Why did we go back to the moon?

6:47Jonathan Jiang:Anne first launched to the ISS in 2018.

6:50Scott Kelly:I just remember feeling the thrust and just kind of this realization that you're leaving the planet. And it's really hard to describe, but it's like you're processing something that your brain doesn't have the capacity to process because there just hasn't been anything like it before.

7:04Jonathan Jiang:As she left the pull of gravity, she turned and she gazed out this little round window.

7:10Scott Kelly:It was all pitch black. And then I saw what looked like a little piece of, like, flame off of a Bunsen burner, you know, like a blue flame. And I thought to myself, well, I wonder what that flame on our spacecraft is. And I realized that as it got larger, it was actually the sun coming up over the curvature of the Earth. and I was watching my first sunrise.

7:33Jonathan Jiang:In total, Anne spent over 300 days on the ISS, surrounded by the cold, dark vacuum of space.

7:41Scott Kelly:The walls of the space station are very thin, which is pretty surprising. You know, when you first get up there, you're like, oh gosh, I don't want to accidentally punch a hole through the wall. It's not really going to happen, but these are the thoughts that cross your mind when you first get there.

7:53Jonathan Jiang:And it didn't take long to notice the types of dangers those walls couldn't keep out. For one thing, there's the ionizing radiation, these tiny, fast-moving particles ejected from the sun or from distant supernova explosions.

8:07Scott Kelly:Just think about, like, if little atoms became bullets.

8:10Jonathan Jiang:Many of these subatomic particles shoot right through the walls of the space station.

8:15Scott Kelly:When we shut our eyes at night up on space station, you can see what actually looks like a shooting star go by your eyes if you get hit by a piece of radiation.

8:22Jonathan Jiang:It's not totally clear how this happens, but one theory is that these particles could be hitting astronauts' retinas and making their rods and cones fire, which would lead them to see a flash of light that isn't really there.

8:34Scott Kelly:And the first time you see it, you're like, wow. Because we hear about radiation on the ground, and then we go, oh man, this like really fast atom moving through my head probably is not great for my body.

8:48Jonathan Jiang:On top of the radiation, there's the issue of gravity.

8:51Scott Kelly:Gravity is an incredibly strong force. Well, when it leaves your body, your fluids shift up.

8:57Jonathan Jiang:Your body is designed to constantly pump blood up from your feet, which makes sense as long as gravity is pushing down.

9:05Scott Kelly:It's like when you pick up the empty can of Coke that you think is full and you kind of go, whoa, and you pick it up real fast.

9:10Jonathan Jiang:And microgravity changes the pressure around astronauts' eyeballs.

9:13Scott Kelly:Some people experience a change in eyesight because you think about maybe there's a little more pressure on the back of your eyeballs. So instead of being shaped like almonds, they get to be a little more round.

9:22Jonathan Jiang:Bone density is a problem, too.

9:24Scott Kelly:That's why now when you see astronauts on the space station, you see us lifting weights.

9:28Jonathan Jiang:And because her spine wasn't constantly being compressed by gravity, the space between Anne's vertebrae actually expanded.

9:36Scott Kelly:I grew just under two inches in space.

9:38Jonathan Jiang:Which was okay, except for her pants.

9:41Scott Kelly:I got up there and I put on the pair of pants and I thought, why did I choose these ones? They only go down to my ankles.

9:48Jonathan Jiang:Until she came back to Earth.

9:49Scott Kelly:I shrunk right back down in a couple of painful days.

9:53Jonathan Jiang:And finally, there's just the fact of being in space, confined to this tiny box for a long time.

9:59Scott Kelly:We do talk a little bit about space fog that just kind of makes you less likely to think quickly through things.

10:06Jonathan Jiang:NASA itself acknowledges that the psychological impact from isolation is one of the most dangerous unknowns of long-term space missions.

10:14Scott Kelly:I mean, there was definitely days where I just, I felt like I never woke up. Like, I felt like I was half asleep all day long.

10:19Jonathan Jiang:And for lots of astronauts, these changes like cognitive troubles, bone problems, vision issues, they can last even after they get back to Earth. But this is all just what space does to people in low Earth orbit. Things get significantly more difficult as astronauts get further from Earth. Take radiation, for example. Because the ISS is so close to Earth, it's actually shielded from most cosmic radiation by Earth's magnetic field. So even though there's enough radiation on the ISS to see these flashes, it gets way worse further out.

10:55Rebecca Boyle:I've got a series of random lines that are moving like a flashing horizon with thunderstorms on the horizon.

11:06Jonathan Jiang:Apollo astronauts have reported tons of these flashes. Oh man, there's a good one. and the left eye right in the middle, it starts out as a semicircle

11:14Rebecca Boyle:and then folds into a point like on a pencil, and then it disappears.

11:20Jonathan Jiang:Only 28 people have spent even a brief time exposed to this kind of radiation. And just from this limited sample, there's reason to worry. According to a 2016 study, these astronauts were four to five times more likely to die from heart disease than astronauts who stayed closer to Earth. just from being outside Earth's magnetic field for less than two weeks. And once NASA goes and builds a permanent moon base, astronauts are going to be spending potentially several months at a time there, which science writer Rebecca Boyle says is going to let them do two main things. One, they'll learn how to survive in an extreme environment, which will help NASA get ready for a mission to Mars.

11:59And eventually people would just live there permanently rotating in and out,

12:03Anne McClain:like the way we do on Antarctica or on the space station.

12:06Jonathan Jiang:And two, there'll be near valuable resources on the moon, including water ice in its south pole.

12:11Anne McClain:In theory, you could get that water, and it could be used for rocket fuel.

12:16Jonathan Jiang:If NASA can extract oxygen from this water ice, the moon can basically be a gas station for future missions to Mars. But despite all this potential, the moon isn't exactly a welcoming place. For starters, even though the pull of gravity is stronger on the moon than it is on the ISS, It's still six times weaker than it is on Earth.

12:37Anne McClain:And turns out that's just at the threshold where it really starts to mess up your perception. People get kind of dizzy. There's actually a lot of videos of astronauts falling down on the moon. I fell down. Just like falling on their face.

12:52Rebecca Boyle:I just got my first initiation to getting very dirty. You sure did.

12:58Anne McClain:They're just totally disoriented. Like, your vestibular system just can't kind of figure out where you are in space. Yeah, I look like an elephant stumbling around here.

13:08Jonathan Jiang:On top of the weaker pull of gravity, astronauts who live on the moon will also have to deal with lunar night.

13:14Anne McClain:That's another thing that makes the moon really unpleasant.

13:16Jonathan Jiang:Any spot on the moon has two weeks per month where it faces away from the sun, which leads to some ridiculously cold temperatures.

13:24Anne McClain:There's no atmosphere. There's no pressure. There's no, you know, warm sun or clouds overhead. It's really difficult for basic technology to survive that, let alone humans.

13:35Jonathan Jiang:And then there's a danger that may be even scarier than radiation, weak gravity, or the freezing cold. Moon dust.

13:43Anne McClain:So because there's no atmosphere to speak of, any dust that's moving around because of a spacecraft arriving or leaving is going to fly around like a scouring pad.

13:53Jonathan Jiang:Apollo astronauts dealt with moon dust constantly. Man, I have so much dust over my visor already, I gotta wipe it off.

13:59Anne McClain:There's kind of a constant stream of micrometeoroids hitting the moon, and that kicks up a bunch of dust.

14:10Anne McClain:Some of it goes fast enough that it goes into orbit, essentially, and there's no air to absorb any of those particles or slow them down.

14:20Jonathan Jiang:I listened back to the tape from Apollo 17, the last mission to the moon, and honestly, barely a few minutes went by without the two astronauts worrying about the dust.

14:30Scott Kelly:Man, that is dusty.

14:33Jonathan Jiang:But the moon doesn't have wind or waves like Earth does to make that dust softer.

14:39Anne McClain:Every piece of moon dust is jagged and sharp, so it's just flying like bullets all over the place.

14:46Jonathan Jiang:The dust would stick to astronauts' suits.

14:48Rebecca Boyle:Quiet, dust. Once you get it on there, you might as well forget it.

14:51Jonathan Jiang:And then when they went inside the landing capsule, it just went everywhere.

14:55Rebecca Boyle:Dust, dust, dust, dust.

14:56Anne McClain:So there's no avoiding breathing it in. And they all complained bitterly about it, and it hurt their throats, and it gave them a feeling like a head cold, like you were congested because there's so much crap you're breathing in.

15:13Jonathan Jiang:One of the astronauts actually got sick from all of it.

15:22Jonathan Jiang:In a post-flight debriefing, astronaut Gene Cernan said, quote, I think dust is probably one of our greatest inhibitors to a nominal operation on the moon. I think we can overcome other physiological or physical or mechanical problems, except dust. Man, I hate this dust. That was his biggest worry after spending just a few days on the moon dealing with moon dust. All of these issues can pose acute problems. But long-term exposure is a whole different ballgame. Take moon dust, for example. We know it made astronauts sick on the moon, but studies have shown that longer exposure could lead to a higher risk of serious diseases like cancer down the line.

16:04Jonathan Jiang:So when you add that to the higher chance of dying from heart disease, from cosmic radiation, it might just be that spending a long time in deep space can't be perfectly safe. There's a real chance it can shorten your life. But even if living in space is always going to be dangerous, NASA isn't going to wait till the long-term risks are zero, which they're fully open about with astronauts like Anne.

16:28Scott Kelly:I understand cognitively the dangers, but I can't say no. It's this passion that I just, I want to explore.

16:35Jonathan Jiang:Rebecca says certain technologies could make long-term survival less risky. Like NASA is researching drugs that could mitigate the effects of weak gravity. Their ideas to make spacesuits out of a type of plastic that would absorb more cosmic radiation. And when it comes to moon dust, NASA's experimenting with a kind of slick coating on spacesuits to keep it off. But there's one interesting solution that could potentially solve a bunch of these problems at once.

17:01Anne McClain:There are actually some caves on the moon that are caused by lava flows that collapsed. And so in theory, like you could go under these domed kind of cave areas and burrow underneath the lunar soil.

17:15Jonathan Jiang:A lunar base inside a cave would be able to stay warmer during lunar night. And it would be shielded from the constant stream of moon dust.

17:23Anne McClain:You're also shielded from cosmic rays and solar rays if you're in a cave. Like, you're protected from being bombarded by any kind of micrometeoroids or radiation.

17:33Jonathan Jiang:And this isn't as far-fetched as it sounds. A couple years ago, NASA found a series of deep pits, or moon caves, that hover at a constant temperature of 63 degrees Fahrenheit. height, which means there's a real possibility that the first permanent settlers on the moon could be cavemen. You know, go back to what worked for humans the first time around.

17:52Anne McClain:Yeah, that's true. Go back to the caves and make their own art, and people in the future can talk about what they meant when they drew their rovers instead of bulls.

18:03Jonathan Jiang:It's a fantastic thing to imagine. A moon base in a lunar cave, a mining operation at work in the background extracting material to power deep space rockets, an orbiting lunar space station serving as a staging point for these missions, and a rocket heading out toward Mars, slowly transforming into one of many tiny lights as it gets further and further away. But at the end of the day, it's also worth asking why. Given that we still only know just a tiny sliver of the risks of being far from Earth for a long period of time, is all of this worth it? Why do we want humans to be living in space to begin with?

18:44Anne McClain:I mean, that's kind of the million-dollar question for a lot of these programs is, what's the point?

18:49Jonathan Jiang:The million-dollar answer, after the break.

19:00Anne McClain:Support for the show comes from Shopify. Before doing anything worthwhile, while it is normal to wonder, what if I fail? Especially if it's something as uncertain as starting a business. But the other side of that coin is, what if I totally knock it out of the park? And Shopify can help get you closer to unlocking that second answer. It is, by their numbers, the commerce platform behind millions of businesses around the world and 10 % of all e-commerce in the U.S. So from household names like Gymshark and Magic Spoon to brands just making a name for themselves. They say their design studio is equipped to help you create exactly the online presence you envision with hundreds of ready-to-use website templates.

19:40Anne McClain:And if you ever wonder, what if I get stuck? Don't sweat it, because Shopify has award-winning 24-7 customer support that can help you get unstuck. So, it is time to turn those what-ifs into Shopify today. You can sign up for your$1 per month trial today at shopify.com slash unexplainable. You can go to shopify.com slash unexplainable. That is shopify.com slash unexplainable.

20:13Anne McClain:Support for this show comes from the Futurology podcast. With so much changing every minute, it can feel silly to think more than a few days in the future, but exploring what could happen in the weeks, years, and even decades to come can reshape how we approach our lives today, which is exactly what futurology is for. This new podcast from the Berggruen Institute can help you get ahead of tomorrow. Futurology isn't sci-fi. Each week, they have thoughtful conversations with scientists, artists, technologists, philosophers, people who illuminate the forces shaping our lives and try to imagine both where they'll take us and also how we can respond.

20:54Anne McClain:They discuss whether the future is something we have to endure or something we can design, And if we can design it, what will we build? Subscribe to Futurology wherever you get your podcasts or watch full episodes on YouTube.

21:13Rebecca Boyle:When I got a new car, I thought my insurance premium would increase and empty my bank account. Like if Fetween won the lottery. I've invested most of my winnings in chicken tenders because they're bomb. But bro, I bought a house and it's sick, bro. I'm thinking the floor is going to be all trampoline, bro. With the helipad on the roof. The contractor said it's structurally unsound. They're just being babies. But switching to Geico saved me hundreds, so my bank account is safe.

21:38Jonathan Jiang:It feels good to save some hard-earned cash. It feels good to Geico.

21:45Rebecca Boyle:We're waiting on the moon. We carry our heart on. The stars on the moon.

21:55Jonathan Jiang:With the Artemis program, NASA's entered into a new era of space exploration. Artemis 2 just took humans around the moon and back for the first time in 50 years. And over the next three missions, NASA's going to test a lunar lander. They're going to put humans back on the surface of the moon. And they're going to start building a moon base. It's all going to teach us about living in space long term, far away from Earth. And ultimately, it's going to help us get ready for a mission to Mars. But it makes you wonder, if this is really about space exploration, why send humans into deep space at all?

22:32Jonathan Jiang:Why not just keep sending rovers? To start, there are some clear geopolitical reasons. China's planning to land people on the moon by 2030, and they're hoping to build a permanent moon base by 2035. So it might just be as simple as being first. But to NASA astrophysicist Jonathan Zhang, living off-world feels a lot more urgent, something that isn't a choice as much as a necessity.

22:58Rebecca Boyle:I think any life likes to spread, you know, and for the long-term survival, you need to move. If you stay one place, you're not going to survive long.

23:07Jonathan Jiang:For all we know, Earth could be the only planet in the universe with life.

23:12Rebecca Boyle:Suppose we are alone and we are precious. If we are destroyed, it means the life in the universe was gone.

23:20Jonathan Jiang:And it's not like this kind of destruction is so hard to imagine. There's a long list of apocalyptic events that could destroy us. Asteroids, pandemics, climate change, global nuclear war.

23:31Rebecca Boyle:People say, ah, nah, it's not going to happen. But you check the Domsday Clock website, the chances have a global nuclear war right now. It's not zero.

23:40Jonathan Jiang:And when you start looking at longer and longer time frames, this kind of destruction starts becoming more plausible.

23:46Rebecca Boyle:Suppose you buy a lottery ticket. The chances to win the lottery ticket is very low. But you buy a lottery ticket every day for millions of years, you're going to win.

23:55Jonathan Jiang:And zooming out even further, Jonathan says that it'll eventually be necessary to move way further out than just Mars. because the sun isn't going to be around forever. If we want to have a future for the humanities, even if our sun is dead,

24:11Rebecca Boyle:we've got to become a multi-planetary species.

24:15Jonathan Jiang:To even think about the dangers of that far, far future, we need to survive long enough to make it there. For Jonathan, the best way to ensure the existence of humanity is to start learning how to live far from Earth right now, no matter how difficult it might be. But not everyone wants to think billions of years into the future.

24:36Anne McClain:I don't want to give up that easily on Earth. You know, this is the planet that we evolved on.

24:42Jonathan Jiang:Science writer Rebecca Boyle again.

24:44Anne McClain:We have one home, and I think it's a little sad to imagine that, like, well, it's too late. This place sucks now because we messed up. We got to go somewhere else.

24:53Jonathan Jiang:And look, something terrible really could happen to Earth. But Mars is pretty apocalyptic right now. It's already kind of like what Earth might end up being after some sort of catastrophic event. So yeah, eventually, like very, very eventually, we're going to have to leave Earth to survive. But it's not exactly the greatest justification for a mission to Mars right now, or even in 2040. Still, there are other compelling reasons to learn to live far from Earth.

25:26Anne McClain:It's a difficult place to go. It's a difficult place to be. It requires a lot of energy and risk, both in terms of life and capital, to do that at all.

25:36Jonathan Jiang:Tackling the dangers of space leads to innovation. New technologies from phone cameras to wireless headphones to athletic shoes, they've all got their roots in the Apollo program. Plus, studying these extreme environments can really help people on Earth.

25:52Anne McClain:A lot of research on things like bone density loss and microgravity has a lot of impact for people with bone density issues on Earth, like osteoporosis.

26:02Jonathan Jiang:And finally, when it comes to science, there's certain things that people can do that rovers just can't.

26:08Scott Kelly:To me, it's the concept of kind of the known unknowns and the unknown unknowns.

26:12Jonathan Jiang:Astronaut and McLean again.

26:14Scott Kelly:Rovers and unmanned aerial vehicles, those are very good for answering questions that we know what the question is. We know where we want to look. We know what we want to look for. But when you put a person in a situation, they have the ability to look off to the side and go, hey, what was that? What just caught my eye? Why does that look different right there?

26:34Jonathan Jiang:This exact thing actually happened on Apollo 15 when astronauts were looking for lunar rocks. Scientists had speculated that finding this specific kind of rock called basalt would indicate volcanic activity.

26:46Scott Kelly:And Houston had put together where they thought they were going to find these rocks, and they had done this whole mission, and they were going back.

26:51Jonathan Jiang:But then one of the astronauts noticed something off the planned route.

26:55Scott Kelly:Out of the corner of his eyes, he sees what he knows to be a basalt rock. Oh, man. Hey, hold on one second. And he said, we've got to go get that.

27:06Jonathan Jiang:But NASA had already told them to end the mission, and he knew they wouldn't give him extra time to go check out the rock.

27:12Scott Kelly:And so they said, OK, let's just tell them our seatbelt's broken so that we have to stop and adjust it.

27:17Rebecca Boyle:Get my seatbelt. Roger, Mark, that you stop.

27:24Scott Kelly:And he gets out of the rover and he runs over and he picks up this rock while the other astronaut's like, I don't want Houston to ask us any questions. So I'm just going to talk. And so you just hear him go, Houston, I just want to paint this picture for you.

27:39Scott Kelly:It's just a beautiful landscape. And he just kept on talking so that he'd go pick up the rock. Oh, I'm talking about maybe a foot three feet in diameter. That rock was very, very scientifically interesting.

27:53Jonathan Jiang:This rock became known as the Seatbelt Basalt. And along with other samples, it pointed to the fact that the moon once had volcanic activity, the same activity that shaped the caves that could house a potential moon base. And Ann says that this rock is the type of thing that only humans would likely be able to find.

28:11Scott Kelly:But if we had relied on rovers, we would never have it.

28:16Jonathan Jiang:So given all of this, the compelling reasons to send humans to space for long periods of time, weighed against the very real risks to health and human survival, most of which are honestly pretty much unknown, I wanted to ask the people I spoke to if they would take part in this new era of living in space. Some people, like Jonathan, are so dedicated to this idea of a multi-planetary future that they'd be willing to make a permanent move.

28:49Jonathan Jiang:Jonathan told me that if his daughter was up for the trip too, he'd actually sign up for a one-way ticket to Mars.

29:03Jonathan Jiang:Other people, like Anne, were less into the idea.

29:06Scott Kelly:It is all about responsible exploration. And for me personally and the team at NASA, responsible exploration means that it's a two-way ticket.

29:15Jonathan Jiang:I also checked in with Scott Kelly, who until recently held the American record for the longest space mission at 340 days.

29:22Rebecca Boyle:I do stupid things sometimes.

29:24Jonathan Jiang:Scott said he'd be willing to go back, but not if it were permanent.

29:28Rebecca Boyle:I understand that there are people out there, most of them have probably never spent any time in space, that say they would be okay with living the rest of their lives on the surface of Mars in some kind of habitat. I am not one of those people. But I would watch that reality show because I think after a couple of years, it'd get pretty interesting.

29:51Jonathan Jiang:What kind of interesting?

29:53Rebecca Boyle:Have you ever read the book The Lord of the Flies?

29:55Jonathan Jiang:Sure.

29:57Rebecca Boyle:Probably that kind of interesting.

30:00Jonathan Jiang:But for other people, the idea of going on any kind of long-term mission outside low-Earth orbit just feels too risky. Like, even Rebecca, who spent her career writing about the moon, who knows everything there is to know about it. She's not sure she'd actually want to spend time there.

30:18Anne McClain:I think I would do it if I could be promised that I would be safe. But as we've been talking about, that's not a promise anybody can make. And so I don't think I would do it. As much as I would love that and to see the curvature of the Earth, which I spent so much time imagining and trying to write about and trying to recreate for people. I don't think if it came down to it that I would actually strap myself into a rocket to have that experience.

30:46Jonathan Jiang:It's easy to compare space exploration with the history of migration and exploration on Earth. You know, we're born to explore, that life always expands, that Mars is just the next logical step on our journey toward this future Star Trek universe. But it's also worth remembering just how risky a proposition this all is and the humans that are involved. This isn't just migration or exploration. This is learning to live in an environment that's actively trying to kill us in a whole bunch of different ways all the time, most of which we don't really understand yet.

31:21Anne McClain:Sometimes we need to ground ourselves in the reality that we have this planet that gave birth to us all. And I think we should remember that, you know, we have a lot to still save here and that we're made for it. And, you know, keeping both of those things in mind keeps us a little bit more feet on the ground, even as we look to the heavens.

31:57Jonathan Jiang:This episode was reported and produced by me, Noam Hassenfeld. It was edited by Catherine Wells, Brian Resnick, and Meredith Hodnot. music from me, mixing and sound design from Christian Ayala, fact-checking from Zoe Mullick, and production assistants from Byrd Pinkerton, Mandy Nguyen, and Neil D 'Anaisha. If you want to hear more from Rebecca Boyle, you should check out her book. It's called Our Moon, How Earth's Celestial Companion Transformed the Planet, Guided Evolution, and Made Us Who We Are. Special thanks to Chris Lainhart, Anna Schneider, and Rachel Hoover for their help. Thanks as always to Brian Resnick for co-creating the show with me and Byrd.

32:33Jonathan Jiang:and if you have thoughts about this episode or ideas for the show, please email us. We're at unexplainable at vox.com and of course, we'd love it if you left us a review or a rating and if you're into supporting the show and all of Vox in general, join our membership program. You can go to vox.com slash members to sign up. Unexplainable is part of the Vox Media Podcast Network and we'll be waiting right here for you next time.

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