Why did we go back to the moon?

Summary

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Unexplainable — "Why Did We Go Back to the Moon?"

Podcast: Unexplainable
Host: Noam Hassenfeld (Vox)
Guests: Anne McClain (NASA astronaut), Rebecca Boyle (science writer), Jonathan Jiang (NASA astrophysicist), Scott Kelly (former NASA astronaut)
Date: April 13, 2026

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Episode Overview

This episode unpacks the motivations, challenges, and scientific mysteries behind humanity’s renewed focus on lunar exploration, specifically through NASA’s Artemis program. The Unexplainable team explores the physiological, technological, and existential questions prompted by the goal of living and working on the Moon—and potentially Mars. Featuring first-hand astronaut experiences and expert commentary, the episode probes both the promise and peril of making space a more permanent home.

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Key Discussion Points & Insights

The Artemis Era: Humanity’s Return to the Moon

• Historic Launch: NASA’s Artemis 2 became the first crewed mission to orbit the Moon in over 50 years, advancing further than any prior mission—without landing ([01:05]–[02:30]).
  • “The crew of Artemis 2 now bound for the moon. Humanity's next great voyage begins.” — Noam Hassenfeld [01:22]
• Ultimate Goal: Artemis signals not just a return, but the intent for permanence: “We’re going back to stay.” [02:43]
• Vision for the Future: By 2040, NASA envisages a lunar base and eventual Mars missions, taking steps toward a multi-planetary future ([03:12]–[03:39]).

The Brutal Reality of Space for Humans

• Space is Hostile:
  • “Space is terrible. It wants to kill us.” — Rebecca Boyle [03:50]
  • Danger comes from weightlessness, radiation, isolation, and microgravity.
• Life in Orbit vs Deep Space:
  • Experience in low Earth orbit (ISS) has given us a glimpse, but only 28 people have been beyond 1,000 miles from Earth ([04:39]).
  • Apollo missions lasted mere days—far shorter than what a moon base would require ([05:02]).
• Astronaut Anne McClain on Living in Space:
  • Describes awe and psychological shock when first entering space ([06:16]–[07:06]).
  • “It’s really hard to describe … there just hasn't been anything like it before.” — Anne McClain [06:23]
• Radiation Experiences:
  • Astronauts see “shooting stars” with their eyes closed—likely radiation particles hitting their retinas ([07:41]–[08:07]).
    • “If little atoms became bullets.” — Anne McClain [07:41]
  • Even with Earth's protective magnetic field, exposure is significant; outside that field, risks multiply ([09:53], [10:53]).

Physiological Challenges

• Impact of Microgravity:
  • Fluid shifts, changes to eyesight, diminished bone density; astronauts’ height increases in space, reverting (painfully) on return ([08:25]–[09:23]).
    • “I grew just under 2 inches in space … I shrunk right back down.” — Anne McClain [09:10], [09:23]
• Psychological Effects: “Space fog” and chronic fatigue are common; long-term cognitive and physical impacts linger even after landing ([09:33]–[09:47]).
• Danger Escalates Beyond Orbit: Apollo astronauts, exposed to more radiation, saw higher rates of heart disease ([10:53]–[11:32]).

Lunar Challenges: Beyond the ISS

• Gravity & Disorientation: The Moon’s gravity is just high enough to confuse the human vestibular system, causing frequent astronaut tumbles ([12:10]–[12:42]).
  • “I look like an elephant stumbling around here.” — Apollo astronaut [12:39]
• Lunar Night: Two weeks of darkness and frigid cold, extreme even for adaptable tech ([12:47]–[13:08]).
• Moon Dust—The Ubiquitous Threat:
  • Sharp, abrasive, pervasive: gets everywhere, is inhaled, and causes illness ([13:17]–[14:56]).
    • “Every piece of moon dust is jagged and sharp. So it’s just flying like bullets all over the place.” — Rebecca Boyle [14:12]
    • “I think Dust is probably one of our greatest inhibitors to a nominal operation on the moon.” — Gene Cernan, Apollo 17 astronaut [14:56]
• Long-Term Health Risks: Prolonged exposure may increase risks of cancer, respiratory illness, and shortened lifespans ([15:14]).

Technological and Survival Innovations

• Possible Solutions:
  • Medications to counter microgravity effects, plastics for radiation protection in suits, coatings to repel lunar dust ([16:09]).
  • Lunar Caves: Using ancient lava-tube caves for shelter—constant temperature, protection from radiation and dust ([16:34]–[17:06]).
    • “A moon base in a lunar cave … it's a fantastic thing to imagine.” — Noam Hassenfeld [17:37]

Existential Questions: Why Bother?

• The Fundamental Question: Is risking human life to live in space worth it? ([18:18])
  • “I mean, that’s kind of the million dollar question for a lot of these programs: what’s the point?” — Rebecca Boyle [18:18]
• Existential Risk: Jonathan Jiang (NASA) frames multi-planetary expansion as vital to the long-term survival of life ([22:20]–[23:28]):
  • “Suppose we are alone and we are precious. If we are destroyed, it means the life in the universe was gone.” — Jonathan Jiang [22:34]
• Geopolitical Motivation: With China’s lunar ambitions, urgency and competition drive some of the mission ([21:18]–[22:20]).

Other Benefits of Space Exploration

• Spinoff Technologies: Solutions developed for space (e.g., camera technology, medical advances) have everyday benefits ([24:59]–[25:14]).
• Scientific Research: Human intuition and flexibility surpass robots; famous example: "seatbelt basalt" discovered on Apollo 15 only because of human improvisation ([25:30]–[27:34]).
  • “When you put a person in a situation, they have the ability to look off to the side and go, hey, what was that?” — Anne McClain [25:36]

Would You Go?

• Different Perspectives:
  • Jonathan Jiang: “I think many people like me, we are not afraid of even death. We would like to explore, to find something new.” [28:05]
    • He’d go to Mars—one way—if his daughter would join him [28:12].
  • Anne McClain: “Responsible exploration means that it’s a two way ticket.” [28:29]
  • Scott Kelly: Not interested in a one-way trip, but jokes he’d “watch that reality show” ([28:50]–[29:13]).
    • “Have you ever read the book The Lord of the Flies? … Probably that kind of interesting.” — Scott Kelly [29:15]
  • Rebecca Boyle: As much as she loves the Moon, the safety risks make a real mission off-limits for her ([29:41]).

Philosophical Reflection

• The Necessity—and Limits—of Expansion:
  • “We have this planet that gave birth to us all … we have a lot to still save here and that we’re made for it. Keeping both of those things in mind keeps us a little bit more feet on the ground, even as we look to the heavens.” — Rebecca Boyle [30:44]
• While humanity is driven to expand, it’s crucial to remember the profound risks of space and the unique gift of Earth ([30:08]–[31:19]).

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Notable Quotes & Memorable Moments

• “Space is terrible. It wants to kill us.” — Rebecca Boyle [03:50]
• “The crew of Artemis 2 now bound for the moon. Humanity's next great voyage begins.” — Noam Hassenfeld [01:22]
• "This time we're going back to stay." — Artemis astronaut [02:43]
• “I grew just under 2 inches in space.” — Anne McClain [09:10]
• “If little atoms became bullets.” — Anne McClain (on cosmic radiation) [07:41]
• “I think Dust is probably one of our greatest inhibitors to a nominal operation on the moon.” — Gene Cernan [14:56]
• "Suppose we are alone and we are precious. If we are destroyed, it means the life in the universe was gone." — Jonathan Jiang [22:34]
• "Responsible exploration means that it's a two way ticket." — Anne McClain [28:29]
• "We have this planet that gave birth to us all. ...we have a lot to still save here and that we're made for it." — Rebecca Boyle [30:44]

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Timestamps for Key Segments

• [01:05–02:30]: Artemis 2 and humanity’s return to lunar orbit
• [03:50–04:28]: Why space is fundamentally hostile to life
• [06:16–07:06]: Anne McClain’s first launch and sunrise in space
• [07:41–08:07]: Experiencing radiation firsthand on ISS
• [09:10]: The surprising effects of microgravity on the body
• [10:53–11:32]: Greater health risks beyond low Earth orbit
• [12:10–13:08]: Lunar gravity and the difficulties it creates
• [14:56]: Apollo astronauts’ warnings about moon dust
• [16:34–17:06]: Lunar caves as potential future habitats
• [18:18, 22:20]: Philosophical and existential reasons for space colonization
• [25:30–27:34]: The "seatbelt basalt"—a story of human discovery in space
• [28:05–29:41]: Guests share whether they would venture out themselves
• [30:44]: The importance of remembering the value of Earth

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Summary

With NASA’s Artemis missions, humanity is taking bold but risky steps toward becoming an interplanetary species. The show thoughtfully explores the scientific, existential, and personal facets of this next chapter—probing why we’re so compelled to go, what it will really take to live beyond Earth, and how the answers might shape not only our future in space but our perspective on life here at home. The episode balances awe and caution, rooting a grand vision for space with both gritty challenges and philosophical humility.

Transcript

[Rebecca Boyle]

Megan Rapinoe. Here. This week on A Touch More, we're bringing you our live show in Phoenix with WNBA four time champion Chelsea Gray and the Naismith coach of the year, Shea Ralph. Together we talk about the NCAA semifinals, the crazy activity in the transfer portal, and of course the final matchup for the NCAA championship. Check out the latest episode of A Touch More wherever you get your podcasts and on YouTube.

[Noam Hassenfeld]

What should we make of the Iran war ceasefire announcement? And where do things go from here? If anything has surprised me over the last 24 hours, it's that Iran agreed to a ceasefire. And particularly that Iran agreed to a ceasefire after that outrageous message that President Trump put out. I'm Jake Sullivan. And I'm John Finer. And we're the hosts of the Long Game, a weekly national security podcast. This week we break down the latest news on Iran and share our net assessment of where things stand for the US the episode's out now. Search for and follow the Long Game wherever you get your podcasts.

[Astronauts (various)]

This is Victor. We are going for our families. This is Christina.

[Anne McClain]

We are going for our teammates.

[Astronauts (various)]

This is Jeremy. We are going for all humanity. Godspeed, Artemis 2. Let's go.

[Noam Hassenfeld]

10, 9, 8, 7. RS 25. Engines lit. 4, 3, 2, 1. Booster ignition and lift off. The crew of Artemis 2 now bound for the moon. Humanity's next great voyage begins. Four astronauts on Artemis 2 just traveled further than anyone in history.

[Astronauts (various)]

We challenge this generation and the next to make sure this record is not long lived.

[Noam Hassenfeld]

It's the first time in over 50 years humans have been so close to the moon.

[Astronauts (various)]

You know, I'm not one for hyperbole, but it's just absolutely unbelievable. This is incredible. Kathy, moonjoy.

[Noam Hassenfeld]

The vibes are so good that mission control just smiles, spontaneously went, copy moon joy. And now it's become this kind of catchphrase.

[Anne McClain]

Everyone is reporting full moon joy.

[Noam Hassenfeld]

Scientists are even talking about putting it on T shirts.

[Astronauts (various)]

Houston, if you could Give me about 20 new superlatives in the mission summary for tomorrow, that'll help my vocabulary out a bit. Thank you.

[Noam Hassenfeld]

The astronauts on Artemis 2 didn't land on the moon, they just orbited it. But the mission was a crucial step towards getting back to the surface again, which NASA is planning to do in 2028. And they've got a different goal this time.

[Astronauts (various)]

This time we're going back to stay.

[Noam Hassenfeld]

We ran a version of this episode a few years ago when Artemis 1 launched, and we wanted to share it again this week because it's easy to get lost in all these incredible photos of the Moon and Earth and miss out on the larger context of just how big a step forward this all is. The entire Artemis program is just setting the stage. Eventually, NASA's hoping to build a perman base on the moon.

[Astronauts (various)]

And our goal is to apply what we've learned living and operating on the Moon and continue out into the solar system for humans to walk on Mars.

[Noam Hassenfeld]

By 2040, a moon base and a mission to Mars could be the first steps toward becoming a multi planetary species where Earth isn't our only home. Eventually, we can imagine a solar system full of human life, human settlements in

[Astronauts (various)]

space in which tens of thousands of people will live and work.

[Noam Hassenfeld]

But there's a pretty basic thing standing in the way.

[Astronauts (various)]

Okay, Houston, we've had a problem here.

[Rebecca Boyle]

Space is terrible. It wants to kill us.

[Noam Hassenfeld]

Science writer Rebecca Boyle.

[Rebecca Boyle]

You know, we've evolved to live on this planet and this planet only.

[Astronauts (various)]

I tell you, Deke is cold up in there.

[Noam Hassenfeld]

Whether it's the weightlessness, the radiation, or even the isolation, space is trouble for lots of different kinds of life.

[Rebecca Boyle]

It's hard to raise fish or rats or mice or any other kind of species that we've taken up there.

[Noam Hassenfeld]

Sadly, 53 mice died in space, as did eight gerbils.

[Rebecca Boyle]

It's hard to even grow plants in

[Noam Hassenfeld]

microgravity, which makes NASA's grand vision of a permanent presence far from Earth a pretty risky proposition.

[Rebecca Boyle]

Space is really nasty, and it's very hard to be there for any period of time, even with a spacesuit and a space station surrounding you.

[Noam Hassenfeld]

Okay, everybody, look.

[Astronauts (various)]

We got a number of long range

[Noam Hassenfeld]

problems right now, and we barely understand the dangers of space, especially when it comes to living far away from Earth. For a long time, like, over 600 people have been to space, but only 28 of them, just 4%, have been more than 1,000 miles from Earth.

[Astronauts (various)]

We'd like to confirm that the world

[Noam Hassenfeld]

is round and that tiny handful barely spent any time out there.

[Rebecca Boyle]

I mean, the longest Apollo missions were just a few days.

[Astronauts (various)]

Odyssey, Houston. Welcome home. Over.

[Noam Hassenfeld]

That's where the Artemis program comes in. It's often presented as just the next logical step in space, but it's also an experiment to see just how possible NASA's grand vision really is.

[Rebecca Boyle]

The real goal of all these programs is to learn how to live and work really far from Earth. How bad is it? How much can we handle?

[Noam Hassenfeld]

I'm Noam Hassenfelb and this week on Unexplainable. What does space do to the human body? And if we're Planning to have a permanent presence on the moon or even Mars? Are we sure we can actually live there? Almost everything we know about the long term effects of humans in space has come from low Earth orbit. This area of space just a couple hundred miles from Earth's surface. That's where astronauts like Anne McClane have spent significant time on the International Space Station.

[Anne McClain]

You wait your whole life to launch to space and then suddenly it happens.

[Noam Hassenfeld]

Ann first launched to the ISS in 2018.

[Anne McClain]

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.

[Noam Hassenfeld]

As she left the pull of gravity, she turned and she gazed out this little round window.

[Anne McClain]

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, that's. I wonder if 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.

[Noam Hassenfeld]

In total, ann spent over 300 days on the ISS surrounded by the cold, dark vacuum of space.

[Anne McClain]

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.

[Noam Hassenfeld]

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.

[Anne McClain]

Just think about like if little atoms became bullets.

[Noam Hassenfeld]

Many of these subatomic particles shoot right through the walls of the space station.

[Anne McClain]

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

[Noam Hassenfeld]

of radiation, 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.

[Anne McClain]

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.

[Noam Hassenfeld]

On top of the radiation, there's the issue of gravity.

[Anne McClain]

Gravity is an incredibly strong force. Well, when it leaves your body, your fluids shift up.

[Noam Hassenfeld]

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

[Anne McClain]

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.

[Noam Hassenfeld]

And microgravity changes the pressure around astronauts eyeballs.

[Anne McClain]

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.

[Noam Hassenfeld]

Bone density is a problem too.

[Anne McClain]

That's why now when you see astronauts on the space station, you see us lifting weights.

[Noam Hassenfeld]

And because her spine wasn't constantly being compressed by gravity, the space between Ann's vertebrae actually expanded.

[Anne McClain]

I grew just under 2 inches in

[Noam Hassenfeld]

space, which was okay, except for her pants.

[Anne McClain]

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.

[Noam Hassenfeld]

Until she came back to Earth.

[Anne McClain]

I shrunk right back down in a couple of painful days.

[Noam Hassenfeld]

And finally there's just the fact of being in space confined to this tiny box for a long time.

[Anne McClain]

We do talk a little bit about space fog. That just kind of makes you less likely to think quickly through things.

[Noam Hassenfeld]

NASA itself acknowledges that the psychological impact from isolation is one of the most dangerous unknowns of long term space missions.

[Anne McClain]

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.

[Noam Hassenfeld]

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.

[Astronauts (various)]

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

[Noam Hassenfeld]

Apollo astronauts have reported tons of these flashes.

[Astronauts (various)]

Oh man, there's a good one. The left eye right in the middle. It starts out as a semicircle and then folds into a point like on a pencil, and then it disappears.

[Noam Hassenfeld]

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.

[Rebecca Boyle]

And eventually, people would just live there permanently, rotating in and out like the way we do on Antarctica or on the space station.

[Noam Hassenfeld]

And two, they'll be near valuable resources on the Moon, including water ice in its south pole.

[Rebecca Boyle]

In theory, you could get that water, and it could be used for rocket fuel.

[Noam Hassenfeld]

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.

[Rebecca Boyle]

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.

[Astronauts (various)]

I just got my first initiation to getting very dirty. You sure did.

[Rebecca Boyle]

They're just totally disoriented. Like your vestibular system just can't kind of figure out where you are in space.

[Astronauts (various)]

Yeah, I look like an elephant stumbling around here.

[Noam Hassenfeld]

On top of the weaker pull of gravity, astronauts who live on the Moon will also have to deal with lunar night.

[Rebecca Boyle]

That's another thing that makes the Moon really unpleasant.

[Noam Hassenfeld]

Any spot on the Moon has two weeks per month where it faces away from the sun, which, which leads to some ridiculously cold temperatures.

[Rebecca Boyle]

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.

[Noam Hassenfeld]

And then there's a danger that may be even scarier than radiation, weak gravity, or the freezing cold moon dust.

[Rebecca Boyle]

So because there's no atmosphere to speak of, any dust that's moving around because of a spacecraft arriving or leaving is gonna fly around like a scouring pad.

[Noam Hassenfeld]

Apollo astronauts dealt with moon dust constantly.

[Astronauts (various)]

Man, I got so much dust over my visor already, I gotta wipe it off.

[Rebecca Boyle]

There's kind of a constant stream of micrometeoroids hitting the moon. And that kicks up a bunch of dust.

[Astronauts (various)]

I tell you, it's. Sure, it's easy to get dusty, but that's nothing new to anybody.

[Rebecca Boyle]

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.

[Astronauts (various)]

You're going to have to give me the Dust of the Year award after this.

[Noam Hassenfeld]

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.

[Astronauts (various)]

Man, that is dusty.

[Noam Hassenfeld]

But the moon doesn't have wind or waves like Earth does to make that dust softer.

[Rebecca Boyle]

Every piece of moon dust is jagged and sharp. So I was just flying like bullets all over the place.

[Noam Hassenfeld]

The dust would stick to astronauts suits.

[Astronauts (various)]

Flat dust. Once you get it on there, you might as well forget it.

[Noam Hassenfeld]

And then when they went inside the landing capsule, it just went everywhere.

[Astronauts (various)]

Dust, dust, dust, dust.

[Rebecca Boyle]

So there's no avoiding breathing it in.

[Astronauts (various)]

Black dust. Get in there really.

[Rebecca Boyle]

And they all complained bitterly about it and it hurt their throats and it gave them like a feeling, like a head cold, like you were congested because there's so much crap you're breathing in.

[Astronauts (various)]

I have never seen so much boost in my whole life, ever.

[Noam Hassenfeld]

One of the astronauts actually got sick from all of it.

[Astronauts (various)]

It's come on pretty fast just since I came back. I didn't know I had Lunar Dante fever.

[Noam Hassenfeld]

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.

[Astronauts (various)]

Man, I hate this dust.

[Noam Hassenfeld]

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 what 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. 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 Ann.

[Anne McClain]

I understand cognitively the dangers, but I can't say no. It's, it's this passion that I just, I want to explore.

[Noam Hassenfeld]

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.

[Rebecca Boyle]

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.

[Noam Hassenfeld]

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.

[Rebecca Boyle]

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.

[Noam Hassenfeld]

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. 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.

[Rebecca Boyle]

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.

[Noam Hassenfeld]

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?

[Rebecca Boyle]

I mean, that's kind of the million dollar question for a lot of these programs is what's the point?

[Noam Hassenfeld]

The million dollar answer after the break.

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[Noam Hassenfeld]

Hi, I'm Brene Brown.

[Scott Kelly]

And I'm Adam Grant.

[Noam Hassenfeld]

And we're here to invite you to the Curiosity Shop, a podcast that's a place for listening, wondering, thinking, feeling and questioning. It's gonna be fun. We rarely agree, but we almost never disagree. And we're always learning. That's true. You can subscribe to the Curiosity shop on YouTube or follow in your favorite podcast app to automatically receive new episodes every Thursday.

[Version History Host]

When you think of a phone, not a smartphone, but like a telephone, you almost certainly think of one particular device. This boxy thing that sat on your desk. It has a bunch of buttons on it. It has a handset that you pick up. It has a braided cable. You're thinking of a phone called the Western Electric 500. And for decades, it was absolutely everywhere in American homes. It was essentially illegal not to have it in your house if you had a phone. This week on Version History, our chat show about the best and worst and most interesting products in tech history, we're telling the story of the Western Electric 500, which is actually the story about the AT&T monopoly and how it fell apart. All that on version history, on YouTube and wherever you get podcasts.

[Astronauts (various)]

We're whalers on the moon.

[Noam Hassenfeld]

We carry a harpoon.

[Astronauts (various)]

The stars are moon.

[Noam Hassenfeld]

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? 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 Jiang, living off world feels a lot more urgent. Something that isn't a choice as much as a necessity.

[Jonathan Jiang]

I think any life like 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.

[Noam Hassenfeld]

For all we know, Earth could be the only planet in the universe with life.

[Jonathan Jiang]

Suppose we are alone and we are precious. If we are destroyed, it means the life in the universe was gone.

[Noam Hassenfeld]

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.

[Jonathan Jiang]

People say, nah, it's not going to happen. But you check the Dome States clock website, the chances have a global nuclear war right now, it's not zero.

[Noam Hassenfeld]

And when you start looking at longer and longer timeframes, this kind of destruction starts becoming more plausible.

[Jonathan Jiang]

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.

[Noam Hassenfeld]

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.

[Jonathan Jiang]

If we want to have a future for the humanities, even if our sun is dead, we got to become multi planetary species.

[Noam Hassenfeld]

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.

[Rebecca Boyle]

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

[Noam Hassenfeld]

Science writer Rebecca Boyle again, we have one home.

[Rebecca Boyle]

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 gotta go somewhere else and look,

[Noam Hassenfeld]

something terrible really could happen to Earth. But Mars is pretty apocalyptic right now. It's already kinda 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.

[Rebecca Boyle]

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

[Noam Hassenfeld]

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.

[Rebecca Boyle]

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.

[Noam Hassenfeld]

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

[Anne McClain]

To me, it's the concept of kind of the known unknowns and the unknown unknowns.

[Noam Hassenfeld]

Astronaut Anne McClane.

[Anne McClain]

Again, 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?

[Noam Hassenfeld]

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.

[Anne McClain]

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.

[Noam Hassenfeld]

But then one of the astronauts noticed something off the planned route.

[Anne McClain]

Out of the corner of his eyes, he sees what he knows to be a basalt rock.

[Astronauts (various)]

Oh, man. How about just hold on one second?

[Anne McClain]

And he said, we've got to go get that.

[Noam Hassenfeld]

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.

[Anne McClain]

And so they said, okay, let's just tell him our seat belt's broken so that we have to stop and adjust

[Astronauts (various)]

it take my seatbelt. Roger. Mark that you stop. Why don't you hand me your seatbelt?

[Anne McClain]

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.

[Astronauts (various)]

These small fresh craters that we've commented

[Anne McClain]

on, it's just a beautiful landscape.

[Astronauts (various)]

There's just a concentration of rocks.

[Anne McClain]

And he just kept on talking so that he'd go pick up the rock.

[Astronauts (various)]

I'm talking about maybe a foot to three feet in diameter.

[Anne McClain]

That rock was very, very scientifically interesting.

[Noam Hassenfeld]

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 Anne says that this rock is the type of thing that only humans would likely be able to find, but

[Anne McClain]

if we had relied on rovers, we would never have it.

[Noam Hassenfeld]

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.

[Jonathan Jiang]

I think many people like me, we are not afraid of even death. We would like to explore, to find something new.

[Noam Hassenfeld]

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.

[Jonathan Jiang]

If there's an opportunity to go to a completely new place, I start something new, I die there, it's fine with me.

[Noam Hassenfeld]

Other people like Ann, were less into the idea.

[Anne McClain]

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.

[Noam Hassenfeld]

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

[Scott Kelly]

I do stupid things sometimes.

[Noam Hassenfeld]

Scott said he'd be willing to go back, but not if it were permanent.

[Scott Kelly]

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 get pretty interesting.

[Noam Hassenfeld]

What kind of interesting?

[Scott Kelly]

Have you ever read the book the Lord of the Flies? Sure, probably that kind of interesting.

[Noam Hassenfeld]

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.

[Rebecca Boyle]

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.

[Noam Hassenfeld]

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.

[Rebecca Boyle]

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.

[Noam Hassenfeld]

This episode was reported and produced by me, Noam Hassenfeld. It was edited by Kathryn Wells, Brian Resnick and Meredith Hodnot. Music from me, mixing and sound design from Christian Ayala, fact checking from Zoe Mullick, and production assistance from Bird, Pinkerton Mandinguin and Neil Denisha. If you want to hear more from Rebecca Boyle, you should check out her book. It's called Our How Earth's Celestial Companion Transformed the Planet, Guided Evolution and Made Us who We Are. Special thanks to Chris Leinhart, Anna Schneider and Rachel Hoover for their help. Thanks as always to Brian Resnik for co creating the show with me and Bird. And if you have thoughts about this episode or ideas for the show, please email us. We're unexplained, [e-mail] 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.commembers to sign up. Unexplainable is part of the Vox Media Podcast Network, and we'll be waiting right here for you next time.

[Astronauts (various)]

Sa.