00:01:35,719 And then it's much much bigger, much older cousin. 35 00:01:35,680 --> 00:01:38,200 Speaker 1: The theoretical planetbuster. 36 00:01:37,799 --> 00:01:40,920 Speaker 2: An object that carries so much velocity it becomes well 37 00:01:41,040 --> 00:01:42,719 a weapon of cosmic proportions. 38 00:01:42,760 --> 00:01:45,319 Speaker 1: So our mission today is to figure out what makes 39 00:01:45,359 --> 00:01:49,840 these things interstellar, look at the frankly insane physics of 40 00:01:49,879 --> 00:01:53,640 how they move, and then run the simulation, the thought experiment, 41 00:01:53,799 --> 00:01:57,719 the necessary thought experiment. What happens when deep time and 42 00:01:57,760 --> 00:02:00,959 that kind of deep space velocity line up with our planet. 43 00:02:01,319 --> 00:02:04,159 Speaker 2: And that word velocity is going to be the key 44 00:02:04,200 --> 00:02:07,040 to everything. Yeah, it's the one factor that turns just 45 00:02:07,079 --> 00:02:09,879 a big old rock into a threat that can reset 46 00:02:09,919 --> 00:02:13,560 the entire course of life on Earth. So to start, 47 00:02:14,039 --> 00:02:17,000 we really need to nail down the terminology. When we 48 00:02:17,039 --> 00:02:19,879 see an object is interstellar, what does that actually mean? 49 00:02:20,159 --> 00:02:22,120 Speaker 1: It means it's not from around here. 50 00:02:22,039 --> 00:02:25,439 Speaker 2: At all, exactly. It originates completely outside our solar system. 51 00:02:25,840 --> 00:02:29,080 This isn't a comet that, say, Jupiter's gravity kicked into 52 00:02:29,159 --> 00:02:30,120 a weird orbit. 53 00:02:30,000 --> 00:02:32,439 Speaker 1: Or something from the Kuiper Belt way out past Neptune. 54 00:02:32,520 --> 00:02:35,879 Speaker 2: Yeah, this is like getting mail, but the return address 55 00:02:36,039 --> 00:02:39,159 is another star system, or maybe it has no return address, 56 00:02:39,240 --> 00:02:41,960 just a drifter unattached to any star that's been wandering 57 00:02:42,000 --> 00:02:43,840 the galaxy for who knows how. 58 00:02:43,719 --> 00:02:46,080 Speaker 1: Long, and for so long. That was just a concept 59 00:02:46,159 --> 00:02:48,199 of model. We figured it had to happen. The universe 60 00:02:48,240 --> 00:02:51,680 is a messy place. But getting confirmation that was a 61 00:02:51,759 --> 00:02:52,319 huge moment. 62 00:02:52,479 --> 00:02:56,039 Speaker 2: It was, and that first visitor was named Umuah. Officially 63 00:02:56,080 --> 00:02:58,000 it's one Eye twenty seventeen U one. 64 00:02:58,199 --> 00:03:00,520 Speaker 1: That designation, the one eye. That's the important part, isn't 65 00:03:00,520 --> 00:03:01,240 it It is? 66 00:03:01,719 --> 00:03:05,599 Speaker 2: The eye stands for interstellar. It was the first of 67 00:03:05,759 --> 00:03:09,080 a completely new class of object. The moment in twenty 68 00:03:09,159 --> 00:03:12,240 seventeen when we could finally track its path with enough 69 00:03:12,280 --> 00:03:15,479 certainty to say this is not bound to our Sun 70 00:03:15,879 --> 00:03:16,400 I love. 71 00:03:16,199 --> 00:03:19,000 Speaker 1: The name though, Umumua. It's Hawaiian, right it is. 72 00:03:19,080 --> 00:03:23,120 Speaker 2: It translates to something like a messenger from Afar arriving first. 73 00:03:23,400 --> 00:03:25,879 Speaker 1: You can't get more fitting than that. It was the herald. 74 00:03:26,039 --> 00:03:27,360 It told us they were out there. 75 00:03:27,560 --> 00:03:29,840 Speaker 2: And it wasn't just that it was there, it was 76 00:03:29,879 --> 00:03:33,439 how was behaving. The initial shock was all about its speed, 77 00:03:33,520 --> 00:03:34,439 its velocity. 78 00:03:34,840 --> 00:03:36,800 Speaker 1: Okay, let's break that down, because this is where the 79 00:03:36,840 --> 00:03:40,280 whole threat discussion starts. What's like a normal speed for 80 00:03:40,319 --> 00:03:43,280 our local stuff, commets, asteroids in. 81 00:03:43,240 --> 00:03:46,120 Speaker 2: Our solar system, things are moving pretty fast, but they're 82 00:03:46,159 --> 00:03:48,879 all sort of tethered by the Sun's gravity. So you're 83 00:03:48,879 --> 00:03:51,479 typically looking at speeds around twenty kilometers a. 84 00:03:51,479 --> 00:03:53,639 Speaker 1: Second, which is about twelve miles per second. That's already 85 00:03:53,680 --> 00:03:54,639 hard to wrap your head around. 86 00:03:54,719 --> 00:03:57,479 Speaker 2: It is. It's incredibly fast, but it's the speed limit 87 00:03:57,599 --> 00:03:59,639 of our neighborhood. You could say if the speed of 88 00:03:59,639 --> 00:04:02,759 things that stuck in the Sun's gravitational well, and uh 89 00:04:02,840 --> 00:04:06,400 Mumua just blew right past that speed limit. When we 90 00:04:06,479 --> 00:04:08,800 clocked it on its way out of our solar system, 91 00:04:09,120 --> 00:04:12,039 it was still moving at eighty seven kilometers per second. 92 00:04:12,199 --> 00:04:14,439 Eighty seven fifty four miles per second. 93 00:04:14,639 --> 00:04:17,199 Speaker 1: Okay, so that's not just a little faster, that's what 94 00:04:17,319 --> 00:04:19,079 more than four times the local speed? 95 00:04:19,319 --> 00:04:23,000 Speaker 2: Yes, And that immediately tells you everything you need to 96 00:04:23,000 --> 00:04:25,920 know about its journey. That speed guarantees what we call 97 00:04:25,959 --> 00:04:27,279 a hyperbolic trajectory. 98 00:04:27,600 --> 00:04:29,160 Speaker 1: That's the key term, right. 99 00:04:29,319 --> 00:04:32,199 Speaker 2: It is if something is moving in an orbit, its 100 00:04:32,240 --> 00:04:35,360 path is an ellipse. It keeps coming back. Yeah, But 101 00:04:35,439 --> 00:04:39,079 if it's moving above a certain speed the Sun's escape velocity, 102 00:04:39,439 --> 00:04:42,519 is path is a hyperbola. It comes in, swings around 103 00:04:42,519 --> 00:04:43,680 the Sun once, and it's gone. 104 00:04:43,879 --> 00:04:44,879 Speaker 1: It's never coming back. 105 00:04:45,040 --> 00:04:47,480 Speaker 2: Never. The fact that its speed was so high meant 106 00:04:47,519 --> 00:04:50,240 it could only have come from deep space. It arrived 107 00:04:50,240 --> 00:04:52,800 here already carrying tremendous momentum from somewhere else. 108 00:04:52,920 --> 00:04:54,920 Speaker 1: So we could be talking about an object that got 109 00:04:54,959 --> 00:04:57,439 what sling shot it out of its home star system, 110 00:04:57,480 --> 00:04:59,839 maybe hundreds of light years away exactly. 111 00:05:00,120 --> 00:05:02,240 Speaker 2: Maybe it got kicked out by a giant planet or 112 00:05:02,279 --> 00:05:05,879 close pass with its star, and then it just coasted. 113 00:05:06,160 --> 00:05:09,040 It traveled through the cold dark void for maybe a 114 00:05:09,120 --> 00:05:12,319 billion years, holding onto that speed the whole time a 115 00:05:12,399 --> 00:05:16,040 billion years. That momentum was gained somewhere else in a 116 00:05:16,160 --> 00:05:20,639 totally different environment, and thankfully, I mean really thankfully, the 117 00:05:20,680 --> 00:05:22,839 calculation showed it was no threat to us. 118 00:05:23,120 --> 00:05:25,160 Speaker 1: Its trajectory was safe completely. 119 00:05:25,279 --> 00:05:27,360 Speaker 2: It cut through our system, gave us a little bit 120 00:05:27,399 --> 00:05:29,720 of a shock, and then headed back out. It's on 121 00:05:29,759 --> 00:05:31,720 its way toward the constellation Pegas is right now. 122 00:05:31,839 --> 00:05:33,959 Speaker 1: It'll just keep going for millions, maybe. 123 00:05:33,759 --> 00:05:36,480 Speaker 2: Hundreds of millions more years. We were just a tiny 124 00:05:36,480 --> 00:05:40,439 little waypoint on an absolutely epic galactic journey. 125 00:05:40,560 --> 00:05:42,720 Speaker 1: So even after we knew and Mumu was safe, the 126 00:05:42,759 --> 00:05:45,199 weirdness didn't stop. It just kept piling up. 127 00:05:45,240 --> 00:05:48,360 Speaker 2: Oh yeah, the mystery was just beginning. Long after it 128 00:05:48,439 --> 00:05:53,000 passed by, scientists were still arguing about its basic physical properties. 129 00:05:52,560 --> 00:05:55,959 Speaker 1: Starting with its shape. It wasn't the usual lumpy, potato 130 00:05:56,000 --> 00:05:58,319 shaped rock we see in the asteroid belt. 131 00:05:58,240 --> 00:06:01,439 Speaker 2: Not at all. That's what was so strange. The data 132 00:06:01,480 --> 00:06:04,879 from its light curve, how its brightness changed as it tumbled, 133 00:06:05,199 --> 00:06:08,560 suggested an extreme shape. The best estimate was that it 134 00:06:08,600 --> 00:06:11,360 was maybe ten times longer than it was wide. 135 00:06:11,120 --> 00:06:14,600 Speaker 1: Which led to all those headlines about a cosmic cigar. 136 00:06:14,600 --> 00:06:16,720 Speaker 2: Right or a cucumber or TUTSI roll. I think I 137 00:06:16,759 --> 00:06:19,480 even saw a comparison to a submarine sandwich. 138 00:06:19,160 --> 00:06:22,079 Speaker 1: A belly buster turkey and bacon sub I think was 139 00:06:22,120 --> 00:06:23,079 the specific one. 140 00:06:23,199 --> 00:06:26,600 Speaker 2: The point is its elongation was extreme. We just don't 141 00:06:26,600 --> 00:06:28,800 see objects shaped like that in our solar system. 142 00:06:29,040 --> 00:06:32,279 Speaker 1: Why not? Why are ours all lumpy? 143 00:06:32,360 --> 00:06:35,600 Speaker 2: Well, it's generally down to gravity and collisions. Over billions 144 00:06:35,600 --> 00:06:38,480 of years. Things tend to either pull themselves into a 145 00:06:38,560 --> 00:06:41,000 rough sphere if they're big enough, or they get smashed 146 00:06:41,040 --> 00:06:45,040 into irregular potato like shapes. A long, thin needle or 147 00:06:45,079 --> 00:06:48,720 cigar shape suggests a very very specific kind of formation 148 00:06:49,800 --> 00:06:52,319 or and this is where the speculation really took off. 149 00:06:52,720 --> 00:06:55,920 It suggests it's not natural, that it's an artificial construct. 150 00:06:55,920 --> 00:06:58,279 Speaker 1: And it was tumbling too, right, not just spinning neatly. 151 00:06:58,560 --> 00:07:01,720 Speaker 2: It was in a chaotic tumble, spinning on multiple axes 152 00:07:01,759 --> 00:07:04,879 as it flew. But even that wasn't the biggest mystery. 153 00:07:05,079 --> 00:07:07,839 The real hit scratcher, The thing that launched a thousand 154 00:07:07,839 --> 00:07:11,480 scientific papers was the acceleration anomaly. Okay, so what's that 155 00:07:11,920 --> 00:07:14,560 When we tracked its path past the Sun, after we 156 00:07:14,600 --> 00:07:17,279 accounted for the pull of the Sun's gravity, it was 157 00:07:17,319 --> 00:07:19,319 still moving faster than it should have been. 158 00:07:19,480 --> 00:07:22,319 Speaker 1: Something else was pushing it. A non gravitational. 159 00:07:21,759 --> 00:07:25,439 Speaker 2: Push exactly, something was giving it a little extra kick. Now, 160 00:07:25,560 --> 00:07:29,240 with comets, this is normal. We see this all the time. 161 00:07:29,439 --> 00:07:31,199 Speaker 1: Right as they get close to the sun. The ice 162 00:07:31,279 --> 00:07:34,279 heats up, turns to gas, and shoots out in jets 163 00:07:34,319 --> 00:07:35,560 like little rocket thrusters. 164 00:07:35,639 --> 00:07:39,439 Speaker 2: Precisely, that process is called outgassing, and it gives the 165 00:07:39,439 --> 00:07:43,120 comet that push. But for that to happen, you need 166 00:07:43,160 --> 00:07:44,680 to see the telltale sign of. 167 00:07:44,600 --> 00:07:47,399 Speaker 1: A comet, the coma, that big fuzzy halo of gas 168 00:07:47,399 --> 00:07:49,000 and dust around it, and the tail. 169 00:07:49,160 --> 00:07:52,560 Speaker 2: And Umu had neither no coma, no tail, nothing. It 170 00:07:52,639 --> 00:07:55,199 just looked like a dead rock, a dead rock that 171 00:07:55,279 --> 00:07:56,920 was mysteriously accelerating. 172 00:07:57,000 --> 00:07:59,720 Speaker 1: And that's the moment the alien hypothesis really took hold. 173 00:08:00,000 --> 00:08:03,720 Speaker 2: It is, if it's being propelled but not by normal 174 00:08:03,800 --> 00:08:07,519 common activity, then maybe the propulsion is deliberate. 175 00:08:07,560 --> 00:08:09,560 Speaker 1: The solar sale idea, the solar. 176 00:08:09,279 --> 00:08:12,399 Speaker 2: Sale or light sale, was the most dramatic theory put forward. 177 00:08:13,079 --> 00:08:16,120 The idea was that maybe Umamura was a piece of 178 00:08:16,160 --> 00:08:20,079 alien technology, a probe or a scoutship, or maybe just 179 00:08:20,079 --> 00:08:23,639 some space junk using the pressure from sunlight itself to accelerate. 180 00:08:23,920 --> 00:08:26,120 Speaker 1: And we should be clear that's not just science fiction. 181 00:08:26,360 --> 00:08:30,959 Solar sale technology is real. Humans have successfully launched spacecraft 182 00:08:30,959 --> 00:08:31,519 that use it. 183 00:08:31,759 --> 00:08:35,480 Speaker 2: Oh. Absolutely, the physics is sound. It was a plausible, 184 00:08:35,639 --> 00:08:38,399 if exotic explanation for what we were seeing. It was 185 00:08:38,480 --> 00:08:39,720 incredibly tantalized. 186 00:08:39,960 --> 00:08:41,840 Speaker 1: But it wasn't the consensus, was it. 187 00:08:42,080 --> 00:08:45,399 Speaker 2: No. After years of debate in analyzing the data, the 188 00:08:45,440 --> 00:08:48,399 majority of the scientific community landed on a different explanation, 189 00:08:48,759 --> 00:08:52,000 one that's still strange but natural. The conclusion was that 190 00:08:52,519 --> 00:08:55,360 probably was a comment after all, just a very very 191 00:08:55,399 --> 00:08:55,799 weird one. 192 00:08:55,840 --> 00:08:57,759 Speaker 1: Okay, But how do they explain the missing tail. If 193 00:08:57,759 --> 00:08:59,879 it's a comment and it's outgassing, where's the gas? 194 00:09:00,080 --> 00:09:03,360 Speaker 2: That's the twist. The leading theory now is hydrogen outcasting 195 00:09:03,480 --> 00:09:08,080 hydrogen ice exactly. The idea is that Umulua formed in 196 00:09:08,120 --> 00:09:10,879 a part of its home system that was so incredibly 197 00:09:10,960 --> 00:09:14,399 cold that hydrogen gas actually froze solid. It became a 198 00:09:14,480 --> 00:09:18,600 hydrogen iceberg. Wow, as a got near our sun, that 199 00:09:18,720 --> 00:09:21,720 solid hydrogen deep inside it would have started to sublimate, 200 00:09:21,759 --> 00:09:25,679 turned directly into gas. That gas would escape and provide 201 00:09:25,720 --> 00:09:26,919 the push the acceleration. 202 00:09:27,039 --> 00:09:28,320 Speaker 1: Well, why couldn't we see it? 203 00:09:28,679 --> 00:09:31,360 Speaker 2: Because hydrogen gas is transparent, It's incredibly light, and it 204 00:09:31,360 --> 00:09:34,840 would dispoose almost instantly. It wouldn't drag dust in heavier 205 00:09:34,840 --> 00:09:37,919 molecules with it to create that visible coma and tail 206 00:09:37,960 --> 00:09:40,759 that you get from water ice or carbon dioxide ice. 207 00:09:40,840 --> 00:09:42,279 Speaker 1: So it had invisible. 208 00:09:41,919 --> 00:09:46,799 Speaker 2: Jets essentially, yes, invisible propulsion. It was a unique chemical 209 00:09:46,840 --> 00:09:50,279 makeup that led to a unique physical behavior. It was 210 00:09:50,360 --> 00:09:53,080 borne in conditions so different from our own solar system 211 00:09:53,279 --> 00:09:55,279 that it broke all our existing rules for what a 212 00:09:55,360 --> 00:09:56,279 comet should look like. 213 00:09:56,399 --> 00:09:58,679 Speaker 1: So the big takeaway from MUA isn't just that these 214 00:09:58,679 --> 00:10:02,120 things exist. It's so that they can be fundamentally chemically 215 00:10:02,120 --> 00:10:04,399 different from anything we know, and that they can carry 216 00:10:04,399 --> 00:10:07,360 these immense velocities, which of course opens up the next 217 00:10:07,360 --> 00:10:11,759 big question. If a small one can do this, what 218 00:10:11,960 --> 00:10:14,519 happens if a really really big one comes along? 219 00:10:14,639 --> 00:10:17,279 Speaker 2: And that brings us directly to the ancient grandfather of 220 00:10:17,320 --> 00:10:19,799 these objects three iet lists atls. 221 00:10:19,879 --> 00:10:23,200 Speaker 1: So this was found much more recently in twenty twenty five, 222 00:10:23,600 --> 00:10:26,360 and it's already been confirmed as the third interstellar object. 223 00:10:26,360 --> 00:10:29,399 Speaker 2: That's right, And if a Wumumoo was like a speedy 224 00:10:29,480 --> 00:10:33,480 little scout three ietlesses, well, it's more like an ancient battleship. 225 00:10:33,480 --> 00:10:37,480 It's moving at similar deadly speeds, but its story is 226 00:10:37,559 --> 00:10:38,919 one of deep, deep time. 227 00:10:39,159 --> 00:10:41,639 Speaker 1: The time scale is what gets me, oohm. Ou might 228 00:10:41,679 --> 00:10:43,879 have been traveling for millions of years, which is already 229 00:10:43,919 --> 00:10:47,759 a long time, but Atlis is on another level, entirely. 230 00:10:47,519 --> 00:10:50,519 Speaker 2: A completely different scale. Yeah. The current thinking is that 231 00:10:50,559 --> 00:10:53,000 three iet Liss is almost certainly older than our entire 232 00:10:53,039 --> 00:10:53,720 solar system. 233 00:10:53,759 --> 00:10:56,759 Speaker 1: Okay, han On, let's really process that our Sun, the Earth, 234 00:10:56,960 --> 00:10:59,360 all the planets, they formed about four and a half 235 00:10:59,440 --> 00:11:01,759 billion years years ago direct and you're saying this thing 236 00:11:01,879 --> 00:11:04,320 was already out there flying through space before any of 237 00:11:04,360 --> 00:11:05,039 that existed. 238 00:11:05,279 --> 00:11:08,519 Speaker 2: That's what the evidence points to. Some estimates put its 239 00:11:08,519 --> 00:11:11,919 age at seven billion years old, maybe even older. And 240 00:11:11,960 --> 00:11:14,519 its origin story is just as fascinating. 241 00:11:14,600 --> 00:11:15,639 Speaker 1: Where did it come from? 242 00:11:16,039 --> 00:11:18,159 Speaker 2: It seems to have originated in what's called the milky 243 00:11:18,200 --> 00:11:22,159 ways thick disc. Now we live in the thin disc, 244 00:11:22,440 --> 00:11:26,159 the familiar flat spiral arms of the galaxy, right. The 245 00:11:26,240 --> 00:11:28,799 thick disc is a much older, more puffed up region 246 00:11:28,799 --> 00:11:32,759 of stars that surrounds the thin disc. It's populated by 247 00:11:32,759 --> 00:11:35,759 primeval stars, stars that formed in a much more violent, 248 00:11:35,840 --> 00:11:38,120 chaotic era of the galaxy's youth. 249 00:11:38,399 --> 00:11:41,440 Speaker 1: So we're talking about a completely different stellar environment, a 250 00:11:41,559 --> 00:11:45,799 time when the galaxy was still I don't know, settling down. 251 00:11:45,720 --> 00:11:50,080 Speaker 2: Yes, and the chemical composition of everything was different. The 252 00:11:50,120 --> 00:11:53,039 building blocks available for making planets and commets were not 253 00:11:53,080 --> 00:11:54,840 the same as the ones in the cloud that formed 254 00:11:54,840 --> 00:11:55,240 our Sun. 255 00:11:55,480 --> 00:11:57,000 Speaker 1: The elements were different. 256 00:11:56,679 --> 00:11:59,440 Speaker 2: The ratios of elements were different. The material in the 257 00:11:59,480 --> 00:12:02,960 thick disc has survived billions of years of cosmic history, 258 00:12:03,240 --> 00:12:06,440 so Atl's isn't just an object. It's a pristine time 259 00:12:06,480 --> 00:12:09,000 capsule from an age before the Earth was even a. 260 00:12:09,000 --> 00:12:12,399 Speaker 1: Speck of dust, and that ancient origin explains the weird 261 00:12:12,480 --> 00:12:14,120 data we got from its composition. 262 00:12:14,519 --> 00:12:17,679 Speaker 2: It does. As it got closer to the Sun, we 263 00:12:17,679 --> 00:12:20,240 were able to analyze the gases it was giving off, 264 00:12:20,679 --> 00:12:23,759 and they were puzzled by what they found, unusually high 265 00:12:23,840 --> 00:12:24,799 levels of nickel and. 266 00:12:24,759 --> 00:12:28,240 Speaker 1: Iron, which isn't typical for our local comets, not at all. 267 00:12:28,320 --> 00:12:31,759 Speaker 2: Our comments are mostly water, ice, dust, silicates. They have 268 00:12:31,840 --> 00:12:35,480 some metals, but not blasting out in these kinds of concentrations. 269 00:12:35,919 --> 00:12:38,240 It suggests a different kind of core, maybe denser, more 270 00:12:38,279 --> 00:12:41,919 metal rich, something forged in the conditions of that ancient 271 00:12:42,000 --> 00:12:42,600 thick disk. 272 00:12:42,840 --> 00:12:47,200 Speaker 1: So it's this ancient metal infused heart wrapped in ice 273 00:12:47,720 --> 00:12:50,840 that's been flying through space for seven billion years. 274 00:12:51,159 --> 00:12:55,159 Speaker 2: That's the picture. And what's interesting is that, unlike Umoa, 275 00:12:55,279 --> 00:12:57,240 it's actually behaving like a proper comet. 276 00:12:57,320 --> 00:12:58,799 Speaker 1: Oh so this one does have a tail. 277 00:12:59,000 --> 00:13:01,519 Speaker 2: It does a big one. The Hubble telescope got some 278 00:13:01,559 --> 00:13:03,759 great images of it in twenty twenty five. It has 279 00:13:03,799 --> 00:13:06,399 the classic coma, the halo of dust and gas, and 280 00:13:06,480 --> 00:13:09,600 the long tail. It's blasting out huge amounts of water 281 00:13:09,639 --> 00:13:12,799 and carbon dioxide ice, just like a textbook comb It should. 282 00:13:12,639 --> 00:13:14,799 Speaker 1: A very very old textbook. 283 00:13:14,360 --> 00:13:16,000 Speaker 2: A very old textbook from a different library. 284 00:13:16,039 --> 00:13:18,879 Speaker 1: Yes, okay, let's talk size, because this is where the 285 00:13:18,919 --> 00:13:21,879 fear factor really kicks in. How big are we talking? 286 00:13:22,200 --> 00:13:24,639 Speaker 2: The estimates are still a bit wide. It's hard to 287 00:13:24,639 --> 00:13:28,320 see the solid nucleus inside that huge bright coma. But 288 00:13:28,440 --> 00:13:30,799 the range we're looking at is a minimum of about 289 00:13:30,840 --> 00:13:33,519 four hundred and forty meters about a quarter of a 290 00:13:33,559 --> 00:13:34,200 mile across. 291 00:13:34,279 --> 00:13:35,519 Speaker 1: Okay, that's already pretty big. 292 00:13:35,679 --> 00:13:38,200 Speaker 2: But the maximum estimate goes all the way up to 293 00:13:38,320 --> 00:13:41,679 five point six kilometers three and a half miles in diameter. 294 00:13:41,840 --> 00:13:45,919 Speaker 1: Whoah, okay, three and a half miles wide. If Umua 295 00:13:46,080 --> 00:13:50,200 was a cosmic cucumber. Atls is a flying mountain. 296 00:13:50,080 --> 00:13:52,039 Speaker 2: At its largest estimate. Yeah, it could be up to 297 00:13:52,080 --> 00:13:55,759 fourteen times bigger than Umua. Yeah, and that size puts 298 00:13:55,799 --> 00:13:59,240 it firmly in the potential planetbuster categories, well over the 299 00:13:59,240 --> 00:14:02,080 threshold for causing a global catastrophe on impact. 300 00:14:02,159 --> 00:14:03,840 Speaker 1: Now, before we go down that rabbit hole, we have 301 00:14:03,879 --> 00:14:06,759 to be absolutely clear this specific object three I at 302 00:14:06,840 --> 00:14:08,519 less it's. 303 00:14:08,320 --> 00:14:10,240 Speaker 2: Not going to hit us, absolutely not. It is one 304 00:14:10,279 --> 00:14:13,080 hundred percent safe. We've tracked its trajectory very carefully. 305 00:14:13,120 --> 00:14:14,639 Speaker 1: We can all breathe a sigh of relief. 306 00:14:14,720 --> 00:14:18,320 Speaker 2: Yes, its closest approach to US is in December twenty 307 00:14:18,399 --> 00:14:21,039 twenty five. But it's going to be about two hundred 308 00:14:21,039 --> 00:14:23,879 and seventy million kilometers away. That's one hundred and seventy 309 00:14:23,879 --> 00:14:25,399 million miles. It's not even close. 310 00:14:25,600 --> 00:14:27,600 Speaker 1: But it is passing through the neighborhood in a pretty 311 00:14:27,639 --> 00:14:28,399 interesting way. 312 00:14:28,559 --> 00:14:31,200 Speaker 2: It is. It's actually going to pass inside the orbit 313 00:14:31,240 --> 00:14:31,720 of Mars. 314 00:14:31,879 --> 00:14:32,200 Speaker 1: Really. 315 00:14:32,399 --> 00:14:34,879 Speaker 2: Yeah, it's going to miss Mars by about twenty eight 316 00:14:34,960 --> 00:14:38,919 million kilometers, which is only eighteen million miles on a 317 00:14:38,960 --> 00:14:42,080 cosmic scale. For an object this big and this fast, 318 00:14:42,279 --> 00:14:44,240 that is an incredibly close shave. 319 00:14:44,639 --> 00:14:46,759 Speaker 1: It's a real reminder that the Solar System is a 320 00:14:46,799 --> 00:14:47,559 shooting gallery. 321 00:14:47,720 --> 00:14:50,480 Speaker 2: And of course it led to the alien hypothesis round two. 322 00:14:50,759 --> 00:14:55,360 Speaker 1: Naturally, if Umumama was a scout ship, then the giant 323 00:14:55,480 --> 00:14:58,440 metal rich Atlas must be the mother ship. 324 00:14:58,919 --> 00:15:01,519 Speaker 2: That was the suggestion for the same group of researchers. Yes, 325 00:15:01,960 --> 00:15:04,279 but again that idea is really on the fringe. The 326 00:15:04,360 --> 00:15:07,360 scientific mainstream is treating this as what it appears to be, 327 00:15:07,759 --> 00:15:12,240 an ancient, massive, and incredibly valuable natural comet. The questions 328 00:15:12,279 --> 00:15:15,840 it raises are about geology and cosmology, not technology. 329 00:15:15,879 --> 00:15:19,320 Speaker 1: But those geological questions, combined with that incredible speed, lead 330 00:15:19,360 --> 00:15:22,759 us right to the big one, the terrifying but necessary 331 00:15:22,759 --> 00:15:23,480 thought experiment. 332 00:15:23,679 --> 00:15:26,120 Speaker 2: What if the geometry had been just a little bit different. 333 00:15:26,399 --> 00:15:28,759 Speaker 1: Okay, so this is where we have to really dig 334 00:15:28,759 --> 00:15:31,919 into the physics of survival. This is hypothetical, but it's 335 00:15:31,960 --> 00:15:36,080 crucial for understanding the stakes of planetary defense. Let's set 336 00:15:36,120 --> 00:15:39,919 the stage. What if that nudge Atlas got seven billion 337 00:15:40,000 --> 00:15:43,120 years ago put it on a slightly different path. What 338 00:15:43,200 --> 00:15:45,440 if Earth was in the crosshairs. 339 00:15:45,639 --> 00:15:48,080 Speaker 2: To understand an impact of this magnitude, we have to 340 00:15:48,120 --> 00:15:51,919 start with our baseline. The most famous impact in Earth's history, 341 00:15:53,000 --> 00:15:54,960 the chixelab asteroid. 342 00:15:54,519 --> 00:15:57,399 Speaker 1: The Dinosaur Killer. Remind us of the specs on that one. 343 00:15:57,519 --> 00:16:01,000 Speaker 2: Chikisel was big, about ten kilometers one so six miles. 344 00:16:01,399 --> 00:16:05,039 It was a carbonaceous asteroid, so mostly rock, minerals and some. 345 00:16:05,000 --> 00:16:06,000 Speaker 1: Metal, and its speed. 346 00:16:06,120 --> 00:16:08,000 Speaker 2: It was coming in at a pretty standard speed for 347 00:16:08,039 --> 00:16:11,200 a Solar system object, about twenty kilometers per. 348 00:16:11,080 --> 00:16:14,440 Speaker 1: Second, and that impact at that size and speed caused 349 00:16:14,480 --> 00:16:18,360 a global extinction, wiped out seventy percent of life, left 350 00:16:18,399 --> 00:16:21,480 a crater over one hundred kilometers wide. That's our baseline. 351 00:16:21,559 --> 00:16:23,600 Speaker 2: That's the baseline. Now let's bring in three ilsts. We'll 352 00:16:23,679 --> 00:16:25,960 use the maximum size estimate of five point six. 353 00:16:25,879 --> 00:16:28,799 Speaker 1: Kilometers, so it's about half the diameter of the Dinosaur Killer. 354 00:16:28,840 --> 00:16:32,519 Speaker 2: Roughly half the diameter and probably less dense, less massive 355 00:16:32,960 --> 00:16:35,679 because it has all that ice compared to Chickalob's solid rock. 356 00:16:35,799 --> 00:16:37,519 So if you only looked at size and mass, you 357 00:16:37,600 --> 00:16:39,279 might think, okay, less destructive. 358 00:16:39,840 --> 00:16:42,759 Speaker 1: But there's the velocity problem. That's the game changer. 359 00:16:42,919 --> 00:16:46,600 Speaker 2: That's the entire game. Chick Salobe hit at twenty kilometers 360 00:16:46,639 --> 00:16:49,360 per second three ia to ls is moving at a 361 00:16:49,399 --> 00:16:51,919 minimum of sixty one kilometers. 362 00:16:51,440 --> 00:16:53,799 Speaker 1: Per second more than three times faster. 363 00:16:53,639 --> 00:16:56,039 Speaker 2: Three times faster. And this is where the math gets 364 00:16:56,039 --> 00:16:58,879 absolutely brutal. The physics is exponential. 365 00:16:59,000 --> 00:17:01,240 Speaker 1: Explain that for us. Why I speed so much more 366 00:17:01,240 --> 00:17:02,559 important than size. 367 00:17:02,240 --> 00:17:05,000 Speaker 2: Here it all comes down to the formula for kinetic energy, 368 00:17:05,119 --> 00:17:08,279 the energy of motion. It's one half mass times velocity 369 00:17:08,319 --> 00:17:10,759 squared k E equals twelve Miliva is. 370 00:17:10,720 --> 00:17:12,559 Speaker 1: Squared, the velocity is squared. 371 00:17:12,400 --> 00:17:14,720 Speaker 2: The velocity is square. That's the killer. So if you 372 00:17:14,759 --> 00:17:17,480 double the velocity, you quadruple the energy. If you triple 373 00:17:17,519 --> 00:17:20,559 the velocity like we have here, you increase the kinetic 374 00:17:20,640 --> 00:17:22,079 energy by a factor of nine. 375 00:17:22,160 --> 00:17:25,519 Speaker 1: So even though ATLS has less mass, every bit of 376 00:17:25,519 --> 00:17:27,960 that mass hits with nine times the energy because of 377 00:17:28,000 --> 00:17:28,440 the speed. 378 00:17:28,799 --> 00:17:32,640 Speaker 2: Exactly when you run all the numbers, accounting for the 379 00:17:32,640 --> 00:17:36,759 different densities and everything, the conclusion is just staggering. If 380 00:17:36,799 --> 00:17:39,599 three I addols were to hit Earth, it would impact 381 00:17:39,599 --> 00:17:42,680 with four and a half times the total energy of 382 00:17:42,720 --> 00:17:43,640 the chick slab. 383 00:17:43,480 --> 00:17:45,279 Speaker 1: Impact four and a half times. 384 00:17:45,519 --> 00:17:48,359 Speaker 2: This isn't just another mass extinction event. This is a 385 00:17:48,359 --> 00:17:52,480 planetary sterilization event. Yeah, hashtag tag tag the immediate cataclysm 386 00:17:52,720 --> 00:17:53,440 in under second. 387 00:17:53,519 --> 00:17:56,440 Speaker 1: Okay, four and a half times the energy that killed 388 00:17:56,440 --> 00:18:00,200 the dinosaurs. It's almost impossible to picture. Let's try us 389 00:18:00,240 --> 00:18:02,480 through the first few seconds of an impact like that. 390 00:18:02,559 --> 00:18:05,319 Speaker 2: At sixty one kilometers per second, it moves through our 391 00:18:05,480 --> 00:18:08,880 entire atmosphere from space to the ground in just over 392 00:18:08,960 --> 00:18:09,720 one second. 393 00:18:09,680 --> 00:18:11,359 Speaker 1: So there's no time for it to burn up or 394 00:18:11,400 --> 00:18:11,920 slow down. 395 00:18:11,920 --> 00:18:14,240 Speaker 2: The atmosphere might as well not be there. It hits 396 00:18:14,240 --> 00:18:17,279 the crust with such force that the impact site doesn't shatter, 397 00:18:17,400 --> 00:18:20,200 it vaporizes the comet and a huge chunk of the 398 00:18:20,240 --> 00:18:23,880 Earth's crust are instantly converted into a superheated plasma. 399 00:18:24,039 --> 00:18:25,839 Speaker 1: So it's not making a crater so much as it's 400 00:18:25,880 --> 00:18:28,319 creating a temporary star on the surface of the Earth. 401 00:18:28,440 --> 00:18:30,599 Speaker 2: That's a good way to put it. That plasma core 402 00:18:30,640 --> 00:18:34,559 would incinerate everything for hundreds of miles around, but the 403 00:18:34,599 --> 00:18:37,759 destruction spreads much faster than that through the shockwave. 404 00:18:38,119 --> 00:18:40,839 Speaker 1: A shockwave from an impact of that energy. 405 00:18:40,599 --> 00:18:43,359 Speaker 2: It would propagate across the continent, across the globe. The 406 00:18:43,359 --> 00:18:46,519 air itself becomes a weapon. The compression wave would generate 407 00:18:46,599 --> 00:18:49,000 winds of over one thousand kilometers per hour. 408 00:18:49,279 --> 00:18:53,200 Speaker 1: That's what six hundred miles an hour that's not wind, 409 00:18:53,279 --> 00:18:54,480 that's a solid. 410 00:18:54,160 --> 00:18:56,480 Speaker 2: Wall of force it is. It's a blast wave that 411 00:18:56,519 --> 00:19:01,400 would scour the landscape clean. It would flatten cities, vaporized forests, 412 00:19:01,640 --> 00:19:02,480 level mountains. 413 00:19:02,680 --> 00:19:05,640 Speaker 1: I remember feeling a minor earthquake once, just a little trimmer, 414 00:19:05,680 --> 00:19:08,920 and the terrifying thing was the ground itself feeling unreliable. 415 00:19:09,359 --> 00:19:12,119 Speaker 2: This would trigger earthquakes globally that would register it beyond 416 00:19:12,200 --> 00:19:15,400 anything the Richter scale was designed to measure. It would 417 00:19:15,400 --> 00:19:17,839 cause volcanoes to erupt on the other side of the planet. 418 00:19:17,880 --> 00:19:21,279 And if it hit the ocean, mile high tsunamis not 419 00:19:21,400 --> 00:19:23,480 waves that crash on the coast, but waves that would 420 00:19:23,519 --> 00:19:27,160 wash hundreds of kilometers inland, just erasing everything. But the 421 00:19:27,200 --> 00:19:30,880 fire is maybe the worst part. The impact would throw 422 00:19:31,000 --> 00:19:35,319 trillions of tons of molten rock ejecta back up into 423 00:19:35,319 --> 00:19:39,480 the atmophere on ballistic trajectories. These glowing hot beads of 424 00:19:39,559 --> 00:19:41,759 glass would rain down all over the planet. 425 00:19:41,839 --> 00:19:43,720 Speaker 1: So it's not just the impact site that burns. 426 00:19:43,799 --> 00:19:45,920 Speaker 2: The entire sky would heat up to the temperature of 427 00:19:45,960 --> 00:19:48,880 pizza oven. It'd be hot enough to ignite every forest, 428 00:19:49,039 --> 00:19:52,599 every blade of grass on the entire planet. A global firestorm. 429 00:19:52,720 --> 00:19:56,079 Speaker 1: So within the first hour, maybe the first day. You're 430 00:19:56,119 --> 00:20:00,759 dealing with a plasma blast, hypersonic shockwave, global earthquakes, megasunamis, 431 00:20:00,799 --> 00:20:02,119 in a planetary firestorm. 432 00:20:02,200 --> 00:20:04,880 Speaker 2: The chances of survival for any complex life on the 433 00:20:04,920 --> 00:20:08,400 surface are effectively zero. But that's just the opening act. 434 00:20:08,480 --> 00:20:10,920 The immediate cataclysm is what gives way to the real 435 00:20:11,200 --> 00:20:14,759 long term planet killer effects hashtag tag do long term 436 00:20:14,839 --> 00:20:17,880 global killer. So once the initial chaos of the impact 437 00:20:17,880 --> 00:20:21,319 subsides phase two begins, all that material that was blasted 438 00:20:21,359 --> 00:20:23,880 into the sky, the vaporized comet, the dirt, the soot 439 00:20:23,880 --> 00:20:26,119 from the fires, it doesn't just disappear. 440 00:20:26,200 --> 00:20:29,319 Speaker 1: It stays up there, creating a shroud around the entire planet. 441 00:20:29,000 --> 00:20:31,680 Speaker 2: A thick global shroud, and that leads directly to an 442 00:20:31,680 --> 00:20:35,319 impact winter, or more accurately, a nuclear winter. 443 00:20:35,400 --> 00:20:36,839 Speaker 1: A supercharged version of it. 444 00:20:36,960 --> 00:20:40,240 Speaker 2: Exactly. This cloud of dust and aerosols would be so 445 00:20:40,400 --> 00:20:43,160 thick it would block out the sun, not just dim it, 446 00:20:43,400 --> 00:20:45,880 but block it out completely. The sky would go. 447 00:20:45,920 --> 00:20:48,559 Speaker 1: Dark and temperatures would plummet, plunge. 448 00:20:49,240 --> 00:20:51,599 Speaker 2: The surface of the Earth would drop to freezing and 449 00:20:51,680 --> 00:20:56,359 stay there for years, possibly for decades, a deep, relentless 450 00:20:56,400 --> 00:20:57,160 global winter. 451 00:20:57,319 --> 00:20:58,920 Speaker 1: And if there's no sunlight. 452 00:20:59,000 --> 00:21:03,880 Speaker 2: Photosynthesis stole ops instantly, the entire foundation of the global 453 00:21:03,880 --> 00:21:06,400 food chain is cut off at the knees. Plants dye 454 00:21:06,839 --> 00:21:09,079 clanked in and the oceans dye, and then everything that 455 00:21:09,160 --> 00:21:13,720 eats them dies. Widespread global starvation is the primary killer 456 00:21:13,759 --> 00:21:15,200 in the post impact world. 457 00:21:14,920 --> 00:21:16,680 Speaker 1: And the atmosphere itself becomes toxic. 458 00:21:16,799 --> 00:21:19,839 Speaker 2: It does as all that debris starts to slowly rain 459 00:21:19,920 --> 00:21:22,799 back down and chemically alters the air. The impact creates 460 00:21:22,920 --> 00:21:25,440 huge amounts of nitrogen and sulfur oxides. 461 00:21:25,039 --> 00:21:27,359 Speaker 1: Which means acid rain, extreme. 462 00:21:26,960 --> 00:21:30,240 Speaker 2: Acid rain, strong enough to poison the oceans and sterilize 463 00:21:30,240 --> 00:21:33,000 any soil that wasn't already burned or frozen. And there's more. 464 00:21:33,599 --> 00:21:36,519 The energy of the impact would blast away the ozone layer, 465 00:21:36,799 --> 00:21:39,039 so when the sun finally did come back, the surface 466 00:21:39,039 --> 00:21:41,119 would be bathed in lethal uv radiation. 467 00:21:41,359 --> 00:21:43,079 Speaker 1: And the colmet itself was full. 468 00:21:42,880 --> 00:21:46,440 Speaker 2: Of metals, right, All that nickel and iron from ATLA 469 00:21:46,519 --> 00:21:50,519 would rain down to leading to widespread toxic metal poisoning 470 00:21:50,599 --> 00:21:53,839 of whatever water was left. It's just it's a multi 471 00:21:53,920 --> 00:21:57,079 pronged attack on the entire biosphere. You freeze it, you 472 00:21:57,119 --> 00:21:59,400 starve it, you poison it, and then you radiate it 473 00:21:59,480 --> 00:22:03,680 hashtag tag tag the climate paradox, deep freeze, discorging recovery. 474 00:22:04,240 --> 00:22:07,319 But there's one final awful twist in this story, a 475 00:22:07,319 --> 00:22:10,279 climate paradox that's specific to an impact from a comet 476 00:22:10,319 --> 00:22:11,400 like three iatl Ice. 477 00:22:11,680 --> 00:22:14,160 Speaker 1: Okay, so we have the ste freeze that last for years, 478 00:22:14,200 --> 00:22:17,200 maybe decades, caused by the dust cloud. But eventually that 479 00:22:17,279 --> 00:22:18,839 dust has to settle, right it does. 480 00:22:19,079 --> 00:22:21,599 Speaker 2: The dust and sub particles are heavy. They're what reflects 481 00:22:21,599 --> 00:22:24,440 the sunlight and causes the cooling. But over time gravity 482 00:22:24,480 --> 00:22:26,920 winds and they rain out of the atmosphere. The sky 483 00:22:26,960 --> 00:22:28,160 would slowly start to clear. 484 00:22:28,359 --> 00:22:30,839 Speaker 1: But something else was put up there that doesn't settle. 485 00:22:30,559 --> 00:22:34,279 Speaker 2: Out precisely, the comet itself. Remember three Iatla is largely 486 00:22:34,279 --> 00:22:35,920 made of carbon dioxide. 487 00:22:35,400 --> 00:22:38,279 Speaker 1: Ice, a giant block of frozen text tootda. 488 00:22:38,079 --> 00:22:40,799 Speaker 2: Which was completely vaporized in the impact. All of that 489 00:22:40,839 --> 00:22:43,640 carbon dioxide. It was released directly into the atmosphere as 490 00:22:43,640 --> 00:22:47,319 a gas, and unlike dust, text toodp gas can stay 491 00:22:47,319 --> 00:22:49,240 in the atmosphere for centuries. 492 00:22:48,920 --> 00:22:51,400 Speaker 1: And it's a greenhouse gas, a very potent. 493 00:22:51,119 --> 00:22:53,160 Speaker 2: One one of the most potent. So as the dust 494 00:22:53,160 --> 00:22:55,599 clears and the sunlight starts to get through again. You 495 00:22:55,680 --> 00:22:58,480 now have an atmosphere that's supercharged with tixto ten to two. 496 00:22:58,960 --> 00:23:01,720 It acts like a thick thermal blanket trapping the Sun's heat. 497 00:23:01,759 --> 00:23:04,480 Speaker 1: So the planet goes from one extreme to the other violently. 498 00:23:04,640 --> 00:23:07,279 Speaker 2: You go from a deep freeze, a nuclear winter that 499 00:23:07,359 --> 00:23:10,240 kills almost everything, and then as the planet tries to recover, 500 00:23:10,640 --> 00:23:13,599 it swings into a period of extreme runaway global warming. 501 00:23:13,680 --> 00:23:15,559 Speaker 1: First you freeze, then you bake. 502 00:23:15,839 --> 00:23:20,079 Speaker 2: First a deep freeze followed by a long, scorching recovery. 503 00:23:20,160 --> 00:23:22,279 It's a one to two punch that makes the planet 504 00:23:22,319 --> 00:23:26,440 completely uninhabitable for an incredibly long time. And it shows 505 00:23:26,440 --> 00:23:31,000 that this class of object, these high velocity interstellar visitors, 506 00:23:31,359 --> 00:23:33,279 they're a unique and terrifying. 507 00:23:32,880 --> 00:23:34,880 Speaker 1: Kind of threat where the speed is so much more 508 00:23:34,920 --> 00:23:36,079 important than the size. 509 00:23:36,160 --> 00:23:39,039 Speaker 2: It forces us to realize that planetary defense isn't just 510 00:23:39,079 --> 00:23:41,440 about looking for big rocks in our own backyard. It's 511 00:23:41,480 --> 00:23:44,480 about looking for these ancient messengers coming in hot from 512 00:23:44,519 --> 00:23:48,039 the depths of the galaxy hashtag tag outro So. 513 00:23:48,160 --> 00:23:53,079 Speaker 1: We circle back to the good news, the slightly boring 514 00:23:53,240 --> 00:23:57,039 but incredibly comforting reality three i E. Less is not 515 00:23:57,079 --> 00:23:58,160 going to hit us it's. 516 00:23:58,039 --> 00:24:01,640 Speaker 2: Flying safely past. The math is solid. We're fine, and. 517 00:24:01,519 --> 00:24:04,200 Speaker 1: That safety is what lets us change your perspective to 518 00:24:04,240 --> 00:24:06,599 stop looking at it as a doomsday machine and start 519 00:24:06,599 --> 00:24:07,759 looking at it as what it. 520 00:24:07,680 --> 00:24:11,799 Speaker 2: Really is, a priceless opportunity, a piece of primordial history, 521 00:24:12,160 --> 00:24:13,839 just swinging by for a brief. 522 00:24:13,680 --> 00:24:16,720 Speaker 1: Visit, a visit that's been maddeningly difficult for astronomers to 523 00:24:16,759 --> 00:24:17,440 get a good look at. 524 00:24:17,519 --> 00:24:20,640 Speaker 2: That's the irony, isn't it. This incredible object is here, 525 00:24:21,000 --> 00:24:23,279 but because of its trajectory and where it is in 526 00:24:23,319 --> 00:24:26,880 the sky relative to the Sun, getting a clear, detailed 527 00:24:26,880 --> 00:24:29,559 look at it with our telescopes is incredibly challenging. 528 00:24:29,680 --> 00:24:32,039 Speaker 1: It's like a cosmic treasure chest is floating by, but 529 00:24:32,319 --> 00:24:34,160 the keyhole is facing the wrong way. 530 00:24:34,359 --> 00:24:37,319 Speaker 2: But it's moving so fast. We only get this one 531 00:24:37,519 --> 00:24:40,279 fleeting glimpse before it disappears back into the void forever. 532 00:24:40,559 --> 00:24:42,279 We can't send a probe to it, we can't catch 533 00:24:42,359 --> 00:24:44,759 up to it. We just get this one snapshot of 534 00:24:44,799 --> 00:24:46,759 a seven billion year old traveler. 535 00:24:46,799 --> 00:24:49,799 Speaker 1: But even that snapshot is so valuable immensely. 536 00:24:50,200 --> 00:24:53,039 Speaker 2: It's a physical sample of the early universe. It's a 537 00:24:53,079 --> 00:24:56,200 time capsule from before our sun even lit up, carrying 538 00:24:56,240 --> 00:24:59,200 the raw materials from the Milky Way's thick disk that 539 00:24:59,279 --> 00:25:02,759 high nickel and i iron content. It challenges our models 540 00:25:02,799 --> 00:25:05,039 of how the building blocks of galaxies come together. 541 00:25:05,519 --> 00:25:07,799 Speaker 1: So this knowledge, this is how we learned about the 542 00:25:07,799 --> 00:25:11,799 galaxy's violent, ancient past. These objects are the. 543 00:25:11,799 --> 00:25:14,720 Speaker 2: Proof they are. They remind us that the Solar System 544 00:25:14,799 --> 00:25:17,480 isn't some isolated island. We are part of a vast, 545 00:25:17,559 --> 00:25:21,440 interconnected galaxy, and matter and energy from deep time and 546 00:25:21,519 --> 00:25:24,680 deep space are constantly flowing through our neighborhood. 547 00:25:24,759 --> 00:25:27,880 Speaker 1: Their proof of a kind of galactic connectivity, bringing the 548 00:25:27,960 --> 00:25:30,759 history of the whole Milky Way right to our front door. 549 00:25:30,680 --> 00:25:32,119 Speaker 2: Condensed into a single object. 550 00:25:32,119 --> 00:25:35,640 Speaker 1: Here and that thought of history being carried on an 551 00:25:35,640 --> 00:25:39,119 object moving at these unbelievable speeds, that gives me a 552 00:25:39,119 --> 00:25:41,759 final idea to chew on. We've just spent all this 553 00:25:41,839 --> 00:25:43,960 time talking at an object that carries the secrets of 554 00:25:44,000 --> 00:25:47,759 the galaxies primordial past seven billion years ago, tells us 555 00:25:47,799 --> 00:25:48,160 where we. 556 00:25:48,119 --> 00:25:50,480 Speaker 2: Came from, Right, It's a message from the beginning. 557 00:25:50,720 --> 00:25:54,359 Speaker 1: But if these hypervelocity objects are like cosmic time travelers, 558 00:25:55,200 --> 00:25:56,640 what about the other direction? 559 00:25:57,079 --> 00:25:57,599 Speaker 2: What do you mean? 560 00:25:57,960 --> 00:26:01,759 Speaker 1: Well, if this visitor carries in information about the galaxy's formation. 561 00:26:02,880 --> 00:26:05,759 What kind of secrets would a theoretical object from the 562 00:26:05,839 --> 00:26:09,640 end of the universe carry? Wow, Imagine something launched somehow 563 00:26:09,680 --> 00:26:12,720 from the ultimate heat death of the Cosmos five billion 564 00:26:12,799 --> 00:26:15,599 years in our future. If that object traveled back through 565 00:26:15,640 --> 00:26:17,920 time and space to us, what would it tell us 566 00:26:17,920 --> 00:26:21,359 about the fate of all matter, the final collapse of stars, 567 00:26:21,680 --> 00:26:23,079 our ultimate future, the. 568 00:26:23,039 --> 00:26:25,680 Speaker 2: Beginning and the end of the universe, both traveling at 569 00:26:25,720 --> 00:26:27,240 eighty seven kilometers per second. 570 00:26:27,359 --> 00:26:30,400 Speaker 1: Now that's the real mystery. These discoveries unlock something to 571 00:26:30,400 --> 00:26:32,039 think about until our next deep dive.