Why this matters for Mars sample return and planetary protection

29:46>> Okay? The gas gun looks like the following. You've got You've got um the projectile which is your flyer plate. Yes. That's another piece of steel. Okay. And that that piece of steel is going to be propelled by gas. It's the same like kind of like, you know, in like car mechanic shops where you have like the the gas hydraulics. >> Yes. >> It's I mean it's obviously more sophisticated than like the car but it's the same thing, right? It's like a gas gun that is like propelling a fly a flyer plate to impact the plate that has your bacteria, okay? And then when you impact that bacteria, that is going to create the microsecond strain that mimics the asteroid impact on Mars. So so the

30:29idea is that this in this in this graphic we see on the left, there is this this this projectile, there's a wedge and a flyer plate. So that is what is shooting out. >> Yeah, with a gas like it's it's high high gas that shoots out and it shoots into a a circular plate. It if you go to the the gas station or a car wash, there when you pump your tires, you click the thing and shoots the air out. >> Yeah. >> Yeah. Just conceptual. >> Yeah, that's exactly this. >> It's it's shooting at at levels that are not pumping your tire. >> Yeah, yeah, yeah. This is this is much higher pressure. And and the advantage here is that so I'm shooting my gas plate and interacting with this plate that has my sample, right?

31:10>> Yes. I can I can polish the other side. Okay. The back side. >> side. Okay. Such that it's a mirror. Okay. >> I can shoot lasers at it. >> Oh my god. >> And then I can really hone in on what the dynamics of the trajectory is. Like how much pressure was there? How much strain was there in each direction? Because I can monitor how the laser is coming out. Because and just to be just to to reiterate, the laser is the means by which you can measure stuff. >> Yes, exactly. >> measurement instrument. >> measurement instrument because we're so good at lasers, right? And measuring like frequency and all this other kind of stuff, we can measure exactly the amount of pressure that was imparted in that microsecond, right?

31:51>> And that's what's hard to measure, but these guys have leveraged all of the optics that physics is very good at. >> That's so clever. It's it's so clever. I I really like that actually. Cuz it's at first at first blush, frankly, their initial reaction is like, "Oh, that doesn't sound like what would happen on the surface of Mars." >> No. However, >> they're recreating exactly the Pascals, like the amount of pressure, the amount of transient, right? Because it only has to happen over a microsecond. So this contact has to happen very quickly. It's got to be a shot, you know? Yes, that's quite nice. It's it's quite nice. And so now let's see what they're actually doing, okay? What are the findings that they actually get?

32:31How they measure is the number of colony forming units. And this is something that we used to do in microbiology lab, as well. Um is you basically like swab and put it into a Petri dish with like agar, which is like a solution that grows bacteria. And then if there's a single bacteria that survived, that's going to create a colony because it's going to replicate over some time. And you can count the number of colony forming units, and that'll give you a proxy for how many survived because you knew the initial concentration of how many bacteria you put in into that like Yes. apparatus, right? And now let's look at the results, okay? It's insane. All the way up all the way

33:12up to 2.4 gigapascals, you had 60% survival. 2.4 is 24,000 times that on Earth, right? The survival falls below detection limit only when pressures exceed three gigapascals. And one of the cool things was um Lily Zhao, who's the one of the senior authors on the paper, >> Yes. she noted that the hardened steel experimental containers began to structurally fail before the bacteria actually got eradicated. >> What? So the point is our own engineering was not even sufficient enough to get to levels where the bacteria were >> bacteria were like chilling,

33:53right? They were like at least 20% were still alive, but like we couldn't test further because the we were testing pressures where the steel was like, "I can't I don't know what you want me to >> the material science for it. >> Yeah, exactly. It's fascinating, right? And if you look at standard microbes, right? E. coli plummets to 10 to the minus three to 10 to the minus six survival rates below 2.2 gigapascals. Yes. Our radio durans, Conan the Bacterium, achieved very high rates. So Conan the Bacterium is the green dots on the very top. All of the other stupid bacteria are surviving way lower. And this is on a log scale on the Y axis. And then so

34:33just to be clear, we're looking at a graph here that has pressure on the X axis. >> And X axis is gigapascals, and then survival rate on a log scale on the Y axis. >> Yeah. And there's all the other stuff that's like in the middle and like >> Yeah, it's like E. coli and yeah, yeah. But at the top is our radio durans at multiple different pressure types, it's very consistent. Okay. So so Conan's Conan Conan is sick, dude. He's He's surviving everything. Okay. Um this is where it gets really, really cool. Okay? Cuz so far, okay, we've we've shown that this radio duran survives. Right. Again, coming back to the original point

35:14here is starting off with this idea of is panspermia a thing, which is life going from one rock through the vacuum of space to another rock. And part of the current paradigm was that in order for an organism not powered by rockets or some advanced technology would require an impact on that planetary body of a level of force such that it would eject it into the vacuum of space. >> Yeah. And initially the idea was There's no way. >> There's the level of force necessary to eject you out there. It's just going to

35:56kill you. You're You're You're dead. >> Yeah. That's the current paradigm that the paper has now experimentally shown on Earth we have organisms that would survive this theoretical impact. >> Yes, exactly. So we have shown that it would survive this theoretical impact. Now let's look at what actually happens to them. Okay? If you look at um transmission electron microscope images of these bacteria, you can actually see that at higher pressure >> Mhm. the cell walls get ruptured. Yes. >> Okay? So, that's why the survival is going down. >> Right. >> Because the the cell compartment around it is getting ruptured.

36:37>> Mhm. And it's consistent with like sort of the physics of what we know about the cell walls. But, the idea is even at that 2.4 gigapascals, a bunch still survive. >> Mhm. Right? Mhm. So, so what we're seeing is there's three images here. On the far left, we see like sea level, I'm guessing. >> Mhm. Uh where you can see the >> like it's like it's normal. Yeah. Control yeah. >> The You can see the structure of these four bacterium. >> Mhm. Totally Totally fine. Totally fine. >> At 1.4 gigapascals, there's clearly a rupture in two There's two There's clearly the rupture that's happening. >> But, they're still fine. >> But, they're still fine. They're still right. Right. And then at 2.4, there's one that's not fine, but two that are

37:18fine. >> Yeah. And it's just like, "Yeah, like you you were just weak." >> Yeah. Yeah. Yeah. Yeah. It's That's evolution baby. >> That's That, but that's I I I want to say >> that's 24,000 times the the pressure on sea level. That's still insane. That's way more than Mariana's Trench, for example, you know? It's it's still insane. But, this I think this was the coolest, okay? This next finding that they had. They went in and they looked at the RNA sequencing, the transcriptome >> Mhm. of the bacteria that survived that pressure, okay? So, you've got an impact. >> Mhm. Certain things die, but you've got colonies that are made. What is the specific DNA that those

38:01bacterium are translating into protein, right? What's the thing that's being made into mRNA that is being translated into protein? What do these bacteria care about >> Yes. >> once they've been hit by a meteorite? >> Yes. Yes. Here's what they cared about. According to their transcriptomic analysis, they vastly increased DNA repair transcription. Okay? So, anything that had to do with DNA repair, they were like, we need that. We need the SOS response. We need the recombinase. We need um a really high active transposase, which is stuff that's like fixing where the DNA is going. So, genome reconstruction was like the number one priority.

38:42>> That's actually so fascinating, especially if you if you've uh are coming back as a listener, this is an area that we've touched on in multiple stories and in the human uh context in terms of how our body does repair. >> Yes. Um in a number of different contexts. And this is fascinating cuz in all of those contexts, there was not an increase in the sort of immune response it's like or or DNA repair response based on an external like pressure. >> pressure >> Like literal physical stress. >> did not cuz the immune response is there, but the DNA repair process, which is kind of its own Yeah, but these guys these guys are just

39:23responding to the fact that they just got hit. >> That's cool. They just got hit with this giant microsecond timescale high pressure, right? Which like totally messed up their internals. And what here here's the other thing. Stuff like um energy production, lipid metabolism, cell cycle, so that's like the reproduction, that's deregulated. So, the idea is the cell halts growth. It's like, I'm not trying to replicate. I'm just trying to stay alive. So, all of my ATP, all of my energy is going to go into structural and genomic repair. Okay? We're going to stop We're going to stop the normal I don't know what just

40:04happened, okay? But I just got hit by a 2.4 gigapascal bullet. >> Yes. We need Let's just stay alive and then and then we'll figure it out. There's such a clear analogy here to economics and society where it's like you know, despite any shocks to the system, capitalism keeps trucking along. >> Yeah, and you just you just reallocate resources. >> reallocate, but it doesn't it doesn't get into it. That's that's fascinating. >> Yeah, I thought it I thought it was really cool. I mean, the fact that they went into the transcriptomic genomic level to show how it's actually surviving this. I thought that was really cool. So, I mean, it shows that this prior assumption that if you have

40:46this giant 5-gigapascal impact it's going to sterilize everything. That's no longer true, right? Certainly, we we have a bacterium on Earth that can survive that. And that that's we have and we only have one source for reference in a in an infinite galaxy. I'm sorry, infinite universe, excuse me. Um an almost infinite galaxy in comparison. And it on the first place, we have the thing. Yeah, so it's like clearly, you know, or statistically speaking it is likely true that across the universe there are other things that if they were to arise that would reach that level.

41:26>> Exactly. And so now that stage of lithopanspermia, right? That first stage of getting into space, that's been validated. Staying in space has been validated. And getting into Earth has kind of been validated. I mean we haven't done astringent tests but like we know how rocks sort of burn up and things like that. So, we can sort of make theoretical predictions. But at the end of the day, this significantly increases the probability mathematically that there's life that could migrate from one planet to the other, right? Now, why is this important? For one, it's getting to the heart of who who are we? Aliens! Aliens? Are we

42:09aliens? Are we aliens? >> Are we aliens? >> We might all be illegal immigrants. so I mean who knows? >> Right. Because Mars, way back in the day, had a very nice climate. Mhm. Right? When the when when the solar system formed, Mars had oceans, had lakes, had water, had an atmosphere, and could be the perfect place to start life. And so it's not completely crazy that perhaps life started there and came to Earth. I mean, that's obviously where Elon is trying to re-bring it back. I mean, he's trying to go back home. >> Um and so it makes total >> Yeah. But in today's world, why does it matter? Well, this is I thought was really cool. Okay. So, there's a Committee on Space Research, it's called COSPAR, and they have this thing called

42:49a planetary protection policy. It prevents forward and backward contamination of life. So, forward meaning like we don't want to contaminate, let's say Europa, with our own bacteria. >> to be the colon- the pilgrims. Yes, exactly. And we don't want backward contamination like, you know, some life coming in on Earth and then killing everybody. Yes. Japan, the Japanese Aerospace Agency, has a mission called the Martian Moons Exploration, which is going to go to Phobos, which is one of the big Martian moons. >> Mhm. Um it's going to launch in 2026, and it's going to return in 2031 with 10 g

43:32of Phobos dirt. I know some people might be like, I get more than that from my local dealer. However, your local dealer is not hundreds of thousands of >> millions millions of miles. >> Millions to get, true. Yeah, millions. Yeah. Where your your window to for delivery is a very narrow window. >> yeah. You got to time it with the planets, you know? Uh it's not it's not a signal text away. >> I just want to identify like technically speaking like that is >> g is like Yeah. Like we have we have a Mars return mission that got nixed because it's too expensive. Yes. So, I don't know why we're talking. >> Yeah, right. Right. Right. So, Japan is

44:13doing this, right? >> Right. But, this new paper now is kind of putting a wrench on things because Phobos orbits in the gravitational well of Mars, right? So, its surface is kind of like a sweeping sponge of all the crap that is spewed out of Mars from all of the meteorite impacts, right? So, when we take out that 10 g of stuff from Phobos, that's going to inevitably have stuff from Mars. >> see what you're saying. >> when we bring it back to Earth, right? There's two possibilities that the Committee on Space Research suggests. One is the restricted Earth return, which is a category five restricted. That requires multi-billion

44:55dollars worth of biohazard containment. >> Yes. >> And then there's unrestricted unrestricted Earth return, okay? That's just unrestricted. You just put it inside standard creation labs. You're good to go. >> Yeah. If that thing has life, right? Or possible life, we might need to upgrade from unrestricted to restricted. >> yeah. And that's going to increase the cost of the mission. And it's something that we have to grapple with. Like, what is the probability? Because the threshold is for unrestricted, it requires the probability of viable unsterilized Martian organism Mhm. to be less than

45:37one in a million. Okay. So, we got to go back to the drawing board now given this paper and try to calculate, okay, what is the probability that in that 10 g of stuff >> Yes. there's going to be something that is possibly alive. >> Right. Because that thing being possibly alive and being brought into our environment Who knows? We have no idea. no >> I mean, a high probability it's going to die. Right. Okay? It's going to be like, "Why is there 20% oxygen?" And then just die. However, >> Okay. cuz Earth is very different from Mars, even back then, right? There's a way more oxygen now. The the pressure is way higher. There's a bunch of nitrogen. I

46:18don't know what that's going to do. However, just like we talked about, on Earth we have things that have the ability to live in conditions that are way more extreme than Earth's environment. So, why is the inverse not true by default in your calcula- in your probabilistic framework of >> the thing with this one in a million, right? We have to do that mathematical calculation and say, "Okay, given the the span of all the organisms, what is the chance that this thing that came out of Mars is going to be in that tiny little regime where it's just going to totally destroy us?" I think it's a it's a very cool paper. >> That this is it's very interesting because it sort of it it's poking in two

46:59different arenas. So, one arena is poking in is the sort of um you know, Fermi paradox, panspermia, can life go from one rock to another? We already had kind of two one and a half-ish of the three where we felt like we have it. It can travel through space fine. Reentry to Earth 50%. But now we know that it can survive the initial impact. Yeah. >> To get actually even into the second two stages. Yeah. Uh so, at least in terms of referencing something we can know as life here on Earth. That is huge. Not only that, based on an active mission coming back because of that

47:40understanding that they've now proven experimentally, an active mission that Japan is doing to bring back samples from Phobos, which is in a range where if there were things impacting Mars and things getting ejected and there was life on it, Phobos would have it. >> Phobos would have it. >> 10 g that we get will have it. >> Would have it. And now we have to have a almost COVID-like conversation. >> Yeah. Yeah. Uh which is funny because our second story >> Yeah. is on immunology. Exactly. >> Which we'll get to in a moment. But fast, you know, for those of you who know, I'm the I'm the one in the pod who loves alien stories. I did not select this one. >> No. So this was organic.

48:21>> Yeah. Uh I'm waiting for NASA to stop tiptoeing around the Mars thing. Yeah. They're continuing to tiptoe around it. Well, it seems like we're not going to return samples. Oh, and and sorry. What I'm Oh, from the from the little lake that we covered Oh, we're not. >> We're not. So this is why funding matters. >> Funding is too expensive. >> Maybe we could save a couple of of of bunker busters. Maybe if like if we just like two Yeah. >> two literally two bunker busters >> Yeah. we could return samples from Mars that would identify that we're not alone in the universe. However, uh we will not see that at the moment, but we may see in the future in terms of funding. Fascinating story. Our first story of the day, astrobiology out

49:03of John John's John's. Johns Hopkins University. Uh normally I think in my head we're known for medical stuff. >> Yeah, but they have an incredible like engineering department, right? Cuz they have the Applied Science Lab. >> So there you go. Um the Applied Is it Applied Physics Laboratory? I think it's the Applied Physics Laboratory. Um and they also are in charge of the Space Telescope Institute. They have they they've they've got a pretty strong like um astronomy and astrophysics and fundamental physics. It it flies under the radar because their medicine is very good. >> just so stellar. If you are in any of those at John Johns Hopkins, uh please send us a note. Uh we'd love to make

49:44sure that we know and have your connection on the ground so we can keep in touch for future stories. But now we will be moving into the rundown. And for those of you who may be joining us for the first time, we cannot cover every frontier and breaking science research story every week because there is so much happening in every aspect and every vertical. However, we reserve the rundown to cover briefly some stories that we are fascinated by but do not have the time to always cover in full in the way that we want to on the pod. And