Artemis II: Deep Dive on the Moon Flyby, Earthset, and Reentry (EP 37)

Hosted by Lester Nare and Krishna Choudhary, this episode is a full deep dive on Artemis II as the crew returns from humanity’s first crewed lunar flyby in more than 50 years. Lester and Krishna break down the mission photo by photo, from launch and translunar injection to Earthset, Earthrise, the in-space solar eclipse, the science of lunar observations, and the skip-entry reentry profile bringing Orion home. Summary Why Artemis II is historic, what the crew saw on the far side of the Moon, and why this mission matters for the long-term return to the lunar surface. Why NASA relied on the Nikon D5 for deep-space photography, and what camera physics, low-light performance, and radiation tolerance have to do with getting these images home. The standout observations from the flyby: Earthset, Earthrise, a rare in-space solar eclipse, planetary alignment during eclipse, and the first crewed visual observations of meteoroid impact flashes on the Moon. How Orion’s reentry works, why Artemis II uses skip entry, what happened to Artemis I’s heat shield, and what NASA changed for the crewed return. Support the show Donate: FFPod.com/donate Follow: @FFPod on X / Instagram / TikTok / Facebook

Speaker names marked ? are inferred from speaking time and the show’s known hosts — they are not voice-verified.

• 0:00Krishna Choudhary?

  This 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.

• 0:11Lester Nare?

  It's, it's just...

• 0:13Krishna Choudhary?

  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.

• 0:22Lester Nare?

  Hello, internet. This is your captain speaking, Lester Nare, joined as always by my co-host and our resident PhD, Krishnan Choudhary. 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.

• 1:07Krishna Choudhary?

  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. The whole point of this mission was to 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,

• 1:50Krishna Choudhary?

  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. And then, second, I wanted to focus on reentry, 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 Lester created with Lego, because apparently that is the...

• 2:20Lester Nare?

  No plural.

• 2:21Krishna Choudhary?

  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 main 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 from that rocket.

• 3:01Krishna Choudhary?

  And I think, I think it's, it's really cool to see that vantage point because we didn't see this live. Right. But now we're getting to see this, you know, sort of after the data has come, come back. Yes. Very, very cool. Yes. 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 these 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.

• 3:41Krishna Choudhary?

  Once we do that, this was all within, that was about eight and a half minutes after launch. Okay. Okay. At about eight and a half minutes after launch is when the core stage right here separates from the top. Okay. So the orange is what's going away. The bottom is what you're seeing is the actual core stage separating. So there's a camera up here that's looking out 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 all of the fuel, it gets really, really cold just because of PV equals NRT. You're compressing a lot of gas into high pressure inside this.

• 4:25Krishna Choudhary?

  So the temperature has to drop, right?

• 4:29Krishna Choudhary?

  Everything went really well. And 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.

• 4:41Krishna Choudhary?

  We've got Reid Weisman, who's the commander, Victor Glover, the pilot on the right, Christina Koch, who's the mission specialist and-

• 4:48Lester Nare?

  And toilet specialist.

• 4:50Krishna Choudhary?

  And yes, apparently she, dude, she must be the favorite of everyone on that, like MVP. Like if someone, if they voted MVP, it would be the one who fixed the toilet, right? On the way up.

• 5:02Lester Nare?

  Right.

• 5:03Krishna Choudhary?

  And then finally, um, Canadian Space Agency astronaut Jeremy Hansen. He's in the corner up 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.

• 5:17Lester Nare?

  Right.

• 5:18Krishna Choudhary?

  You know, so it's not because he's Canadian that they just like, oh, you get to, yeah, you get to be in the corner. It's, there's like physical reasons behind it.

• 5:28Krishna Choudhary?

  It's very, very cool. And we're going to cover all of the photos that they took and, you know, their re-entry procedure.

• 5:35Lester Nare?

  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 the show is called From First Principles. To support what we do, you can like, share, comment, follow. It really helps us get seen by more people. If you go to ffpod.com backslash donate, there are a variety of ways that you can support the show, monetarily or not monetarily. And we really do appreciate the curiosity that exists in so many of you and the love

• 6:18Lester Nare?

  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.

• 6:29Krishna Choudhary?

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

• 7:08Lester Nare?

  Yes.

• 7:09Krishna Choudhary?

  The difference between the two cameras is if we actually, if you were to pull up that photo again, on the left, we see the Nikon sort of like dissected.

• 7:19Lester Nare?

  Yeah.

• 7:20Krishna Choudhary?

  The difference between 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 goes up and is reflected up to an autofocusing 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?

• 7:55Lester Nare?

  Nepotism or nostalgia is my guess.

• 7:57Krishna Choudhary?

  Yeah, it's it's science. It's actually it's actually well thought out. The basic idea is that the D5, the Nikon D5, was selected because of sensor physics and extreme low light performance.

• 8:11Lester Nare?

  Yeah, that makes sense.

• 8:12Krishna Choudhary?

  Okay. First, 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.

• 8:43Krishna Choudhary?

  Has a maximum ISO of 3 million.

• 8:45Lester Nare?

  That's so crazy because we're, we have these cameras that I manipulate.

• 8:50Krishna Choudhary?

  Yeah.

• 8:50Lester Nare?

  The triangle that you're talking about.

• 8:51Krishna Choudhary?

  Yeah.

• 8:52Lester Nare?

  We don't have 3 million.

• 8:53Krishna Choudhary?

  No, we don't. I don't think we would need 3 million given our like studio lights, right?

• 8:58Lester Nare?

  Right, right. If we have a podcast in the dark.

• 9:00Krishna Choudhary?

  Yeah, yeah, then we probably would. The Apollo era film cameras, the Hasselbads, they had an 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 CMOS detector.

• 9:17Lester Nare?

  Yes.

• 9:17Krishna Choudhary?

  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.

• 9:27Lester Nare?

  Yeah, that makes some sense.

• 9:28Krishna Choudhary?

  Right? Okay. So the other big thing about the Nikon D5 is it features a pretty modest 20 megapixel sensor. That's the CMOS sensor inside of it. 20 megapixels nowadays is not a lot.

• 9:40Lester Nare?

  No.

• 9:41Krishna Choudhary?

  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 photo diodes 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. So it's collecting more photons before getting saturated.

• 10:09Lester Nare?

  Yeah, yeah, yeah. Okay.

• 10:10Krishna Choudhary?

  And that's huge.

• 10:10Lester Nare?

  Yes.

• 10:11Krishna Choudhary?

  For low light scenarios.

• 10:12Lester Nare?

  Right.

• 10:12Krishna Choudhary?

  Okay.

• 10:13Lester Nare?

  Right. You, you're getting more original data before you start manipulating with computational photography. All this, all the, I should say processing.

• 10:21Krishna Choudhary?

  Yeah.

• 10:21Lester Nare?

  Because computational photography is a term of art that's specific.

• 10:24Krishna Choudhary?

  Mm-hmm.

• 10:24Lester Nare?

  Just the processing.

• 10:25Krishna Choudhary?

  Exactly. We can get the raw data and that can have a lot higher fidelity.

• 10:29Lester Nare?

  Yeah.

• 10:29Krishna Choudhary?

  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 gonna work.

• 10:49Lester Nare?

  Right.

• 10:50Krishna Choudhary?

  Right? It works on the ISS. And now with Artemis, we're leaving the Earth's sphere of influence, right? Oh, we're, we're leaving the Van Allen belts. What's gonna happen? What's gonna happen? Right? Everyone's like, oh, what's gonna happen? Well, actually, that's a concern if you have electronics.

• 11:05Lester Nare?

  Right.

• 11:06Krishna Choudhary?

  Because the Van Allen belts, which trap all of that radiation.

• 11:11Krishna Choudhary?

  Are no longer there to shield you, right? 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

• 11:25Lester Nare?

  Right.

• 11:26Krishna Choudhary?

  to really, you know, perturb those galactic cosmic rays

• 11:30Lester Nare?

  Yep.

• 11:30Krishna Choudhary?

  and those high-energy particles. So we know that the D5 works on the ISS, and we can take a gamble that perhaps they will 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.

• 11:48Lester Nare?

  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,

• 11:57Krishna Choudhary?

  Yeah.

• 11:57Lester Nare?

  you have a test environment, which for NASA might be the pool, it might be the desert.

• 12:01Krishna Choudhary?

  Or in this case, the ISS, the International Space Station, low-Earth orbit.

• 12:05Lester Nare?

  Where you're in the environment that you want your outcome to happen in.

• 12:09Krishna Choudhary?

  Mm-hmm.

• 12:10Lester Nare?

  And so you're trying to replicate the dynamics of that environment, so that you know that when you test, you can only do so much.

• 12:17Krishna Choudhary?

  Yeah.

• 12:18Lester Nare?

  And this is one of the situations where production, there's very few people who make it to production.

• 12:23Krishna Choudhary?

  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.

• 12:32Lester Nare?

  Exactly.

• 12:32Krishna Choudhary?

  So the astronauts also have the newer Nikon Z7, or sorry, the Z9.

• 12:37Lester Nare?

  Yes.

• 12:37Krishna Choudhary?

  But NASA was like, no, no, this is going to be your primary because we know it works.

• 12:42Lester Nare?

  Yes.

• 12:42Krishna Choudhary?

  The low-light sensitivity is good, and we just know that the sensor electronics are robust to whatever random crap you're going to be thrown at.

• 12:51Lester Nare?

  Yes, yes, we don't want to test new stuff on the first try.

• 12:56Krishna Choudhary?

  No, no, not at all, right? And so now let'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.

• 13:08Lester Nare?

  Yes.

• 13:08Krishna Choudhary?

  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,

• 13:17Lester Nare?

  Yes.

• 13:17Krishna Choudhary?

  which is right down here.

• 13:19Lester Nare?

  Yes.

• 13:20Krishna Choudhary?

  Did a translunar injection burn, so they gained velocity and now they're going straight to the moon?

• 13:24Lester Nare?

  I just want to pause here really quick because 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?

• 13:41Krishna Choudhary?

  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 miles, 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.

• 14:12Lester Nare?

  And we're returning because we're being pulled back to earth by the

• 14:16Krishna Choudhary?

  The gravity.

• 14:16Lester Nare?

  The earth's gravity.

• 14:17Krishna Choudhary?

  Yeah, by the, by the earth's gravity. Now, as we're returning, we're going to gain speed. When 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 gotta 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

• 15:01Krishna Choudhary?

  has to be really high and the angle has to be exactly right to go all the way into the stands.

• 15:07Lester Nare?

  Which is why we don't see home runs on these new 40 mile an hour pitches that we've seen coming.

• 15:12Krishna Choudhary?

  Oh, I haven't heard about this.

• 15:14Lester Nare?

  It's mostly because people can't hit it.

• 15:15Krishna Choudhary?

  Yeah, yeah, exactly. That's probably why. Must have been the Blue Jays.

• 15:21Lester Nare?

  I'm gonna leave that one.

• 15:23Krishna Choudhary?

  Yeah, yeah, yeah, there's a look, it is what it is. So what was I saying? The idea is we want to attain a high velocity when we're leaving Earth.

• 15:35Lester Nare?

  Right.

• 15:36Krishna Choudhary?

  And that way we can attain a high height, height meaning a distance from the earth. And that's what that trans lunar injection is doing. There'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 gonna come back.

• 15:58Lester Nare?

  And not to be pedantic, but when you say velocity, you're saying we're just turning the dial to 11.

• 16:04Krishna Choudhary?

  Yeah.

• 16:04Lester Nare?

  And saying, let's go as fast as possible in that direction at a very specific time as we're coming back from that high elliptical orbit.

• 16:14Krishna Choudhary?

  Yeah.

• 16:15Lester Nare?

  And so we're just putting a bunch of juice thrust through the back. That's gonna shoot us off at a moment of also where the earth's gravity and how it's impacting the craft is gonna assist us in getting more height than we otherwise would if we were just putting that amount of thrust behind us.

• 16:34Krishna Choudhary?

  Yeah.

• 16:35Lester Nare?

  Without the assistance of earth's gravity.

• 16:37Krishna Choudhary?

  Yes, I mean, we're fighting earth's gravity.

• 16:39Lester Nare?

  Right.

• 16:39Krishna Choudhary?

  Is the thing, right? We use earth's gravity to gain that velocity back.

• 16:43Lester Nare?

  Yes.

• 16:44Krishna Choudhary?

  And then, and then now we're doing that burn to gain more velocity using the over earth effect. And then we're going to get even higher.

• 16:52Lester Nare?

  Got it.

• 16:52Krishna Choudhary?

  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.

• 16:58Lester Nare?

  Yeah.

• 16:59Krishna Choudhary?

  You know? And then, and then it's gonna go even higher.

• 17:01Lester Nare?

  Yep.

• 17:02Krishna Choudhary?

  Right, that's the idea. It's kinda like if you bounced a ball on a trampoline. The trampoline is this trans lunar injection burn in some sense.

• 17:10Lester Nare?

  Yes.

• 17:10Krishna Choudhary?

  You know what I mean?

• 17:11Lester Nare?

  I just wanted to harp on that a little bit because there's 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.

• 17:27Krishna Choudhary?

  Yeah, and so if we go back to photo number nine, if you don't mind.

• 17:30Lester Nare?

  Yes.

• 17:31Krishna Choudhary?

  These are two photos that were taken around basically the same time, I think within a minute of the two. 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.

• 17:48Lester Nare?

  Yes.

• 17:49Krishna Choudhary?

  We're in the shadow of the earth right now.

• 17:50Lester Nare?

  Right.

• 17:51Krishna Choudhary?

  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 gonna 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.

• 18:07Lester Nare?

  Yeah.

• 18:07Krishna Choudhary?

  Right? That's that.

• 18:08Lester Nare?

  Yep.

• 18:08Krishna Choudhary?

  Nikon D5 ISO, right?

• 18:10Lester Nare?

  Yes.

• 18:11Krishna Choudhary?

  And I wanted to harp on this particular image a little bit longer. Because I think there's a few details that are really, really cool. So, let's go to some of the insets that I've prepared. If we go to the next photo, which is photo number 10. So this is in the lower left corner of that image.

• 18:27Lester Nare?

  Yes.

• 18:27Krishna Choudhary?

  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?

• 18:33Lester Nare?

  Uh huh.

• 18:34Krishna Choudhary?

  That part of earth is Europe and Africa and the Mediterranean Strait and the Gibraltar Strait there, upside down.

• 18:42Lester Nare?

  I was gonna say, the F flip, the A.

• 18:44Krishna Choudhary?

  To 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.

• 18:55Lester Nare?

  Yeah, yeah, yeah.

• 18:56Krishna Choudhary?

  Right? Which way is north and which way is south? We've just decided, but on the right-hand side, it shows an inset of a map where the earth is actually upside down, but the text is correct, correctly, like, you know, positioned. It, I think it's really cool exercise in like knowing, okay, actually, it's completely arbitrary in space.

• 19:16Lester Nare?

  Yes.

• 19:17Krishna Choudhary?

  Which way is down, which way is up?

• 19:18Lester Nare?

  For those who are listening, we're looking at the map and we see Libya and Algeria at the top.

• 19:23Krishna Choudhary?

  And Morocco.

• 19:24Lester Nare?

  And Morocco above like Spain, Portugal, etc.

• 19:28Krishna Choudhary?

  Yeah.

• 19:29Lester Nare?

  It's such a bizarre.

• 19:30Krishna Choudhary?

  Yeah, 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.

• 19:39Lester Nare?

  Yeah.

• 19:40Krishna Choudhary?

  Which is kind of cool.

• 19:40Lester Nare?

  Yeah.

• 19:41Krishna Choudhary?

  The other thing we see on this image is, in the left-hand side, we see faint glows, greenish glows.

• 19:48Lester Nare?

  Yeah.

• 19:48Krishna Choudhary?

  That's the aurora.

• 19:49Lester Nare?

  Yes.

• 19:49Krishna Choudhary?

  In the northern hemisphere, the aurora borealis. If we go to the next photo.

• 19:53Lester Nare?

  Yes.

• 19:54Krishna Choudhary?

  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 Allen belt. You know, I said the Van Allen belt is a donut, right?

• 20:08Lester Nare?

  Yes.

• 20:08Krishna Choudhary?

  Well, the donut has to intersect.

• 20:10Lester Nare?

  Somewhere.

• 20:11Krishna Choudhary?

  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.

• 20:22Lester Nare?

  Yes.

• 20:23Krishna Choudhary?

  Right?

• 20:23Lester Nare?

  Yes.

• 20:23Krishna Choudhary?

  Absolutely beautiful. And finally, at the bottom right corner, we see a tiny glow.

• 20:30Lester Nare?

  I love this photo.

• 20:31Krishna Choudhary?

  Coming out of the Earth.

• 20:32Lester Nare?

  Yeah.

• 20:33Krishna Choudhary?

  That glow in deep space is called a zodiacal light.

• 20:37Lester Nare?

  Oh.

• 20:38Krishna Choudhary?

  So there is dust that is trapped in the same plane as all of the planets.

• 20:45Lester Nare?

  Thankfully, not nuclear dust, but that's.

• 20:46Krishna Choudhary?

  No, just, 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.

• 21:09Lester Nare?

  Yes.

• 21:09Krishna Choudhary?

  That never got to any, and the dust is stuff that never got to any planet. And it's just there in our plane.

• 21:16Lester Nare?

  Yes.

• 21:16Krishna Choudhary?

  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.

• 21:23Lester Nare?

  Yes.

• 21:23Krishna Choudhary?

  And on the left-hand side, you see the zodiacal light, sort of out in deep space.

• 21:27Lester Nare?

  So beautiful.

• 21:28Krishna Choudhary?

  Just absolutely wonderful.

• 21:29Lester Nare?

  In California, we, we like to try to pretend we call this golden hour, but this is above what we get as golden hour.

• 21:36Krishna Choudhary?

  Yeah, yeah, yeah. This is, um, 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.

• 21:45Lester Nare?

  Makes sense, that makes sense.

• 21:47Krishna Choudhary?

  You know? And as you get farther away from Earth, so that was right after the translunar injection.

• 21:52Lester Nare?

  Yeah.

• 21:52Krishna Choudhary?

  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.

• 22:02Lester Nare?

  Yeah.

• 22:02Krishna Choudhary?

  And I don't know if you can see, but there's a tiny crescent in the lower left, where astronauts Glover and.

• 22:11Krishna Choudhary?

  Jeremy Hansen.

• 22:13Lester Nare?

  Yes.

• 22:13Krishna Choudhary?

  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.

• 22:21Lester Nare?

  That's unbelievable.

• 22:22Krishna Choudhary?

  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.

• 22:28Lester Nare?

  Yeah.

• 22:29Krishna Choudhary?

  They're at this distance where now the moon and the earth are the same size.

• 22:33Lester Nare?

  That's so bizarre.

• 22:34Krishna Choudhary?

  It's just crazy, dude, that we're going so far.

• 22:38Lester Nare?

  We're going so far.

• 22:39Krishna Choudhary?

  We're going so far compared to what we've been doing for the past 50 years.

• 22:42Lester Nare?

  Yeah, yeah.

• 22:43Krishna Choudhary?

  Oh, my gosh. It's just, I, I, I thought it was really, really cool.

• 22:46Lester Nare?

  No, no, 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 camera because it basically has boosted stats as compared to our eyes.

• 23:15Krishna Choudhary?

  Yeah. Well, there's a, there's a caveat there, which I'm gonna 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.

• 23:25Lester Nare?

  I, I promise that was not planned, everybody.

• 23:28Krishna Choudhary?

  So before, before we move on to getting closer to the moon.

• 23:31Lester Nare?

  Yes.

• 23:32Krishna Choudhary?

  I want to do a quick recap of what the Apollo astronauts saw.

• 23:35Lester Nare?

  Yes.

• 23:36Krishna Choudhary?

  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.

• 23:57Lester Nare?

  Yes.

• 23:58Krishna Choudhary?

  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 away from the moon.

• 24:12Lester Nare?

  Yes.

• 24:13Krishna Choudhary?

  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.

• 24:22Lester Nare?

  Yes.

• 24:22Krishna Choudhary?

  Now, that gives us two advantages. Okay? The first advantage is you get to see big, big parts of the moon.

• 24:31Lester Nare?

  Right.

• 24:31Krishna Choudhary?

  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 gonna run into a horizon issue.

• 24:45Lester Nare?

  Okay.

• 24:46Krishna Choudhary?

  Right? Because imagine you're close to a round body.

• 24:48Lester Nare?

  Yeah, yeah, yeah.

• 24:49Krishna Choudhary?

  So you can only look so far, even even up here. If you go to the beach, right? You can't see.

• 24:54Lester Nare?

  Right.

• 24:55Krishna Choudhary?

  Because the earth is not flat. Like, you can't see all the way, right? There's gonna 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 gonna be a horizon issue.

• 25:07Lester Nare?

  Yes.

• 25:07Krishna Choudhary?

  So over here, what we're seeing is the lighter regions.

• 25:12Lester Nare?

  Yes.

• 25:12Krishna Choudhary?

  Are what the Apollo astronauts saw.

• 25:14Lester Nare?

  Mm-hmm.

• 25:15Krishna Choudhary?

  And you can see that the poles.

• 25:17Lester Nare?

  Yes.

• 25:17Krishna Choudhary?

  You can't really see because imagine you're going around the moon like this.

• 25:20Lester Nare?

  Yeah.

• 25:21Krishna Choudhary?

  You can't see past the horizon.

• 25:23Lester Nare?

  Right. They just saw the middle belt.

• 25:25Krishna Choudhary?

  Mm-hmm. 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 gonna be pretty far away.

• 25:34Lester Nare?

  Right.

• 25:34Krishna Choudhary?

  So it's gonna be able to see the entire thing. And one of the cool things that that was happening was, you know, this is gonna be their first time. These four individuals, it's gonna be the first time going around the moon. It's gonna be the first time the humanity's gonna be this far away. They're gonna have like, you know, the course of like five hours to observe the whole thing. You gotta do dry runs.

• 25:54Lester Nare?

  Right.

• 25:54Krishna Choudhary?

  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.

• 26:04Lester Nare?

  That's incredible.

• 26:04Krishna Choudhary?

  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 gonna use. And they're practicing what the moon will look like. They're exactly the right distance away.

• 26:19Lester Nare?

  Yeah.

• 26:19Krishna Choudhary?

  To to have the moon be how big they would see it.

• 26:22Lester Nare?

  Yeah, yeah.

• 26:23Krishna Choudhary?

  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.

• 26:42Lester Nare?

  Yes.

• 26:43Krishna Choudhary?

  But like to have that dry run is super important.

• 26:46Lester Nare?

  That's so, that's so interesting. I love that they're giving, they're going through basically like photography tutorial class.

• 26:52Krishna Choudhary?

  Yeah.

• 26:52Lester Nare?

  Which, again, I think, you know, the the functions that an astronaut needs to be not only competent, but exceptional in. Are so so orthogonal to each other. Right? You have to be, you understand, a camera, you have to be an engineer, you have to know math, you have to be able to fly.

• 27:13Krishna Choudhary?

  Yeah.

• 27:13Lester Nare?

  And I know I'm being a little, I know different members of the crew are exceptional in different categories.

• 27:20Krishna Choudhary?

  Yeah.

• 27:21Lester Nare?

  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.

• 27:32Krishna Choudhary?

  Yeah.

• 27:32Lester Nare?

  That you need to actually commit to, to survive in space.

• 27:36Krishna Choudhary?

  Yeah.

• 27:36Lester Nare?

  Uh, long term is non trivial.

• 27:39Krishna Choudhary?

  Exactly. I I think that's a really good point. And there's a lot of practice.

• 27:43Lester Nare?

  Yes, yes.

• 27:44Krishna Choudhary?

  Right? It's not just, you're just winging it.

• 27:46Lester Nare?

  You don't.

• 27:46Krishna Choudhary?

  You can't do that.

• 27:47Lester Nare?

  Yeah, right, right.

• 27:48Krishna Choudhary?

  When you've got five hours to do one of the greatest things that humanity has done.

• 27:52Lester Nare?

  Yes.

• 27:52Krishna Choudhary?

  Over the past 50 years.

• 27:53Lester Nare?

  Yes.

• 27:54Krishna Choudhary?

  Right?

• 27:54Lester Nare?

  Yeah.

• 27:54Krishna Choudhary?

  So I I thought that was really cool that they're just straight up practicing.

• 27:57Lester Nare?

  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.

• 28:15Krishna Choudhary?

  Yeah.

• 28:15Lester Nare?

  Right? It's very like understandable.

• 28:17Krishna Choudhary?

  Yeah.

• 28:17Lester Nare?

  And yet, when we go to space, everyone just like forget, like there's this weird.

• 28:21Krishna Choudhary?

  Oh, yeah, they're like, why, why aren't we landing?

• 28:22Lester Nare?

  Why?

• 28:22Krishna Choudhary?

  It's like, no, we didn't practice.

• 28:25Lester Nare?

  Like we just, it's just, it's very simple. Like, you know, I I don't, I just don't.

• 28:30Krishna Choudhary?

  That's so true.

• 28:31Lester Nare?

  Anyway.

• 28:32Krishna Choudhary?

  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.

• 28:37Lester Nare?

  Yes.

• 28:37Krishna Choudhary?

  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.

• 28:46Lester Nare?

  Yes.

• 28:47Krishna Choudhary?

  Got into my head.

• 28:48Lester Nare?

  Also, when we don't know stuff, we call it dark, like dark matter and dark energy.

• 28:51Krishna Choudhary?

  Yeah, yeah, but 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 same 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.

• 29:15Lester Nare?

  Yeah.

• 29:15Krishna Choudhary?

  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.

• 29:26Lester Nare?

  Yes.

• 29:26Krishna Choudhary?

  You know, and so the far side of the moon is in this case my the back of my hand. We don't get to see that a lot.

• 29:31Lester Nare?

  Yeah.

• 29:32Krishna Choudhary?

  And so that was a big deal. This is a photo of Artemis two 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 of like flat mare is what they're called.

• 29:49Lester Nare?

  That's a mare.

• 29:50Krishna Choudhary?

  Yeah, yeah, I I think it means seas. So maybe that's, I don't know if that has anything to do with love.

• 29:56Lester Nare?

  No, no, it doesn't, it doesn't.

• 29:57Krishna Choudhary?

  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 cool and 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.

• 30:22Lester Nare?

  Okay.

• 30:23Krishna Choudhary?

  The side of the moon that is facing the earth is going to have a greater gravitational attraction towards the earth 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. Especially given that tidal lock that I was telling you about. 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.

• 30:55Lester Nare?

  Because of the gravitational.

• 30:56Krishna Choudhary?

  Because of the gravitation. What that means is there's going to be lopsided volcanic activity. 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.

• 31:11Lester Nare?

  That makes sense.

• 31:11Krishna Choudhary?

  Right?

• 31:12Lester Nare?

  That makes sense.

• 31:12Krishna Choudhary?

  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, is this like giant crater that you see there. It's called a Mare Oriental, the Oriental Basin.

• 31:57Krishna Choudhary?

  It's a giant meteor impact with multiple rings around it, 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 in the actual moon's crust. And those ripples hardened into rings. There's an inner ring and an outer ring. Isn't that so cool to think about? Over several hours, people have done modeling and it takes like several hours for that ringing to happen. Because it's literally lava that's ringing at some point, right?

• 32:37Lester Nare?

  It's like a wave pool, but a little slower because it's lava.

• 32:39Krishna Choudhary?

  Because 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. The 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.

• 33:25Krishna Choudhary?

  The like, the marijuana farm 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, it's like, there's like integrity farms that's going around the moon. Anyways, the second crater is actually really cool. It's named after Commander Reed.

• 33:44Krishna Choudhary?

  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.

• 33:55Lester Nare?

  Yes.

• 33:56Krishna Choudhary?

  And so they knew Carol Wiseman. And when she died of cancer in 2020, it was obviously very unfortunate. Commander Reed, like a single father, still going to the moon. You know, leaving behind his two daughters on Earth. Like, that takes cajones.

• 34:15Lester Nare?

  Look, we saw this play out in the movie Interstellar, literally.

• 34:19Krishna Choudhary?

  Literally, actually.

• 34:20Lester Nare?

  He had two kids. It wasn't two daughters. It was a son and a daughter.

• 34:23Krishna Choudhary?

  That's, no, dude, he's literally Matthew McConaughey.

• 34:25Lester Nare?

  In Interstellar. And it's, there's a real emotional toll.

• 34:28Krishna Choudhary?

  Yeah.

• 34:29Lester Nare?

  Especially if you're, you know, a widow.

• 34:32Krishna Choudhary?

  Yeah.

• 34:32Lester Nare?

  And you're an astronaut.

• 34:35Krishna Choudhary?

  Yeah. Dude, that's, that's crazy. Yeah, I didn't even think about that. But yeah, so the, the crew named a crater after Carol Wiseman, which is, I think, pretty cool.

• 34:45Lester Nare?

  Shout out to the crew. That's awesome.

• 34:46Krishna Choudhary?

  Yeah, kind of a high bar to set for all the other dudes on Earth. But, you know, I get it.

• 34:54Lester Nare?

  Anyway.

• 34:55Krishna Choudhary?

  Yeah, it's great. I, I thought that was just a really cool gesture.

• 34:59Lester Nare?

  Yeah.

• 34:59Krishna Choudhary?

  You know, just the human part of the story, I think, is just pretty awesome.

• 35:05Lester Nare?

  And 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.

• 35:21Krishna Choudhary?

  Yeah.

• 35:22Lester Nare?

  Because it just would be a little bit empty.

• 35:24Krishna Choudhary?

  Yeah, yeah. The next image is the one that Commander Reed Wiseman took. Do you have photo 18?

• 35:31Lester Nare?

  Oh, sorry, excuse me.

• 35:33Krishna Choudhary?

  This is the one that's very, very famous.

• 35:35Lester Nare?

  Oh, yeah.

• 35:36Krishna Choudhary?

  This is called Earth Set, taken by Commander Reed Wiseman with his Nikon D5.

• 35:41Lester Nare?

  The D5.

• 35:43Krishna Choudhary?

  It's captured an image showing the crescent of the earth setting behind the moon.

• 35:48Lester Nare?

  Yes.

• 35:49Krishna Choudhary?

  As the Orion integrity capsule goes around.

• 35:52Lester Nare?

  Yes.

• 35:53Krishna Choudhary?

  You know, absolutely beautiful to think.

• 35:55Lester Nare?

  Beautiful image.

• 35:56Krishna Choudhary?

  Right? Just staggering detail that you see on the moon on the earth. It's a counterpart to Earthrise 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.

• 36:10Lester Nare?

  I think we need a monologue because when we had Carl Sagan around, he was phenomenal at orating these types of moments. So I'm just arbitrarily bestowing you with that responsibility.

• 36:21Krishna Choudhary?

  Yeah, I'll come up with something, but the next one is my favorite. And that is the one that I had predicted many, many episodes ago.

• 36:30Lester Nare?

  Yes.

• 36:30Krishna Choudhary?

  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.

• 36:45Lester Nare?

  The entire, right.

• 36:46Krishna Choudhary?

  And here we see that.

• 36:47Lester Nare?

  We see that.

• 36:47Krishna Choudhary?

  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.

• 37:00Lester Nare?

  It's from the top of the screen. I just want to know, if you're still listening and not watching this particular episode.

• 37:06Krishna Choudhary?

  Yeah.

• 37:06Lester Nare?

  We really encourage you to, to take a, a watch because the imagery is incredible. So what we're saying is the sun's coming in from the top.

• 37:14Krishna Choudhary?

  Yeah.

• 37:14Lester Nare?

  Which is why the top of both spheres.

• 37:17Krishna Choudhary?

  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, the earth is so small that it's about the size of what the moon is to us.

• 37:36Lester Nare?

  Right.

• 37:36Krishna Choudhary?

  Which means they could, they could put up their thumb or a few fingers and cover up the entire earth with a few fingers.

• 37:43Lester Nare?

  Classic.

• 37:43Krishna Choudhary?

  Right? That's seven billion, close to eight billion people, just like that. And there's four people behind that photo.

• 37:50Lester Nare?

  It's, it's almost everybody except the people on the ISS and any classified missions.

• 37:54Krishna Choudhary?

  No, even the ISS is right there.

• 37:55Lester Nare?

  It's right there. Yeah, no, no, no, it's so close.

• 37:57Krishna Choudhary?

  Yeah. 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.

• 38:06Lester Nare?

  It's, it's just.

• 38:07Krishna Choudhary?

  That's where all of humanity is, right?

• 38:10Lester Nare?

  Everyone you know.

• 38:11Krishna Choudhary?

  Yeah.

• 38:11Lester Nare?

  Everyone you love.

• 38:12Krishna Choudhary?

  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.

• 38:22Lester Nare?

  And it's, we covered it in our February episode when Artemis was originally supposed to launch. And I understood what you were saying. But obviously I didn't visualize.

• 38:33Krishna Choudhary?

  Yeah.

• 38:33Lester Nare?

  And kind of internalized the emotional connection to like what it feels like to see us in that context.

• 38:40Krishna Choudhary?

  Yeah, it's pretty, it's pretty insane.

• 38:42Lester Nare?

  And I know we've seen it kind of before, right?

• 38:44Krishna Choudhary?

  Yeah.

• 38:45Lester Nare?

  With the one you mentioned earlier, but this is, I'm alive for this one.

• 38:49Krishna Choudhary?

  Yeah.

• 38:49Lester Nare?

  You know what I mean?

• 38:50Krishna Choudhary?

  And it's like, and there was a human being behind that photo.

• 38:52Lester Nare?

  Yes.

• 38:52Krishna Choudhary?

  That literally saw that out his window.

• 38:54Lester Nare?

  Yes.

• 38:54Krishna Choudhary?

  Or her window.

• 38:55Lester Nare?

  Yes.

• 38:56Krishna Choudhary?

  Right? Oh, my gosh.

• 38:57Lester Nare?

  It's quite nice.

• 38:58Krishna Choudhary?

  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 can 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?

• 39:18Lester Nare?

  Yes.

• 39:18Krishna Choudhary?

  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. Now, one of the funniest things was they reported that the earth from the other window was too bright. And so NASA was like, uh, I don't know, 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.

• 39:47Lester Nare?

  No, you can't.

• 39:47Krishna Choudhary?

  You know?

• 39:48Lester Nare?

  Yeah.

• 39:48Krishna Choudhary?

  So when you're up there, you've got like, time is running out. We're, we're going around the moon at thousands of kilometers an hour.

• 39:54Lester Nare?

  Yes.

• 39:55Krishna Choudhary?

  And time is running out. What do we do? Okay, shirt, like just put a shirt, like it's like stuff that I would think of.

• 40:00Lester Nare?

  Yes.

• 40:00Krishna Choudhary?

  You know?

• 40:01Lester Nare?

  Yes.

• 40:01Krishna Choudhary?

  On like, if I did an astrophotography thing, it's like, okay, let's put a shirt around the telescope because this random light is coming through.

• 40:08Lester Nare?

  No matter, 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.

• 40:14Krishna Choudhary?

  There's a window over there and the earth is going to be exactly in the right spot that it's like coming in. And like, it's actually. Actually hella bright.

• 40:21Lester Nare?

  Yeah, yeah, yeah.

• 40:21Krishna Choudhary?

  You know, for some reason.

• 40:23Lester Nare?

  Yeah, but if anyone's trying to take a photo with your iPhone, right? Like, and I mean, we all see it.

• 40:29Krishna Choudhary?

  Yeah.

• 40:29Lester Nare?

  The glare and the reflection and all kinds of.

• 40:32Krishna Choudhary?

  Yeah, and if there's another, even even if the photo, even if the um, the light source is not in the photo frame.

• 40:38Lester Nare?

  Right.

• 40:38Krishna Choudhary?

  It's gonna, so one of the good ways to do it is just to put something over.

• 40:42Lester Nare?

  Yeah.

• 40:43Krishna Choudhary?

  And like.

• 40:44Lester Nare?

  That makes sense.

• 40:44Krishna Choudhary?

  Block that light, right? Okay, so finally, now that they've had Earth set.

• 40:51Lester Nare?

  Yes.

• 40:51Krishna Choudhary?

  Cause the Earth is set, now they're going around the moon.

• 40:54Lester Nare?

  Yes.

• 40:54Krishna Choudhary?

  And now the sun is going to set around the moon.

• 40:57Lester Nare?

  Yes.

• 40:58Krishna Choudhary?

  But if the sun sets around the moon, that's a eclipse.

• 41:02Lester Nare?

  Yes.

• 41:02Krishna Choudhary?

  Right? That's a solar eclipse, so you need some solar eclipse glasses.

• 41:06Lester Nare?

  Yes.

• 41:06Krishna Choudhary?

  So they put on their solar eclipse glasses to watch the sun set.

• 41:11Lester Nare?

  Yeah.

• 41:11Krishna Choudhary?

  And then once they're in total solar eclipse territory, which we saw.

• 41:15Lester Nare?

  Yes.

• 41:15Krishna Choudhary?

  In Texas, now you can remove your glasses and you can see the actual solar eclipse. So before we get into that, actually, I want I want to show one more photo, which is the solar eclipse lasted about fifty four 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.

• 41:39Lester Nare?

  Yeah, yeah, yeah.

• 41:39Krishna Choudhary?

  Where is that light coming from?

• 41:42Lester Nare?

  I don't know.

• 41:42Krishna Choudhary?

  That's from the Earth.

• 41:44Lester Nare?

  As it's pass, as the light is passing from the sun across the Earth and it.

• 41:50Krishna Choudhary?

  It's bouncing off the Earth. The Earth is literally so bright.

• 41:53Lester Nare?

  That's so crazy.

• 41:54Krishna Choudhary?

  That it is creating a crescent on the moon. It's acting like another sort of lighting.

• 41:59Lester Nare?

  Light source.

• 42:00Krishna Choudhary?

  You know?

• 42:01Lester Nare?

  Yeah, yeah.

• 42:01Krishna Choudhary?

  Yeah, when we think about in movies, right? There's like the primary light source. It's behind.

• 42:05Lester Nare?

  Yeah.

• 42:05Krishna Choudhary?

  But there's a secondary light source from the Earth that is bouncing.

• 42:08Lester Nare?

  Yeah.

• 42:09Krishna Choudhary?

  Light.

• 42:09Lester Nare?

  Yeah.

• 42:10Krishna Choudhary?

  To the moon.

• 42:10Lester Nare?

  Yep, we got a little hair light.

• 42:13Krishna Choudhary?

  Yeah, it's called Earth Shine.

• 42:14Lester Nare?

  This is Earth Set, Earth Shine. These are, I didn't.

• 42:20Krishna Choudhary?

  Just incredible, incredible photographs. And there around the moon, you see the corona, which is the sun's outer atmosphere.

• 42:28Lester Nare?

  Right.

• 42:28Krishna Choudhary?

  That is spewing out. Solar wind and all sorts of other stuff. There's a lot of really cool heliophysics that goes on in the corona. One of the biggest unsolved mysteries about the sun is why is the corona so hot?

• 42:40Lester Nare?

  Right.

• 42:41Krishna Choudhary?

  It's like 2 million Kelvin, 2 million degrees Celsius. Really shouldn't be.

• 42:45Lester Nare?

  Right.

• 42:45Krishna Choudhary?

  Given that the surface of the sun is only like 6,000 degrees Celsius. 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.

• 42:58Lester Nare?

  Yep.

• 42:58Krishna Choudhary?

  You, you go, you go from millions to 6,000, back to millions. Doesn't make any sense.

• 43:03Lester Nare?

  Doesn't make any sense.

• 43:04Krishna Choudhary?

  So this is one of the things that astronomers are working on. We've got a pretty good handle on it. It has to do with magnetic fields and things like that. But it's always nice to, you know, observe and get more data.

• 43:15Lester Nare?

  Yes.

• 43:16Krishna Choudhary?

  One of the things that I wanted to talk about and linger on the solar eclipse a little bit more was to try and predict where the planets should be.

• 43:25Lester Nare?

  Right.

• 43:26Krishna Choudhary?

  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?

• 43:39Lester Nare?

  So, so just for all my astrology, you know, people who care about planet alignments. This seems like this is a moment to lean in.

• 43:48Krishna Choudhary?

  Exactly. Yeah. Here we're going. How are the planets aligned around the moon? When it comes to the solar eclipse from the vantage point of Artemis that's going around?

• 43:57Lester Nare?

  Right, because we've never had this discussion.

• 44:00Krishna Choudhary?

  Yeah.

• 44:00Lester Nare?

  Before.

• 44:00Krishna Choudhary?

  Yeah.

• 44:01Lester Nare?

  Really.

• 44:01Krishna Choudhary?

  Yeah.

• 44:01Lester Nare?

  Because it's never been practical to, or it's never been a thing.

• 44:05Krishna Choudhary?

  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 safe?

• 44:20Lester Nare?

  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.

• 44:38Lester Nare?

  In context of where you are on.

• 44:41Krishna Choudhary?

  Yeah, like at this moment.

• 44:43Lester Nare?

  Which is, I didn't know this until you brought this up to me earlier today.

• 44:46Krishna Choudhary?

  It's pretty cool, right? And so here what we're seeing is the sun in the center, obviously. You've got Earth, Venus, Mercury, Mars, Saturn.

• 44:52Lester Nare?

  Yes.

• 44:53Krishna Choudhary?

  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 solar eclipse that Artemis saw? Okay?

• 45:08Lester Nare?

  This, this, this is, I'm so excited about this. I just want everyone to know Christian did not tell me about this.

• 45:13Krishna Choudhary?

  Yeah.

• 45:14Lester Nare?

  And so I'm very.

• 45:14Krishna Choudhary?

  This is gonna be, this is gonna be really cool. So let's move on to the next photo where I have a bit higher fidelity photograph.

• 45:19Lester Nare?

  Okay.

• 45:21Krishna Choudhary?

  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.

• 45:31Lester Nare?

  Yep.

• 45:31Krishna Choudhary?

  But the, the source of all of these rays is where the moon is.

• 45:34Lester Nare?

  Got it.

• 45:34Krishna Choudhary?

  Okay, we've got a center line that passes from the moon to the sun.

• 45:38Lester Nare?

  Yes.

• 45:38Krishna Choudhary?

  Okay, that's the white line.

• 45:40Lester Nare?

  In white, yes.

• 45:41Krishna Choudhary?

  That is the direction you would be looking if you looked through the moon because the sun is behind the moon.

• 45:46Lester Nare?

  Right.

• 45:47Krishna Choudhary?

  Yes?

• 45:47Lester Nare?

  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.

• 45:56Krishna Choudhary?

  Yeah, the larger big glow is because the sun is behind the moon. So basically, if you were to draw a line from the moon to the sun, that would be that white line.

• 46:03Lester Nare?

  Yes.

• 46:04Krishna Choudhary?

  Okay, and now let's look at the positions of the planets, Mercury, Mars, Saturn and Venus.

• 46:09Lester Nare?

  Yes.

• 46:09Krishna Choudhary?

  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.

• 46:17Lester Nare?

  Yeah.

• 46:18Krishna Choudhary?

  Because Mercury is right next to the sun.

• 46:20Lester Nare?

  Right.

• 46:20Krishna Choudhary?

  But that's not what matters.

• 46:21Lester Nare?

  Okay.

• 46:21Krishna Choudhary?

  What matters is the angle.

• 46:23Lester Nare?

  Yay.

• 46:24Krishna Choudhary?

  Not physical distance.

• 46:26Lester Nare?

  Right.

• 46:26Krishna Choudhary?

  Right? When it comes to the solar system, what matters is if I'm looking at the sun.

• 46:32Krishna Choudhary?

  And I'm scanning across, what's the first thing with the smallest angle?

• 46:36Lester Nare?

  Yeah, so I'm looking at the sun in the center of my view. And if I like were to pivot and my angle and look left to the left or the right of this, or the left or the right of the sun, what am I going to see first?

• 46:48Krishna Choudhary?

  Exactly, that's the question. And according to the positions of all of our planets, the first thing you should see is Saturn.

• 46:54Lester Nare?

  Which is interesting.

• 46:55Krishna Choudhary?

  Saturn is behind the sun, but it's close to our vantage point.

• 46:59Lester Nare?

  It's almost about to pass behind the sun in the same white line that the moon and the sun are in.

• 47:05Krishna Choudhary?

  Exactly, so Saturn should be first.

• 47:07Lester Nare?

  Right.

• 47:07Krishna Choudhary?

  Then it should be Mars, which is the red line.

• 47:10Lester Nare?

  Yes.

• 47:10Krishna Choudhary?

  And then it should be Mercury.

• 47:12Lester Nare?

  Right.

• 47:12Krishna Choudhary?

  If I were to look to the right of the sun.

• 47:15Lester Nare?

  Yes.

• 47:15Krishna Choudhary?

  If I were to look to the left of the sun, I should see Venus.

• 47:18Lester Nare?

  Got it.

• 47:19Krishna Choudhary?

  Okay, so do we agree?

• 47:20Lester Nare?

  Yes.

• 47:21Krishna Choudhary?

  On the right of the sun, we should see Saturn, Mars, and Mercury, because that's how the angles line up. And on the left of the sun, we should see Venus.

• 47:28Lester Nare?

  Let me check my watch. Um, yep, I see Saturn to the right. I see Mars to the right.

• 47:34Krishna Choudhary?

  Right.

• 47:34Lester Nare?

  Neptune is kind of further back a little bit in between the two.

• 47:38Krishna Choudhary?

  In between, yeah, but in this zoomed version, we don't see it.

• 47:41Lester Nare?

  Yeah.

• 47:41Krishna Choudhary?

  But Neptune would be in between Saturn and Mars.

• 47:44Lester Nare?

  And then I see Venus. I literally am looking at my Apple Watch right now.

• 47:48Krishna Choudhary?

  Yeah, okay, now let's go to the next photograph. Here's the labels, Saturn, Neptune, as you were saying.

• 47:55Lester Nare?

  Oh, yes, yes.

• 47:56Krishna Choudhary?

  Mars and Mercury.

• 47:57Lester Nare?

  I'm telling you guys, we didn't manufacture that.

• 48:00Krishna Choudhary?

  No.

• 48:00Lester Nare?

  Like, I literally brought it up.

• 48:01Krishna Choudhary?

  This is the first time you've seen that.

• 48:03Lester Nare?

  That's so funny. Isn't that cool, though?

• 48:06Krishna Choudhary?

  That's incredible.

• 48:07Lester Nare?

  That like from your Apple Watch, you can deduce positions of planets and also positions of planets on photographs from Artemis.

• 48:14Krishna Choudhary?

  Right.

• 48:15Lester Nare?

  So there are people who are on the far side of the moon. They took a photo, they are able to see the planets because it was during a...

• 48:25Krishna Choudhary?

  Solar eclipse.

• 48:27Lester Nare?

  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.

• 48:37Krishna Choudhary?

  Exactly. That's incredible.

• 48:39Lester Nare?

  Isn't it cool? It just makes sense. The whole thing, the planets, the positions, the whole thing makes sense.

• 48:46Krishna Choudhary?

  Yes. Yes.

• 48:48Lester Nare?

  That's that. That was quite nice.

• 48:49Krishna Choudhary?

  It's pretty cool.

• 48:50Lester Nare?

  That was quite nice.

• 48:51Krishna Choudhary?

  Right?

• 48:52Lester Nare?

  I like that. Yeah.

• 48:54Krishna Choudhary?

  I thought you would.

• 48:54Lester Nare?

  You were like, oh, that's so special for you. This I was like, okay.

• 48:57Krishna Choudhary?

  Yeah.

• 48:58Lester Nare?

  You can never surprise me. This was quite nice.

• 49:01Krishna Choudhary?

  And in the next photo, we'll actually see Venus. It's on the left.

• 49:04Lester Nare?

  Yes.

• 49:04Krishna Choudhary?

  Yes. Right? It's peeking out right behind the Artemis module. So the other planets that we saw are would be like, you know, out of frame.

• 49:12Lester Nare?

  Yes, out of frame to the right.

• 49:13Krishna Choudhary?

  Yeah.

• 49:15Lester Nare?

  This is pretty cool. This is quite nice.

• 49:17Krishna Choudhary?

  Right?

• 49:17Lester Nare?

  Look, if you're not enjoying the this endeavor into curiosity and discovery, I just, I don't know what to tell you. This is so, this is like the most fun I've had in a long time.

• 49:30Krishna Choudhary?

  Yeah.

• 49:31Lester Nare?

  In general, it's been so much happening.

• 49:34Krishna Choudhary?

  Yeah.

• 49:34Lester Nare?

  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.

• 49:44Krishna Choudhary?

  Yeah.

• 49:45Lester Nare?

  Cause there's headlines and all there but like.

• 49:47Krishna Choudhary?

  No, but it makes sense. If you just, if you just peel away the layers a little bit and you think about it.

• 49:53Lester Nare?

  Right.

• 49:53Krishna Choudhary?

  It's like, yeah, no, the thing that you saw in the Apple Watch is the thing that the astronauts saw on Artemis when they were going around the moon.

• 50:01Lester Nare?

  It's so good.

• 50:03Krishna Choudhary?

  I think that was pretty cool.

• 50:05Lester Nare?

  This is quite nice.

• 50:06Krishna Choudhary?

  Okay. We've been focusing a lot on the photographs.

• 50:09Lester Nare?

  Yes.

• 50:10Krishna Choudhary?

  But one thing that I don't want to leave out is the human observer.

• 50:14Lester Nare?

  Yes.

• 50:14Krishna Choudhary?

  Okay, so there are a lot of recorded observations. This is a photograph of, I believe, Commander Reed Wiseman just looking through the.

• 50:25Krishna Choudhary?

  Window and taking observations. They had iPads that, you know, because when you go to the, through the far side of the moon and then the earth is no longer in view.

• 50:34Lester Nare?

  Yes.

• 50:34Krishna Choudhary?

  You can no longer communicate with earth.

• 50:36Lester Nare?

  Right.

• 50:36Krishna Choudhary?

  But that doesn't mean that you're not gonna be taking observations, right? You're gonna be taking photographs and you're also gonna be relaying observations about what your human eye is seeing. In some cases, the human eye is worse than cameras.

• 50:50Lester Nare?

  Yes.

• 50:51Krishna Choudhary?

  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.

• 51:08Lester Nare?

  Yes.

• 51:08Krishna Choudhary?

  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. It has to excite the atoms in the sensor to then produce some kind of digital fingerprint that we then record as 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.

• 51:51Krishna Choudhary?

  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. Here'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. 50% light coming in, 50% response. The human eye is a logarithmic curve, meaning lower light has a much higher

• 52:21Lester Nare?

  Yes.

• 52:22Krishna Choudhary?

  Output.

• 52:23Lester Nare?

  Yes.

• 52:24Krishna Choudhary?

  Right? So we are really highly sensitive to that low light condition.

• 52:28Lester Nare?

  Shout out evolution.

• 52:29Krishna Choudhary?

  Shout out evolution, especially when it comes to going around the moon, being in the eclipse, the corona is gonna be this faint glow around the moon. The human observer can see a lot more in real time than a camera ever could. Because we've had a billion years and a camera, what, 100?

• 52:47Lester Nare?

  Right, right. It might get quite nice.

• 52:50Krishna Choudhary?

  It might get quite nice, but so far.

• 52:52Lester Nare?

  Not yet, not.

• 52:52Krishna Choudhary?

  Not yet. This is, this is one of those things where biology is just beating hardware.

• 52:58Lester Nare?

  I mean, it's such an interesting, because we talked about it earlier, about this advantage of having, what was it? That 3 million, 1 million, 3 million ISO? On the Nikon.

• 53:09Krishna Choudhary?

  But even then.

• 53:10Lester Nare?

  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.

• 53:20Krishna Choudhary?

  Yeah.

• 53:20Lester Nare?

  Um, and our ability to perceive through our core senses, not through, uh, how we are able to intuit, like in our internal monologue and cognition, but literally just through the input sensors of our physical body.

• 53:39Krishna Choudhary?

  Yeah.

• 53:40Lester Nare?

  Those input sensors are quite nice. Eyes are quite nice. Maybe the meat fingers could be a little bit better.

• 53:44Krishna Choudhary?

  Yeah, yeah, definitely.

• 53:45Lester Nare?

  Low, the, the.

• 53:46Krishna Choudhary?

  But the eyes are just like insane.

• 53:48Lester Nare?

  The eyes are quite nice.

• 53:49Krishna Choudhary?

  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?

• 53:55Lester Nare?

  Sure.

• 53:55Krishna Choudhary?

  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. What 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,

• 54:40Krishna Choudhary?

  and there's this nonlinear integration that's happening in the brain. That's something that you can't replicate with just like straight hardware on a camera.

• 54:50Lester Nare?

  We have the best image stabilization of all time.

• 54:52Krishna Choudhary?

  Yeah, it's ridiculous, right? And that image stabilization is creating more signal to noise.

• 54:58Lester Nare?

  Right.

• 54:58Krishna Choudhary?

  Right? It's not actually like trying to like deal with.

• 55:03Lester Nare?

  Stabilize the signal almost.

• 55:04Krishna Choudhary?

  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 stabilization. But what that's actually doing is taking a really bad sort of jittery video and trying to do the best that it can.

• 55:20Lester Nare?

  Right.

• 55:20Krishna Choudhary?

  Here, we're actually making it better.

• 55:23Lester Nare?

  Right.

• 55:23Krishna Choudhary?

  The sensitivity is becoming better.

• 55:25Lester Nare?

  Yes.

• 55:25Krishna Choudhary?

  Which is, which is very non trivial. It's quite a distinct difference.

• 55:29Lester Nare?

  It's a really important point. No, it's a really important point. And it, that is, you know, I, there's a condition that I can't remember where the, the eye movement is a little like it's above the baseline. And so it's very visible when you're, because when you look at somebody and you look at them in the eye.

• 55:46Krishna Choudhary?

  You can't really tell.

• 55:46Lester Nare?

  You can't really tell.

• 55:47Krishna Choudhary?

  Yeah, but it's happening all the time.

• 55:49Lester Nare?

  It's happening, it's happening all the time. And it's, it's sort of why like you get sort of like, you don't, you'll, you're not paying attention and you'll see something in your perif.

• 55:58Krishna Choudhary?

  Yeah.

• 55:58Lester Nare?

  And then be like, wait, what's that?

• 55:59Krishna Choudhary?

  Yeah, because, because it, our eyes are, and the algorithm in our brain is just so sensitive.

• 56:04Lester Nare?

  Right.

• 56:04Krishna Choudhary?

  To all kinds of stuff. Our algorithm in our brain is also really sensitive to change.

• 56:09Lester Nare?

  Right.

• 56:09Krishna Choudhary?

  Okay? Like you see a static photo and then 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.

• 56:29Krishna Choudhary?

  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 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 confirmation, visual confirmation of meteorites.

• 56:53Krishna Choudhary?

  striking the moon and these things are going at like 20 kilometers per second because there's no atmosphere to slow them down.

• 56:58Lester Nare?

  I was actually gonna ask you is part of the reason they are making contact with the surface, no atmosphere.

• 57:02Krishna Choudhary?

  Yeah, these are tiny, tiny little things, but because they're going so fast, they're gonna pulverize whatever rock, there's gonna be a lot of heat and a brief amount of plasma that's gonna form and that's gonna 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.

• 57:22Lester Nare?

  Right.

• 57:23Krishna Choudhary?

  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.

• 57:33Lester Nare?

  Right.

• 57:34Krishna Choudhary?

  In the time that they were on the far side when it was completely dark and they could see these flashes.

• 57:37Lester Nare?

  So, so we're gonna need a meteor defense force.

• 57:40Krishna Choudhary?

  Yeah.

• 57:41Lester Nare?

  An MDF.

• 57:42Krishna Choudhary?

  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.

• 57:51Lester Nare?

  And with these observations, the idea is you can, even though it wasn't from a sensor, a, a, an instrument sensor versus a human sensor, we can still pontificate on velocity and such that we can make those preparations accordingly.

• 58:07Krishna Choudhary?

  Exactly.

• 58:08Lester Nare?

  Even if it's not explicit or extremely precise in the measurement quality.

• 58:13Krishna Choudhary?

  Yeah.

• 58:14Lester Nare?

  The fact that we just were able to do it at all.

• 58:16Krishna Choudhary?

  At all.

• 58:17Lester Nare?

  Now we're like, okay, we now need to think about this as an issue.

• 58:20Krishna Choudhary?

  Right? The other thing that the human eye is really good at is 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 out distinct vibrant hues, so the astronomers, the astronauts were reporting orange, brown and green colorations. This is a photograph that's highly

• 58:44Krishna Choudhary?

  Photoshopped.

• 58:44Lester Nare?

  Yes.

• 58:45Krishna Choudhary?

  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 are the presence of distinct minerals.

• 59:03Lester Nare?

  That's cool. I just so.

• 59:04Krishna Choudhary?

  But this is kind of what humans would see.

• 59:07Lester Nare?

  This is for those listening, it kind of basically looks like Earth in the top third.

• 59:13Krishna Choudhary?

  That's the near side of the moon.

• 59:15Lester Nare?

  Yeah.

• 59:15Krishna Choudhary?

  With the mare.

• 59:16Lester Nare?

  Ocean, like grass, you know, a little bit of land. And then it's just all the moon white that you think of.

• 59:22Krishna Choudhary?

  Yeah.

• 59:23Lester Nare?

  If that's literally what they're seeing, that's crazy.

• 59:26Krishna Choudhary?

  Yeah, that's literally what they're seeing because their human eyes are so good.

• 59:30Lester Nare?

  That's.

• 59:30Krishna Choudhary?

  And this, this was also reported by the Apollo astronauts.

• 59:33Lester Nare?

  Also fair.

• 59:33Krishna Choudhary?

  You know? So this is not new.

• 59:35Lester Nare?

  Yeah.

• 59:35Krishna Choudhary?

  But again, it just goes to show just how good the human eye is for this kind of stuff.

• 59:39Lester Nare?

  And also the difference between the instruments 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, because this goes back to like, how do you interpret the data?

• 59:54Krishna Choudhary?

  Mm hmm.

• 59:54Lester Nare?

  Right?

• 59:55Krishna Choudhary?

  No.

• 59:55Lester Nare?

  And so this is an example of saying, hey, the camera is not how people see.

• 1:00:01Krishna Choudhary?

  Yeah.

• 1:00:03Lester Nare?

  Right?

• 1:00:03Krishna Choudhary?

  Yes.

• 1:00:03Lester Nare?

  People are like, well, why are you manipulating it after the fact? Because the instrument is not a human eye.

• 1:00:08Krishna Choudhary?

  No, it's not.

• 1:00:09Lester Nare?

  And so we're trying to translate from English to French.

• 1:00:13Krishna Choudhary?

  Yeah.

• 1:00:13Lester Nare?

  Right? And, and yeah, there might be some subtle differences, but fundamentally where you're born, what's my name? All translates. I, I think it's an important.

• 1:00:23Krishna Choudhary?

  Yeah.

• 1:00:23Lester Nare?

  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.

• 1:00:36Krishna Choudhary?

  Exactly. And that's why I kind of wanted to linger on this point about the human.

• 1:00:39Lester Nare?

  Yeah.

• 1:00:40Krishna Choudhary?

  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.

• 1:00:51Lester Nare?

  Yeah.

• 1:00:51Krishna Choudhary?

  Over and over, like, describe what you're seeing, but put it down on the iPad. We gave you iPads. Like, put it down, you know?

• 1:00:57Lester Nare?

  Right.

• 1:00:58Krishna Choudhary?

  There was this really funny part where. Commander, not Commander Reed Wiseman, I think it was Jeremy Hansen, was describing how the hues are changing as they change angle around the moon of these Maure, 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 bated 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, you're on, you're seeing the moon for the first time.

• 1:01:31Lester Nare?

  And if it was Hansen, it's his first time.

• 1:01:32Krishna Choudhary?

  Yeah, and it's in space, in space. And he's seeing the moon and like, you're gonna be overcome with just like loss for words.

• 1:01:40Lester Nare?

  Right.

• 1:01:40Krishna Choudhary?

  And, and mission control is like, you need to lock in, bro.

• 1:01:44Lester Nare?

  Lock in.

• 1:01:45Krishna Choudhary?

  This is all we, we got like, we, this is all we got.

• 1:01:48Lester Nare?

  Right.

• 1:01:48Krishna Choudhary?

  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. So, you know, he's doing his job really well. I'm just saying like, when you're up there.

• 1:02:00Lester Nare?

  Yeah.

• 1:02:00Krishna Choudhary?

  You know, and you're kind of overwhelmed with what you're seeing. And at the same time, there's all these scientists on the ground being like, I need my data. Right? I'm trying to publish, bro.

• 1:02:13Krishna Choudhary?

  You know?

• 1:02:13Lester Nare?

  As per my last email.

• 1:02:14Krishna Choudhary?

  As per my last email, please provide more verbose description. You're doing great, but like, come on.

• 1:02:20Lester Nare?

  I need more. I need more.

• 1:02:22Krishna Choudhary?

  So I thought that was like a really cool, like, uh, human, human moment there. And finally, one of the last ones that I wanna highlight is Earth Rise, which is on the back of the moon.

• 1:02:32Lester Nare?

  Yes.

• 1:02:32Krishna Choudhary?

  They see the Earth rise 54 minutes later.

• 1:02:35Lester Nare?

  Cause we saw Earth set earlier.

• 1:02:37Krishna Choudhary?

  On 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 wanna note, this is really high zoom.

• 1:02:53Lester Nare?

  Yeah.

• 1:02:54Krishna Choudhary?

  This is like they got their 300 millimeter and they're really zooming in. The Earth is something that you can probably cover up with a finger or two.

• 1:03:01Lester Nare?

  Right, 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.

• 1:03:16Krishna Choudhary?

  Yeah.

• 1:03:17Lester Nare?

  Than where our current vantage point is. And so, you know, it just.

• 1:03:22Krishna Choudhary?

  It's incredible.

• 1:03:23Lester Nare?

  I can't wait for some granola snack company to name itself Earthrise.

• 1:03:28Krishna Choudhary?

  Yeah. Oh, my gosh. And put this.

• 1:03:31Lester Nare?

  But this.

• 1:03:32Krishna Choudhary?

  Cause it's like NASA, so it's like probably free.

• 1:03:34Lester Nare?

  Exactly. It's taxpayer money. We paid for it.

• 1:03:37Krishna Choudhary?

  Yeah. Yeah. 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. 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 meetup when they get back and we're going to see all of the data that they have, you know?

• 1:04:14Lester Nare?

  Right. I, I just want to take a moment to

• 1:04:20Lester Nare?

  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. 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.

• 1:04:58Krishna Choudhary?

  No.

• 1:04:59Lester Nare?

  It's not the Super Bowl halftime show. But it is for millions and millions of people on the planet. And we just don't have a venue that.

• 1:05:12Lester Nare?

  It really is able to make it compete with these other things. This is so.

• 1:05:17Krishna Choudhary?

  But we're building it.

• 1:05:18Lester Nare?

  We're trying to build that because this is some of the most important. 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 sensational curiosity and were focused on doing the work.

• 1:05:40Krishna Choudhary?

  Yeah.

• 1:05:41Lester Nare?

  And I, I'm gonna get off my soapbox, but.

• 1:05:44Krishna Choudhary?

  And one more thing that I wanted to just comment about this photo is it's such a stark difference from the Apollo mission.

• 1:05:50Lester Nare?

  Yeah, that's a really good point.

• 1:05:52Krishna Choudhary?

  Because there's so many women in this photo.

• 1:05:53Lester Nare?

  That's a really good point.

• 1:05:54Krishna Choudhary?

  I think that's just so cool.

• 1:05:55Lester Nare?

  Yes.

• 1:05:55Krishna Choudhary?

  Right, that we, I think, you know, we have a long way to go as a society.

• 1:06:00Lester Nare?

  Yeah.

• 1:06:00Krishna Choudhary?

  When it comes to gender equality in the sciences.

• 1:06:03Lester Nare?

  Yes.

• 1:06:04Krishna Choudhary?

  But I think this shows just how far we've come, that there are all these women on the science team.

• 1:06:10Lester Nare?

  Yes.

• 1:06:11Krishna Choudhary?

  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 observations 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.

• 1:06:35Lester Nare?

  A hundred percent.

• 1:06:36Krishna Choudhary?

  Just a shout out.

• 1:06:37Lester Nare?

  And it's, it's huge progress. Thank you to all of those who've supported, whether you're employed, members, families.

• 1:06:46Krishna Choudhary?

  Yeah, just incredible stuff.

• 1:06:48Lester Nare?

  Like, this is a really big deal.

• 1:06:50Krishna Choudhary?

  Yeah.

• 1:06:52Lester Nare?

  And as Cat Williams says, we need haters.

• 1:07:00Lester Nare?

  So, you know, let, let, you know, we're continuing 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.

• 1:07:10Lester Nare?

  If you're not doing anything important, you don't have any haters. You guys are doing something important and so naturally you're gonna get people who push back on it. And that's, that's the way the world works.

• 1:07:18Krishna Choudhary?

  That's the way the world works. Be proud of the haters. You know, okay, the final

• 1:07:23Lester Nare?

  Frankly, we need more haters.

• 1:07:24Krishna Choudhary?

  Yeah, yeah.

• 1:07:25Lester Nare?

  We're not, we're not important enough yet.

• 1:07:27Krishna Choudhary?

  Yeah, yeah, yeah.

• 1:07:28Lester Nare?

  We don't have enough haters.

• 1:07:29Krishna Choudhary?

  Although, there are a few people in the comments who are like, they're definitely AI. That makes me feel good, that you know, so many things that we're so good.

• 1:07:37Lester Nare?

  We're big science, we're paid off by NASA.

• 1:07:40Krishna Choudhary?

  Who's paying us?

• 1:07:41Lester Nare?

  Yeah, I would love to be paid.

• 1:07:42Krishna Choudhary?

  Yo!

• 1:07:43Lester Nare?

  If anyone wants to pay us, that would be great. Like, I would be lovely, I would love to get paid.

• 1:07:49Krishna Choudhary?

  That would be great, um, okay, so the final part of our segment.

• 1:07:52Lester Nare?

  Yes.

• 1:07:53Krishna Choudhary?

  I want to talk about reentry.

• 1:07:54Lester Nare?

  Yes.

• 1:07:55Krishna Choudhary?

  Which is going to be happening on Friday.

• 1:07:57Lester Nare?

  Yes.

• 1:07:57Krishna Choudhary?

  Around 5pm, I believe, is when they're gonna be reentering the Earth's atmosphere.

• 1:08:00Lester Nare?

  Yes.

• 1:08:01Krishna Choudhary?

  And, um, landing somewhere right off the coast of San Diego.

• 1:08:04Lester Nare?

  And that's gonna be Friday, um, April 10th.

• 1:08:08Krishna Choudhary?

  Yes, yes.

• 1:08:09Lester Nare?

  Yeah.

• 1:08:10Krishna Choudhary?

  Okay, so atmospheric reentry, you're approaching the Earth's atmosphere, and all of that energy that was put into that trans lunar injection burn has to get shed.

• 1:08:20Lester Nare?

  Right.

• 1:08:20Krishna Choudhary?

  Right? Conservation of energy.

• 1:08:21Lester Nare?

  Right.

• 1:08:22Krishna Choudhary?

  In space.

• 1:08:23Lester Nare?

  There's nothing.

• 1:08:23Krishna Choudhary?

  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 bit 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 gonna have a velocity, a speed of 40,000 kilometers per hour. Almost the same as the velocity that they left the Earth with.

• 1:08:55Lester Nare?

  Right, right. A- a- and it's funny, I mean, the space is a vacuum, right?

• 1:08:59Krishna Choudhary?

  Yeah, so they didn't go anywhere.

• 1:09:01Lester Nare?

  There's no way to dissipate.

• 1:09:02Krishna Choudhary?

  Yeah, yeah, it's just in the motion.

• 1:09:04Lester Nare?

  Right.

• 1:09:04Krishna Choudhary?

  And all of that motion, all of that kinetic energy has to go somewhere. And so, what we want to do fundamentally is dump all of that kinetic energy as heat into the atmosphere.

• 1:09:16Lester Nare?

  Right.

• 1:09:16Krishna Choudhary?

  That's, that's the equation that we're doing. Before is kinetic energy and you know, whatever the temperature.

• 1:09:23Lester Nare?

  Which, which just to be clear for those of mine, it means just movement or motion. Like when you say kinetic energy.

• 1:09:28Krishna Choudhary?

  Yes.

• 1:09:29Lester Nare?

  Can you just be a little?

• 1:09:30Krishna Choudhary?

  Yeah, yeah, yeah, yeah. Fair enough. Um, when I say kinetic energy, I mean, this thing, the Orion capsule up here. This little triangle pyramid part.

• 1:09:39Lester Nare?

  Yes.

• 1:09:39Krishna Choudhary?

  Is moving at forty thousand kilometers per hour. One half MV squared, that's the kinetic energy of this guy, just on the motion of the thing. We want to slow it down so that it doesn't slam into the earth like a meteorite.

• 1:09:53Lester Nare?

  Right.

• 1:09:54Krishna Choudhary?

  Okay?

• 1:09:54Lester Nare?

  Right.

• 1:09:55Krishna Choudhary?

  And in order to do that, all of that energy from the motion has to go somewhere.

• 1:09:59Lester Nare?

  Right.

• 1:09:59Krishna Choudhary?

  So the model is always, we dissipate it as heat in the atmosphere. Okay, we gotta be careful though, okay? There's gotta be a method to this madness.

• 1:10:11Lester Nare?

  Right.

• 1:10:13Krishna Choudhary?

  And this is where the reentry procedure comes in. So in the next segment, we're going to talk about, how long does that take? So if we, we're actually going to start over the Indian Ocean. If you go to photo number thirty-three.

• 1:10:25Lester Nare?

  Yes.

• 1:10:27Krishna Choudhary?

  Look at how much, look at how much, just real estate.

• 1:10:32Lester Nare?

  Distance.

• 1:10:33Krishna Choudhary?

  The re, the distance, yeah. Look at how much distance the reentry procedure is taking. They're entering the atmosphere somewhere over India, just south of India in the Indian Ocean.

• 1:10:43Lester Nare?

  It's like, it's Sri Lanka area.

• 1:10:44Krishna Choudhary?

  Yeah, exactly. And they're going across more than half of the earth in order to dump all of that kinetic energy.

• 1:10:52Lester Nare?

  The, the point here being, once Orion reenters Earth's atmosphere, you know, four hundred thousand feet above the Earth's surface.

• 1:11:00Krishna Choudhary?

  Yeah.

• 1:11:01Lester Nare?

  It's gonna traverse across, it's not just, it's not just gonna come straight down.

• 1:11:06Krishna Choudhary?

  Yeah, exactly.

• 1:11:07Lester Nare?

  It's gonna traverse across the surface of the Earth. And the reason, that's a proactive choice because we need to dissipate the heat.

• 1:11:15Krishna Choudhary?

  Yeah, we need to dump all that energy.

• 1:11:17Lester Nare?

  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.

• 1:11:26Krishna Choudhary?

  And 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.

• 1:11:35Lester Nare?

  That's a, that's a really good point.

• 1:11:37Krishna Choudhary?

  I mean, a meteor, right, just goes in.

• 1:11:39Lester Nare?

  Right.

• 1:11:40Krishna Choudhary?

  Okay, it dumped all of that kinetic energy, but it did it over such a small amount of time that the temperature gets to like lava. You don't want that to happen here. 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 degrees Fahrenheit.

• 1:11:56Lester Nare?

  Makes sense.

• 1:11:57Krishna Choudhary?

  Which only, yeah, only about 5,000 degrees Fahrenheit. But that's kind of manageable. And this is the procedure. What we're gonna do is something very different, very unique, and something that has not been done for any crewed mission. It has been done for the Artemis 1, which was the precursor to the Artemis 2.

• 1:12:15Lester Nare?

  That was the test drive where we had the mannequins in there.

• 1:12:17Krishna Choudhary?

  Yeah.

• 1:12:17Lester Nare?

  You know, 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's okay. Artemis 2 now is we're going up all the way around the moon because we're scoping out a parking spot and making sure all the systems to go that distance are working well.

• 1:12:35Krishna Choudhary?

  With humans.

• 1:12:36Lester Nare?

  With humans inside are working well. Artemis 3 now is going to be testing the docking procedure. It's gonna 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 dock, redock is all good. Artemis 4 then is now, we're going.

• 1:13:01Krishna Choudhary?

  Yeah.

• 1:13:02Lester Nare?

  And we're gonna land.

• 1:13:03Krishna Choudhary?

  Yep.

• 1:13:04Lester Nare?

  And then 5 and beyond is going to be building the neighborhood, the establishment of a permanent lunar presence. Again, funding agreeable.

• 1:13:12Krishna Choudhary?

  Yes.

• 1:13:12Lester Nare?

  I just wanted to quickly recap what the schedule is in relation to this.

• 1:13:17Krishna Choudhary?

  No, that's very good. And the reentry procedure here is gonna be very different.

• 1:13:22Lester Nare?

  Yes.

• 1:13:22Krishna Choudhary?

  Was the point with this image. Because usually when we reenter, like Apollo or like the ISS, when they reenter, it's 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 come back. Now, reentering from the moon is very different from reentering from the ISS because the ISS, you're not moving that fast.

• 1:13:45Lester Nare?

  Right.

• 1:13:45Krishna Choudhary?

  Right? Here, you went all the way to the moon and back. You're moving real fast.

• 1:13:49Lester Nare?

  Yeah.

• 1:13:50Krishna Choudhary?

  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 gonna 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?

• 1:14:05Lester Nare?

  Yes.

• 1:14:06Krishna Choudhary?

  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 gonna 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.

• 1:14:22Lester Nare?

  Mm hmm.

• 1:14:23Krishna Choudhary?

  We're skipping over the earth's atmosphere first.

• 1:14:25Lester Nare?

  Yes.

• 1:14:26Krishna Choudhary?

  To reduce velocity.

• 1:14:27Lester Nare?

  Yes.

• 1:14:28Krishna Choudhary?

  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 one that actually show this maneuver. So this is from Artemis one. We've got a camera up here that's looking backwards.

• 1:14:46Lester Nare?

  Yes.

• 1:14:47Krishna Choudhary?

  Or sorry upwards. So you know, the the the Artemis one capsule is coming like this and the camera is looking in the opposite direction.

• 1:14:54Lester Nare?

  Yes.

• 1:14:55Krishna Choudhary?

  And here you can see the earth is moving, moving underneath.

• 1:14:59Lester Nare?

  Yes.

• 1:14:59Krishna Choudhary?

  The speed there is thirty nine thousand kilometers per hour.

• 1:15:03Lester Nare?

  It's moving.

• 1:15:04Krishna Choudhary?

  Yeah, that thing is moving.

• 1:15:05Lester Nare?

  Moving.

• 1:15:06Krishna Choudhary?

  And here you can see now it's entering the earth's atmosphere. This is the first entry.

• 1:15:10Lester Nare?

  Yes.

• 1:15:10Krishna Choudhary?

  And all of that heat from the friction of the earth's atmosphere is creating like a plasma bubble above the Artemis, like up here.

• 1:15:20Lester Nare?

  Yes.

• 1:15:20Krishna Choudhary?

  You know, it's like all of the heat is down here as it's moving through and it's creating a plasma bubble.

• 1:15:26Lester Nare?

  Yes.

• 1:15:26Krishna Choudhary?

  Behind it in its wake.

• 1:15:27Lester Nare?

  Yes.

• 1:15:28Krishna Choudhary?

  And the thing is getting hot.

• 1:15:30Lester Nare?

  That is so.

• 1:15:30Krishna Choudhary?

  Dude, that thing is getting real hot.

• 1:15:33Lester Nare?

  As just as as a camera and gearhead guy, I I'm loving this.

• 1:15:38Krishna Choudhary?

  This is just so cool.

• 1:15:39Lester Nare?

  Because I'm just there's there's so much hardware engineering that goes into being able to even pull off the like, and I know we're we're sort of coming from this, but like. There's the intensity of that environment.

• 1:15:53Krishna Choudhary?

  Yeah.

• 1:15:54Lester Nare?

  And the ability to protect the craft in that high intensity environment is unbelievable.

• 1:16:01Krishna Choudhary?

  It's just 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.

• 1:16:09Lester Nare?

  Yeah, yeah, yeah, yeah, yeah.

• 1:16:09Krishna Choudhary?

  So in free fall, it's zero Gs, but as you start slowing down, the Gs start going up and up.

• 1:16:15Lester Nare?

  And when you say Gs, what do you mean?

• 1:16:17Krishna Choudhary?

  In Gs, what I mean is like the effective acceleration, like you're, you're starting to feel your own weight.

• 1:16:23Lester Nare?

  Yeah, yup.

• 1:16:24Krishna Choudhary?

  If you slow down a lot, the Gs go up. We want to also minimize the amount of Gs because when Apollo did it just a single, just a single reentry, the, the amount of Gs was exceptionally high. We want also lower the amount of Gs. So that's another reason why we're doing the skip entry. Okay, so this is that first skip.

• 1:16:43Lester Nare?

  Yes.

• 1:16:43Krishna Choudhary?

  Okay, now the second skip, what we'll do is we'll take our aircraft and we will rotate it.

• 1:16:51Lester Nare?

  Okay.

• 1:16:51Krishna Choudhary?

  Okay, so this is after the first skip and you can also see the speed has reduced down to 26,000 kilometers per hour.

• 1:16:58Lester Nare?

  Yes.

• 1:16:58Krishna Choudhary?

  So we've already dumped a lot of kinetic energy in that first skip. Now we turn.

• 1:17:03Lester Nare?

  Yeah, we're rotating.

• 1:17:05Krishna Choudhary?

  We're rotating, we do a roll about the spacecraft and once that roll is finished, again, we're free falling. So we've done the skip, we're coming back.

• 1:17:16Krishna Choudhary?

  And now we're back into reentering the Earth's atmosphere. Again, this is Artemis one, we've already done this and we've tested it and this,

• 1:17:24Krishna Choudhary?

  this skip reentry does work.

• 1:17:26Lester Nare?

  Y- yes.

• 1:17:27Krishna Choudhary?

  Okay?

• 1:17:28Lester Nare?

  Yes.

• 1:17:29Krishna Choudhary?

  Now, it's not completely foolproof, okay? Artemis one had a few issues.

• 1:17:37Lester Nare?

  Okay.

• 1:17:38Krishna Choudhary?

  And the NASA administrator.

• 1:17:42Lester Nare?

  Isaacman.

• 1:17:42Krishna Choudhary?

  Isaacman did in fact allude to that issue.

• 1:17:47Lester Nare?

  Yes.

• 1:17:48Krishna Choudhary?

  The next photo shows exactly what he's talking about.

• 1:17:50Lester Nare?

  Yes.

• 1:17:50Krishna Choudhary?

  Okay, this is the heat shield from Artemis one. And what we can see is that this heat shield is covered by something called.

• 1:18:01Krishna Choudhary?

  The avocat. It's an ablative thermal protection material. It's like the tiles on the back of the 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. What ended up happening with Artemis one was there were about 100 locations where the avocat experienced severe spalling, meaning chunks were sort of fractured and broke away. The root cause is that the heat shield didn't maintain a high enough temperature to fully melt and become porous. It's designed to do that, but it wasn't maintaining a high enough temperature to do that. And so the solution now with Artemis two, because it's got the same heat shield,

• 1:18:45Krishna Choudhary?

  the engineers have modified that reentry procedure to steepen

• 1:18:50Lester Nare?

  Oh, the initial angle.

• 1:18:52Krishna Choudhary?

  Not make it more shallow, actually steepen it to get it up to that high temperature so that it doesn't blow off. It's actually designed to melt. And that's what they're doing with Artemis two. Okay. It hasn't been tested before, this steeper angle of entry. And so in a in a recent press conference, the NASA administrator Jared Isaacman like talked about that a little bit.

• 1:19:17Lester Nare?

  Yes.

• 1:19:17Krishna Choudhary?

  And

• 1:19:18Lester Nare?

  I did see that.

• 1:19:19Krishna Choudhary?

  Yeah, yeah. And it was like, you know, he he said that I know that we've done all of the necessary calculations.

• 1:19:25Lester Nare?

  He was totally backing the team.

• 1:19:27Krishna Choudhary?

  Yes.

• 1:19:27Lester Nare?

  Uh, multiple times.

• 1:19:28Krishna Choudhary?

  Yeah, yeah, yeah.

• 1:19:29Lester Nare?

  He was like, these are my guys.

• 1:19:31Krishna Choudhary?

  Yeah.

• 1:19:31Lester Nare?

  We got it. But he did have a sober tone about, and I think part of it was playing with, you know, he's working in a dynamic where NASA is being systemically defunded for other things. And he made an homage or a reference point to being hardware rich.

• 1:19:54Krishna Choudhary?

  Yes.

• 1:19:54Lester Nare?

  Quote that he kept talking about.

• 1:19:56Krishna Choudhary?

  That was a good one. That was a good quote.

• 1:19:57Lester Nare?

  For, for, you know, the private space companies like SpaceX. 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. Because we, you know, we had, we had whatever the percent of their GDP going towards this, so.

• 1:20:14Krishna Choudhary?

  Two percent.

• 1:20:14Lester Nare?

  Two percent. So we were hardware rich, meaning that we just had the money to spend. And so did 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 diagnose it.

• 1:20:29Krishna Choudhary?

  Yeah.

• 1:20:30Lester Nare?

  They just replaced it with another thing to get the launch off in time. And then afterwards, when they diagnosed it, it failed getting into orbit. But his point was just that 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, confidence to be able to do these things. We have to be clever and frugal is not the white word, but just resourceful.

• 1:21:04Krishna Choudhary?

  Resourceful, yeah. And I think, I mean, it was, it was really cool to see the transparency.

• 1:21:10Lester Nare?

  Yeah, 100%.

• 1:21:11Krishna Choudhary?

  I thought that was, that was quite cool.

• 1:21:12Lester Nare?

  It was great.

• 1:21:13Krishna Choudhary?

  Yeah, because I'm looking forward to the reentry. I'm sure the engineers have done the work. This new angle is going to be good and we will see them soon on Friday evening off the coast of sunny Southern California. You know?

• 1:21:28Lester Nare?

  Yes. And I, I just, you know, one last sort of good night and good luck and God bless to the crew.

• 1:21:35Krishna Choudhary?

  Yeah.

• 1:21:36Lester Nare?

  I think like you mentioned earlier, you can only plan for so much.

• 1:21:42Lester Nare?

  But if there is any team on the planet that is.

• 1:21:47Lester Nare?

  Anal retentive about details, it's, it's the NASA team.

• 1:21:52Krishna Choudhary?

  It's the NASA team and it's the Artemis team. I'm really looking forward to watching the reentry. The integrity capsule is going to do an amazing job.

• 1:22:03Krishna Choudhary?

  They're gonna be right over the Pacific Ocean. The US Navy is gonna go pick them up, give them an Uber ride.

• 1:22:09Lester Nare?

  Off the coast of San Diego, same place those UAPs are at.

• 1:22:12Krishna Choudhary?

  Yeah, yeah, maybe the Tic Tacs, maybe the Tic Tac will come and watch.

• 1:22:15Lester Nare?

  Oh, they're going back to the moon, guys. We gotta get reactivated. That's why we went away. We thought you guys were coming to space and then you gotta stop. So, you know, that's why we stopped kind of popping up.

• 1:22:26Krishna Choudhary?

  Yeah, yeah, so I'm really looking forward to it. Best of luck to the crew.

• 1:22:31Lester Nare?

  Absolutely.

• 1:22:31Krishna Choudhary?

  We will watch it in two days' time and I can't wait to keep covering NASA, keep covering the Artemis mission, you know. Artemis III is gonna be going up, I think, next year.

• 1:22:42Lester Nare?

  Yes.

• 1:22:43Krishna Choudhary?

  With that docking and all that stuff. I can't wait for Artemis IV.

• 1:22:46Lester Nare?

  Yes.

• 1:22:47Krishna Choudhary?

  Landing on the moon.

• 1:22:48Lester Nare?

  Artemis IV is about to be fire.

• 1:22:49Krishna Choudhary?

  Yeah, that's gonna be great.

• 1:22:51Lester Nare?

  Artemis IV.

• 1:22:52Krishna Choudhary?

  And hopefully by then, we'll have the clock to actually be in Cape Canaveral.

• 1:22:56Lester Nare?

  Yeah, so also, yeah, NASA, if someone in your content team...

• 1:23:00Krishna Choudhary?

  Hey, if you guys like our coverage, you know, we're trying.

• 1:23:03Lester Nare?

  Look at the production value.

• 1:23:04Krishna Choudhary?

  Look at the Lego that we made.

• 1:23:06Lester Nare?

  Lego 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 our social clips in...

• 1:23:25Krishna Choudhary?

  Yeah, 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.

• 1:23:34Lester Nare?

  Yes.

• 1:23:34Krishna Choudhary?

  By Pink Floyd.

• 1:23:35Lester Nare?

  Yes.

• 1:23:36Krishna Choudhary?

  But is not the correct scientific term. The scientific term is the far side of the moon because of that title locking that I talked about earlier in the episode. So, sorry for any confusion.

• 1:23:47Lester Nare?

  With that, we will wrap up. This episode is... It was, I think, the most... Episode we might have had yet.

• 1:23:57Krishna Choudhary?

  Yeah.

• 1:23:57Lester Nare?

  Uh, I'm just so, you know, I'm just so excited about all this. I've been obsessed obsessed with space since I was a kid. And I always used to look back at the like, the Apollo era of being like, I wish I grew up then because there was just this like, there is 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 them again. Also, Apple, you guys did for all mankind, season five promo. No call? Y'all didn't call? That's unbelievable.

• 1:24:42Lester Nare?

  I've been promo you guys all year.

• 1:24:45Krishna Choudhary?

  Yeah.

• 1:24:46Lester Nare?

  I'm, I'm gonna have, I'm gonna have a conversation with agents. No, but I am Lester Nare, uh, joined as always by my co-host and our resident PhD, Krishna Choudhary. 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 reentry. 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 zealot. You are a 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.

• 1:25:32Lester Nare?

  We will see you all next week.