Talk Description to Me
Talk Description to Me
Episode 44 - The Moon
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With the first of four monthly SuperMoons set to rise this weekend, we’re turning our attention to Earth’s little buddy. If you’ve ever wondered about the look of the moon, its phases, craters, or size, this is the episode for you! Plus, Christine poses questions asked by listeners about the Apollo moon landing, and of course, the famous Moonwalk by astronaut Michael “Buzz” Jackson. Wait, that doesn’t sound quite right…
For audio direct from the surface of Mars check out: https://mars.nasa.gov/mars2020/multimedia/audio/
And for Visual Descriptions from the Chandra X-Ray Observatory, visit:https://chandra.harvard.edu/resources/podcasts/description_audio.html
Talk description to me with Christine Malec and JJ Hunt.
Christine Malec:Hi, I'm Christine Malec.
JJ Hunt:And I'm JJ Hunt. This is talk description to Me where the visuals of current events and the world around us get hashtag in description rich conversations.
Christine Malec:On this episode, we're going to talk about the moon. And there's a really good reason for that, which we're going to get to in a minute. But before we do that, there are two short things I want to bring to listeners attention if you're a space or astronomy geek, like me, of the first one is, there is audio coming from the Mars perseverance lander. So depending on how closely you're following this stuff, you may or may not know, if you follow us on social media, you'll definitely have seen it if you have not, Google "Mars, perseverance, audio". And what you will get is some audio from another planet. And I'm just gonna say that, again, it's audio from another planet. And so the rover has two mics on it. And they're mostly there for diagnostic purposes to try check out what the machinery is doing. But they're sending back recordings from Mars and not just gives me the biggest geek chill possible. So if you're interested, Google "Mars, perseverance, audio", and you will find some links to that. And you should also follow us on social media because that's where we post. The second thing is a project that the Chandra X ray observatory is doing to make their images more accessible. And so this is something JJ and I have been fortunate enough to be involved in for several months now. And what they are doing is they regularly post visual representations of their data. And what has been added is audio description, visual descriptions written by our very own JJ and consultant on by myself as a blind person who loves astronomy. And so what Chandra has done is come up with a web page that includes all of these written descriptions. And they're also available in audio format. So if you Google,"Chandra, X ray, visual descriptions", or even just"Chandra visual descriptions", you will come to a webpage that has visual descriptions of the images that they're creating from infrared and X ray data. And there's also some amazing sonification, which is data turned into sound. So I just wanted to make sure that any listeners who are interested in astronomy and space stuff know about those things, because they're pretty amazing. So the reason we're talking about the moon today, as opposed to any other episode is because we have four super moons in a row coming up. So JJ, can you tell us what a super moon is going to look like?
JJ Hunt:Yeah, so a super moon is, it's not actually a recognized scientific term. a super moon is, is a full moon when it's closest to Earth. So the moon's orbit is, is imperfect around Earth. And so sometimes it's farther away, sometimes it's closer. And when it's closer, it makes the full moon appear up to 14% bigger and up to 30% brighter. And you're right, we're gonna get four in a row, we're gonna get one at the end of March, March 28. The end of April, the end of May and the end of June. Apparently, the one in May is going to be the biggest and the brightest.
Christine Malec:Can you talk about the moon just seen from the naked eye? So if you're just looking up on a clear night, when there's not a lot of light pollution, what are you going to see? Yeah, so
JJ Hunt:if you step outside on a clear, dark night to watch, let's say, a full moon rising as if you're somewhere where there's a clean horizon line, what you're going to see is the moon starting to rise behind the horizon, and it creeps up bit by bit, and it's often red, or like a blood orange has a blood orange tint when it's at the horizon. This is I'm going to try not to mangle the science here, but it's a function of the way the light waves travel through the atmosphere when when the moon is close to the horizon, but it's also frankly, has a lot to do with pollution that's close to the ground. dust particles that's close to that are close to the ground. So visually, the moon as it's rising above the horizon may look like might have a silky red tint or maybe a dusty brick orange tint as it rises and when it's like closest to the horizon, and the moon can look really large at the horizon. But it's not actually any larger the horizon than it is up in the sky. We've talked about optical illusions in the last few episodes. This is the world's oldest optical illusion, the moon illusion, the moon looks bigger at the horizon than it does when it's in the sky. And this is because I mean, there are a couple of different theories. But one of the main theories is that when the moon is rising behind objects, like trees, buildings, mountains, even children flying bicycles with aliens in the handlebar basket, whatever, if the moon is rising behind something that our brains understand, then the moon looks larger. The moon we understand to be larger, we can place it against an understood object behind an understood object, and therefore it looks larger. Once the moon goes up into the great big, vast sky. It actually looks smaller, because it's surrounded by sky.
Christine Malec:Oh! Does that happen with the sun?
JJ Hunt:I imagine it does. Yeah, the the same principle would apply to the sun, but you don't stare at the sun in quite the same way. You can stare at a sunset or a sunrise, but once it's up in the sky, you're probably not staring at it as much. And it's also glowing in a different way. So the the outer edges, once it's up in the sky, are a little bit harder to to define a rise, a rising or setting sun has cleaner edges. So you can see this the size of it more precisely, but not not so much when it's in the sky.
Christine Malec:Okay, interesting.
JJ Hunt:The weird thing about the size of the moon is... So when I was doing my research on this and looking things up and trying to figure out how to describe the size of the moon, I realized how off my memory of this was. So I started asking around, I asked some friends I put it out on Twitter, I asked some kids in the neighborhood. I asked, "Hey, think about this for a minute. How big is the moon? Like from Earth, if you were to hold something in your hand at arm's length, like whatever, a basketball or a penny or a ping pong ball, whatever, what what object would be about the same size as the moon up in the sky?" And I got a whole bunch of different answers. I heard someone say it was probably if I if I'm thinking back, it's probably about the size of a pancake. And I heard someone say it's about the size of a big Gumball. And I heard a baseball and they heard a quarter and a dime, and a loony which is, for those not in Canada, it's a $1 coin about the size of a silver dollar. All kinds of ideas about how big the moon is, when you're seeing it in the sky.
Christine Malec:Those are radically different answers.
JJ Hunt:And they're all wrong! And they're all big! The moon from Earth is about the size of a pea held at arm's length. A pea! you can Eclipse it with your pinky finger.
Christine Malec:That's crazy. Why does everyone have such different perceptions in their memory of it?
JJ Hunt:I think it looms so large, the idea of the moon, the pictures we've seen of the moon when you see a full moon went on a clear night. It is it has an impact. And so we imagined this thing to be quite a bit bigger than it actually is. The fact is, it's small. And even in a super moon when it's 14% bigger, it just looks like a big pea like it doesn't grow into Gumball territory.
Christine Malec:Wow.
JJ Hunt:It's relatively small. Yeah, so the moon rises up, it loses, generally speaking, it loses that color as it gets further away from the horizon and higher into the air. There are other times of year where there are specific phenomenon that might give it a different color. But as it's rising, it tends to go through like a while it comes out of that red orange color and maybe fades through a golden yellow color. Perhaps it maybe becomes the color of heavy cream. And then maybe it's going to turn into something like a crisp, bright white color and appear quite luminous. If it's a really clear night that sometimes there's a gray tint to the whole surface of the moon. Sometimes it's actually a blue tint or a yellow tint. That's how the moon looks. It's very mottled in color. So none of this colour is clear. It's not like the sun that has a uniform clear, bright look. It is modeled there are darker spots. There. Lighter spots with the naked eye. Even though it's just the size of a pea, you can still on a clear night, see a little pinpricks on it, little white dots. These are the craters, you can see them, especially the craters that are in the darker spots on the moon. You can see them. That's how the moon hangs in the sky. Is this a relatively small but looming large object, you know, hanging in the sky above us.
Christine Malec:So what happens when you start applying a bit of magnification to it?
JJ Hunt:Well, what's amazing is you only need a very little bit of magnification for the details to really start to reveal themselves. So the craters in particular become really quite clear right away. Even if you're just using like binoculars. You don't have to have fancy telescopes, even binoculars, you'll start to see the craters that the whiter centres of the craters with a darker ring around them. And you and you get a sense of how covered the surfaces with these impact craters. And they range from the tiniest little pinpricks to craters that are so big, you can't actually tell that it's a single crater that some of these dark spots are actually craters. They're they're big indentations in the planet from meteoroids, comets and asteroids hitting the biggest crater, I think it's called Aitken Basin, it's that it's near the South Pole, and it occupies about a quarter of the surface of the moon. And in parts, it's like five miles deep, which is deep enough to fit Mount Everest, it's massive, but it's so big, that it's actually difficult to see with the naked eye you don't see the clear ring around the outside. And you certainly can't tell the depth of it. The depth that this point is at this distance is too difficult to discern. You can see that it's that there are areas that are darker, and you can see that there are other craters inside, but you can't really tell that this particular crater is a single crater. The other thing that becomes clear with binoculars are what are sometimes called crater rays. Have you ever heard of crater rays?
Christine Malec:No.
JJ Hunt:They're really cool. So these are very fine, quite distinct, often very straight white lines that appear to burst from the rims of the craters like sun beams. So and when the craters are close together, they can actually criss cross. These crater rays can crisscross and create networks of fine straight white lines. And these are created by ejecta - material that is thrown out by meteorites and asteroids during the moment of impact. So the meteorite comes in hits the planet, it shoots out like it shatters and debris flies in all directions. And that actually creates these straight lines that blast from the center and you can see them very clearly. Sometimes the biggest craters will have or some of the bigger craters you can see the the crater rays with the naked eye but really with binoculars or certainly with a telescope, you can see these the networks of these and I think this is you know when there were some ideas that there are, you know, straight lines on the planet straight lines must be man made right this is this is human interaction on the moon. Nature doesn't make these straight lines. No, no, no, these are made by by getting out the ejecta from meteorites and asteroids. Very cool.
Christine Malec:Um, the phases of the moon are obviously well well known and well understood. For for someone who's never seen it, can you describe the crescent moon, the half moon, the three quarter moon.
JJ Hunt:So full moons are wonderful and they're bright. Sure they wash out the stars, but the full moon is bright. Half moons are pretty cool. Seeing that line down the center, and with a with a halfmoon it looks like a straight line and then just a half of a ball. A half of a circle. So that's kind of neat, because you get this straight line. But as the light line moves, then you get what are closer to slivers. So you get like you get these concave shapes, these slivers, these bowls or cups, and they're really, they're neat. I don't I'm not entirely sure why they're so cool. But maybe it's because they look very delicate, right? What we're seeing of this massive planetary object is just a very fine line that can be as thin as a fingernail, they can get really, really fine. And of course, you're not seeing much detail on On the moon at this point, because you're just seeing a sliver of it, there's not enough light being reflected off of it to really allow us to see much in the way of detail and a half moon or or maybe a quarter moon, you're able to still see some detail on that on the side that you can see. But by the time it gets to a fingernail, it really is just this sliver, this curve, little sliver of brightness in the sky.
Christine Malec:Now until the conversation you and I had a few, several months ago, I never thought to wonder about the orientation of a crescent moon, it just hadn't really even crossed my mind. But you were talking about the experience of having looked at the moon when you were traveling in East Asia. So can you can you describe that that blew my mind? I'm still trying to figure that out.
JJ Hunt:Yeah, so the moon is always in the same phase, wherever you are around the world. But the observers orientation is different depending on latitude, right? So northern hemisphere, southern hemisphere, we're gonna see the moon from the opposite point of view. And yeah, I did notice this for the first time when I traveled to Southeast Asia. I was outside and I looked up at the moon, and it was... wrong. It was the crescent moon, it was a bowl, and it was an upside down. Or, I can't even remember! This is part of it! The moon is just it's ever present so you're used to seeing it in the ways that you are used to seeing it. And with the crescent on one side or the other angle the little bit this way or a little bit that way. But I stepped outside on the night of a crescent moon in Southeast Asia. And it was just wrong. This was pre Google, right? I couldn't just pick up my phone and figure out what was going on. So I'm asking everyone "Like what's going on with the moon?"
Christine Malec:Ha ha!
JJ Hunt:And they're all like,"That's what the moon looks like. What is your problem, Canadian?" But it's true that your orientation to the moon is, is upside down or right side up, which are both judgment terms and not accurate at all. But we're standing on a sphere, and if you're standing on in one direction, looking at the moon or standing on the other side, you're upside down relative to the person who is in the Northern Hemisphere. You're looking at this object in the sky from the opposite angle.
Christine Malec:This is hurting my head.
JJ Hunt:I know.
Christine Malec:So if if you're in Toronto, and you look up at a crescent moon, where is the crescent? Is it like a smiley? Is it like a forehead? Is it lower left or right upper left, upper right? See, you're not even sure.
JJ Hunt:I truly am not. Because it's just... it's so natural. I don't... it's hard to conjure in a funny way what you see all the So if are in the southern hemisphere then that would be time. If I remember correctly, the crescent, the bowl would be pointing up to the upper left. But it also depends on the season, right? That will shift a little bit depending on the season. So it might be pointing straight to the left in the summer and then the bowl kind of slides down a little bit so it looks more like a satellite dish pointing up to the upper left I think? I think I've got that right... opposite. The opposite.
Christine Malec:That hurts my head
JJ Hunt:I know the whole thing is really hard. It can it can end up looking like a bowl. I don't think it ever ends up ends up looking like a cap
Christine Malec:Okay
JJ Hunt:But I might be wrong. This is...
Christine Malec:I won't put you on the spot.
JJ Hunt:My gawd. Ha ha!
Christine Malec:I'm still, my mind just like loves to sort of play with that like plasticine. It just wants to keep malyon trying to make sense of it. And I think I need an astronomer
JJ Hunt:Yeah, yeah, that's right. So maybe if we've got any Australian listeners who can send us a note...
Christine Malec:Who are also astronomers and can parse this mystery out....
JJ Hunt:Help us out, man!
Christine Malec:Oh man, that is trippy. That must have really freaked you out.
JJ Hunt:It really did. It genuinely did. I found it disconcerting. As I walked around the markets all evening I kept like glancing up. "Has it changed yet?"
Christine Malec:And they're all like "Put down the rice wine buddy."
JJ Hunt:"You're done. You're done, fella. Cut off."
Christine Malec:Now, a lot of listeners have requested and me too, of course, to talk about the human presence on the moon and, and also images that have come from that and one of the things that captivates me is the idea. And this partly from my sci fi obsession is watching Earth rise from the perspective of the moon. So being on the moon, and instead of seeing the sunrise that like we would or that the moon rise from Earth You see Earth rise as as an object rising in the sky. And so I understand that you were able to find some images of that.
JJ Hunt:Yeah, there are some videos online, some that are filmed, like actually filmed by astronauts on early Apollo missions. And then there are some composite videos, from footage captured by lunar satellites. So I'm not sure if they're actually on the moon, or if they're just on the far side of the Moon. And they're in their composite images. So they're, they're pieced together using photographs. And they might be tweaked and color corrected in some in some ways. But the earth rises behind the lunar horizon, obviously, in much the same way as the moon rising on Earth, but there are some very important visual differences. So first of all, there's nothing to be silhouetted against the rising Earth, there are no buildings, no trees, I haven't seen any mountain footage. I mean, there are, you know, there's topography to the moon. So theoretically, you would have that, but I haven't seen any of that footage. So all of the footage I've seen is just the surface of the moon this pocked dusty grey lunar surface, and that's the surface, but uh, you know, in front of this rising Earth, and the scale is also reversed. So the composite videos that are taken from lunar satellites, they actually depict the lunar surface with a curve. So you can see the curvature of the moon, with the earth rising behind it, which is different than on earth on any time you're taking that on Earth, it's going to be at the horizon is going to look either flat, or it's going to be filled with buildings and trees or whatever, but you're never going to see the curvature of the of the of this body, which is pretty fantastic. And this also makes the moon look small, and the earth look big. Of course, the Earth is bigger than the moon. So when you take that into account, you can see the curvature of the of the moon, it just makes the earth look to our minds that trick us sometimes, look even bigger, right? And then the most striking difference, of course, is the color. So the moon appears to be in black and white. Everything on the surface is gray, and the background is black space. It's not blue sky, or cloudy or anything. It's a just jet black. So when the earth this blue ball streaked with swirling white clouds and green and tan land formations when it starts rising up, it's the first bit of color in this video. It's a little bit like the Wizard of Oz, when did everything turns to color the first time really quite striking.
Christine Malec:Heh heh heh.
JJ Hunt:"Oh! Suddenly this video is in color!" You know, it's really quite amazing. I'm honestly getting chills just thinking about it. It's really you see how clear and crisp this blue ocean planet with the white clouds. You see how clean and crisp and colorful that is, compared to the gray and black of space and the moon.
Christine Malec:I feel like there's also some trippyness , there would be some trippyness. And once the moon the earth has fully risen, and you're looking at it, it would look just floaty, and like it's just floating around. And we're used to the earth being something that pulls us to it because of gravity. And it's this huge place where we live, but to see it just hovering there would make it seem maybe a bit unreal, like an earth shaped beach ball or something.
JJ Hunt:That's it. Yeah, every one every astronaut I've ever heard speak about this talks about this moment of seeing the earth floating in space. And there are moments when you're in something like the international space station where you're seeing the earth from a distance, but you're not necessarily seeing it set against the vastness of space when you're on the moon when you're that far away, or further away. And you can see the entire planet floating in space, as you say it does. It had it looks like a marble it looks on. It looks unreal, at the same time as being very tangible. That's us. That's our home. That's Earth.
Christine Malec:We've had, as I say, a lot of requests from listeners have to talk about the moon landing the first time someone set foot on on the moon and what the visuals of that work and can we walk through a bit of that?
JJ Hunt:Yeah, let's take a quick look at some of this stuff. So the Apollo 11 mission, July 20th 1969, there was something like 650 million people tuned in. As the lunar module Eagle landed on the surface of the moon and on YouTube. NASA has posted a full three hour video Have the original footage that was captured on the surface. So it's, it's largely unedited, it's been restored a little bit, but it essentially covers every minute that Neil Armstrong and Buzz Aldrin were on the surface of the moon.
Christine Malec:And whereas the viewpoint of where's the camera?
JJ Hunt:It changes a couple of times. The first bit of the video is, it's underneath the lander pointing at the ladder, so that Neil Armstrong could basically film himself, you know, descending the ladder and landing on and touching down. So for the first part, the camera was under, filming the ladder, and then they move it. And they set up I think it's on a tripod, and they set up the camera so that it is aimed at the lander itself, and covers the area of the surface just around it so that when they planting the flag when they're doing instrument checks, and when they're gathering a few bits of of material, most of the time, the app both astronauts and the lander are in frame. And then sometimes the astronauts leave frame they go about 300 feet, I think away from the lander, and then come back but from that point on the camera is static on tripod aimed at the lander and the footage. It's wonderfully grainy and black and white. It is very imperfect, high contrast. So the whites are very bright. And the darks are quite dark, the blacks are really dark. And there are these ghostly trails. The astronauts were kind of ghostly, sometimes they're a little bit translucent, there's slight visual echo trails when they move, the video is just not very clean. But I love that. To me, like when I hear the audio of this, you know, the talking back and forth with Houston, and I hear the imperfections and the crackles and whatnot. I think that's perfect. And I would say the same about the video footage. It's imperfectly perfect or perfectly imperfect, depending on your point of view.
Christine Malec:Ya, ya.
JJ Hunt:I mean, part of the glory of the moment was that this was a massive technological reach. And for me the quality of the images and the quality of the film, it illustrates that. It is grainy, it is black and white, because, you know, we went to the moon in black and white!
Christine Malec:Right, right, right.
JJ Hunt:That's how this was perceived. And I think it's absolutely appropriate. So that's really the look of the footage itself.
Christine Malec:So when Neil Armstrong one comes into view, does he even look like a person with the spacesuit? How bulky is the spacesuit?
JJ Hunt:Yeah, so the spacesuits are large, they're very puffy, they're very thick. And they're white. Especially in this footage, they they're very contrasty. So it's glaring, sometimes. The helmets are full helmets with face shields. And for the most part, the face shields present as being black. Dark face shields. They're not obviously, but that's how they appear in this footage. And they're in these large puffy suits. They've got big boxy backpacks on that go from shoulder to shoulder from, you know, the the back side all the way to the top of the helmet. And in the movements, whether they're, you know, it's it's coming down the ladder or trying to walk around on the moon. It's really interesting that the the movement because of these suits because of the gravity, it's a funny mix of like lumbering and light, laborious and light. There's a bounce in their step because of the gravity, but there's less flexibility because of the suit the knees and the hips don't really have movement. So they end up the astronauts moving on the planet end up with this springy, but lumbering gait. It's really quite, it's very distinctive.
Christine Malec:Can we say much anything about the lander? What do we see of the lander?
JJ Hunt:Yeah, so in real quick, broad strokes, the lander has two stages, the ascent stage on top and the the descent stage on the bottom. So the descent stage, the bottom half, has four angled exposed legs, one at each corner, and the legs each have like a saucer like landing pad on each foot. And one of the legs has the leg, the ladder affixed to it and between the legs, so you know kind of connected to all four legs underneath the ascent stage. There's a platform and this platform has what I believe is the rocket nozzle underneath it. It looks like an upside down bucket. And then rising up from this platform is what looks like a box. An irregular box covered in gold and black foil. And by the way, you can't see anywhere near that amount of detail in the footage that is filmed on the moon. I'm taking that description from other images because the footage on the moon, it's just too dark, it's too contrasty, you can't get that kind of detail. The top part, the ascent stage above that gold foil box is this completely irregular vessel in silver and black. I was trying to figure out how to describe this thing. And it's so glommed together it looks like... What I imagined is... We've got a stovetop espresso maker, an aluminum stovetop espresso maker. And I imagine that like some kid took two or three of these things, unscrewed all of the parts, the funnels inside, the tops where the coffee ends up the bottoms where the water goes, took them all apart, and then welded them back together in a random shape. So they're pieces stuck onto the side and pieces coming off the top. It's this glommed together aluminum, and I think black painted aluminum, odd looking vessel. And what's remarkable to me about this is, is comparing that to how hyper design conscious space programs are today. Think about SpaceX. They actually have a Hollywood designer on their team to to design their ships and suits.
Christine Malec:Um hmm.
JJ Hunt:And, you know, back then they were like, "Oh, we need this module." "Stick it on the side!" Ha ha ha!"What are we gonna do about this?" "Stick it on the other side!" It's amazing. It really is quite fantastic.
Christine Malec:And when Armstrong descends, he's, I remember someone asking this specifically, he's descending down backwards. Is that right?
JJ Hunt:Yeah, so he's climbing down the ladder, holding on with both hands, facing the ladder. So walking down backwards, I guess is that's how you would say it. And then he gets pretty close. In the video, there's a bit of back and forth where they're testing a little bit. He puts one foot down and touches a surface and you know, they're talking back and forth. He's making sure he's got the moment, right. And then he says, "Okay, ready to go?" or something. And then he actually kind of jumps down the last step. He kind of jumps down so that he lands with a little in a little bit of a jump.
Christine Malec:Okay.
JJ Hunt:I mean, it's a pretty dramatic moment. They do a good job with just the one angle from under the ship, kind of looking across at him. You can see him gripping the ladder in this giant suit this big, puffy white suit.
Christine Malec:I'm going to try and make a great tie into an earlier episode. Is there any connection between what it looks like when Neil Armstrong is strolling around on the moon and the dance called the moonwalk?
JJ Hunt:Ha ha ha! I haven't watched the entire three hour video...
Christine Malec:Heh heh heh.
JJ Hunt:In the parts that I have seen, neither Buzz nor Neil do anything quite like the moonwalk while they're on the moon. I think it might be more about the slow motion look, the gliding look, that kind of lumbering springiness, which I know doesn't quite translate But you know what, for you, Chris, I'm gonna all sit down nd watch all three hours and I'm going to double check jus in case. Just in case. Heh he.
Christine Malec:You're the an. You
JJ Hunt:I'll let you know. Yeah, for sure. Follow me on Twitter!
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