Artemis II: Deep Dive on the Moon Flyby, Earthset, and Reentry

0:00This is pretty historic. It marks the first time that humans are back near the moon since 1972. >> Everyone except for those four are in that sliver. It's It's just such >> That's where all of humanity is. Right? And they're going across more than half of the Earth in order to dump all of that kinetic energy. >> Hello internet. This is your captain

Intro — Artemis II is headed home

0:23speaking Lester NRA joined as always by my co-host and our resident PhD Krishan Chaundry. We have a very special episode for you all this week. We are awaiting the return of the Artemis 2 crew on Friday. They are currently on their way back from the moon and we will be covering all the things about this historic mission from the ground up because this is from First Principles.

Why this mission is historic

1:07>> Artemis 2 just flew past the moon a few days ago and what they saw has not been seen by human eyes ever. Okay? It's April 2026. This is pretty historic. It marks the first time that humans are back near the moon since 1972 when Apollo 17 landed. And yes, they did in fact land. Um the whole point of this mission was

Mission goals and episode roadmap

1:34to have a highly complex and crude test flight for future operations on the moon when we're going to build a base on the moon, maybe even a nuclear reactor, all sorts of crazy things to really start having a permanent presence on the moon. And in this episode, you know, a few days after their historic flyby, I wanted to focus on a few things. One, I wanted to give a photo by photo recap of the mission and the science that was done because the photos are just absolutely incredible.

Launch recap and why the pad is flooded with water

2:03Um, and then second, I wanted to focus on re-entry, which is coming up in a few days, some of the challenges, and what we should be looking forward to. Okay? So, first let's start with the launch. We started with the space launch system, which um Lester created with LEGO cuz apparently that is the >> No plural. >> Yeah, no plural. LEGO is the plural. This is a video that was taken from a camera that was mounted on the space launch system. And if you notice, there was a lot of water that was sprayed on the launch platform. That's there just to dissipate sound. That's the primary reason. Like it also absorbs heat, but one of the

2:43main things that comes out of a launch of a rocket like this is there's a lot of sound, and that sound can damage the platform, and it can also bounce back and damage the rocket. So, the water is all there to absorb all of that. And all of that plume that you see, most of that is actually steam >> Interesting. >> from that rocket. >> Interesting. >> And I think I think it's it's really cool to see that vantage point because we didn't see this live, but now we're getting to see this, you know, sort of after the data's come come back. >> Yes. >> Very, very cool. So, it launched into space out of complex 39B at the Kennedy Space Center. And the second video that we have, we're showing the separation of the solid rocket boosters, which are

3:24these white two things on either end. It looks kind of like the space shuttle >> Yes. >> minus the actual space shuttle, but this is how you would launch. And there the solid rocket boosters are separating, and the main stage is still firing to get us into the high Earth orbit. Okay? Once we do that this was all within That was about 8 and 1/2 minutes after launch. >> Okay. >> Okay? At about 8 and 1/2 minutes after launch

Core stage separation

3:50is when the core stage, right here, separates from the top. >> Mhm. >> Okay? So, the orange is what's going away. The bottom is what you're seeing is the actual um core stage separating. So, there's a camera up here that's looking out >> Yep. >> to the main Orion capsule plus a little bit. >> Yes. >> And all of the white particulate matter is actually ice and ice particulates that have crystallized because when you load up >> Mhm. >> it gets really, really cold just because of PV equals nRT. You're compressing a lot of gas into a high pressure inside this. So, the temperature has to drop, right? Um everything went really well.

4:31And now we've got the Orion spacecraft that went all the way to the moon and came right back. These are the four astronauts that did it.

Meet the Artemis II crew

4:41We've got Reid Wiseman, who's the commander, Victor Glover, the pilot on the right, Christina Koch, who's the mission specialist, and >> specialist. >> And yes, apparently she Dude, she must be the favorite of everyone on that like MVP. >> Yeah. >> Like if if someone if they voted MVP, it would be the one who fixed the toilet. Right, on the way up. >> Right. >> And then finally um Canadian Space Agency astronaut Jeremy Hansen. He's in the corner of there. He It's not because he's Canadian. He's literally bigger than everyone and I think like that's the sort of best This is like the best configuration for everyone to be on camera. >> Right. >> You know? So, it's not because he's Canadian that they just like oh, you get

5:22to Yeah, you you get to be in the corner. It's There's like physical reasons behind it. Um very, very cool and we're going to cover all of the photos that they took and you know, their re-entry procedure. >> Yes, so I just want to take a quick pause for show notes. There are so many of you who may be listening to this pod for the first time. Welcome to the best science show on Earth. We are very happy to have you. My name is Lester, joined by Krishna, as you know, and this show is run by the two of us, where we really try to cover the fundamentals of science from the ground up, which is why this show is called From First Principles. To support what we do, you can like, share, comment, follow. It really helps us get

6:03seen by more people. If you go to ffp pod.com/donate, there are a variety of ways that you can support the show monetarily or not monetarily, and we really do appreciate that exists in so many of you and the love that you give us to continue to do this show. And with that, we will return to the meat and bones of why all of you are here, which is nerding out about Artemis. >> Yes. So, before we get into all of the photos that were taken, you know, whenever it comes to science and whenever it comes to experiments, we always on this show talk about what was the apparatus? What was the method by which you took the data? In this case,

6:44the data is photos. I want to focus a little bit on the cameras that were used on Artemis, okay?

Why NASA used the Nikon D5

6:51Most of the photos that we see come from the Nikon D5. This is a pretty old camera. It's a traditional digital single-lens reflex, so the DSLR that we know and love. It was released in 2016, so it's quite old. The crew also had the Nikon Z9. >> Yes. >> The difference between the two cameras is if we actually if you if you were to pull up that photo again. On the left, we see the Nikon sort of like dissected. >> Yeah. >> The difference between uh DSLR and the Nikon Z9 is the DSLR has a little mirror that takes the light that's coming in from the lens, and part of that light

7:32goes up and is reflected up to an auto-focusing mechanism, okay? And only about 80% of the light tops gets through to the CMOS detector at the end. So, you would think that, you know, this is an old camera and it's got this mirror mechanism, which means not all of the light is coming through. Why is NASA still using this super old camera? >> Uh nepotism or nostalgia is my guess. >> Yeah, it's it's science. It's actually it's actually a well-thought-out. The basic idea is that the D5, the Nikon D5, was selected because of sensor physics and extreme low-light performance. Yeah, that makes sense.

8:12First, let's get into the low-light performance. The D5, the Nikon D5, is engineered to maximize high ISO. ISO is, for all the photographers out there, it's effectively one of the triangles of exposure, aperture, and ISO. It lets you control just how much light you're putting in and how high fidelity you can make your image with really, really low light, right? The Nikon D5 has a maximum ISO of 3 million. >> That's so crazy cuz we're we have these cameras that I manipulate the triangle that you're talking about. We don't have 3 million.

8:53>> No, we I don't think we would need 3 million given our like studio lights, right? >> If you have a podcast in the dark. >> Yeah, yeah, then we probably would. The Apollo era film cameras, the Hasselblads, they had a ISO of 160. So, several orders of magnitude lower. And the Nikon Z9, which don't have this mirror mechanism, that just goes straight from lens all the way to um CMOS detector. >> Yes. >> Those only top out at 102,000. So, from 3 million to 102,000, it's a very good reason why we would want to use this Nikon D5. >> Yeah, that makes sense. >> right? Okay. So, the other big thing about the Nikon D5 is it features a pretty modest 20-megapixel sensor.

9:35That's the CMOS sensor inside of it. 20 megapixels nowadays is not a lot. Back Back in the day when I was like, you know, getting into cameras, 20 megapixels was a lot. But that lower megapixel count, what that actually means is each of the pixels, each of the photodiodes on my CMOS sensor is larger. Literally physically larger. If you were to fit more pixels in, the each of the sensors would actually be smaller. Each of the pixels would be smaller. And what that means is you've got a greater full well capacity. >> Okay. >> collecting more photons >> Mhm. >> before getting saturated. >> Yeah, yeah, yeah. Yeah, okay. >> And that's huge for low-light scenarios, okay? >> Right. You You're getting more original data before you start manipulating with

10:17computational photography. All the All the I should say processing. Yeah, cuz computational photography is a term of art that's specific. Just the processing. >> Exactly. We can get the raw data and that can have a lot higher fidelity is the idea. And the other big thing is that deep space exposes your electronics to galactic cosmic rays, solar particles, all kinds of stuff, right? And so NASA has already used the Nikon D5 on the ISS. And they know that at least it's going to work. >> Right. >> Right? It works on the ISS. And now with Artemis, we're leaving the Earth's sphere of influence, right? Oh, we're

10:57we're leaving the Van Allen belts. What's going to happen? What's going to happen? Right? Everyone's like, oh, what's going to happen? Well, actually that's a concern if you have electronics because the Van Allen belts which trap all of that radiation are no longer there to shield you, right? And the the magnetic field, I should say, of the Earth are no longer there to shield you. So when you get out of there, now you're just the cosmic rays are just coming and the Earth's magnetic field isn't strong enough at that vantage point to really stru you know, perturb those galactic cosmic rays Yep. those high-energy particles. So we know that the D5 works on the ISS and we can take a gamble that perhaps they

11:38will work when we go outside of the Van Allen belts, right? We don't want to start testing new electronics equipment when we're in this like high radiation space in deep space. >> This is actually a really interesting point I don't think I've ever thought about which is you know when you have to go into production as we say in software engineering, right? You have a test environment which for NASA might be the pool, it might be the desert. >> Or in this case the ISS, the International Space Station, low Earth orbit. >> Where you're in an you're in the environment that you want your outcome to happen in. And so you're trying to replicate the dynamics of that environment. Uh so that you know that when you test you can only do so much. >> Yeah.

Translunar injection explained

12:18>> Um and this is one of the situations where production there's very few people who make it to production. >> Yeah. Yeah, four four four people made it to production here, right? And it's like we better give them a camera that we know is going to work. So, the astronauts also have the newer Nikon Z7 or sorry, the Z9. But NASA was like, "No, no, no. This is going to be your primary because we know it works. The low light sensitivity is good and we just know that the the sensor electronics are robust to whatever random crap you're going to be thrown at." >> Yes. Yes, we're we don't want to test new stuff uh on the first try. >> No. No, not at all, right? And so now

12:58let's finally get to the photographs because these were just absolutely amazing. The first set of photographs that I'm going to talk about is right after the trans lunar injection burn. So, this was Artemis did a high elliptical orbit around the Earth to check that everything was working and then they powered up their engines, which is right down here. >> Yes. >> Did a trans lunar injection burn so they gained velocity and now they're going straight to the moon. >> I I want to pause here really quick because I I just want to when you talk about the translunar injection burn, just to help people understand, we touched on this briefly in our recap of Artemis, but I think it's helpful when you What do you mean when you say that?

13:41>> So, what I mean when I say that is Artemis, like any other object out in space, is orbiting the Earth because it's got some velocity, and so the Earth keeps pulling on it, and as it pulls on it, the Earth pulls back, and you're going to do some kind of orbit. Now, before the translunar injection burn, we had a high elliptical orbit where we went, I think something like 35,000 mi, which is like a sixth of the way to the moon, just to test out all of the components here because this stuff hasn't been tested on manned crew expeditions. As we're returning, >> and we're returning because we're being pulled back to Earth by the Earth's gravity. >> by the by the Earth's gravity. Now, as we're returning, we're going to gain speed.

14:21When we're closest to the Earth, if we burn all of the engines that are down here, we're going to gain velocity, and when we gain velocity, that means we're going to gain kinetic energy. From undergrad physics, we know that, you know, energy is always balanced. So, when we gain kinetic energy here, as we move farther away, we're going to attain a higher height. Right? It's like if we if we throw a baseball at a high velocity, it's going to reach a higher height. That's I mean, that's how home runs work, right? You got to really get the sweet spot and really knock that thing out of the park. How do we do that? The the velocity of the baseball right after it hits the bat has to be really high, and the angle has

15:03to be exactly right to go all the way into the stands. >> Which is why we don't see home runs on these new 40-mph pitches that we've seen coming. >> Oh, I haven't >> Cuz it's mostly because people can't hit it. >> Yeah. >> Yeah, exactly. That's probably why. Must have been the Blue Jays. No. >> I I'm going to leave that one where it is. >> Yeah, yeah, yeah. There's a Look, it is what it is. Um so, I What What was I saying? It was The idea is we want to attain a high velocity when we're leaving Earth. >> Right. >> And that way we can attain a high height. Height meaning a distance from the Earth. And that's what that trans inject translunar injection is doing.

15:44There's engines at the back of this white part here that are going to expend all of their fuel and they're going to attain that high velocity so that we're throwing this baseball, this entire thing, all the way to the moon and then it's going to come back. >> And not to be pedantic, but when you say velocity, you're saying we're just turning it the dial to 11 and saying let's go as fast as possible that direction at a very specific time as we're coming back from that high elliptical orbit. Yeah. And so, we're just putting a bunch of juice, thrust, through the back that's going to shoot us off at a moment of also where the Earth's gravity

16:24and how it's impacting the craft is going to assist us in getting more height than we otherwise would if we were just putting that amount of thrust behind us without the assistance of Earth's gravity. >> Yes, I mean, we're we're fighting Earth's gravity is the thing, right? We We used Earth's gravity to gain that velocity back. >> Yes. >> And then and then now we're doing that burn to gain more velocity using the Oberth effect and then we're going to get even higher. >> Got it. >> Right? That's the idea. It's like It's like when the ball bounces back, as it's bouncing back, we like push it even more, you know? And then and then it's going to go even higher. >> Yep. >> Right? That's the idea. It's kind of like if you bounce the ball on a

17:05trampoline, the trampoline is this translunar injection burn in some sense. You know what I mean? >> I just wanted to harp on that a little bit because there has been some discussion and I think a little bit of confusion about the intersection between Earth's gravity, the craft, what does it mean that it's falling back to the Earth? What do we mean by escaping that gravity? So, that I think that's really helpful. >> Yeah. And so, if we go back to photo number nine, if you don't mind. >> Yes. >> Um these are two photos that were taken

The first deep-space Earth photos

17:34around basically the same time. I think within a minute of the two. Um one shows sort of what your eyes would see, which is on the left-hand side, you've got the the tiny sliver of the atmosphere where the sun is leaking through. We're in the shadow of the Earth right now. >> Right. >> We're in the shadow of the Earth, and most of the Earth is dark. But, if you increase the exposure time, and you increase the aperture, then you're going to get to see the Earth in that low light, because you've sort of the ISO at this point is like I think 50,000, right? That's that >> Yep. >> Nikon D5 ISO, right? >> Yes. >> And I wanted to harp on this particular image a little bit longer, because I

18:15think there's a few details that are really, really cool. So, let's go to some of the insets that I've prepared. Um if we go to the next photo, which is photo number 10. So, this is in the lower left corner of

Aurora, zodiacal light, and seeing Earth from Orion

18:26that image. What we're seeing is some kind of landmass. And a lot of people were really confused. Like, oh, what part of Earth is that? >> Uh-huh. >> That part of Earth is Europe and Africa and the Mediterranean Strait and the Gibraltar Strait there, >> Right. >> upside down. >> I was going to say the uh flip. Yeah, yeah yeah. >> It's us, it's upside down, because the Europeans conquered the world. And so, north is like where Europe is. But, I think what's cool about this photo is that it shows it's completely arbitrary. >> Yeah, yeah, yeah. >> Right? Which way is north and which way is south? We've just decided, but on the right-hand side, it shows a inset of a map where the Earth is actually upside down, but the text is correct

19:07>> Yes. >> correctly like, you know, positioned. It it it I I think it's really cool exercise in like knowing, "Okay, actually it's completely arbitrary in space." >> Which way is down, which way is up. >> For those who are listening, we're looking at the map and we see Libya and Algeria at the top. >> And Morocco. >> And Morocco above like Spain, Portugal, etc. >> Yeah. >> Uh it's such a bizarre >> Yeah, it's it's a bizarre thing to see because usually we see the Mediterranean and that area, you know, turned around. But I'm just saying it's completely arbitrary and I think that image kind of proves that. >> Yeah. >> It's kind of cool. The other thing we see on this image is in the left-hand side we see faint glows, uh greenish glows. That's the aurora

19:49>> Yes. >> in the northern hemisphere, the aurora borealis. If we go to the next photo, >> Yes. >> we will see the aurora australis, which is over the South Pole. That's where the magnetic field of the Earth is coming out, interacting with those particles. So the all of the particles from the Van Van Allen belt, you know, I said the Van Allen belt is a donut, right? >> Yes. >> Well, the donut has to intersect >> somewhere. >> with the Earth somewhere and it intersects at the north and south magnetic poles. And when it intersects, you get the beautiful aurora northern and southern lights. In this case, we're seeing the southern lights. >> Yes. >> Right? >> Yes, beautiful. >> Absolutely beautiful. And finally at the bottom right corner, we see a tiny glow

20:30>> I love this photo. >> right? Coming out of the Earth. >> Yeah. >> That glow in deep space is called a zodiacal light. >> Oh. >> So, there is dust that is trapped in the same plane as all of the planets. >> Thankfully not nuclear dust, but that's not nice. >> just normal dust. And if you're really lucky as a photographer, you can observe the zodiacal light on Earth right after sunset, right before sunrise. On the right-hand side we see Jupiter and Venus, so that we know that the plane of the zodiac is over there, right? Because that's where the planetary plane is. And you can see the sort of glow of dust. That dust is literally just dust hanging around that never got to any

21:11The dust is stuff that never got to any planet and it's just there in our plane, but it's scattering off the sunlight and we're seeing that. And so on the right-hand side we see it from Earth if you have perfect conditions and on the left-hand side you see the zodiacal light sort of out in deep space. Just absolutely wonderful. >> In California we we like to try to pretend we call this golden hour, but this is above what we get as golden hour. >> Yeah, yeah, yeah. This is You'd have to go like way out in like Joshua Tree or something to see zodiacal light. We have too much light pollution around LA to see this kind of stuff. >> sense. That makes sense. >> You know? And as you get farther away from Earth

When Earth and Moon looked the same size

21:50so that was right after the translunar injection. They were maybe an hour or two into the whole thing. As you get farther and away from Earth you start seeing the moon which is there in the image and I don't know if you can see but there's a tiny crescent in the lower left where astronauts Glover and um Jeremy Hansen they're looking at this tiny crescent. That's the Earth. So the Earth is getting smaller and smaller in the window and the moon is getting a little bit bigger. And at this point I think the moon and the Earth were the same size even though the moon is about, you know, a sixth of the size of the Earth. It they're at this distance where now

22:30the moon and the Earth are the same size. >> That's so bizarre. >> it's just crazy, dude, that we're going so far. >> We're going so far. >> We're going so far compared to what we've been doing for the past 50 years. >> Oh my gosh, it's just I I I thought it was really, really cool. >> you love to see it. >> Right? >> And and I I think it's really important to kind of that we again on this pod because we talk about it from first principles, not just show the photos but explain the camera selection, why the camera selection looks different, how it impacts what we're viewing, I think it was really important that you made the note that this is what the eye sees versus this is what we get out of the

23:11camera because it basically has boosted stats as compared to our eyes. >> Yeah. Well, there's a there's a caveat there which I'm going to get to later which is our eye also has boosted stats compared to cameras. So, we'll we'll be getting to that a little bit later because >> I promise that was not planned everybody. >> So, before before we move on to getting

Why Artemis II can see more than Apollo did

23:30closer to the moon, I want to do a quick recap of what the Apollo astronauts saw when they got to the moon and why Artemis is so different compared to what Apollo saw. The Apollo astronauts did not see everything. Okay? They flew very close to the moon. So, over here we we keep hearing about the record that was broken, right? Artemis 2 is going to be the farthest humans ever in the history of ever. >> Yes. >> Okay? The reason for that is that Artemis 2 is really far away from even the moon. On the lower picture there you're seeing where Apollo 13 was, very close to the surface, only about hundreds of miles

24:11away from the moon. >> Yes. >> Apollo Artemis 2 is thousands of miles away from the moon. It's overshooting the moon by quite a bit. >> Okay? And so that's why it's so much farther. Now, that gives us two advantages okay? The first advantage is you get to see big big parts of the moon. >> Right. >> Right? And so, what I mean by that is if you look at what the Apollo astronauts were doing, they didn't actually see everything. This is a map of what the Apollo astronauts saw. If you're close to the moon, you're going to run into a horizon issue. >> Okay. >> Right? Because imagine you're close to a round body. >> Yeah. Yeah. Yeah. >> So, you can only look so far. Even even

24:52up here, if you go to the beach, right? You can't see >> Right. >> Because the earth is not flat. Like you can't see all the way, right? There's going to be some limit to what you can see. Despite how high you get, if you don't get high enough to really see the entire circle, there's still going to be a horizon issue. So, over here what we're seeing is the the lighter regions >> Yes. >> are what the Apollo astronauts saw. >> Mhm. >> And you can see that the poles >> Yes. >> really see because imagine, you're going around the moon like this. >> Yeah. >> You can't see past the horizon. >> Right. They just saw the middle belt. >> Mhm. >> Right. >> Because you're so close to the to the to the surface of the moon, only hundreds of miles. On the other hand, Artemis is going to be pretty far away.

25:34>> Right. >> So, it's going to be able to see the entire thing. And one of the cool things that that that was happening was, you know, this is going to be their first time these four individuals is going to be the first time going around the moon. It's going to be the first time that humanity is going to be this far away. They're going to have like, you know, uh the course of like 5 hours to observe the whole thing. You got to do dry runs. >> Right. Okay. >> It can't be the first time that you're seeing everything and like trying to plan, "Oh, point the camera here. Point the camera there." So, NASA very astutely had practice runs at their mission control center where on the right you see Reid Wiseman, the commander, and Jeremy Hansen with the Nikon D5 camera and the lenses that they're going to use. And they're

26:14practicing what the moon will look like. They're exactly the right distance away >> Yeah. >> to to have the moon be how big they would see it. >> Yeah. Yeah. >> And they're like, "Okay, when we get to this part," the science team is telling them, "I need you to take photos of See that crater there? I need you to take photos of that crater with high fidelity. I need you to when you get to this part, as the moon is turning around, I need you to get over here." So, there's a dry run and a practice run. It's not their first time that they're like seeing this. Obviously, it's different when you're up there, >> Yes. >> but like to have that dry run is super important. >> That's so that's so interesting. I love that they're giving they're going through basically like fo- photography tutorial class. >> Yeah. >> Which again, I think you know, the the functions that

26:56an astronaut needs to be not only competent but exceptional in are so so orthogonal to each other. All right, you have to be under you understand how to a camera, you have to be an engineer, you have to know math, you have to be able to fly. Like I know I'm I'm being a little I know different members of the crew are exceptional in different categories. But this is why a lot of space TV shows and stuff where like society is spacefaring, I'm like not this society in its current state. Because just because the the level of like rigor >> Yeah. >> that you need to actually commit to uh to survive in space >> Yeah.

27:36>> uh long term is non-trivial. >> Exactly. I I think that's a really good point and there's a lot of practice involved. >> Yes. Yes. >> Right? It's not just you're just winging it. >> You don't put >> You can't do that. >> Yeah, right. Right. >> When you've got 5 hours to do one of the greatest things that humanity has done over the past 50 years, right? So I thought that was really cool that they're just straight up practicing. >> I just also want to say that we appreciate and respect this in every other space. When athletes talk about oh I trained hard and people go to the gym like goals like fit goals and all this stuff. Like clearly we know in everyday life that quote unquote what they told us in school practice makes perfect. >> Yeah. >> Right? It's very like understandable.

28:17>> Yeah. >> And yet when we go to space everyone just like forget like there's this weird thing where they're like >> why why aren't we landing? It's like no, we didn't practice.

Far side of the Moon geology explained

28:25>> Like we just it's just it's very simple like you know, and I I don't I just don't >> That's so true. >> Anyway. >> That's so true. Okay, so moving on. One one of the things that I want to talk about was the far side of the moon, which I'm sorry that in the last episode I kept saying dark side of the moon. I'm a big fan of Pink Floyd and I think that brain worm got into my head. >> Also, when we don't know stuff we call it dark like dark matter and dark energy. >> Yeah, yeah, but th- this one was was I I just like associated the Pink Floyd album to like that side. But by I I always meant far side of the moon because there's one part of the moon that we never get to see as humans on Earth because the moon rotates at the

29:06same rate that it revolves around the Earth. So, you know, my hand is pointing over here. If the moon was rotating faster than it evolves, then the moon would have a day-night cycle compared to Earth, right? But like because the moon is rotating at the same rate, the the the sort of the moon goes like this and I will only see that part, you know? And so the far side of the moon is in this case the back of my hand. We don't get to see that a lot. And so that was a big deal. This is a photo of Artemis 2 approaching the moon and you can see a stark difference between the near side of the moon, which is what we normally see, and that far side of the moon. Biggest difference is there's all these like gray areas >> Mhm. >> of like flat mare is what they're

29:49called. >> That's a mare. >> Yeah. Yeah, I I think it means seas. So maybe that's I don't know if that has anything to do with love. >> no, no, it doesn't. It doesn't. >> But Yeah. In any case, the you you see these flat sort of dark gray areas compared to the light gray that's only what you see on the far side. Um one of the cooling cool things that I learned about was why is the far side so different from the near side. The near side has all of these dark gray regions. Effectively, what's happening is it's because of the Earth. >> Okay. >> The side of the moon that is facing the Earth is going to have a greater gravitational

30:30attraction towards the Earth >> Mhm. >> compared to the side that's away. What does that mean? That means that if you've got heavy elements inside the moon during its formation, they're going to be lopsided. They're going to be ah especially given that tidal lock that I was telling you about. >> Yes. >> More of the heavy elements, those radioactive elements that are high up on the periodic table, are going to be closer to the Earth than they are to the far side. >> Because of the gravitational >> Because of the gravitation. What that means is there's going to be lopsided volcanic activity. >> Mhm. >> There's going to be geologic activity on the side that's facing us because the Earth keeps pulling those radioactive elements, but on the other side, you're not going to get that geologic activity.

31:11>> sense. >> Right? >> That makes sense. >> And so the mare are really these like basalt volcanic plains where you had geologic activity. And on the other side the craters are coming in, but there's nothing there's no lava that's outpouring to flatten everything up. And early early in the moon's history in the solar system history, there was bombardment right? 3.8 billion years ago, there was this thing called late heavy bombardment. And so on the far side, you're going to get a lot of that bombardment, it's not going to get clean washed away. This is a photo from the far side, and one of the main features that the Artemis crew was told to focus on because we never see it from our side

31:51is this like giant crater that you see there. It's called a Mare Orientale, the Oriental Basin. It's a giant meteor impact with multiple rings >> Mhm. >> around it. >> Okay. >> Something very cool. The initial crater that formed is no longer active. When that initial crater happened, it sort of emulsified the lunar surface, and there was ringing that happened. You can imagine ripples >> Ah. >> in the actual moon's crust. >> Yeah, yeah, yeah, yeah. >> And those ripples hardened into rings. There's an inner ring and an outer ring. >> Ah, that's so nice. >> Isn't that so cool >> Yeah, that's very nice. Yeah, yeah, yeah yeah. >> It over several hours, people have done modeling, and it takes like several hours for that ringing to happen cuz

32:33it's literally lava >> Right. >> that's ringing at some point, right? >> It's like a wave pool but a little slower cuz it's lava. Yeah, it's super viscous like molten rock. But at the end of the day, you're getting these rings from those ripples solidifying on the lunar surface. Very, very cool. So, they got to the far side of the moon. The far side of the moon has a lot of craters, some of which are unnamed.

Naming craters and the Carol Wiseman tribute

32:59The crew decided to name two craters. I thought this was very cool. The first one was named after integrity, which is the name that they gave to their Orion capsule. So, a lot of times, you know, when NASA mission control was talking to Orion, they'd be like, "Integrity, how's it going?" Things like that. That's because integrity is the name of this With integrity, I'm always reminded of like that South Park episode, Integrity Farms. Integrity Farms. The like the the the marijuana farm that that Stan does. So, like it's it's it's a good name, but like to me, I'm just like always like, "Oh, so there's like Integrity Farms that's going around the moon." Anyways, the second crater is actually really

33:40cool. It's named after Commander Reid a Wiseman's late wife who died of cancer in 2020. This crew, the four of them, have been together for a very long time, right? They've been practicing for this for a very long time. This has been something that NASA has been looking forward to. And so, they knew Carol Wiseman. And when she died of cancer in 2020, it was obviously very unfortunate. Commander Reid, like a single father, still going to the moon, you know, leaving behind his two daughters on Earth. Like that takes cajones. >> Look, we saw this play out in the movie Interstellar literally. >> Literally, actually.

34:20>> He had two kids. It wasn't two daughters. It was a son and a daughter. >> That's No, dude, he's literally Matthew McConaughey. >> In Interstellar. I mean, and it's it's there's a real emotional toll. Um, especially if you're, you know, a widow. >> Yeah. >> Um and you're an astronaut. >> Yeah. Dude, that's that's crazy. Yeah, I didn't even think about that. But yeah, so um the the crew named a crater after Carol Wiseman, which is I think pretty cool. >> Shout out to the crew. That's awesome. >> Yeah, kind of a hard high bar to set for all the other dudes on Earth, but you know, I I get it. >> Anyway, very nice. >> Yeah, it's great. Um I I thought that was just a really cool gesture. Um you know,

35:00it just the human part of the story I think is just pretty awesome. >> And it it is always a part of the story. I think one of the things that is so interesting when I watch space movies is there's all the cool science and technical aspects, but you can't have a space movie without the human story. >> Yeah. >> Cuz it just would be a little bit empty. >> Yeah. Yeah. The next image is the one that Commander Reed Wiseman took. Um the F 408. >> Oh, sorry. Excuse me.

Earthset

35:33>> This is the one that's very very famous. >> Oh, yeah, yeah, yeah. >> This is called Earth set, taken by Commander Reed Wiseman with his Nikon D5. >> The D5. >> It's captured an image showing the crescent of the Earth setting behind the moon >> Yes. >> as the Orion integrity capsule goes around. >> Yes. >> You know, absolutely beautiful to think, right? Just staggering detail that you see on the moon, on the Earth. It's a counterpart to Earth rise from Apollo 8, which is one of the most famous photos ever taken. I think this is going to be another one of these most famous photos ever taken. >> I think we need a monologue because when we had

36:14Carl Sagan around, he was phenomenal at orating these types of moments. So, I'm just arbitrarily bestowing you with that responsibility. >> Yeah, I'll I'll come up with something. But the next one is my favorite. Um and that is the one that I had

The Earth-and-Moon photo

36:28predicted many, many episodes ago. >> Yes. >> Because we had gotten data about where the Orion was going to be and how far away from the moon it was going to be. And I said, "If they're that far away, then there should be an opportunity to get the moon and the Earth in the same shot. The entire moon." >> The entire, right. >> And here we see that. The entire visible part of the moon and the Earth in the same shot. They have the same crescent facing the same direction because in this case the moon the the sun, where all the light is coming from, is you know, up. >> It's from the top of the screen. I just want to know, if you're still listening and not watching this particular episode, we really encourage you to to take a a

37:09watch because the imagery is incredible. So, what we're saying is the sun's coming in from the top, which is why the top of both spheres >> Yeah, is the same crescent in the same direction. And it's just absolutely a phenomenal photo because it shows just how small Earth is compared to the big moon. The moon is much smaller than the Earth, but here in this perspective, they're so far away that the Earth is so small. The Earth is so small that it's about the size of what the moon is to us, which means they could they could put up their thumb or a few fingers and cover up the entire Earth with a few fingers. >> Classic saying, "I've got the whole world >> billion, close to 8 billion people just like that. And there's four people behind that photo.

37:50>> It's It's almost everybody except the people on the ISS and any classified missions. >> No, even the ISS is right there. >> there. Yeah, like, "No, no, no, it's so close to >> Yeah. >> Is similar >> Everyone The classified missions, I'm not so sure. I don't know where they are. But, everyone except for those four are in that sliver. >> It's It's just such >> That's where all of humanity is. Right? >> Everyone you know. >> Yeah. >> Everyone you love. >> Yeah. All of the wars, all of everything. And so, that that that is by far my favorite photo that has come out of this mission. >> And it's we covered it in our February episode when Artemis was originally supposed to launch and I understood what you were saying.

38:30>> Mhm. >> But obviously I didn't visualize and kind of internalize the emotional connection to like what it feels like to see us in that context. >> Yeah. >> It's pretty it's pretty insane. I know we've seen it kind of before, right? With the one you mentioned earlier, but this is I'm alive for this one. >> You know what I mean? >> Yeah, and it's like and there was a human being behind that photo that literally saw that out his window. >> Yes. >> window. >> Yes. >> Right? >> Yeah. >> Oh my gosh. >> It's quite nice. >> One of the cool things that they were doing on this lunar flyby, I was watching the live stream and they were using camera shrouds to protect from the glare of the internal lights because you

39:10can imagine if the lights are on and I'm trying to take a photo through a window, then the lights are going to bounce off the window and they're going to get into the photo, right? So so they had these camera shrouds where it would cover the entire window, but it would have a hole where the lens could go through. >> Mhm. >> Now, one of the funniest things was they reported that the Earth from the other window was too bright. And so NASA was like, "I don't know they use a t-shirt." And they used a t-shirt to cover up the Earth because the Earth was coming in from the other window and ruining the photographs. And it just goes to show that like you can't think of everything. >> No, you can't. >> Yeah, yeah, yeah. >> So when you're up there, you've got like time is running out. We're we're going

39:51around the moon at thousands of kilometers an hour and time is running out. What do we do? Okay, sure. Like just put a shirt like it's like stuff that I would think of, you know? >> Yes. >> On like if I did a astrophotography thing, it's like, "Okay, let's put a shirt around the telescope because this random light is coming through." >> No, they and they this is after having done training on the ground for how to shoot and it's like, "Oh, we forgot that there's a window over there." >> There's a a over there and the Earth is going to be exactly at the right spot that it's like coming in and like it's actually hella bright. >> Yeah, yeah, yeah. >> You know, for some reason. >> Yeah. >> If If anyone's tried to take a photo with your iPhone, right? Uh like and I mean you we all see it. You get the glare and the reflection and all kinds

40:32of stuff. >> Yeah, and if there's another even even if the photo even if the um the light source is not in the photo frame, >> Right. >> it's going to So, one of the good ways to do it is just to put something over. >> Yeah, yeah. >> And >> Yeah, that would make sense. >> block >> that light, right? Okay, so finally, now that they've had Earth set, >> Yes. >> cuz the Earth is set, now they're going around the Moon. >> Yes. >> And now the Sun is going to set around the Moon. >> Yes. >> But if the Sun sets around the Moon, that's a eclipse. >> Yes. >> Right? That's a solar eclipse, so you need some solar eclipse glasses. >> Yes. >> So, they put on their solar eclipse

Solar eclipse and Earthshine

41:08glasses to watch the Sun set. >> Yeah. >> And then once they're in total solar eclipse territory, which we saw >> Yes. >> in Texas, now you can remove your glasses and you can see the actual solar um eclipse. So, before we get into that, I actually I want I want to show one more photo, which is the solar eclipse lasted about 54 minutes and that's what it looks like. The Sun is behind the Moon. The Earth is pointing up here and so you see that crescent on the Moon. >> Yeah, yeah. >> Where is that light coming from? >> I don't know. >> That's from the Earth. >> Earth. As it's pass as the light is passing from the

41:48Sun across the Earth and it >> It's bouncing off the Earth. The Earth is literally so bright >> That's so crazy. >> that it is creating a crescent on the Moon. It's acting like another sort of lighting light source, you know? >> Light light >> movies, right? There's like the primary light source, it's behind, but there's a secondary light source from the Earth that is bouncing >> Yeah. >> light >> Yeah. >> to the Moon. >> Yeah. We got a hair light. >> Yeah, it's called Earth shine. >> This is >> Earth set, Earth shine. Uh these are I didn't this >> Just incredible. Incredible photographs. And there are around the moon you see the corona, which is the sun's outer atmosphere >> Right.

42:28>> that is spewing out solar wind and all sorts of other stuff. There's a lot of really cool helio physics that goes on in the corona. One of the biggest unsolved mysteries about the sun is why is the corona so hot? >> Right. >> 2 million Kelvin, 2 million degrees Celsius. Really shouldn't be >> Right. >> given that the surface of the sun is only like 6,000 degrees Celsius. >> Mhm. >> So, why is the outer outer atmosphere the same temperature as the core when you've got the photosphere, the outer surface of the sun at like 6,000? >> Yep. >> You you go you go from millions to 6,000 back to millions. Doesn't make any sense. >> Doesn't make any sense. >> So, this is one of the things that astronomers are working on. We've got a pretty good handle on it. Has to do with

43:09magnetic fields and things like that. But, it's always nice to, you know, observe and get more data. >> Yes. >> Um one of the things that I wanted to

Predicting the planets with an Apple Watch

43:17talk about and linger on the solar eclipse a little bit more was to try and predict where the planets should be >> Right. >> if we take a photo of the solar eclipse. Because with the solar eclipse you're blocking out the sun, so now you can see planets that are behind the sun. On the sideways you can see the entire solar system without having the sun blind you. >> Okay. >> So, >> So, just for all my astrology, you know, people >> Mhm. >> who care about planet alignments, this seems like this is a a moment to lean in. >> Exactly. Yeah. Here we're going. How are the planets aligned around the moon >> Yeah. >> comes to the solar eclipse from the vantage point of Artemis that's going around.

43:58>> Right, because we've never had this discussion >> Yeah. >> before. >> Yeah. >> Really. >> Yeah. >> Because it's never been practical to or that's never been a thing. >> So, to do this I wanted you uh right before this episode, I had you take a photo of your Apple Watch where the Apple Watch has a feature where you can look at where the planets are right now. Right? There's a way to I think is it is it part of the safety like >> Yeah, so if you if you have an Apple Watch right now, you probably know that you can install different watch faces on your Apple Watch. So, you can have a photo, you can have a bunch of graphs about your activity, or you can have the literal position of the planets in real time

44:38in context of where you are on Earth. >> Yeah, like at this moment. >> Which is I didn't know this until you brought this up to me earlier today. >> cool, right? And so here what we're seeing is the sun in the center obviously. You've got Earth, Venus, Mercury, Mars, Saturn, okay? And from this, what I want to do is predict from your Apple Watch, where are the planets going to be in that photo of the moon solar the the solar eclipse that Artemis saw. Okay? >> This is this this is I'm so excited about this. I just want everyone to know Christian did not tell me about this. And so I'm very excited. >> be this is going to be really cool. So, let's move on to the next photo where I have a bit higher fidelity photograph.

45:19>> Okay. >> Um the Earth is where the the moon is actually where where that is. The the where the rays are coming out. So, the Earth is right there. It's kind of occluded by all the lines that I drew. But the the source of all of these rays is where the moon is. >> Got it. >> We've got a center line that passes from the moon to the sun. >> Yes. >> Okay? That's the white line. >> In white, yes. >> That is the direction you would be looking if you looked through the moon because the sun is behind the moon. Yes? >> And based on the photos we were just looking at, uh which is why that light source is happening. We had the crescent on the moon from the Earth, but the light the like the larger >> Yeah, the larger big glow is because the sun is behind the moon. So, basically if

46:00you were to draw a line from the moon to the sun, that would be that white line. >> Yes. >> Okay? And now let's look at the positions of the planets, Mercury, Mars, Saturn, and Venus. Okay? >> We want to ask, what is the what is the planet that's going to be right next to the sun? You would think naively it would be Mercury because Mercury is right next to the sun. But that's not what matters. What matters is the angle. >> Yeah, yeah, yeah, yeah, yeah, yeah. >> Not physical distance. Right? When it comes to the solar system, what matters is if I'm looking at the sun and I'm and I'm scanning across, what's the first thing with the smallest angle? >> Yeah. So I'm looking at the sun in my my in the center of my view and if I like were to pivot and my angle look left to

46:42the left or the right of this or the left or the right of the sun, what am I going to see first? >> Exactly. That's the question. And according to the positions of all of our planets, the first thing you should see is Saturn. >> Which is interesting. >> Saturn is behind the sun, but it's close to our vantage point. >> It's almost about to pass behind the sun in the same white line that the moon and the sun are in. >> Mhm. Exactly. So Saturn should be first. >> Right. >> Then it should be Mars, which is the red line. And then it should be Mercury. If I were to look to the right >> of the sun. >> Yes. If I were to look to the left of the sun, I should see Venus. >> Got it. >> Okay? So do we agree? >> Yes. >> On the right of the sun, we should see Saturn, Mars, and Mercury because that's

47:24how the angles line up. And on the left of the sun, we should see Venus. >> Let me check my watch. Um yep, I see Saturn to the right. I see Mars to the right. Neptune is kind of further back a little bit in between the two. >> In between, yeah. But in this in this zoomed version, we don't see it. Yeah. But the but Neptune would be in between Saturn and Mars. >> And then I see Venus. I literally am looking at my Apple Watch right now. >> Yeah. Okay, now let's go to the next photograph. Here's the labels. Saturn, Neptune, as you were saying, Mars, and Mercury. >> The I'm telling you guys we didn't manufacture that. Like I literally brought it up >> This is the first time you've seen that. >> That's so funny. Yes.

48:05>> Isn't that cool though? >> That's incredible. >> That like from your Apple Watch you can deduce positions of planets and also positions of planets on photographs from Artemis. >> Right. There are people who are on the far side of the moon. >> Mhm. >> They took a photo. They are able to see the planets because it was during a a solar eclipse. >> Yes. >> From the vantage point of being on the far side of the moon. And literally I just looked at my watch and that is exactly what it looks like. >> Exactly. That's incredible. >> Isn't it cool? It just makes sense. The whole thing, the planets, the positions,

48:45the whole thing makes sense. >> Yes. Yes. That's that That was quite nice. >> It's pretty cool. >> That that that was quite nice. >> Right? >> I I'm I like that. >> Yeah. >> I thought you would. >> You were like, "Oh, I got something special for you this." I was like, "Okay." You can't never surprise me. This was This was quite nice. >> And in the next photo we'll actually see Venus. It's on the left. >> Yes. >> Right? It's peaking out right behind the Artemis module. So the other planets that we saw are would be like, you know, out of frame here. >> Yes, out of frame to the right. >> Yeah. This This >> Pretty cool. >> This is This is quite nice. >> Right? >> Look, if you're not enjoying the this endeavor into curiosity and discovery um

49:25I just I don't know what to tell you. I mean, this is so >> This is like the most fun I've had in a long time. >> Yeah. >> Um in general, just it's been so much happening. And there's so much information and detail and conversation and this is where I know you and I both love to kind of dig in is in the substance. >> Yeah. >> Cuz there's headlines and oh there But like >> No, but it makes sense. If you just If you just peel away the layers a little bit and you think about it. It's like, yeah, no, the thing that you saw in the Apple Watch is the thing that the the astronauts saw on Artemis when they were going around the moon. It's so good.

Why the human eye still beats the camera

50:03I I I think that was pretty cool. This is quite nice. Okay. Um we've been focusing a lot on the photographs, but one thing that I don't want to leave out is the human observer. Yes. Okay? So, there are a lot of recorded observations. This is a photograph of I believe Commander Reid Wiseman just looking through the window and taking observations. They had iPads that, you know, cuz when you go to the through the far side of the moon and then the Earth is no longer in view, you can no longer communicate with Earth. But that doesn't mean that you're not going to be taking observations, right? You're going to be taking photographs and you're also going to be relaying

50:43observations about what your human eye is seeing. In some cases, the human eye is worse than cameras, but in a lot of other cases, the human eye is actually vastly superior to any digital camera that we have for deep space observation. The digital sensor has strong limitations. It has to do with the response. Okay? The digital camera uses CMOS sensors. And what it's doing is literally just counting photons and the photons have to excite the silicon atoms, the metal oxide silicon, that's what MOS is, metal oxide silicon. Uh it has to excite the atoms in the sensor to then produce some kind of digital fingerprint that we then record

51:26as data. The human eye uses rods and cones in our retina. The rods are really highly sensitive to low light and the cones are really high-resolution color vision. The big difference, though, comes in their response curve. This is the input-output relationship between how much light is coming in and what you perceive. >> Mhm. >> For a digital camera, how much light is coming in is exactly what you would perceive. If I have 10 photons that come in or 100 photons that come in, I would sense 10 times the brightness, 100 times the brightness, right? Human eye has a logarithmic response.

52:06Here's what that means. In the blue is your linear curve from a camera. If I have 20% of light coming in, I get 20% response. >> Mhm. >> 50% light coming in, 50% response. The human eye is a logarithmic curve, meaning lower light has a much higher >> Yes. >> output. >> Yes. >> Right? So, we are really highly sensitive to that low light condition. >> Shout out evolution. >> Especially It's Shout out evolution. Especially when it comes to going around the moon, being in the eclipse, the corona is going to be this faint glow around the moon. >> Mhm. >> The human observer can see a lot more >> Mhm. >> in real time than a camera ever could. >> Mhm. Mhm. >> Cuz we've had a billion years and a camera what? 100

52:47>> A camera yeah, you're right. >> Right. >> It might get quite nice. >> It might get quite nice, but so far >> Not yet. Not not yet. >> is This is one of those things where biology is just beating um hardware. >> I mean, that that's it's such an interesting cuz we talked about it earlier about this advantage of having what was it? 3 million 1 million 3 million ISO? >> ISO. >> Um on the D the Nikon D5. >> But even then >> Right. And and that's kind of the you know there's a je ne sais quoi right? About the the meat sacks that we're in. >> Yeah. >> Um and our ability to perceive through our core senses, not through uh

53:29how we are able to intuit like in our internal monologue and cognition, but literally just through the input sensors of our physical body. >> Yeah. >> Those input sensors are quite nice. Eyes are quite nice. Maybe the meat fingers could be a little bit better. It's it's it's low the the >> But the eyes are just like insane. And the other thing you might think is like, "Okay, well, if it's just an input-output thing, what if I just like mathematically make the curve the same?" >> Sure. >> Right? If the input is coming in, I could just do that. The other thing that the eye does is it operates via rapid micro movements called saccades. Because the eye, when it's focusing, your eye is not actually perfectly still. It's doing tiny movements.

54:09What the brain is doing is integrating all of those tiny movements into this fully formed conscious experience that we have. But what that means is your signal to noise goes up like crazy because you're doing tiny little movements and taking a bunch of photographs, you can think of, and then you're integrating that. There's a stabilizer in some sense. And so, if if at a particular angle there's like noise, if you if you look just a little bit of this way, just a little bit this way, the fact that the eye is doing these saccades and there's this non-linear integration that's happening in the brain, that's something that you can't replicate with just like straight hardware on a camera.

54:50>> We have the best image stabilization of all time. >> Yeah, it's ridiculous, right? And that image stabilization is creating more signal to noise, right? Right? It's not actually like trying to um like deal with >> stabilize the signal almost. >> Yeah, yeah. It's like when we think about image stabilization with our iPhone, for example, right? Like if we're taking video and we want to upload that to Instagram, there's like internal image image stabilization. But what that's actually doing is taking a a a really bad sort of jittery video and trying to do the best that it can. Here we're actually making it better. >> Right. >> The sensitivity is becoming better. >> Yes. >> Which is which is very non-trivial. It's it's it's quite a distinct difference. >> point. No, it's a really important

55:30point. And and it it that is, you know, I I there's a condition that I can't remember where the the eye movement is a little bit like it's above the baseline. >> Mhm. >> And so it's very visible when you look cuz when you look at somebody and you look at them in the eye. >> Yeah, you can't really tell. >> really tell. >> Yeah, but it's happening all the time. >> happen if it's happening all the time and it it's it's sort of why like you get sort of like you you don't you you'll you're not paying attention and you'll see something in the your periph. >> Yeah. >> And then you'll be like, wait, what was that? >> Yeah, because because it our eyes are and the algorithm in our brain is just so sensitive >> Right. >> to all kinds of stuff. Our algorithm in our brain is also really sensitive to change. >> Right. >> Okay? Like you see a static photo and

56:11then tiny bit changes the the brain is like, what was that? And as you were saying the the observations that the crew got is the first time in history they saw six sudden bright flashes of light on the lunar surface. >> Mhm.

Meteoroid flashes on the Moon

56:29>> Those were meteorites that were impacting the moon. It's the first time that we've ever observed meteorites impacting the moon. They can't get that with their camera because it it it takes too long to oh, I saw it, let me adjust the lens and all this stuff, but your eyes looking at that thing, they saw bright flashes. It's the first time that we got visual con- confirmation visual confirmation of meteorites striking the moon. And these things are going at like 20 km per second because there's no atmosphere to slow them down. >> going to ask you, is part of the reason they are making contact with the surface there's no atmosphere? >> Yeah, these are tiny tiny little things, but because they're going so fast, they're going to pulverize whatever rock. There's going to be a lot of heat and a brief amount of plasma that's

57:11going to form and that's going to release a lot of light and you can actually see that, right? So, they were seeing these flashes. Now, that's huge scientific value because, you know, if we're trying to build something on the moon >> Right. >> like a permanent base, we need to know what's the frequency of these guys and we have never observed them before. So, now we've got some rudimentary ballpark number. Okay, six in the time at least six in the time that they were on the far side when it was completely dark and they could see these flashes. >> So so we're going to need a meteor defense force. >> Yeah. >> An MDF. >> Yeah, or at least like yeah, at least like whatever habitat we build has to be able to withstand these really high impact high velocity >> tiny particles

57:51>> these observations the idea is you can even though it wasn't from a sensor an instrument sensor versus a human sensor we can still quantificate on velocity and such that we can make those preparations accordingly even if it's not explicit or extremely precise in the measurement quality. The fact that we just were able to do it at all. >> at all >> Now like okay, we need to now need to think about this as an issue. >> Right? The other thing that the human eye is really good at is um color distinction in low light. Okay? In low light cameras are just like it's gray. That's a little bit darker. Humans are able to figure

58:33out distinct vibrant hues so the astronomers the astronauts were reporting orange brown and green colorations. This is a photograph that's highly photoshopped >> Yes. >> to show some of the hues that they were seeing. They had to really sort of constrain the pixels and be like how much red is there boost the red up as much as possible boost the blue up as much as possible but this is kind of what they were seeing and all of those distinct colors

What the Moon’s colors really looked like

59:01are the presence of distinct minerals. >> That's I I just so for >> But this is kind of what humans would see. >> This is for those listening it kind of basically looks like Earth in the top third. >> That's the near side of the moon. >> Yeah. >> with the mare >> oceans like grass you know a little bit of land and then it's just all the moon white that you think of. If that's literally what they're seeing yeah, >> literally what they're seeing Because their human eyes are so good. That's >> And this this was also reported by the Apollo astronauts. >> Also fair. Yeah. >> So this is not new. But again, it just goes to show just how good the human eye is. >> And also the difference between the

59:41instruments we build to perceive the world versus our perception of the world and the delta or distance between those two things. You know, and and what that means for how cuz this goes back to like how do you interpret the data? >> Mhm. >> Right? >> Yeah. >> And so this is an example of saying hey the camera is not how people see. >> Yeah. >> Right? And then but people are like, well, why are you manipulating it after the fact? Because the instrument is not a human eye. >> No, it's not. >> And so we're trying to translate from English to French. >> Yeah. >> Right? And and yeah, there might be some subtle differences, but fundamentally where you're born, what you what's my name, all translates. I I I think it's

1:00:22an important >> Yeah. >> note that that part of the reason we have to take instrument data and interpolate it is because we don't have the way to perceive it as the machine in which we got to capture the data perceives it. >> Exactly. And that's why I kind of wanted to linger on this point about the human >> Yeah. >> eye and the difference between the human eye and the camera. Because I think it is a very important point and they made it abundantly clear on the live stream. The mission control and the science team was asking them >> Yeah. >> over and over like describe what you're seeing. Put put it down on the iPad. We gave you iPads. Like put it down, you know? Um there was this really funny part where um commander not commander Weisman, I think

1:01:04it was Jeremy Hansen was describing how the hues are changing as they change angle around the moon of these mare, right? And the the mission control was just like, you need to be a bit more descriptive here. Because we're all we're all like waiting by baited breath and the photos are not showing. You need to be more like I need I need you to stop because you know, when you're there, dude, imagine you're on you're seeing the moon for the first time like >> it was handsome this is his first time. >> Yeah, and it's handsome's first time in space and he's seeing the moon and like you're going to be overcome with just like loss for words. >> Right. >> And and mission control is like you need a lock in, bro. Like

1:01:44>> Lock in. >> Lock in. This is all we we got like we got this is all we got. >> Right. >> We got one flyby like if you if you're seeing stuff you need to explain stuff. And he's the actual one who actually brought up the six bright flashes. >> Mhm. >> So, you know, he's doing his job really well. I'm just saying like when you're up there >> Yeah. >> you know, and you're kind of overwhelmed with what you're seeing. >> 100%. >> time there's all these scientists on the ground being like I need my data. Right? I'm trying to publish, bro. You know? >> As per my last email. >> As per my last email, please provide more verbose description.

Earthrise

1:02:18Um you're doing great, but like >> I need more. I need more. >> So, I thought that was like a really cool like human human moment there. And finally, one of the last ones that I want to highlight is Earth rise, which is on the back of the moon. >> Yes. >> They see the Earth rise 54 minutes later. >> Earth set earlier. >> the other side and now 54 minutes later Artemis is on the other side and there's the moon. You can see sort of ridges on the moon and then the Earth is rising as a crescent. Just absolutely incredible images. And again, I want to note this is really high zoom. >> Yeah. >> Okay? This is like they got their 300 mm and they're really zooming in. The Earth is something that you can probably cover

1:02:59up with a finger or two. >> right right right right right right. Which is important for those who don't work with cameras or kind of have that mental model of how it works. Right? We're basically encroaching in so that the thing we're looking at looks significantly larger >> Yeah. than where our current vantage point is. And so, you know, >> It's incredible. >> I can't wait for some granola snack company to name itself Earthrise. >> Yeah. Oh my gosh, and put this >> Put this >> Cuz it's like NASA, so it's like probably free. >> Exactly. We It's taxpayer money, we paid for it. So >> Yeah.

The Artemis science team in Houston

1:03:38>> Um the last photo that I want to show is from the Artemis science team that was in Houston. They did an incredible job. They did an incredible job preparing the astronauts for their mission and then guiding the astronauts through what they wanted to look at. Like, "Hey, look at this. What did you mean by that? Keep going. Keep talking. Um do all those observations." They've just done an incredible job and created a huge scientific reservoir that we're only really going to get the meat of when they get back and we're going to see all of the data that they have, you know. >> Right. >> I I I just want to take a moment to

1:04:18um congratulate and thank all of those who have been in many different aspects, whether it's within NASA directly, through contractors that were sourced to provide a number of services and ultimately products related to this mission. Um it is You are all unsung heroes in this story of human discovery. And uh one of the endeavors we're trying to do with this show is elevate the names, faces, and voices of many of you who are doing a lot of this fundamental work. But it it's not the Grammys, and it's

1:04:59not the Super Bowl halftime show. Uh but it is for millions and millions of people on the planet, and we just don't have a venue that ha really is able to make it compete with these other things. This is so >> But we're building it. >> We're trying to build that because this is some of the most important fun When When people look back in history, whose names do they remember? They remember Galileo. They They They remember Newton. They remember those who at the time were heretical, they didn't understand, they were pushing the envelope, but had this insatiable curiosity and were focused on doing the work.

1:05:40>> Yeah. >> Uh and I I'm going to get off my soapbox but >> And one more thing that I wanted to just comment about this photo is it's such a stark difference from the Apollo mission control. >> Yeah, that's a really good point. >> Because there's so many women in this photo. >> a really good point. >> that's just so cool. >> Yes. >> Right? That we I think, you know, we have a long way to go >> Yeah. >> as a society when it comes to gender equality in the sciences. >> Yes. >> But I think this shows just how far we've come. That there are all these women on the science team. >> Yes. >> On Artemis that are guiding the astronauts what to look for. What is this What are the questions that we want answered? What are the new questions that you are asking or the new

1:06:21observations that you've made that are making us ask new questions. It's just a complete night and day between mission control during Apollo, which was all men, and now, you know, quite quite a few women. I think that's very cool. >> 100% >> Just a shoutout. >> And it's it's huge progress. Um thank you to all of those who've supported, whether you're employed members families >> Yeah, just incredible stuff. >> Like this is a really big deal. >> Yeah. >> Um and uh if as Kat Williams says, uh we need haters. So, you know, let let you know, we're

1:07:02continuing to try to help people find a way to connect with these subjects. And just because they're not into it right now, that's okay. Um, if you're not doing anything important, you don't have any haters. You guys are doing something important and so naturally you're going to >> Exactly. push back on it and that's that's the way the world works. >> That's the way the world works. Um, be proud of the haters, you know? Okay, the final >> Frankly, we need more haters. We're not We're not important enough yet. We don't We don't have enough haters. >> Although there are a few people in the comments who are like they're definitely AI. That makes me feel good. >> You know, somebody thinks that we're so good We're we're big science, we're paid off by >> We're paid off Who's paying us? >> I would love to be paid. If anyone wants

1:07:43to pay us, that would be great. Like I would be lovely. I would love to get paid.

Reentry basics

1:07:49That would be great. Okay, so the final part of our segment, I want to talk about re-entry. >> Yes. >> Which is going to be happening on Friday around 5:00 p.m. I believe is when they're going to be re-entering the Earth's atmosphere and landing somewhere right off the coast of San Diego. >> And that's going to be Friday, April 10th. >> Yes. >> Yes. >> Yeah. Okay. So atmospheric re-entry, you're approaching the Earth's atmosphere and all of that energy that was put into that translunar injection burn has to get shed. >> Right. >> Right? Conservation of energy. >> Right. >> In space >> There's nothing. >> that energy hasn't gone anywhere. It's just in the motion, right? Um, sure, when you're at the moon, you're going a

1:08:29bit slower, but that's because you have so much gravitational potential energy. By the time they're falling and currently as we as we record this episode, they are falling from the moon, right? All the way from the moon back here by the time they enter our Earth's atmosphere, they're going to have a velocity, a speed of 40,000 km/h. Almost the same as the velocity that they left the >> Right. Right. And it's funny, I mean, the space is a vacuum, right? So there's There's no way to dissipate. >> Yeah, it's just in the motion and >> of that motion, all of that kinetic energy has to go somewhere. And so, what we want to do fundamentally is dump all

1:09:12of that kinetic energy as heat >> Mhm. >> into the atmosphere. >> Right. >> That's That's the equation that we're doing. Before is kinetic energy and, you know, whatever the temperature >> Which Which just to be clear for those who might means just movement or motion. Like when you say kinetic energy >> Yes. >> Can you just be a little >> Yes. Yeah. Yeah. Yeah. Yeah. Fair Fair enough. Um when I say kinetic energy, I mean this thing, the Orion capsule up here, this little triangle pyramid part >> Yes. >> is moving at 40,000 km/h. 1/2 mv squared, that's the kinetic energy of this guy just on the motion of the thing. >> Mhm. >> We want to slow it down so that it doesn't slam into the Earth like a

1:09:52meteorite. >> Okay? >> Right. >> And in order to do that, all of that energy from the motion has to go somewhere. Right. So, the model is always we dissipate it as heat in the atmosphere. >> Mhm. >> Okay? We got to be careful though, okay? There's got to be a method to this madness. >> Right. >> And this is where the re-entry procedure comes in. So, in the next segment we're going to talk about how long does that take?

Why Orion starts reentry over the Indian Ocean

1:10:21So, if we We're actually going to start over the Indian Ocean. If you go to photo number 33, >> Yes. >> look at how much Look at how much just real estate >> distance >> the the distance. Yeah. Look at how much distance the re-entry procedure is taking. They're entering the atmosphere somewhere over India, just south of India in the Indian Ocean. >> it's a Sri Lanka area. >> Yeah, exactly. And they're going across more than half of the Earth in order to dump all of that kinetic energy. >> The The point here being once Orion re-enters Earth's atmosphere, you know, 400,000 ft above the Earth's surface. Yeah. >> It's going to traverse across It's not

1:11:04just It's not just going to come straight down. >> Yeah, exactly. >> It's going to traverse across the surface of the Earth. And the reason that's a a proactive choice because we need to dissipate the heat >> need to dump all that energy. >> And so we need a longer amount of time in order to allow that to burn off so that the vehicle can slow down enough to be able to land safely. >> we need to manage that heat exactly right, right? We need to It's over such a long period because we don't want it to get so hot. The temperature can't get too hot. >> That's really important. >> If it I mean, a meteor, right? Just goes in. >> Right. >> Okay, it dumped all of that kinetic energy, but it did it over such a small amount of time that the temperature gets

1:11:45to like lava. You don't want that to happen here. We want to do We want to do it over a long enough distance and a long enough time that the temperature is sort of managed. It's only about 5,000° F. >> Makes sense. >> Which is only Yeah, only about 5,000° F.

Artemis 1, 2, 3, and 4 in context

1:12:00But that's kind of manageable. And this is the procedure. What we're going to do is something very different, very unique, and something that has not been done for any crude mission. It has been done for the Artemis 1, which was the precursor to the Artemis 2. >> That was the test drive where we had the mannequins in there. >> Yeah. >> You know, the the the schedule just really quick before we continue. Artemis 1 was the test drive with mannequins to make sure we can go up and everything is okay. Artemis 2 now is we're going up all the way around the moon cuz we're scoping out a parking spot and making sure all the systems to go that distance are working well. >> With humans inside are working well. Artemis 3 now is going to be testing the

1:12:41docking procedure. It's going to be closer to Earth. It's less about going around the moon for Artemis 3. And there's a little bit of change up recently after the rescheduling and funding stuff and all these other things. And so that's just we're making sure we can park and do all this stuff and the doc re-doc is all good. Artemis 4 then is now we're going. >> Yeah. >> And we're going to land. >> Yep.

Skip entry explained

1:13:04>> And then five and beyond is going to be building the neighborhood, the establishment of a permanent lunar presence. Again, funding agreeable. But I just wanted to quickly recap what the schedule is in relation to to this point. >> that's very good. And the re-entry procedure here is going to be very different. That was was the point with this image because usually when we re-enter like Apollo or like the ISS when they re-enter is just one thing. You just slow down, slow down, slow down. You have a nice little shallow angle that like lets you burn off that heat and then you and then you come come back. Now re-entering from the moon is very different from re-entering from the ISS because the ISS you're not

1:13:44moving that fast. Right? >> Here you you went all the way to the moon and back. You're moving real fast. >> Yeah. >> Okay. You're moving real fast. So you got a lot more energy to dump. They're doing a skip entry sequence. What this means is you're going to come along and it's Have you ever done skipping stones like rocks where you like throw a rock and the rock skips over the water? What's happening is you do it at a shallow enough angle where the sort of surface tension or the the rebound force from the water is going to give you an upward velocity and let you skip over the water. We're doing the same thing with the Earth. With the Earth's atmosphere. >> Mhm. >> We're skipping over the Earth's

1:14:24atmosphere first to reduce velocity. It's a twofold thing. Once you reduce velocity, you also have time for the capsule to to cool down before you try again. Okay, so that's that skip entry sequence. And we've got a few videos from Artemis 1 that actually show this maneuver. So this is from Artemis 1. We've got a camera up here that's looking backwards >> Yes. sorry, upwards. So, you know, the the the Artemis 1 capsule is coming like this and the camera is looking in the opposite direction. And here you can see the Earth is moving moving underneath. >> Yes. >> The speed there is 39,000 km/h. >> It's moving. >> Yeah, that thing is moving.

1:15:06>> Moving. >> And here you can see now it's entering the Earth's atmosphere. This is the first entry. >> Yes. >> And all of that heat >> Yes. >> from the friction of the Earth's atmosphere is creating like a plasma bubble >> Yes. >> above the Artemis, like up here. >> Yes. >> You know? >> Yes. >> It's like all of the heat is down here >> Yes. >> as it's moving through and it is creating a plasma bubble >> Yes. >> behind it, in its wake. >> Yes. >> And that thing is getting hot. >> That is so incredible. >> that thing is getting real hot. >> I as just as as a camera and gear head guy, I I'm loving this. >> This is just so cool. >> Because I'm just there's there's so much hardware engineering that goes into being able to even pull off the like that I know where we're sort of coming

1:15:47from the but like there's the intensity of that environment. >> Yeah. >> And the ability to protect the craft in that high intensity environment is unbelievable. >> unbelievable, right? And here you can also one of the meters there shows that it's zero Gs because you're you're just free falling, right? So, in free fall it's zero Gs, but as you start slowing down the Gs start going up and up. >> And when you say Gs, what do you mean when you say Gs? >> what I mean is like the effect of um acceleration, like you're you're starting to feel your own weight. >> Yeah, yep. >> If you slow down a lot

1:16:27the Gs go up. >> Mhm. >> We want to also minimize the amount of Gs because when Apollo did it just a single just a single re-entry, the the amount of Gs was exceptionally high. We want also lower the amount of Gs, so that's another reason why we're We're the skip entry. Okay? So, this is that first skip. Okay, now the second skip what we'll do is we'll take our aircraft and we will rotate it. >> Okay. >> Okay, so this is after the first skip and you can also see the speed has reduced down to 26,000 km/h. So we've already dumped a lot of kinetic energy in that first skip. Now we turn. >> Yeah, we're rotating. >> We're rotating, we do a roll about the

1:17:07spacecraft and once that roll is finished, again, we're free falling so we've done the skip, we're coming back and now we're back into reentering the Earth's atmosphere. Again, this is Artemis 1. We've already done this and we've tested it and this the skip re-entry does work. >> Yes. >> Okay. >> Yes. >> Now it's not completely full proof. Okay, Artemis 1 had a few issues. >> Okay. >> And um the NASA administrator >> Isaacman >> Isaacman did in fact allude to that issue. >> Yes.

1:17:48>> The next photo shows exactly what he's talking about. Okay, this is the heat

Artemis I heat shield spalling

1:17:52shield from Artemis 1 and what we can see is that this heat shield is covered by something called um the avo cat. It's an ablative thermal protection material. It's like the tiles on the back of the um space shuttle things like that. It's it's it's there to absorb a lot of heat and make sure that you know nothing burns up. Um what ended up happening with Artemis 1 was there were about 100 locations where the avo cat experienced severe spalling meaning chunks were sort of fractured and broke away. The The

1:18:32root cause is that the heat shield didn't maintain a high enough temperature to fully melt and it wasn't maintaining a high enough temperature to do that. And so, the solution now with Artemis 2, because it's got the same heat shield, the engineers have modified that re-entry procedure to steepen >> Oh, the initial angle of >> Not make it more shallow, actually steepen it to get it up to that high temperature so that it doesn't blow off. >> Yeah, yeah, yeah, yeah. >> It's actually designed to melt, and that's what they're doing with Artemis 2, okay? It hasn't been tested before, the steeper angle of entry, and so, um in a in a recent press conference, the NASA administrator, Jared Isaacman,

1:19:14like talked about that a little bit. >> Yes. >> And um I did I did see that. >> Yeah, yeah. And it was like, you know, he he said that I know that we've done all of the necessary calculations, >> backing the team. >> Yes. >> Uh multiple times >> Yeah, yeah, yeah. Totally backing their my guys. >> Yeah. >> We got it. >> Mhm. >> But he did have a sober uh tone uh about and I think part of it was playing with, you know, he's working in a dynamic where NASA's being systemically defunded for other things. >> Mhm.

Jared Isaacman on being “hardware rich”

1:19:48>> Um and he made an homage or or a reference point to uh being hardware rich, which is a quote that he kept talking >> a good one. That was a good quote, yeah. >> Um for for, you know, the private space companies like SpaceX, cuz he's like, "Look, back in the Apollo era, if we were to fabricate something and it didn't work, we would throw it out and just fab a new one uh because we, you know, we had we had whatever the percent of our GDP going towards it, so, you know, we were 2% so we were hardware rich, meaning that we just had the money to spend. >> Um and so do these private companies like SpaceX, they have the money to say, "If this doesn't work," he made a reference to a launch he was working on with SpaceX where something wasn't working and they just didn't even

1:20:29diagnose it. Yeah. They just replaced it with another thing to get the launch off in time and then afterwards when they diagnosed it it failed uh getting into orbit. Um, but his point was just like that's not where we are as an organization right now with NASA. And so and he was very just very matter-of-fact about it. But we did the work and we figured out how to make it work. But he was I think subtly effectively saying we're not being funded at a degree that we can have the necessary you know, uh, confidence to be able to do these things. We have to be clever and frugal's not the right word, but just resourceful. >> Resourceful, yeah. And I think I mean I it was it was really cool to see the um,

1:21:09transparency. >> Yeah, 100%. >> that was that was quite cool. >> It was great. Yeah, because um, I'm looking forward to the re-entry. I'm sure the engineers have done the work. Um, this new angle is going to be good and we will see them soon on Friday evening off the coast of sunny Southern California. >> Woo! >> You know? >> Yes. And I I I just, you know, one last sort of, uh, good night and good luck and God bless to the crew. >> Yeah. >> Um, I think like you mentioned earlier

Final thoughts before splashdown

1:21:38you can only plan for so much. >> Mhm. >> Um, but if there is any team on the planet that is, um, uh, anal-retentive about details, um, it's it's the NASA team. >> It's the NASA team and it's the Artemis team. Um, I'm really looking forward to watching the re-entry. The integrity capsule is going to do an amazing job. Um, they're going to be right over the Pacific Ocean. The US Navy is going to go pick them up, give them an Uber ride. >> Off the coast of San Diego, same place as UAPs are going to be. >> yeah, maybe the Tic Tacs maybe the Tic Tac will come and watch. >> Oh, they're going back to the moon, guys. We got to get reactivated.

1:22:19That's why we went away. We thought you guys were coming to space and then you kind of stopped. So, you know, that's why we stopped and kind of popping up. >> Yeah, yeah. So, um I'm really looking forward to it. Um best of luck to the crew. >> Absolutely. >> Um we will watch it in 2 days time and I can't wait to keep covering NASA, keep covering the Artemis mission, you know. Um Artemis 3 is going to be going up I

Artemis roadmap and far side correction

1:22:41think next year. >> Yes. >> With that docking and all that stuff. I can't wait for Artemis 4 landing on the moon. >> Artemis 4 is about to be fire. >> Yeah, that's going to be great. >> Artemis 4 >> And hopefully by then we'll have the clock to actually be in Cape Canaveral. >> So, also yeah, NASA if someone in your contact team >> our coverage, you know, we're trying. >> Look look at the production value. >> at the LEGO that we made. >> we did. This is great branding. This is great product placement. Clearly the scientific knowledge and detail is top-notch. And so, we are available and open. We are hitting our correction section which we already touched on earlier from

1:23:23our social clips in >> Yeah, there's there's only one correction that I want to make which is I meant far side, not dark side. Dark side of the moon is one of the greatest albums of all time by Pink Floyd but is not the correct scientific term. The scientific term is the far side of the moon because of that tidal locking that I talked about earlier in the episode. So, sorry for any confusion. >> Uh with that, uh we will wrap up this episode is uh it was I think the most

Wrap-up

1:23:55episode we might have had yet. >> Yeah. >> It was a good one. >> Uh I'm just so you know, I'm just so excited about all this. I've been as fast obsessed with space since I was a kid and I always used to look back at the like the Apollo era being like I wish I grew up then because it was just this like there's this like bigger than us thing that at the time was mired in geopolitical conflict. Now it's sort of no longer the frontier for geopolitics, and so it's purely exploration and curiosity until someone starts manipulating the stuff on the moon, and then it's going to start back up again. Shout out For All Mankind. Also, Apple, you guys did For

1:24:36All Mankind season 5 promo. No call? Y'all didn't call? That's unbelievable. I've been promoting you guys all year. >> Yeah. >> I'm I'm going to have I'm going to have a conversation with the agents. No, but I am Lester Nari, joined as always by my co-host and our resident PhD Krishna Choudhury. It's been an incredible week as we've seen this transpire. By the time you listen to this episode, we will have known or be close to the re-entry. So, be sure to take a listen. We really appreciate you all again. If you are listening at this point in the podcast, uh you are a zealot. You are an FFP

1:25:18zealot. You are core part of our ultras. We greatly appreciate you. Please like, share, comment, five-star review if you're listening to this as a podcast. It's one of the best ways to help us get this to more people. We will see you all next week.