Have interstellar meteors hit the Earth?

00:00:08
Speaker 1: Hey, Kelly, do you have strong feelings about invasive species?

00:00:12
Speaker 2: Yeah?

00:00:13
Speaker 3: I mean, on the one hand, it's usually our fault. But I do think that in general, ecologists get a bit unnerved when you mess with a local ecosystem.

00:00:21
Speaker 1: But shouldn't you have some sort of like respect for these invaders. I mean, they just like came in and they were better suited to survival, right.

00:00:28
Speaker 3: I mean, I guess so, but in a lot of cases, like the new environment doesn't have their usual parasites or predators, so they have like an unfair advantage at least initially. But like, also, would you feel that way if advanced aliens came and started killing us, Like, would it be okay because they can? Would you have grudging respect?

00:00:51
Speaker 1: I actually would have grudging respect, And I hope that you know, they would share the physics behind their laser beams and immolation devices and all that stuff, and it might be worth it.

00:01:01
Speaker 3: Okay, wait, hold on, remember both my kids, who I know you're always trying to kill and your kids are included on the list of being fried by aliens in the scenario.

00:01:13
Speaker 1: I know, but I still learned the secrets of the universe, so I already factor that in. I'm still pro invasion.

00:01:20
Speaker 3: All right, that's the first shuttle that goes to Mars. I'm putting your name on the manifest I don't want you on the same planet as my.

00:01:28
Speaker 1: Kids, no way, fair point. Hi. I'm Daniel. I'm a particle physicist and a professor at UC Irvine, and I'm happy to be negotiating on behalf of Earth when the aliens arrived.

00:01:57
Speaker 3: I'm Kelly Waiiner Smith, adjunct at Race University, and I hope that Daniel is far away from Earth when the aliens arrive. He might trade our children for some tiny little physics secret.

00:02:10
Speaker 1: Look, it's all going to be on the table, right You never know what the aliens are gonna want. Maybe they just want to like scoop up some algae and slurp it. But maybe they want to fry our children.

00:02:20
Speaker 3: You keep my children off the table. They can have the algae, although I can imagine there being some bad downstream effects. My phycology friends would not be happy. But definitely you're not giving them my kids.

00:02:32
Speaker 1: Oh you're so parochial. You're on the wrong side of history here, Kelly.

00:02:36
Speaker 3: I'm alright with that.

00:02:40
Speaker 1: Well, welcome to the podcast Daniel and Jorge explain the universe, where we do our best not to fry our children and sacrifice them to invading aliens, but to understand the universe anyway. Somehow, with all the photons and the particles and the little bits of rock that arrive here on Earth, we've managed to piece together and understanding of how the universe works. Out there, what's out there? What the tiny little quantum particles are, the super massive black holes that shape our galaxies. All that is sending us clues, and we're trying to digest them and explain them to you.

00:03:11
Speaker 3: And that's why we don't need the aliens and their information.

00:03:17
Speaker 1: But Kelly, we've been doing it for thousands of years, and there's still so much we have left to figure out. Wouldn't you like to fast forward to a super advanced understanding.

00:03:25
Speaker 3: Not if I'm trading my kids for it?

00:03:29
Speaker 1: All right, everybody, you heard it. If we are living in ignorance, it's because of Kelly's selfishness.

00:03:33
Speaker 3: Wait wait, I'll trade Daniel's kids for it, so problem, So.

00:03:38
Speaker 1: Okay, see the negotiation begins. All right, We're starting to thaw that cold position of yours. But nobody wants anybody's kids to fry, absolutely, But we do want to understand the universe, and frustratingly, we are mostly limited to figuring it out based on the clues that arrive here on Earth, photons that have traveled for billions of light years across the universe, little bits of protons and electrons and all sorts of cosmic rape particles. We are working hard to piece that together to get a picture of everything that's out there in the universe.

00:04:12
Speaker 3: And we'll get there without the aliens.

00:04:15
Speaker 1: And while the photons that arrive here on Earth do travel almost all the way across the universe, I mean we see things from very very early in the universe, we are limited when it comes to the stuff that arrives here, the actual chunks of stuff that we can use to study things that happen on other planets. We found little bits of Mars on Earth. We sometimes get rocks from elsewhere in the Solar System. But the universe is vast, and we would love to have a sample of bits from other places. Wouldn't you like to have a scoop of a distant star or a sample from an atmosphere of an exole planet.

00:04:49
Speaker 3: Yeah. Note that would be pretty awesome.

00:04:51
Speaker 1: Who knows what we could find. Is our solar system the same as all those other solar systems? Is it totally different? What can be found in the hearts of distant stars under the surface of distant exo moons. We don't know, and we'd love to find out. And we know that the universe is always holding surprises for us.

00:05:08
Speaker 3: Oh, I want to start asking you questions about what we might expect, how we might expect those things to be different than what we found on Earth. But I'm probably jumping the.

00:05:14
Speaker 1: Gun you are a little bit. But today on the podcast, we're going to be exploring that question, whether it's possible to sample planets around other stars, whether we can just sit here on our own little rock and wait for those bits to come to us. So today on the podcast, we'll be answering the question, have interstellar meteors hit the Earth?

00:05:41
Speaker 3: Oh, there's nothing better when the data comes to you.

00:05:45
Speaker 1: We would you love to just sit at home and have all the parasites like walk through your kitchen and report for duty.

00:05:53
Speaker 3: Ah, you know what, I actually have mixed feelings about that. It depends on the parasites.

00:06:01
Speaker 1: So your kids do live in that same kitchen and eat breakfast there, so probably you want to keep a sharp line between those.

00:06:07
Speaker 3: Things, all right, Right, it's great when physics data comes to us, but the parasitology data I'll go collect.

00:06:14
Speaker 1: And we have done a little bit of exploring, you know, we've been to the Moon, and we've sent probes to Mars and to orbit other places in the Solar System, but really the amount of stuff that we have to study that comes from off of Earth is vanishingly small, like a few pounds of Mars rocks, a little bit of an asteroid that we managed to collect, and most of the stuff that isn't from Earth that we can study came to us automatically. We didn't send a robot together. We just waited for rocks to hit the Earth and gather them.

00:06:45
Speaker 3: Is it possible that there's just like loads of rocks from our Solar System that are still on Earth, But we just look at them and we're like, that's a rock. And my friend Callon would say all rocks are interesting, but he's a geologist. I'm not quite sure he's right about that. But do we probably have tons more data, but we just don't recognize it. As being different than the Earth rocks.

00:07:08
Speaker 1: Oh, absolutely, Meteors are hitting the Earth all the time, and they have four billions of years and so these things are scattered all around the surface of the Earth and even buried within it. I recently read a study that showed that they see traces of the proto planet that hit the Earth and led to the formation of the Moon. They call it fear. It's probably happened four billion years ago. They can see bits of it lodged in our mantle, like they can identify underground which bits came from that proto planet and how it created this weird distortion in the shape of our mantle.

00:07:41
Speaker 3: Oh my god.

00:07:42
Speaker 1: So everything on the surface of the Earth and underneath reveals its history, its history of bombardment. So yeah, there's probably stuff all over the surface of the Earth for people to just pick up and learn about our solar system.

00:07:53
Speaker 3: So when my kids come home with like pockets full of rocks, I shouldn't throw them out the window when they're not looking, because they might be more valuable than I realize.

00:08:02
Speaker 1: They absolutely might be. But I agree with your geologist friend. Every rock is interesting because every rock tells a story. It was formed at a certain moment, and then it was weathered, it was oxidized, it captures stuff within it. Each of them really tells us something about the billion years long journey that they've survived. They're like a little time capsule.

00:08:22
Speaker 3: Yeah, I know you're right.

00:08:24
Speaker 1: But the most interesting ones are not the ones in your kid's pocket, which probably come from Earth, and also not the ones that even come from our solar system. While little bits of Mars are fascinating, we would love to explore much deeper out into the universe and see things from other planets, remnants from other solar systems. And that's why today we're asking the question about interstellar meteors. So before we dig into what, I wanted to know what people out there thought about the question of whether interstellar metiors have hit the Earth. So thank you very much to everybody who participates in this audience play along segment of the podcast. If you'd like to join for future episodes, don't be shy. Write to me you questions at Daniel and Jorge dot com. So think about it for a minute. Do you think interstellar meteors have hit the Earth? Here's what people had to say.

00:09:14
Speaker 4: Well, it's been around for an extremely long time, so you would think that sooner or later some interstellar meteors would have hit the Earth. So I'm just gonna go with a guess that, yes, interstellar meteors have hit the Earth.

00:09:32
Speaker 1: I suspect they have, but it would be surely very rare.

00:09:39
Speaker 5: I would side probably, but none that we know.

00:09:42
Speaker 2: Of interstellar videos would have to be very lucky to even head out galaxy. And even if they made it to a galaxy, they would have to be very lucky to make it through all the other stars and planets and the gravitation gravity that they have to actually if but I feel like there's a chance that maybe one or two has made it through. So I'm going to say yes.

00:10:10
Speaker 5: I'm gonna say no because I imagine coming into our Solar system I would probably be caught up in the gravitational pull of a different planet or become an orbit in one of the asteroid belts.

00:10:29
Speaker 1: Maybe what do you think of these answers?

00:10:31
Speaker 3: Kelly, Well, so for starters, I had never heard O how do you say that? Okay, So for starters, I had never heard of. Oh muamua and that is an incredible name. I love it. It's so much fun to say it's beautiful. Uh, and no, I thought these were all good responses. I mean, but you know, so like we've only been watching the skies for you know, a small fraction of humanity's existence. How how do we know, Like, you know, if you find a rock in your backyard and you're like, well, maybe this is from Mars, how could you be sure that it was an interstellar Like how do you know that it wouldn't look the same because everything's made out of the same stuff.

00:11:12
Speaker 1: Yeah, it's a great question, and we don't know for sure. Right, we know something about the formation of our solar system, and so we know what rocks on Earth look like. And we can tell if a rock was from Mars because it has a different chunk of stuff, Like Mars is made of different elements and different ratios of those elements and different isotopes because of where it was formed and how it was formed and its history. So we can tell when our rock is from Mars rather than from Earth. But what we don't know is if solar systems out there have Earth like planets and Mars like planets with the same elements, whether you could tell the difference between a rock from Earth and a rock from some exo Earth, or if they're very very different, and our Solar System is unique in some way, so that planets formed around other stars could be very different from the planets that formed around our star. That's sort of the basic question.

00:12:04
Speaker 3: Okay, so it seems like you are sort of starting to already tell me why we would want interstellar your meteors in the first place, not just because you like rock so much, but these rocks in particular could tell us something cool.

00:12:17
Speaker 1: Exactly we want interstellar meteors for the same reason we want to study meteors. Meteors give us a sample of the rest of the Solar System. How exactly did the asteroid belt form? What is Pluto made out of and where does that tell us about the formation of the Solar System? What is really at the core of Jupiter? Where did Jupiter form in the inner Solar System or in the outer Solar System? Samples from these planets can give us clues about the story of the formation of our Solar System and the dance of the planets made as the whole thing was evolving. And in the same way, samples from planets around other Solar systems would tell us about how those formed and give us the context for the formation of our own solar system. That's sort of the most specific answer, that most general answer for like why you would want to see in interstellar meteors is just curiosity, Like who knows what's in it. We've been thinking about the universe and exploring it with photons, But every time we've developed a new capability, every time we've figured out a way to probe the universe and a way we haven't before, it's always revealed something surprising, sometimes mind blowing, sometimes in a way that really up ends our entire understanding of the universe and the context of our lives. So if we got an interstellar media and it could study it, it could reveal something totally crazy, things beyond what even science fiction authors could imagine.

00:13:34
Speaker 3: Okay, so you've convinced me that this is interesting, and I've been convinced that ooh muamoa see how do you say it? Oh muama, oh muhamoa is also fascinating. Tell me tell me more about that.

00:13:49
Speaker 1: Right, So, we know that some interstellar objects have come through our solar system, but we've only ever seen two of them, Like, there's thousands and thousands of asteroids out there and things hit the Earth all the time, but only twice have we identified things that we are sure didn't come from within our Solar system. And the first, the most famous one. But what I'm kind of embarrassed for you, Kelly, that you never heard of as a as a deputized physics nerd is O Muamula, which came through the Solar system in twenty seventeen.

00:14:18
Speaker 3: I'm a deputized physics nerd.

00:14:20
Speaker 1: Yes, congratulations, thank you.

00:14:23
Speaker 3: Oh I'm sorry I've let you down. This is a real emotional rollercoaster for me. But tell me more.

00:14:29
Speaker 1: No, you officially have a PhD in podcast physics from Daniel and Jorge University.

00:14:34
Speaker 3: Fantastic, I'm putting it on my TV.

00:14:38
Speaker 1: But in twenty seventeen, the pan Star's telescope noticed this rock and it was moving really fast twenty six kilometers per second. But most importantly, it had a non solar trajectory, meaning it was moving along a path, a direction, a location of velocity which would not allow it to orbit the Sun. Meant that had come in from outside the Solar System was going to bend around the Sun and then shoot again out of the Solar system.

00:15:05
Speaker 3: Was there some giant smashing happening in a different solar system and this thing got shot out of their solar system super fast?

00:15:13
Speaker 1: It's a great question. There's lots of question marks about this object. We saw it sort of on its way out of the Solar system. It sort of passed near the Sun, and by the time we spotted it, it was already headed out. It was moving really really fast. So we have really limited data about it. We don't know a lot about its shape, we don't know a lot about its reflectivity. The best speculation is that it's a chunk of ice, probably lost by some other star. You know, most stars have not just planets, but like big chunks of frozen ice balls and a halo around the star, like we have the Ort cloud, which is a source of long period comets. These things are little chunks of ice and they're really really far away from the star, so they are gravitationally bound. But they can also be kicked out of their stable orbit by a passing star, interactions with other galactic stuff, and so sometimes that means it falls inwards towards the inner Solar System it becomes a comet, or maybe smashes into a planet and kills all of its dinosaurs, And sometimes it means they might be lost by that star and just float through interstellar space, occasionally randomly encountering another Solar system And is.

00:16:19
Speaker 3: That the only one we've seen? Or maybe I shouldn't ask any more questions because I don't want to lose my dju physics degree.

00:16:27
Speaker 1: No, once you have tenure, you can't lose it, Kelly, it doesn't matter.

00:16:30
Speaker 3: Oh my goodness.

00:16:32
Speaker 1: So that was the first one, and it was very spectacular and people really wondered about it. There's a lot of stuff we still don't understand about it, like very weirdly, as Omuamua was leaving the Solar System, it seemed to accelerate a little bit, like it wasn't just moving on a pure gravitational orbit. It actually sped up a little bit as it was leaving, which led some people to speculate, like, oh, is this an alien ship or is it like a little bit of alien junk, like maybe a light sail lost by some alien civilization these days, the best explanation is that it's probably a chunk ice and as it was leaving, some of that ice boiled off and gave it like a little poof.

00:17:09
Speaker 3: I have decided that my feelings are hurt and that it was an alien ship that, you know, maybe was watching one of our news channels and was like I'm out, and they left as best.

00:17:20
Speaker 1: As they could. Maybe most of the astronomy community and the astrophysics community thinks that the chunk of interstellar ice is the most likely explanation. On the other side of the debate is famous Harvard astrophysicist Avi Loeb, who wrote a book about how Omumua was probably a chunk of alien tech, though most people think he doesn't know what he's talking about, and we did a whole podcast episode sort of dissecting his claims and why there's no basis for them.

00:17:45
Speaker 3: Yeah, let's just be clear. I really think the ice answer is the way to I was joking.

00:17:52
Speaker 1: But these things are pretty rare that we did see a second one. In twenty nineteen, an amateur astronomer, someone who makes his own tellelescopes, a guy named Borisov, saw a second one. This thing also came through the Solar system on a trajectory that makes us sure that it didn't come from our solar system. The additive velocity in a direction that just is not compatible with motion around the Sun. And this thing is probably a ten kilometer wide comet.

00:18:19
Speaker 3: Wow, that's like extinction level, right.

00:18:23
Speaker 1: Yes, exactly. The closest approach to Earth was about two au, so we were in nowhere in danger. But yeah, these things can be moving really fast relative to our solar system because they're not linked to us gravitationally, and as the Sun moves through the galaxy, these things could be going in any direction. So yeah, they are a little dangerous, fortunately, and unfortunately they're.

00:18:42
Speaker 3: Pretty rare, and they come and go so quickly that there's no chance for us to plan a mission to go explore them. Is that right?

00:18:49
Speaker 1: Exactly? People thought, oh, let's go sample something from Omuamua, but it was already moving so fast that if you launched a probe it would take forever to catch up and then forever to send back data. And so these things are basically once and gone. You're lucky to get any pictures of them, not to mention samples, which is why everyone would love if one of these things would hit the Earth. Obviously, not a really big one, you know, not one that's going to vaporize us, but one that's going to survive the atmosphere, land on the ground, not hurt anybody, and leave us a bunch of clues about what's going on out there in the universe.

00:19:23
Speaker 3: But gosh, this was a quick podcast episode because that hasn't happened. Right.

00:19:30
Speaker 1: Well, that's exactly what we're going to dig into as soon as we come back from this break.

00:19:47
Speaker 3: All right. So Daniel was just about to tell us that the podcast episode is over because we don't have any interstellar meteors.

00:19:53
Speaker 2: Right.

00:19:54
Speaker 1: Well, there's a really interesting discussion about one possible blob that could have been interested.

00:20:00
Speaker 3: Tell me more about that.

00:20:02
Speaker 1: So in twenty fourteen, this is now ten years ago, a meteor hit over Papa, New Guinea, and this thing is about the size of a dishwasher. They're pretty sure. It weighs about half as much as a giraffe.

00:20:15
Speaker 3: All right, so pretty big but not gonna kill us. All that's great.

00:20:19
Speaker 1: The thing is big enough to make a detonation in the atmosphere, but not big enough we think to like land on the surface and like have a chunk of rock that you can look at and point to and even find.

00:20:30
Speaker 3: But it was traveling. So you just told us that our other two potentially interstellar visitors were coming from a trajectory where we knew that they weren't from our solar system, and so this one was was it doing that?

00:20:44
Speaker 1: So that's one of the questions, and av LOBE in twenty nineteen, together with the Harvard undergraduate combed through a bunch of data from US Intelligence satellites and looked for meteors that had a trajectory that might have been interstellar. So they combed through this database and they found this one. They're like, oh, this is interesting. According to the measurements of this thing's velocity and direction, it might have been interstellar. And so they got kind of excited about it.

00:21:10
Speaker 3: And by might have been what are the error bars on a phrase like that?

00:21:15
Speaker 2: Mmm?

00:21:16
Speaker 1: Yeah, And so there's a lot of discussion about exactly that. The thing is that this data comes from US Space Command and it was observed by US intelligence satellites. But the data from those satellites are a little bit obscure, Like we don't get the super high precision data from US intelligence satellites because the US doesn't want to reveal like everything it can measure. This is like classified secrets. But in early twenty twenty two, US Space Command issued this declaration saying that it was probably interstellar. They said that their trajectory was quote sufficiently accurate to indicate an interstellar trajectory.

00:21:51
Speaker 3: All right, that's I mean, that's awesome. That sounds that's pretty confident.

00:21:58
Speaker 1: That sounds pretty exciting. And so in twenty twenty three, Lobe and his team at Harvard decided they were going to go try to find this thing like it hit over the ocean, and they think maybe it fragmented in a fireball and then sprayed little bits of itself into the ocean, and if they went and dragged a sled across the surface of the bottom of the ocean, they might pick up little bits of it.

00:22:21
Speaker 3: So that sounds like the ultimate needle in a haystack. Activity how hard would it be to retrieve fragments from the seafloor.

00:22:32
Speaker 1: It's definitely not easy. But Avy Lobe was like, hey, let's at least try. Let's see if we can figure it out. And his thought was that some of the bits of this meteor were gonna be iron, and these things are gonna be magnetic, and so if you could drag a magnetic sled across the seafloor. Maybe you'll pick up little bits of this thing, little like chunks of the meteor that survived the atmosphere and hit the ocean and then sank down to the bottom. Now, if you have a science mind at all, there's lots of questions here, like how sure are you where it landed? How do you know about the tides and the currents, how do you know where it's going to fall? What else might be there? How could you distinguish it from the other stuff, How would you know if it was interstell or All of these questions are raised immediately by this fishing expedition.

00:23:18
Speaker 3: It's a long list.

00:23:19
Speaker 1: They went and they did it, and so for two weeks they dragged this custom built sled equipped with magnets and cameras and lights, across the seafloor, and at regular intervals they pulled it up and they gathered any metallic bits, and in the end they have a bunch of these things they call spherules, like basically tiny little iron balls around like a quarter of a millimeter up to two millimeters in radius.

00:23:43
Speaker 3: Okay, so, first of all, why would you be sure that this object had iron in it, And then also, aren't there a lot of iron containing objects on the seafloor to.

00:23:53
Speaker 1: Begin with, yes, absolutely. It turns out the seafloor is covered with these iron spherules from Solar System meteorites and from other sources of iron, so it's not that rare to find sperials. And in a minute we'll talk about analysis by experts in this area and how skeptical they are of the claims that Lobe and his team ended up making.

00:24:14
Speaker 3: They Okay, they found some, and then what evidence did they provide to suggest that these were interstellar instead of just like boring old Earth iron.

00:24:21
Speaker 1: They found like seven hundred these things in the area where they thought this meteorite had hit, and they also went and checked a couple other areas and they found fewer of these little spherials, So that led them to conclude, like, oh, maybe we found the right region, Maybe we have hit on this sort of destruction path, this wreckage from this meteorite, because there are more Sperials here than there are nearby. And then they did an analysis of these things. If you look at their paper, you can see they have like super close up pictures of these things, and they are like tiny little iron bebes, and they did things like measure the elemental composition, like how much beryllium, how much uranium, how much iron, what kind of isotope of iron are there? And from that they try to learn whether or not these things are consistent with bits of our solar system or inconsistent with bits of our solar system.

00:25:09
Speaker 3: And you said, tried to, which makes me think that the argument was not iron clad.

00:25:16
Speaker 1: So they make two kinds of arguments. One is about the ratio of iron isotopes. Like iron is an element, but there's a few different varieties of iron. There's iron with more or fewer neutrons in it, so it's like a tiny bit heavier and a tiny bit lighter. By the ratio those isotopes, you can tell something about where it came from and like the chemical interactions it's been involved in, which will dig into in a minute. But they also looked at the beryllium, the lanthanum, and the uranium in these things, so like more exotic elements, and some of these things have like more beryllium, lanthium, and uranium than they expected, and so they claim that these things are consistent with an interstellar meteor, for example, there's a lot of beryllium in there, and beryllium kind of hard to make, so they suggest that maybe the beryllium in this thing was made as this interstellar meteor passes through interstellar space and it's hit with radiation, which is one of the ways that you make beryllium.

00:26:12
Speaker 2: Hmm.

00:26:14
Speaker 3: But couldn't something that got shot from Mars get hit with interstellar radiation before it landed on Earth or the argument is that it would have taken a lot more time for that, but it could take a long time to get from Marster Earth.

00:26:26
Speaker 1: Yeah, you could be floating around in the Solar System for a long time. And this is a bit of a weak argument, I agree, But the interstellar radiation is a little bit different than the inside the Solar system's solar wind, so there might be a little bit of an argument there.

00:26:40
Speaker 3: Okay.

00:26:41
Speaker 1: So they had these spuriles and they looked a little weird according to them and based on their expertise, so they posted this paper in late twenty twenty three claiming spurials of likely extrasolar composition. So like this was a big claim. This made a huge splash, like discovering bits of an interstellar would have enormous scientific consequences, and.

00:27:03
Speaker 3: So I'm sure they did an enormous amount of work to make sure that they were correct before they released this. And so my first thought is, you say paper post it? Do you mean like paper posted after peer review or I mean, I know physicists do things a little differently. They tend to post things on archive first before peer review. Is that right? So maybe that would be standard, But tell me what paper posted meant?

00:27:29
Speaker 1: So they put it on the internet. They put it on the archive. It had not yet been peer reviewed. And in some fields it's a standard, like actually, in particle physics, we post our papers assume as we're done with them before they're peer reviewed, but everybody knows they're not yet peer reviewed, and so you got to wait and see if it really stands up. In astronomy and in astrophysics it's actually the opposite. People wait and post their papers to the archive after they're peer reviewed. And so this was a pretty unusual move, not just because they posted the paper before peer review, but also because the claims in the paper, Like they didn't just claim that these things were likely extra solar composition like a hunk of rock from another solar system, they said, and I have to quote this because it's amazing. They quote, may reflect an extraterrestrial technological origin. Like, yes, not only are they suggesting these things could just be bits of rock from another solar system, already amazing, but bits of technological junk from an intelligent civilization from another solar system. Like to make that leap to me is just incredible.

00:28:35
Speaker 3: Wait, have we just not yet talked about the evidence that they used to support that claim, or because we've like skipped it so far, or have we really talked about everything.

00:28:46
Speaker 1: No, there is no evidence to support that claim. Just like, hey, look, these are weird and they have a strange mix of elements. Maybe they come from an alien iPhone. That's really the whole argument there, and then and then add to the mix. The same day this paper is posted. In twenty twenty three, Ivi Lobe publishes a popular book for a mass audience called Interstellar, The Search for Extraterrestrial Life that's all about his search for little bits of technology from alien species elsewhere in the colex and then he gives a bunch of interviews and in the interview He sort of like conflates whether the paper has been published as in Peer reviewed or just post it online, And so he really gives people the impression like, oh my gosh, look this is really backed up with scientific study.

00:29:35
Speaker 3: Doesn't sound good.

00:29:38
Speaker 1: And so everybody was like, hmm, that's interesting. We'd love to believe it, right, we're scientist. Let's keep an open mind. Maybe Lobe did discover bits of an alien iPhone. That would be fantastic. Nobody wants to reign on the parade if it's true, right, But you know, extraordinary claims extraordinary evidence, And so I for one, was waiting for a detailed critique from experts, people who know, like, how likely is a meteor to survive this thing? How likely was it that it had an interstellar origin? What can we conclude from the elemental composition of this stuff? And very recently there was a paper by Stephen Desh and Alan Jackson, two experts in this area, professors at ASU and Towson University, and they went through in a meticulous fashion and took apart his claims.

00:30:24
Speaker 3: Oh boy, so who's who are we going to side with? By the end of this episode.

00:30:29
Speaker 1: We're going to decide with the evidence, of course.

00:30:32
Speaker 3: All right, so where do we start then, digging into the many arguments we just talked about.

00:30:36
Speaker 1: I want to start by reading this paragraph from desh and Jackson's paper, which I think sums it up pretty well and like, this is not the kind of thing you typically find in a science paper. This is fire. So what they wrote is quote. Because of the boldness of the claim, it might be expected that Lobe at all exercise due diligence to eliminate alternative, more prosaic explanations for the data, and would report their results carefully and deliberately. They did not flight lowbit all hardly considered, and did not test the simplest alternative hypothesis. The spherals they found were of a common and well understood type found worldwide from Solar System asteroids. Apparently, the authors did not seek expert opinion and posted the discovery manuscript before it had been peer reviewed and accepted or even submitted to a science journal.

00:31:27
Speaker 3: En quote, I am getting I'm getting heart palpitations. As a fellow scientist, I cannot handle this. This is very My empathy is through the roof right now. But if they should have done due diligence.

00:31:38
Speaker 1: I know, being publicly called out like this, not just like, hey, look we disagree, we took another look at the evidence. We think maybe you were wrong. Have you considered, But this is really calling them out for sloppy science, for not considering reasonable alternatives, and basically for looking to confirm the story they were hoping to find. It's really pretty damning.

00:31:58
Speaker 3: Well let's dig in, Okay, So tell me about more about those. Should we start with the spherals or should we talk about the you know, how good were the trajectories suggesting it was interstellar?

00:32:12
Speaker 1: Yeah, let's start with whether or not this thing even was interstellar, which is sort of the reason this whole thing got started, right, Like, the US Space Command issued this statement that it was an interstellar trajectory. That sounds pretty solid, right Yeah, But you know, then NASA chimed in and said the short duration of collected data less than five seconds, makes it difficult to definitively determine if the object's origin was indeed interstellar. What this comes down to is the precision of the measurements of this thing, Like how well do we know how fast it was going and the direction of its motion?

00:32:46
Speaker 3: Wow? So what that doesn't sound good? So how often, like when you only have about five seconds worth of data, like, how much error do you have in that?

00:32:58
Speaker 1: That's exactly the question to ask. And so in this case, whether or not it was interstellar comes down to its velocity. Like, anything at our radius that's going about faster than forty two or forty three kilometers per second has escaped velocity and is not bound to the Sun. So if this thing was moving faster than forty two kilometers per second relative to the Sun, it's not bound to the Sun and it was interstellar. So that's the question. Now, they measure the velocity of this thing to have like sixty one kilometers per second relative to the Sun, which is like almost twenty kilometers per second above the threshold. So it seems pretty safely interstellar. But then the question is, well, what are the uncertainties. If it's sixty kilometers per second plus or minus one or two, yeah it's interstellar. If it's sixty kilometers per second plus or minus sixty kilometers per second, then you really don't know very much, right, Yeah, so low, But his paper claims that based on US space command, we can be ninety nine point ninety nine percent certain this thing is interstellar. But in Desh's paper they reveal the source of this, and it's basically just an assumption. They assume that the uncertainties are like ten percent, that this thing is like, you know, sixty kilometers plus or minus six kilometers.

00:34:07
Speaker 3: Oh that's not good.

00:34:11
Speaker 1: Yeah, but it's basically just an assumption. And there are other people who have studied the accuracy of these measurements from US Space Command. Sometimes you get like two different measurements of the same rock as, so you can say, oh, well, let's see how accurate it is. And it turns out that this data from the intelligence satellites, maybe because they're not precise, maybe because it's fudged, maybe because it's purposely smudged because it's intelligence data, shows really large variations. So the uncertainty could easily be much more than ten kilometers per second.

00:34:40
Speaker 3: So there's there's pretty good reason to believe that the error is so big that it would include objects that are not of interstellar origin exactly.

00:34:50
Speaker 1: So even if this thing is measured to be sixty kilometers per second with an uncertainty of ten or fifteen, that seems to still keep it above the forty two kilometer threshold. But remember how the statistics here like it gives it like a one in one thousand chance of being mismeasured. And you might think, oh, that's still pretty good, Like it's got a one in one thousand chance of being mismeasured and a nine hundred and ninety nine out of a thousand chance of being accurately measured to be interstellar. But remember that there are lots and lots of these rocks, and so if you look at thousands or millions of rocks, you're going to see one in a thousand events every once in a while. It's like if you roll the dice a thousand times, you're going to see really rare stuff eventually.

00:35:31
Speaker 3: And we have essentially been rolling the dice thousands of times, right exactly.

00:35:37
Speaker 1: There are thousands of things in this database, and so if you look through the whole database, you'll see really rare looking events just because you've looked lots and lots of times. And so the evidence that this thing is interstellar is actually pretty weak. It might just be a very mismeasured solar system asteroid, and you expect a mismeasured solar system asteroid to it looked like an interstellar object one in a thousand times.

00:36:03
Speaker 3: About okay, so it might not have been traveling from an interstellar location. That's problem one. Let's move on to critique two. Where are we going next?

00:36:16
Speaker 1: So next, Dish points out that this thing probably would not have survived reentry. The idea that enough of it survived to like land in the ocean and cause these spherals seems really unlikely. This thing was coming into like one hundred and forty times the speed of sound, and at that speed, like the front of it gets melted and heated and vaporized and the whole thing would have come apart. So Desh did a calculation that showed that ninety nine point nine nine nine nine nine percent of it would have been vaporized. So basically, like almost all this thing is gone. It's just like in little individual particles by time it reaches the ocean surface.

00:36:54
Speaker 3: And then it's going to slowly sync to the bottom, and your chance of finding it, if anything survived, would have been pretty low. But yeah, basically, and we probably have pretty good data on this right because we've probably observed a lot of stuff that hits our atmosphere and burns up in the atmosphere.

00:37:10
Speaker 1: Absolutely people know how this works. And DSH actually went back to Lobe's paper and checked their calculations, and they found a mistake, like they cannot confirm the number that load calculates for like how this thing would have melted in the atmosphere. So they suspect that they just like plugged in the wrong number and that's why they misunderstood exactly. So so far, it looks like this thing was probably not interstellar, and even if it was, probably would not have left any remnants when it hit the atmosphere. It's just too small for anything to survive all the way through the atmosphere.

00:37:45
Speaker 3: Okay, all right, But so let's say it was interstellar and something did survive, how likely are we to have been able to find it and then know that it was interstellar once we got it.

00:37:58
Speaker 1: Yeah, this is basically or question when you first heard this, right, like, how would you even find this thing? It's a needle in a haystack. So yeah, assume it's interstellar and that some of it survives, and then you get enough iron that it hits the surface of the ocean that sinks down that you could potentially find it, that it's even there for you to find it. Another big problem is, hey, the ocean is really big. It turns out and find finding like basically Bebe's on the bottom of the ocean. You need to really know where you're looking. And there's a lot of uncertainty about this thing. We got like five seconds of data about its trajectory, and if you extrapolate that to the surface of the ocean, there's a pretty wide range where this thing could be. And now you're going to like drag your tiny little magnetic sled over this thing. You know, what are the chances you're even dragging it in the right place?

00:38:50
Speaker 4: Well?

00:38:50
Speaker 3: And can we take one more step back? And I'm sorry if you said this, and my brain was just discombobulated at the time. How do we know for sure that it's gonna be that it would be iron, and that this magnet is what we should be using to collect it. How can we be sure that this intertellar thing is iron?

00:39:08
Speaker 1: We can't. But there's a lot of iron out there and a lot of heavy metals, and iron is a pretty common thing because it's like the end point of nuclear fusion, making things heavier than iron is hard, and so iron is pretty widely distributed in rocks in the solar system and maybe in rocks in other solar systems. But it's a great question, like maybe our solar system is weird, and once we get samples from other solar systems, we'll discover, Wow, iron isn't as common as we thought. So yeah, this is a big assumption that rocks from other solar systems will have enough iron to make little metal balls we can pick up with our magnets.

00:39:44
Speaker 3: Okay, all right, So let's assume it is iron for sure, and that the magnet method is gonna work. The ocean is big and deep, and so what like range of like locations where it would have fallen, like how good was there certainty? And where it would have potentially fallen.

00:40:07
Speaker 1: So the location data we have, if you believe it, gives a box that's like twenty kilometers by twenty kilometers or where this thing might have landed, and like that's huge, Right, You're not going to drag your magnetic sled to cover an entire square twenty kilometers by twenty kilometers. So lob in them did is use a little bit more data. There's a seismometer on an island about ninety kilometers away that also measured like a blip around the same moment, And so they use that information to try to narrow it down a little bit, and they find like a little band through this box that they think maybe is where this thing landed. So they have like a slightly narrower region, and they drag their sled basically through this band and then a couple other spots to get control measurements.

00:40:54
Speaker 3: Did that blip on the seismometer. Does that increase our confidence that maybe something did make it to the ocean bottom or did survive re entry.

00:41:03
Speaker 1: The seismometer is actually most likely measuring the detonation in the atmosphere, right, because this thing, as it comes through the atmosphere, it's going to explode as like pockets of gas or whatever inside of it heat up unevenly. So probably this is measuring the explosions in the atmosphere. But as deshan All point out number one, all these measurements are very uncertain, like the seismometer itself is very uncertain if you take a look at the data, like there are a lot of blips nearby that could have been anything, so lob in them assigning this blip from the seismometer to this particular bit of rock is very very speculative, you know. Basically, they were just looking for a way to slice the region down and hope they find something. There's not really strong evidence that this is the region. The most damning thing that Desh points out is that according to Space Command, there's two possible locations. There's the box that lobe serch, and then there's another location that could have been where it hit like sixty kilometers away. So it could be they were looking in completely the wrong place.

00:42:03
Speaker 3: Oh man, okay, all right, So might not have been interstellar, probably wouldn't have survived reentry. If it did survive re entry, where we're not super sure where it landed, and only one of two possible spots was searched, and maybe not even all of the possible of one of the two spots. Let's take a break to build suspense and then and then let's talk about the spheres that they did find and how they tried to argue that. How good was the evidence that those were not from here?

00:42:49
Speaker 2: All Right?

00:42:49
Speaker 3: I feel like my blood pressure is going up as I'm watching someone else's arguments get dismantled. It's a weirdly personal it's a weird experience.

00:42:58
Speaker 1: But okay, so I know, I know, you don't want anybody out there in science to like be publicly dismantled. It's terrible, it's embarrassing. If people are making good faith efforts to do their science, we should treat it with respect and we should take it seriously. The question here is like whether Lob and A really are making a good faith analysis of this data or whether Lobe is just promoting his book.

00:43:20
Speaker 3: Well, And also, at the end of the day, sometimes people are going to be made uncomfortable because science needs to be picked apart for the process to work. And so so here we go. Okay, so tell me more about those speruals and how certain we are that they were interstellar, right.

00:43:38
Speaker 1: Because even if you don't believe this thing was interstellar and might have not a survived reentry and you don't know where to look, they did drag something across the seafloor, and if they found something weird that we can't explain, those other arguments don't really matter, right, Like they found something cool, maybe it was a different interstill in media or whatever. So let's think about what they actually found. So they did find a bunch of these ferules, and they did compare the number that they found on their drags, so numbers in other areas. They're like, you know, boat it over to other regions and drive the sled across a couple other spots to try to understand what was typical, what was common? How many ferals do you expect to find on the ocean floor. And according to their analysis, they found more in this region where they were looking for this interstellar meteor than in the other spots.

00:44:22
Speaker 3: But there's not only one reason for why one area could have more spherals than others, right.

00:44:28
Speaker 1: Exactly exactly, And so when you readsh this paper, you realize, boy, it'd be helpful to understand this field at all before you dive into it, because it turns out number one, the ocean floor is littered with these things, like the Earth is getting slammed by meteors all the time, where little bits of it are making to the ocean surface and then sinking to the ocean floor. Like you drag a magnetic sled across anywhere in the ocean, and you're gonna find these fuerals and then they're going to vary. Apparently, the variation in the number of ferials you find depends on lot of stuff, the currents, the shape of the ocean floor, all sorts of stuff affects the variation. And the number of sphereals is just huge. There's millions of these little balls of iron per square kilometer, and so even if this thing did happen to land here, this metior would contribute like much less than one percent of all the little spheres you find on the ocean floor. Even if it was there, it'd be very hard to find spheres from this particular meteor among the like millions of spheres you expect to find on the ocean floor. And Lobe's team only found like seven hundred, So you would expect like a very small number to be from this medior even if it did hit in this region.

00:45:41
Speaker 3: Okay, all right, and so that but the seven hundred that they found, and.

00:45:45
Speaker 1: One more comment on the number, even the seven hundred they found, Lobanoll claim is like, ooh, we found extra in the region we were searching compared to the control regions. They didn't take enough data in the control regions to really measure how much should be in the control regions. So the variation the claim like oh we found more here than elsewhere, is not even statistically significant. But all right, maybe they were lucky and maybe they found something really exciting. So what they did is they measured what's in these spherules, like how much iron is there and which iron isotopes, and then also what are the weird elements that are in it. So first the iron isotopes, they measure iron in all these different isotopes. There's iron fifty four, iron fifty six, iron fifty seven, and the ratio of these isotopes tells you something about wars formed and what's happened to it since, and.

00:46:36
Speaker 3: Was it weird?

00:46:37
Speaker 1: So low in them look at the ratios and they see something a little weird. That's true. Earth isotopes tend to have a particular ratio of fifty seven to fifty four and fifty six to fifty four, and a lot of these little iron balls that they found had like more or less of one of these two iron isotopes. The problem is that this can be very easily explained by chemistry, like a m out where you take an iron sphereal from the Earth and you do some chemical process like interaction in the atmosphere or interaction with seawater. Even then it tends to lose the lighter isotopes faster because the interaction depends on the mass, and things that are lower mass will move around more and interact more. So this changes like these ratios in a very predictable way. And all of the iron balls that they found on the seafloor lie exactly across the line you would expect stuff to happen if it came from our solar system and then interacted with seawater. This is like exactly what you would expect for a solar system iron balls.

00:47:38
Speaker 3: And they'd been sitting down there for a decade or something, right, so there's plenty of time. If this is from the right asteroid that they were trying to find, it would have been down there for a decade.

00:47:49
Speaker 1: Reacting yeah, exactly. And so Lobes team seem to claim, oh, look, these are different from the nominal ratio we expect, but they doesn't seem to understand like the seawater chemistry will give you exactly this kind of variation. Did they took us like a real dagger in the heart of their claims. It proves that these are Solar system iron balls because they lie exactly on this line. If things came from another Solar system, you might expect them to have a very different elemental composition. If it came from a star from like five billion years ago, maybe there was less iron form because it was earlier in the universe, and just like less metal had been made, and so you might expect like really weird elemental compositions. But what they found is like pretty normal, the kind of stuff you find on the sea floor all the time. They just didn't seem to understand the context.

00:48:38
Speaker 3: Ouch uh, so have we is the massacre done? Or is there is there more?

00:48:47
Speaker 1: There is a tiny little bit more. They claim that the composition of the other elements like beryllium, lanthanum, and uranium is very unusual. But it turns out also that this beryllum can be explained with just interaction with the seawater. And you would never even get this much beryllium from interstellar travel, Like even interstellar travel would not create this much beryllium, But you can do it just by sitting on the seafloor and interacting with seawater. We'll do this. If they've done a more systematic scan of the ocean floor, they would have found lots more examples of this stuff, not just where they thought the interstellar media hit, but elsewhere in other places. These things are not that unusual.

00:49:27
Speaker 3: So you know, there's always a part of me that holds out a little bit of hope for the scientist who's getting kind of destroyed in an argument like this. Have they has Loben his collaborator responded to these arguments to provide some counterpoints or is this pretty much the final word?

00:49:47
Speaker 1: It's hard to imagine them responding in a way that their claim survives. So far, we haven't heard anything from them. But before this paper came out, Lobe complained that nobody is taking his sign seriously. That is like dismissed by the mainstream science community. And this is evidence that like academia's closed minded and science is dogmatic. And you know, it's the kind of thing people tend to say when their work isn't taken seriously, that there's some other reason other than like, well, maybe your work is not that serious. And so Lobe, because he's a Harvard astrophysicist, you know, he has a lot of credibility with the media, and so he complains that nobody took him seriously. And then he said, quote, if someone comes to me and says, for these scientific reasons, I have a scenario that makes much more sense than yours, then I'd rip up that paper and accept it. That's a direct quote from Lobe. So now it stands to see like somebody has come forward with scientific reasons, with a much more plausible scenario that fits the data much better. Let's see if Lobe concedes or if he comes back where the scientific Rebuttalance says, actually, here's another way to analyze the data.

00:50:51
Speaker 3: How long has it been since the counter paper came out?

00:50:55
Speaker 1: So Deshen Jackson's paper came out November thirteenth, so it's in about a month since this recording. So everybody's waiting to see what Lobe is going to come back with. But I thought it was important that we discussed this today in the podcast, because you know, we're teaching everybody to think like a physicist, to be skeptical but also excited, and you have to balance those things. You have to remember, like we want to be open to crazy, new surprising discoveries and learn things about the universe, but we also have to be very careful in our methods, and we have to make sure that what we're doing is reasonable, so that we're building knowledge and not just spinning fantasies.

00:51:30
Speaker 3: Yeah. Absolutely. And it's so easy to get super excited about a results that you know would be a real game changer. But those are the times when you really need to think, Okay, how what do I need to know? You want to try to prove yourself wrong in as many ways as possible, and it doesn't feel like that due diligence was done here.

00:51:52
Speaker 1: Yeah. Before I publish any paper, I'm always attacking it myself. I'm always asking what could we have done wrong? Or how could we have been confused? Used, et cetera, et cetera, Because it'd be terrible to publish something and be like, oops, sorry, we misled everybody, even if it was in good faith. And so while it seems clear here that the science is not solid, we can't actually say it wasn't in good faith. But it certainly doesn't feel like a good faith science argument.

00:52:17
Speaker 3: Yeah, agreed. Whenever Zach and I are talking to someone about their new results, our go to question is what is the least interesting explanation for your results, because often it's problem, it's probably the answer, And it seems like here the least interesting explanation wasn't considered thoroughly enough exactly.

00:52:38
Speaker 1: And I'm like the biggest cheerleader for this kind of stuff, Like I would love to meet aliens, and I would love for it to be evidence that aliens have visited Earth, or even that rocks from other solar systems have landed on Earth and we could study them. I so much want to believe that, but that makes me also need to be skeptical, because again, we want to uncover the truth, not just tell ourselves stories.

00:52:58
Speaker 3: Right, And you want to know when you're emotionally invested in an answer, so that you can try to particularly keep your eye on those sorts of questions.

00:53:06
Speaker 1: Or financially invested because you're selling a book about how you discovered alien technology. That's right, all right, Well, thank you very much everybody for listening to today's episode, and thank you for Kelly for taking his ride with me where we take a careful and critical look at some astounding claims in science.

00:53:26
Speaker 3: Thank you for letting me ride shotgun on this uncomfortable journey.

00:53:31
Speaker 1: So far, our children are safe and your children are safe, and no aliens have arrived for us to negotiate away with their lives. But stay tuned.

00:53:38
Speaker 3: If those aliens come, I am hiding my kids from you, all right.

00:53:44
Speaker 1: Thanks for listening, everybody, See you next time. For more science and curiosity, come find us on social media where we answer questions and post videos. We're on Twitter, Disport, Instant and now TikTok. Thanks for listening, and remember that Daniel and Jorge Explain the Universe is a production of iHeartRadio. For more podcasts from iHeartRadio, visit the iHeartRadio app, Apple Podcasts, or wherever you listen to your favorite shows.