[RADIOLAB INTRO]

LULU MILLER: Hey, I'm Lulu Miller.

LATIF NASSER: And I'm Latif Nasser.

LULU: This is Radiolab.

MOLLY: No, we're gonna run with that.

LATIF: And today, we're gonna kick off with senior correspondent Molly Webster.

MOLLY: So you may have heard we had a big solar eclipse which I was unabashedly pumped about. I've never—I don't eclipses so much, but this was my year. And for anyone who was like ...

LULU: Coming into the office every day with the glasses on.

MOLLY: [laughs] Yeah. And for anyone who might be wondering what eclipse are you talking about, Molly? The one I'm referring to started kind of—it hit land in Mexico, and then it swept up through the United States, so from, like, Texas to Maine, and then glanced across Canada and was then back out into the ocean.

LATIF: Yeah.

MOLLY: So basically an eclipse is, like, the moon gets between the Earth and the sun, and so then it, like, blocks the light of the sun. And the shadow of the moon is cast upon the Earth. And the shadow is actually about 115 miles wide.

LULU: Oh!

LATIF: Okay.

MOLLY: And so when I say it, you know, passes through these states or sweeps, it's like the shadow of the moon is pressed upon the Earth, and then as the Earth rotates, the moon kind of sweeps—the shadow of the moon sweeps across the Earth.

LATIF: Hmm.

MOLLY: Passing over mountains and forests and cities and towns—and maybe your house.

LATIF: Fully—fully blocking.

MOLLY: Yeah, so fully—fully blocking. That's why this one was such a big deal. It was a total solar eclipse.

LULU: Ooh! Okay!

MOLLY: And so when we were—when I was thinking about this eclipse, I was like, okay, how—like, would there be an interesting way for our show to cover this? Like, do we want to think about this? What am I interested in? And I started to notice this funny thing, which is that everything I was coming across was all about ...

[ARCHIVE CLIP: The sun.]

[ARCHIVE CLIP: The sun.]

MOLLY: ... the sun.

[ARCHIVE CLIP: Understanding the sun is important for understanding our place in the universe.]

MOLLY: What happens to the sun, what we can learn about the sun. But also ...

[ARCHIVE CLIP: There it is!]

MOLLY: ... if it wasn't about the sun ...

[ARCHIVE CLIP: There it is!]

MOLLY: ... it was something about Earth and Earthlings.

[ARCHIVE CLIP: I'm speechless. I'm literally speechless.]

MOLLY: About what we'll feel or what it'll be like.

[ARCHIVE CLIP: Bumper-to-bumper traffic.]

MOLLY: About ...

[ARCHIVE CLIP: How the atmosphere behaves.]

MOLLY: ... the atmosphere. About ...

[ARCHIVE CLIP: These amazing shadows.]

MOLLY: ... the shadows, the light, the wind.

[ARCHIVE CLIP: About what you should keep in mind when it comes to our furry friends.]

MOLLY: And I was like wait, what about the moon?

LULU: Hmm.

MOLLY: Like, the only reason any of this is happening is because of the moon, and yet we're treating it like it's like the, you know, silly best friend who only has a couple of scenes.

LULU: Treating it like the photo bomber ...

MOLLY: Yeah.

LULU: ... in the way of the thing.

MOLLY: Yeah. And I'm like, you're—this—the only reason this is happening is because the moon's causing it.

LULU: Yeah.

MOLLY: And no one's really talking about it. And I feel like that's sort of the case with the moon. Like, it doesn't really get talked about that much. It sort of gets short shrift.

LATIF: What are you talking about? People talk about the moon all the time! There was just like a—wasn't there a whole thing about something that landed on the moon and fell over, and everyone was, like, rooting for this thing on the moon? And I mean, just in general, NASA's going back to the moon. We already went to the moon. We haven't gone to the sun. Like ...

MOLLY: Yeah, fair point about the sun. We haven't gone there.

LATIF: [laughs]

MOLLY: But I would just say, like, I feel like you see the moon.

LATIF: Sure.

MOLLY: So you think you know about the moon. But I don't—like, what do you know? Like, tell me what do you know about the moon?

LATIF: Um ...

LULU: Okay.

LATIF: Craters. It has craters.

LULU: Craters.

MOLLY: Uh-huh.

LULU: It's, um, a rock, I think? That is in orbit with us.

LATIF: Yeah.

LULU: It's circling us.

LATIF: Yeah, that's right.

LULU: Uh, does it also spin? Probably?

LATIF: Yeah.

LULU: Yeah.

LATIF: Yeah.

LULU: Okay.

LATIF: Sure. [laughs]

MOLLY: Okay, so just to sum up your—your deep knowledge of the moon is that it's a round rock that orbits the Earth ...

LULU: Like, it's a round rock ...

MOLLY: ... and that may or may not spin.

LATIF: Yeah. And has craters. You forgot about the craters.

LULU: It has craters! And it has craters.

MOLLY: Right. Right. I think you've just underscored my point.

LATIF: Okay.

MOLLY: That I think we think we feel like we know a lot about the moon because we spend a lot of time looking at it, but I would say that one, like, that's kind of the collection of facts most people know about the moon. But it's ...

LATIF: And that we've been there. That we've been there, of course.

MOLLY: Yeah, exactly. So that's the other thing is that we often think of the moon in relation to us, and I just felt like when I realized this I thought: oh, the moon is our closest neighbor, and it feels a little weird how little we know about it.

LATIF: Hmm.

MOLLY: It feels a little rude. And so I just started to wonder: can I know this cosmic neighbor more than it may or may not be round and rocky? Like, can I get to really know it? And so that led me to this idea that what we should do today is a moon show.

LATIF: Ah, nice!

LULU: Like, you want a profile of the moon.

MOLLY: I absolutely want to profile the moon.

LATIF: Yeah!

MOLLY: And that—that is what we're going to do. We're gonna do, like, a birth, a middle age ...

LULU: Ooh!

MOLLY: ... a death!

LULU: Oh. I don't want it to die.

MOLLY: Well, just stay tuned, Lulu.

LULU: Okay.

MOLLY: Stay tuned. Okay, so the first part of our moon profile comes from managing editor Pat Walters.

PAT WALTERS: Yeah, so I got curious about where the story starts.

LATIF: Okay.

PAT: Like, where did the moon come from?

LATIF: New Jersey.

LULU: [laughs]

PAT: [laughs]

LULU: I mean, New Jersey does make and the world just takes, takes, takes. So ...

PAT: [laughs] I mean, really though, where—do you have any idea where it came from?

LULU: I mean, I guess I've always thought it sort of just was something in space whizzing by, and Earth's orbit caught it at some point.

PAT: Hmm.

LATIF: Hmm.

LULU: Maybe?

LATIF: I think I always thought that it was just like—it's always been around. Like, it came from wherever the Earth came from, and they've always just been here together.

PAT: Yeah. Yeah, good guesses. Not correct.

LULU: [laughs]

PAT: But those are both ideas that people have had for a long time.

SIMON LOCK: Yeah, so there was sort of a number of different suggestions.

PAT: This is according to Simon Lock. He's a research fellow at the University of Bristol in England.

SIMON LOCK: And I study the formation and early evolution of planets.

PAT: And the moon.

SIMON LOCK: Mm-hmm.

PAT: And he says for most of modern history, people thought what you thought.

SIMON LOCK: Another idea was that the moon could have actually been sort of thrown out from the Earth itself.

PAT: Like, as the Earth was spinning, a chunk of it flew off and became the moon.

SIMON LOCK: An idea called fission.

PAT: This was apparently a Darwin idea.

SIMON LOCK: Not the Charles Darwin, but his son, I believe.

PAT: George.

SIMON LOCK: Yeah.

PAT: He actually thought the Pacific Ocean was the hole left behind by the moon when it flew off into space.

LATIF: Weird!

PAT: Totally, yeah! And also wrong.

SIMON LOCK: What all scientists probably agree on is ...

PAT: Simon says what most likely happened was a bit more explosive.

SIMON LOCK: Yeah. The moon formed as the result of a giant impact.

PAT: I should say there are a couple different versions of this theory, but the one Simon told me is wild. And it starts about 4.4 billion years ago.

LATIF: Okay, so let's begin at the beginning.

PAT: Okay, so just to set the scene.

SIMON LOCK: The overall picture is this.

PAT: We're on Earth. And Earth is only about 100 million years old.

SIMON LOCK: So it's quite early in the whole history of Earth. It's really sort of the—you know, still the overture of Earth.

PAT: But even in these early days, it looked kind of like Earth does now.

SARAH STEWART: Just imagine a slightly smaller Earth. It probably had oceans and an atmosphere.

PAT: This is Sarah Stewart.

SARAH STEWART: Professor at the University of California at Davis.

PAT: And she and Simon explained to me that if you were standing on this baby Earth all those billions of years ago, gazing up into the night sky, it would have been full of stars, just like it is now. The stars would look different because they won't yet have reached their current configuration. But it would be a starry sky.

LATIF: Yeah.

PAT: If you were staring up at it, at some point a new little glimmer would have appeared in the sky. Next night, that dot would've gotten bigger. Night after that, a little bit bigger still. And by the time it got big enough for you to tell what it was, which is a planet that's rushing towards Earth at 20,000 miles an hour, it would have consumed the entire sky, and then smashed into the baby Earth.

LATIF: Damn! Dramatic!

PAT: Yeah.

SARAH STEWART: The energy the collision dumped into the Earth was the power of the Sun. And as a result ...

SIMON LOCK: You vaporize—vaporize—so turn to gas, the rock of Earth.

PAT: And, of course, the planet that hit it. And what's left ...

SIMON LOCK: Is this sort of huge, swirling ball of gas.

PAT: A big spinning cloud.

SIMON LOCK: But made out of vaporized rock.

PAT: And Simon says this cloud is extremely wide ...

SIMON LOCK: Ten times the size of the present-day Earth.

PAT: ... incredibly hot ...

SIMON LOCK: 2,000 Kelvin or so.

PAT: ... and spinning super fast.

SIMON LOCK: The central part is rotating with a sort of three-hour day.

PAT: But it doesn't stay that way for very long.

SIMON LOCK: It's cooling really rapidly, causing the vapor to condense into droplets of magma.

SARAH STEWART: Clouds are forming that are magma clouds

PAT: Sarah Stewart again.

SARAH STEWART: The magma droplets fall.

PAT: As rain, basically.

SARAH STEWART: And the magma rain would have been torrential.

PAT: Pretty quickly, the magma rain starts clumping together with ...

SIMON LOCK: Bigger lumps of molten rock.

PAT: And at some point, several of these lumps clump together and start ...

SIMON LOCK: Pulling nearby stuff towards it, and using that to grow in mass.

PAT: And this lump of magma, this will eventually become the moon. And the rest of this rocky gas cloud, that will become the Earth.

SIMON LOCK: Yeah. The moon is forming within this huge extended Earth.

PAT: But this gas cloud version of Earth ...

SIMON LOCK: It's contracting.

PAT: ... is getting smaller as it cools, and more and more of the gas turns into liquid magma. Until eventually, Simon says ...

SIMON LOCK: There's this sort of wonderful dramatic moment ...

PAT: Where the moon, which has been forming inside the gas cloud of Earth ...

SIMON LOCK: Would emerge from the Earth as sort of this newly-born satellite.

PAT: And begin orbiting the Earth. And that, according to Simon and Sarah's theory, is how we got our moon.

LATIF: What? So it literally popped out of us?

PAT: Yeah.

PAT: And how long did this whole process take?

SIMON LOCK: The—the moon probably takes about, you know, on the order of ten to a few tens of years to form.

PAT: Ten years?

SIMON LOCK: Yeah, it's fast.

LATIF: What? That took less than one of us. Less than me or you, less than our life.

PAT: Yeah. And what I think is so amazing about this moment is that it didn't only give birth to the moon.

SIMON LOCK: This event is really significant not only because it formed the moon, but it also actually formed the Earth if you think about it.

PAT: Like, before that giant impact, there was a version of the Earth, but it was different. It was smaller, it was made of different stuff. It wasn't, like, tilted off at a slight angle away from the sun in the way that it is now. Like, if the giant impact hadn't happened, it's not just that we wouldn't have a moon, but Earth wouldn't really be Earth in the way we know it. This moment when the moon became the moon is also ...

SIMON LOCK: How Earth became Earth.

PAT: Cool. Yeah, amazing. Um ...

PAT: And not only were they born in the same moment, but they're also sort of twins.

PAT: What do we have here?

PAT: Like, when you look at a moon rock ...

PAT: What's that?

MUSEUM CURATOR: You can hold that, by the way.

PAT: Oh, I can hold it? Oh my God!

PAT: ... which I actually got to do recently at a museum in Maine.

PAT: It's quite heavy.

MUSEUM CURATOR: Yeah.

PAT: Yeah.

PAT: It looks surprisingly familiar.

PAT: In some ways it's, like, not that dissimilar from rocks that I've held before.

PAT: It just looked like a chunky gray and black rock.

PAT: But obviously it's from the moon.

MUSEUM CURATOR: It's a rock.

PAT: Which is insane to think about. [laughs] But yeah, it's just a—it is just a rock.

PAT: And it turns out it's not just that moon rocks look like Earth rocks, but if you were to break them open and examine their geochemistry, you would find that Earth rocks and moon rocks are almost identical.

LATIF: Wait, can I just understand—because okay, so if you tell me they're the same ...

PAT: Yeah.

LATIF: ... I would just be like, oh, of course. Like, everything in the universe is—or everything in the solar system was made at the same time. Like, of course this thing is gonna have the same as that thing. Like, would—is Mars the same?

PAT: No.

PAT: This looks quite different.

PAT: I got to hold a piece of Mars at that museum, too.

LATIF: What?

PAT: Yeah, it was awesome.

PAT: I can't believe this is a piece of Mars.

PAT: And it looks totally different than a moon rock or an Earth rock.

PAT: It looks more metallic.

PAT: Kind of red with green streaks through it. And according to Simon, is also geochemically very different.

SIMON LOCK: Because all of the things that were happening in the galaxy ...

PAT: As the solar system's forming ...

SIMON LOCK: ... produce different amounts of different elements.

PAT: In different parts of the solar system.

SIMON LOCK: Yeah, exactly.

PAT: So Mars looks different than Venus or Mercury, but Earth and the moon look the same.

SIMON LOCK: And nothing else in the solar system looks quite the same.

PAT: Why, if the moon and the Earth are made of the same stuff and both were sort of born out of this one explosive moment, why didn't the moon just become a little Earth?

SIMON LOCK: Yeah, just because it's so much smaller.

PAT: Hmm.

SIMON LOCK: So it is only about one percent the mass of the Earth, but what that means is that the moon can't really hold onto an atmosphere. If you, you know, open, you know, a bottle of air on the moon, very quickly that'll get driven off into space.

PAT: So it's not big enough, so meaning it doesn't have enough gravity to hold that stuff down?

SIMON LOCK: Yeah. This is why when you see, you know, the astronauts bouncing across the surface of the moon, they can do that just because the gravity's so much lower.

PAT: Hmm.

SIMON LOCK: And so the force that's holding onto our atmosphere just doesn't work as well when it—the gravity's that much lower.

PAT: Okay.

SIMON LOCK: And without the atmosphere, none of the rest of it can happen.

LATIF: Oh, that is kinda shocking and it makes you—because it's like the whole—you know, so often we talk about, like, oh it's the Goldilocks zone, and it's like we're in the right spot. Like ...

PAT: Like, distance from the sun and everything.

LATIF: Yeah, exactly.

PAT: Yeah.

LATIF: Like, it's like oh, this is perfect for being habitable. But then you look at the moon and you're like, oh, it makes life and Earth seem pretty special and rare and unique again in a way.

PAT: Yeah. Like, if that giant impact that gave birth to the Earth and the moon had gone down a little bit differently, and some chunk of Earth had gotten blasted off into space and we had ended up smaller, we might not have been able to develop oceans and birds, dogs, babies, music. We might have just ended up like a slightly bigger version of our cold, dry, airless twin, the moon.

LULU: Managing Editor Pat Walters. [laughs] All right, Molly. Where are we—where are we going from here? That felt kind of like a punctuation point, this poor, dusty dead moon.

MOLLY: Honestly, by Pat's description, it sounds kind of dead to me too. But I want to liven it up. I want to take you up there and liven it up.

LATIF: But there's nothing alive. What are you gonna do?

MOLLY: There is, it's true. There are no palm trees or anything up there.

LATIF: [laughs]

MOLLY: But—but there is, after months of reading about the moon, it turns out there's just so much stuff happening there. I am sort of a pressure cooker of facts, and I just have to tell them to somebody.

LATIF: Okay.

MOLLY: So you are my captive audience. Are you ready?

LULU: Let's do it.

MOLLY: So the moon does look a lot more like Earth than I would have expected.

LULU: Huh!

MOLLY: There are the craters that Latif remembered.

LATIF: Right.

MOLLY: Plus it has a bunch of mountain ranges ...

LULU: Okay.

MOLLY: ... a point that's higher than Everest.

LATIF: Hmm!

MOLLY: Scientists have found moon caves.

LULU: Ooh!

MOLLY: And they've also found volcanoes that are billions and billions of years old.

LULU: With—with—with lava?

MOLLY: With lava.

LATIF: Whoa!

MOLLY: It's very, very dry old lava.

LATIF: [laughs] Okay.

MOLLY: But really, the first thing I learned about the moon that really arrested me and made me want to know so much more about it is that the moon is covered in soil that kind of looks like sand. People will call it moon dust ...

LATIF: Hmm.

MOLLY: But it's incredibly sharp.

LATIF: Whoa!

LULU: Like a little grain of it?

MOLLY: Yeah, a tiny, tiny grain of it is, like, razor sharp.

LULU: Hmm.

MOLLY: And it is that way because there's no wind on the moon or flowing water.

LULU: Oh!

MOLLY: There's nothing to, like, erode and give you ...

LULU: And, like, dull it?

MOLLY: ... that soft, like, fine surface.

LULU: Hmm.

LATIF: So, like, let's say you're on the moon, you take off your boots and you try to do the beach, squish your toes in the sand thing, just like the instant you put your foot down it'd get all cut up or—like ...

MOLLY: Likely, yeah.

LATIF: … like, how—whoa!

MOLLY: And then probably before that happened, depending on where you were, it would either burn up or freeze your foot.

LULU: What?

MOLLY: You wouldn't—because, like, the temperature on the moon is super extreme.

LULU: Hmm.

MOLLY: It's like, one scientist said to me it's either kill ya hot or kill ya cold.

LULU: [laughs]

MOLLY: And that's because on the moon, if you're in the sun, it can be something like 250° Fahrenheit.

LULU: Wow!

MOLLY: But if you're out of the sun, it can be -250° Fahrenheit.

LULU: Whoa!

LATIF: That's like 500°difference.

MOLLY: Yeah, it's a 500° difference, and the strange thing is is that you can actually get that 500° difference, like, within centimeters of two different objects. Like, you can have one molecule that's 250° and you can have another molecule that's -250°, and they're only centimeters apart from each other.

LULU: What?

LATIF: Wow! How—how can that even happen?

MOLLY: Well, since there's almost no atmosphere on the moon, there's not a way to, like, transfer heat through space, right? So when a hotter molecule gives off heat, there's no way to pass that to a colder molecule.

LATIF: Hmm.

MOLLY: So then you can get two things extremely close together with extremely different temperatures.

LATIF: Wow!

LULU: Huh.

MOLLY: The other thing this lack of atmosphere causes is that on the moon, there is no sunrise or sunset.

LATIF: What do you mean?

MOLLY: You just turn from day to night or night to day. Just goes from light to dark or dark to light. Just like—boom!

LATIF: What?

MOLLY: And so ...

LULU: It ...

MOLLY: Lulu, ask your question. What is your question?

LULU: Well, I guess my questions are like, what is that—is it, like, from ...

MOLLY: What the freak? How does that happen?

LULU: Yeah. Just so fast and such a change so fast, yeah.

MOLLY: Yeah. Well, the only reason that shift is gradual on Earth and we have the dreamy sunset and a dreamy sunrise is because our atmosphere and the clouds and stuff are, like, trapping the light and, like, diffusing it.

LATIF: So it's like the atmosphere is like a dimmer? Is that what you mean, kind of?

MOLLY: For us, yes. But since there's almost no atmosphere on the moon, there's nothing to do that, so it's kind of like just pulling up a blind and it's like—boom!—there's the sun.

LULU: Huh!

LATIF: Whoa! Okay, so—okay, so so far we have—so there's the dirt, there is the temperature extremes, there is the lack of dawn and dusk.

MOLLY: Do we—do we need like a seventh-inning stretch? Like, do we need a quick ...

LATIF: Yeah! I mean, I would like to adjust the thermostat here.

MOLLY: Because we're—because I'm—I'm about to keep going. I'm about to keep going, so I need you to, like, collect yourself.

LATIF: Okay. Okay. Okay. All right. Okay, keep going. Keep going.

MOLLY: Because what those temperature shifts do on the moon ...

LATIF: Mm-hmm?

MOLLY: ... is they actually cause the moon to shake.

LATIF: Really?

MOLLY: Yeah, there are moonquakes.

LULU: What?

MOLLY: So many kinds for actually so many different reasons. The ones I think are sort of super interesting are the ones that are caused by the tides.

LATIF: With our tides?

MOLLY: With our tides.

LULU: Oh.

MOLLY: And basically how that works is the moon causes the tides on the Earth, which means the moon's gravity pushes and pulls the water in the oceans on the Earth.

LULU: Right.

MOLLY: Which then changes the gravity of the Earth, which actually fiddles with the moon itself again. It's like a feedback loop.

LULU: Huh!

MOLLY: And the way that it fiddles with the moon is kind of complicated, but stick with me.

LATIF: Okay.

MOLLY: Basically the moon is just one plate. Whereas if you think of the Earth, we have plate tectonics. Like, we have different plates that smash into each other, but the moon is just one. And so Earth's gravity is just pulling on one single plate.

LATIF: Huh.

MOLLY: And if you're one plate getting pulled on, the only thing you can do is change your entire shape. So the plate, aka the moon, goes from being a sphere to an oblong object to a sphere ...

LATIF: Whoa!

MOLLY: ... to an oblong object.

LATIF: Holy!

MOLLY: I know. It's so rad! And moonquakes are happening quite often. So just know when you look up there, it's trembling.

LATIF: Stage fright.

LULU: Oh, that's lovely!

LATIF: Yeah.

MOLLY: I know.

LATIF: And I guess when you're—like, when we're looking at the moon, the whole thing is kind of grayscale, right? Are there colors on the moon?

MOLLY: Everything is pretty gray. One thing I did hear was that when things land on the moon, like an asteroid or a meteor, there's like a whiteness to it that's really bright. It's almost like newborn material that has hit from—from far away in the solar system. And then over time, as it starts getting pummeled by, you know, the solar wind from the sun and different types of, like, charged radiative particles from space, that those cause that whiteness to kind of like heat and condense and heat and condense, and then it becomes dark. And so the moon seems like it's a place of light and shadow.

LULU: Hmm. I feel like having this conversation with you, the veil—the wool is pulled from my eyes. Because—because I think you were very successful in your premise. But more than that, like, it's like—this—most of our images are either the ones we can see with the naked eye where it's this, like, comforting twinkle. It's this source of light in darkness. And it's so twinkly and forgiving and welcoming, and then it's like, "No. Take off your shoes. Welcome to this place. The dust is daggers. You're gonna bleed if you scrinch into the dust."

LATIF: Temperature extremes!

MOLLY: I mean, it is probably both twinkly and dagger dust, and then also cold and alive. And probably a thousand other things, because we still don't know it that well. Like, in all of time, we've only spent three-and-a-half days up there. It hasn't—we haven't actually spent that much time on the surface of the moon.

LATIF: Oh really?

MOLLY: Yeah. Three days and, like, a handful of hours.

LULU: We've only—that feels—I mean, quite literally like we've only scratched the surface. [laughs]

MOLLY: Exactly. We really don't know this friend of ours that well, actually.

LULU: Huh.

MOLLY: And, like, one of the things that came out of these conversations with scientists is just how many questions they still have about the moon and, like, how much we have yet to discover about it.

LULU: Hmm.

MOLLY: And it's just like, you know, they would just rattle them off, like, what is the history of impact events on the moon? Or what is the moon like below the surface? Or why don't we ever see moonquakes on the far side of the moon?

LULU: Hmm!

MOLLY: Or what is the little bit of lunar atmosphere that is up there made of? And how can the moon help us understand other planets? Like, the list goes, like, on and on. Like, someone sent me a 120-page NASA book ...

LULU: Wow!

MOLLY: ... that was a lot about the questions on the moon. So it just feels like what we've done here is, like, this is what we know about the moon day to day right now.

LULU: Yeah.

MOLLY: But that could just get blown up again in—as we learn more.

LULU: Yeah. But still I just—I don't know. It's like, instead of going to bed thinking about the little boys fishing off the moon, which is a nice image, I'm gonna think about the long-ago volcanoes exploding on it.

MOLLY: Young lunar craters, that's what you're gonna go to bed thinking about.

LULU: I am. For real. It's beautiful. It's beautiful.

MOLLY: Yeah.

LULU: We will continue to moon you after this short break.

MOLLY: Yeah! [laughs]

LULU: Lulu.

LATIF: Latif.

LULU: Radiolab. Back from break.

LATIF: On our lunatic journey here.

LULU: With the story of a celestial-sized what if?

LATIF: How you doing, Alan?

ALAN GOFFINSKI: Good, man. Good to see ya.

LATIF: Good to see you!

LATIF: Comes to us from reporter Alan Goffinski.

LULU: Okay, so I guess to begin, Alan, you should tell Latif the highly intellectual place where this quandary was born.

ALAN: Right. Just like every good Radiolab story, it all started watching ...

[ARCHIVE CLIP, Despicable Me: Hello, everybody!]

ALAN: ... one of the Minions movies, Despicable Me.

[ARCHIVE CLIP, Despicable Me: Simmer down! Thank you.]

ALAN: The bad guy in the movie is named Gru, and for reasons that aren't really worth going into right now ...

[ARCHIVE CLIP, Despicable Me: We are going to steal ... the moon!]

ALAN: ... he steals the moon. He shrinks it down to the size of a grapefruit, pulls it right out of orbit.

[ARCHIVE CLIP, Despicable Me: Ah-ha!]

ALAN: And in his moment of victory, floating up in space, holding the moon in his hands ...

[ARCHIVE CLIP, Despicable Me: I've got it! I've got the moon!]

ALAN: ... the movie jump cuts back to Earth. You see this wave stop. And then there's this werewolf. He suddenly changes back into a human with no clothes on.

LULU: [laughs]

LATIF: [laughs]

ALAN: I mean, these just immediate and absurd consequences of the moon disappearing.

LATIF: Right. Right. Right.

ALAN: And while it's really just a short scene in the movie, it got me curious about what would happen if the moon just—just disappeared?

LATIF: Like, what physically would happen?

ALAN: Right. Right. Like, down here on Earth.

LATIF: Right.

LULU: Which—can I just say, I don't—would there be that much? Like, I know that the poets would be sad, I'd be sad to lose my object of evening contemplation, but besides maybe tides, does it have—like, does it do that much here?

ALAN: Well, I started searching around to see if anyone had thought about this, and I quickly found someone who was kind of the perfect person.

MIKA MCKINNON: Can you hear me?

ALAN: Hi! Hello!

MIKA MCKINNON: Hello, hello.

ALAN: How are you doing?

MIKA MCKINNON: I'm doing well.

[baby whimpers]

MIKA MCKINNON: Sorry. I gotta stand so the baby falls asleep. And we're, like, right on the edge of naptime, so you might hear a few more whimpers, but I think we're set.

ALAN: So this is Mika McKinnon.

MIKA MCKINNON: I am a geophysicist with a Masters in disasters. Possibly the best degree title ever!

LULU: [laughs]

ALAN: No!

LULU: Masters in disasters!

ALAN: That's a real thing?

MIKA MCKINNON: Yes, yes. I did geophysics of catastrophic-scale landslides. That's what I did my grad school in.

ALAN: Today, when she's not helping agencies like FEMA plan and prepare for disasters, you know, helping to save lives ...

MIKA MCKINNON: I am a science consultant in the entertainment industry, so I sit with directors and come up with interesting science to support their plotlines.

LATIF: Cool!

ALAN: Tell me about it. So I put this question in front of her.

ALAN: What would happen if all of a sudden just one day the moon sort of disappeared?

MIKA MCKINNON: Yeah, so do we want to have a destroyed moon or a vanished moon?

LULU: Ooh!

ALAN: Why don't you tell us what would happen if it was destroyed first?

MIKA MCKINNON: Okay. So if the moon got destroyed ...

ALAN: Say we shot a bunch of nukes at it, detonated them, something like that.

MIKA MCKINNON: ... suddenly we would have a whole bunch of meteorites crashing down on Earth, a whole bunch of impact events. So death, destruction, suffering and misery immediately.

LULU: [laughs]

ALAN: Okay, so ...

MIKA MCKINNON: So destroyed, I actually think is less fun than ...

ALAN: Yeah, yeah, yeah.

MIKA MCKINNON: ... the moon disappearing, because I think the very, very first thing that would happen if the moon disappeared is confusion. Everyone would go, "Wait, what?"

LULU: But, like, in all languages?

MIKA MCKINNON: Yeah, simultaneously.

LULU: N'es quoi?

MIKA MCKINNON: Yeah.

LULU: [laughs] Yeah. Okay, okay.

MIKA MCKINNON: And I would think that there'd be a lot of instantaneous conspiracy theories about this too.

ALAN: Oh, for sure.

LULU: Who did it? You did it. Let's bomb you!

MIKA MCKINNON: Yeah, so the human aspect is just gonna be a mess.

LULU: Oh yeah.

MIKA MCKINNON: But let's look at—ignoring the people ...

LULU: We'll come back to that. Yeah.

MIKA MCKINNON: Ignore the people.

LULU: Ignore the people for a little.

MIKA MCKINNON: The moon has some major spheres of influence. So in the first place: tides.

ALAN: I mean, as you noted, Lulu, as the Earth rotates, the moon's gravity is actually tugging on it, sort of pulling the oceans in and out.

MIKA MCKINNON: All the time. It's like a little gravitational massage. And so take away the moon, the tides would be a lot smaller.

ALAN: By what percent?

MIKA MCKINNON: A lot. Like, a 65- to 75-percent reduction.

ALAN: Huh!

MIKA MCKINNON: So suddenly your tidal range gets tiny. And this would impact everything. And so if you were at the beach ...

ALAN: Standing in the sand, she says, probably the first thing that you'd notice is it sounds eerily quiet.

MIKA MCKINNON: Yeah, it would be quieter, the waves calmer. But ...

ALAN: As you walk closer towards the water ...

MIKA MCKINNON: The stench would be eye watering. Looking at the water, it'd be full of dead crabs and fish.

ALAN: Because, you know, with the water moving less ...

MIKA MCKINNON: Everything that is a filter feeder, like all of the little barnacles and mussels and clams and all that are having less food show up. And if all of your, like, clams and, like, crabs and everyone start dying off, then everything that eats them dies off.

LULU: Oh!

MIKA MCKINNON: Then everything that eats them dies off. And so you have an entire coastal system/ecosystem food chain collapse.

ALAN: And for the animals that weren't immediately affected by the tides, the difference in the night sky would leave many of them just totally lost. Eels, jellyfish, others literally use the moon to navigate. And there are other species that actually use it to time their reproduction.

MIKA MCKINNON: Like, the Great Coral Reef is one that's so precise, all the reef is like, "All right, so sometime between October and November, we're gonna pick a full moon." Then they wait a few days. And then four hours after moonrise, they all release their reproductive goodies. And so you have, like, these giant pink clouds that you can see from space! So you just start going like, okay, so if there's no moon, what happens with all of that?

ALAN: The eels would maybe be chasing their tails, the jellyfish bobbing toward the bottom, coral reefs dead and vacant. Not good.

LATIF: Yeah, but it sounds like all of this is watery stuff.

ALAN: I mean, don't discount the watery stuff. That's most of the planet. [laughs]

LATIF: Yeah, yeah, yeah. Watery stuff is most of the planet. Fair. Fair. Fair. Good point.

ALAN: And as Mika points out, the water is going to affect the land. Again, because the tides aren't moving water, the warm water is going to be pooling out in the ocean.

MIKA MCKINNON: Concentrating and piling up all in one place.

ALAN: And because warmer water means harsher hurricanes ...

[ARCHIVE CLIP: If these roofs collapse, if these signs go down ...]

MIKA MCKINNON: The hurricane season is gonna start even earlier and last even longer.

ALAN: I mean, entire states might have to be evacuated.

LATIF: Hmm.

ALAN: And as we move inland, we're gonna be running into ecosystems in total flux.

MIKA MCKINNON: So let's look at the Serengeti and the wildebeest.

LULU: Okay, great!

ALAN: Typically on new moons when it's the darkest is when wildebeest are most vulnerable to their number one predator: lions. You know, the lions can sneak up on them more easily in the dark, so to protect themselves the wildebeest stay packed together and don't eat or move much, holding tight, waiting for a brightly-lit, moon-filled night.

MIKA MCKINNON: But if it's a perpetual new moon ...

ALAN: Perpetually moonless nights ...

MIKA MCKINNON: ... well, then eventually the wildebeest are gonna have to come up with a new plan. And they're herding animals, so they're all gonna have to agree on a plan together to do something.

ALAN: They could travel, expose themselves and probably get eaten. Or stay hunkered down and quickly eat up everything around them. And weirdly, if they go that route, they're gonna make themselves even more vulnerable because there'll be no foliage left for them or anyone else to hide behind, so the lions will be swarming them and they're gonna be fighting back.

ALAN: Chaos on the Serengeti, chaos on the Serengeti.

MIKA MCKINNON: Exactly.

ALAN: But this chaos on land, it might not be bad news for everybody. Take, for example, the badger.

MIKA MCKINNON: Badgers pee more ...

ALAN: Wait, say that again?

MIKA MCKINNON: Badgers?

ALAN: Badgers urinate more.

MIKA MCKINNON: So badgers will pee better and more on new moons when it's darker, and less on full moons when it's brighter.

ALAN: Are they a little shy?

MIKA MCKINNON: So that's the joke, except for what it is is they're peeing in order to mark territory, saying, "Hey, I'm ready to mate." And it takes them, like, 90 minutes to get it on, so they want to be in darkness where they're less likely to be spotted and eaten.

LULU: They like doing it with the lights out! [laughs]

MIKA MCKINNON: Exactly. Badgers prefer dark nights for their romantic endeavors.

LULU: So they might actually do quite nicely without a moon.

MIKA MCKINNON: Yeah, yeah.

ALAN: [laughs] The badger population explodes.

LULU: It just skyrockets. [laughs]

MIKA MCKINNON: But when you were asking about, like, who were the winners, who were the losers? One of the winners would be geophysicists.

LULU: Why?

MIKA MCKINNON: Because we would finally be able to tell the difference between several theories that we've had that we're, like, "Uh, I can't really tell."

LULU: Like what? Can you give us one?

MIKA MCKINNON: Yeah, so a perpetual question is whether or not the moon is responsible for the Earth's magnetic field.

LULU: Huh.

ALAN: What?

MIKA MCKINNON: Okay, so wait—so here on Earth, we've got the outer crust where we're all hanging out. Under that, we've got the mantle, under that, we have the liquid outer core, and then there's the solid inner core.

ALAN: And this liquid core moving around this solid core, that's what generates our magnetic field.

MIKA MCKINNON: And the Earth's magnetic field, it's like our shield. It's what protects us from all the nasty, nasty radiation of space.

ALAN: I mean, it literally deflects cosmic, cancer-causing particles that are bombarding us, and yeah, it's all thanks to that metal moving inside the Earth's core.

MIKA MCKINNON: So why is the metal moving inside the Earth? Why is the outer core moving?

ALAN: Do they ...?

MIKA MCKINNON: Yeah. Yeah, why? Right?

ALAN: We don't know?

LULU: Is it the moon?

MIKA MCKINNON: That's one of the ideas.

ALAN: The thinking goes that in the same way the moon's gravity pulls the water of the oceans ...

MIKA MCKINNON: The gravitational massage is having that same impact to a smaller amplitude on the inside.

ALAN: Causing some of that metallic movement. And I mean, if this theory's right, well then the Earth without a moon is really no Earth at all.

MIKA MCKINNON: If we lost our magnetic field, I mean it wouldn't happen right away, but if it started slowing down, if it started getting weaker, goodbye remaining life.

LULU: Man, that is—all of this is such a bigger effect than I would have ever fathomed. I'm kind of in awe.

ALAN: I feel like the big takeaway from this is we don't want this scenario. This is not like a world that we want to live in.

MIKA MCKINNON: No, we don't want this. Without the moon up there really, just every—there's gonna be death. There's definitely gonna be slow and confusing death. So I would like to keep the moon, please.

LULU: Coming up, we are headed to the dark side of the moon. And not in a Pink Floyd way. Like, we're actually going—we're going there, we're looking at it, we're really going there. Stay with us.

LULU: Hey, this is Radiolab. I'm Lulu Miller. And today, we are talking about the moon. We're on a moonbender, this big beautiful, mysterious celestial body that we all stare up at from time to time. And our final story comes to us from producer Simon Adler from a live show he performed all over the country. Here's Simon.

SIMON ADLER: Okay. I got one more story for you. I think it's the story of the craziest collective experience we human beings have ever had, and the one dude that was left out. It's a story that was originally told to me by Zack Taylor. He is a documentary filmmaker, also a fellow fan of cassette tapes.

ZACK TAYLOR: I shot and directed a documentary called "Cassette: A Documentary Mixtape."

SIMON: How many cassette tapes do you think you have?

ZACK TAYLOR: Oh my gosh. I probably have a couple thousand.

SIMON: Anyhow, story starts summer of 1969 as the crew of Apollo 11 are about to blast off to the moon. And along with all their space gear and all their training, these guys were carrying a thing with them that no man had ever held before.

ZACK TAYLOR: The name of the thing was the TC-50. It looked like a sleek, elegant, minimalist aluminum brick.

SIMON: And what it was, really, was a Sony Walkman. It's a little bit heavier than the Walkman that they would publicly release 10 years later, a little bit bulkier. But functionally, the only real difference is this little red 'Record' button on the top. And this red record button is actually the reason why they allowed these things on board.

ZACK TAYLOR: Because the gloves that these guys used, even today I'm sure like an astronaut's glove is not conducive to, like, jotting down your thoughts. And I mean, the more I think about it, the more mission critical this thing is.

SIMON: Mission critical?

ZACK TAYLOR: Yes, mission critical! Because they're going, like Star Trek, where no man has gone before.

SIMON: Gotta record it like no man had done before. And so July 16, 1969 ...

[ARCHIVE CLIP, NASA: Lift off. We have a lift off, 32 minutes past the hour. Liftoff on Apollo 11.]

ZACK TAYLOR: These three astronauts had about a three-day's journey to get to the moon, or to get to the moon's orbit.

SIMON: And as they're flinging through space, the folks at NASA, of course, they're listening to everything going on up there. And they could actually hear these guys using their Walkmans, just not as recorders.

[ARCHIVE CLIP, NASA: This is Apollo control at 59 hours, 9 minutes. Apollo 11 now 182,000 nautical miles from Earth. And a velocity down to 3,072 feet per second. [music] The intermittent music that we're getting is apparently coming from the spacecraft. The crew has onboard portable tape recorders with music on the tapes.]

SIMON: Yeah, each of the astronauts had a personalized mixtape with music on it that they brought up there with them.

[ARCHIVE CLIP, NASA: And apparently, the music is triggering the vox-operated microphones, and we're getting intermittent music down from the spacecraft.]

SIMON: Now NASA did cosign on all this. The thought was: we gotta send them up there with tapes to record onto, might as well fill them with music first. So ...

ZACK TAYLOR: Mickey Kapp the record executive would go ask each astronaut, "Hey, what's your favorite song? Okay, thank you. Hold my beer, I'll come back with a mixtape for you."

SIMON: And as Zack there tells it, the music these guys brought with them, well it offers a little peek into each of their personalities. So for example, the straight-laced, mission commander ...

ZACK TAYLOR: Neil Armstrong's cassette has ...

[music]

ZACK TAYLOR: ... this kooky album from the '40s on it.

[ARCHIVE CLIP, Neil Armstrong: That's an old favorite of mine. It's an album made about 20 years ago called "Music Out of the Moon."]

SIMON: He's a little hard to hear there, but if you caught it, yes, Neil Armstrong went to the moon with an album called "Music Out of the Moon."

[laughter]

SIMON: [laughs] Take a listen.

[theremin plays]

ZACK TAYLOR: Neil Armstrong, like that was his jam.

[laughter]

SIMON: And I mean, he played this stuff onboard so much that there were times where NASA would call up and say, "Hey Neil ..."

[ARCHIVE CLIP, NASA: Eleven, we appreciate you turning that off.]

ZACK TAYLOR: "Can you turn that music off, please?"

[ARCHIVE CLIP, NASA: [beep] Thank you.]

ZACK TAYLOR: "Thank you."

SIMON: Story goes that Buzz, the big-talking space cowboy of the group, requested a very specific song on his tape, so that the moment they touched down on the lunar surface, he'd be able to reach behind him, pull out his tape player ...

ZACK TAYLOR: And press play to ...

[ARCHIVE CLIP: "Fly Me To the Moon" - Frank Sinatra]

ZACK TAYLOR: Do do do do doo ...

SIMON: Are you serious?

ZACK TAYLOR: That's how—that's the legend. That's the legend. That's how the story goes.

SIMON: Now yes, Buzz told this story on multiple occasions, but years later, oddly enough after he sobered up, he said "Ah, maybe none of that happened. I'm not sure."

ZACK TAYLOR: But listen, if a whole building of rocket scientists can believe enough to send these three young men out into space, then I am gonna exercise this little faith the size of a mustard seed and believe that Buzz Aldrin reached behind his seat to play "Fly Me To the Moon," because what an amazing moment.

SIMON: Now this moment and these cassette tapes generally are the sort of strange, forgotten, possibly partially invented bits of history that cassette lovers like me can't get enough of. And I sort of think that's all they would be, if it weren't for the third astronaut on the mission, a guy by the name of Michael Collins. Now unfortunately, it turns out that Collins's playlist has been totally lost to time. I reached out to the NASA archives, to the National Archives, to the Smithsonian, no one has any idea where this tape is, or really much of what was ever on it. Which I actually think is sort of fitting.

ZACK TAYLOR: Michael Collins is the one guy nobody knows. The third wheel. He's just the guy who, like, in history, they couldn't have done it without him? Like, they really needed him? What did they need him for? But Michael Collins was the linchpin in all this stuff. Michael Collins was the one who made sure that they first of all got to the moon and more importantly made sure that they got home.

SIMON: So to pick the story back up, July 20, four days into the mission, around 11:00 am here in Seattle, it was time for them to actually go down onto the moon. And so Buzz and Neil, they crawl over into the far end of the spacecraft, the lunar landing module they called the Eagle, they sealed the airlock and they detached. Meaning that the whole time that those guys were down there on the moon, Collins, he was going to be up there all by himself, just waiting.

ZACK TAYLOR: Michael Collins had 21.5 hours, almost a full day, where it's just him alone, orbiting the moon from about 60 miles above.

SIMON: And not only is he alone, but half the time he's up there, he is in total darkness. Every 48 minutes, he'd pass behind the dark side of the moon, meaning no light and no contact.

[ARCHIVE CLIP, NASA: Apollo 11, this is Houston. All your systems are looking good going around the corner. We'll see you on the other side. Over.]

[ARCHIVE CLIP, Michael Collins: Roger.]

[static]

[ARCHIVE CLIP, NASA: This is Apollo control, we have lost the signal now. We'll reacquire the spacecraft again on the 13th revolution in about 45 minutes.]

SIMON: Collins did this 23 times, 23 times for 45 minutes at a time. All he had was his heartbeat, his thoughts and the darkness. And I mean, if that wasn't enough, the whole time that he's sitting up there, he knows that the hardest, the riskiest moment of this mission is actually yet to come because before they can go home, Buzz and Neil need to get off of the moon. They need to blast off at just the right time so that they will land in the moon's orbit at just the right spot so that Collins could grab them. And as if that wasn't enough ...

ZACK TAYLOR: There was no way to test the engines on the Eagle taking off from the moon. There was no way to test it. It was completely untested. It was an unknown.

SIMON: Yeah, we did not understand the moon's surface well enough to know how this would go.

ZACK TAYLOR: So what happens if, you know, the engine doesn't have quite enough gas to get them back to the orbiter? Or what if they overshoot it? And privately, the three astronauts gave themselves about a 50/50 chance of getting off the moon.

SIMON: So ...

ZACK TAYLOR: Michael Collins is orbiting all by himself, wondering if he's gonna return to Earth alone, or as part of a three-person crew successfully having visited the moon.

[ARCHIVE CLIP, NASA: This is Apollo control. Collins has gone behind the moon on the 23rd lunar revolution while he waits for his comrades to rejoin him for the trip back to Earth.]

SIMON: I mean, just picture this for a moment with me: on one side of the moon facing Earth you've got Armstrong who has just stepped onto the surface of the moon and broadcast back to Earth his famous line.

[ARCHIVE CLIP, Neil Armstrong: It's one small step for man, one giant leap for mankind.]

SIMON: And then on the other side of the moon, in total darkness, totally alone, you've got Mike Collins. So in this moment that literally the entire Earth is experiencing something together, he remains alone, disconnected and out of touch from all of it.

ZACK TAYLOR: Exactly. So my gosh, this is—this is what I keep going back to. This is where having a Walkman, having this hunk of aluminum with the record button, this is where this suddenly becomes, as I said, mission critical.

SIMON: Because while Collins was up there, the loneliest man in the history of the universe, to calm his nerves or get the voices out of his head, he turned to a cassette tape. He pulled out his Walkman and he hit that little red button.

ZACK TAYLOR: And said, "My secret terror for the last six months has been leaving them on the moon and returning to Earth alone. Now I am within minutes of finding out the truth of the matter." Dude, if you're alone. If you're on the dark side of the moon and all you have is a Walkman, how is that cassette not your very best friend? The closest thing you have to another human being, a listening ear, a shoulder to cry on. I think that cassette is a life raft.

[applause]

LULU: That was senior producer Simon Adler, live at the Town Hall Seattle, in Seattle, Washington.

-30-

Copyright © 2024 New York Public Radio. All rights reserved. Visit our website terms of use at www.wnyc.org for further information.

New York Public Radio transcripts are created on a rush deadline, often by contractors. This text may not be in its final form and may be updated or revised in the future. Accuracy and availability may vary. The authoritative record of programming is the audio record.

Unlock member-only exclusives and support the show

Exclusive Podcast Extras

Entire Podcast Archive

Listen Ad-Free

Behind-the-Scenes Content

Video Extras

Original Music & Playlists

Unlock exclusives in The Lab

Sign up for the newsletter