Short Wave - Why scientists launched two little robots to the moon

Episode Date: June 19, 2026

Two tiny transforming robots landed on the moon! These baseball-sized bots accompanied Japan's first successful lunar lander. They rolled out of SLIM as balls and transformed into a rover. The bots cracked down the middle to reveal a little camera in the center. The halves then acted as spinning wheels that helped them waddle, bounce and roll over hard terrain as they explored. In this roundup of space news, we also get into the latest turn about how much the universe is expanding and the Earthly analogs NASA astronauts are using to prepare for the forthcoming Artemis mission.Interested in more space science? Email us your question at [e-mail] public media with NPR+ and enjoy perks for over 25 podcasts like this one. It includes perks like bonus episodes, early access, archive access, curated playlists and sponsor-free listening. Learn more at plus.npr.org. See pcm.adswizz.com for information about our collection and use of personal data for sponsorship and to manage your podcast sponsorship preferences.NPR Privacy Policy

You're listening to Shortwave from NPR. Hey, sure wavers, Regina Barber here. And it's time for my favorite monthly episode, our space news segment, spacing out with Gina. We're here today with my space buddy, my partner in spacing out crime, all things considered host, Scott Detrow. Welcome back to the show, Scott. I'm excited to be here since we last taped. I now have a giant picture of the moon at my desk. And I love it.

You do. I've seen it. It's big. And joining us today, Scott, is our producer, Burley McCoy. Burley, welcome to your first spacing out with Gina. Hey, Gina. Hey, Scott. I'm excited to be here.

It sounds like my jam. I'm a big nerd. I'm excited. I am excited. You're here. Welcome. She is a big nerd because she's the other PhD scientist on Shortwave. So she's going to feel right at home in our nerd space, I think.

You know? I agree. I'll just represent all the non-PHD holders out there and do my best. I have a question. for both of you, though. Yes. Have you seen any of the Transformer movies? Of course.

I haven't seen any of them. Whoa. Have you, Burley? Oh, I've definitely seen some, and they were cool at the time, but, like, I think they're kind of forgettable. I don't know. It's true. No hate mail, please.

It's true. But, you know, just to link all of this together, our first story in this segment is about Transformers on the moon. But I'm going to pop your bubble a little, Scott. It's not about Optimus Prime. Whomp. They're very different. But hopefully equally as cool.

Are they still robots in disguise? Yes, they still shape shape. Oh, okay. I'll take that. They're really small. They're really cute. They're round little guys about the size of a baseball. Essentially, they rolled out of this moon lander, and each half of the sphere moves outward,

kind of expanding, revealing this cute little camera in the center, and the halves are now spinning wheels. Okay, that's even better than a transformer. So it's like a little car that rolls around then? Yeah, sort of. But they kind of waddle because they can kind of waddle over hard terrain and navigate. They navigate on their own. And this was a test for future explorations. Oh, my God, waddling around.

This reminds me of my toddler a little bit, like always exploring, always expanding, which brings me to our next topic, the expansion of the universe. Oh, I'm just going to applaud that really smooth transition. Congratulations. What's the latest, though, on the expanding universe? So there's some drama in the astronomy world about how our universe is. expanding. Some scientists are debating this right now. And the stakes of that debate? Just the fate of the universe, though most astronomers are still on one side of the debate. Right. Like me. And we're going to

talk about Artemis 2 and Artemis 3, which now has a crew. Yep. That's right, Scott. So today on the show, we go from the moon to the farthest reaches of the cosmos and back. You're listening to Shorewave, the science podcast from NPR. Okay, Scott, Burley, I'm going to start with these little cute autonomous robots that, you know, strolled on the moon. I got a bunch of questions. Let's just start with why, though, why they were on the moon. You said it was for testing? Yeah, they were part of the first successful Japanese lunar mission that landed on the moon a

couple years ago. And there's a new study out last week in the journal Science Robotics, analyzing how these little guys performed up there on the lunar surface. Other than kind of waddling around and seeming like Wally characters, what was their scientific job? So they took a lot of pictures of the moon's surface and of the lunar surface and of the lander. They're basically scouting out the terrain ahead of bigger rovers and going places they can't. And Scott, just to underline this, they're really small. They only weigh about a half a pound.

And that's huge for space travel, right? The lighter something is, the easier and cheaper it is to put up into space. And I talked to Roger Wienes, a planetary scientist who didn't work on this program, and he was thoroughly impressed. He said that the redundancy was a huge benefit to these devices. These are not expensive devices. You can have several of them. And if one or two fails, then you still have others. One other thing, though, I'm thinking about the fact that the moon has one sixth of the Earth's gravity. So does that affect how they move around? Totally. Yeah. These little guys actually kind of bounce, though.

So it's another reason why they're super cool. They're designed for low gravity so they can explore other places like Mars or even asteroids. Here's Roger again. These could go to small asteroids where hopping is extremely easy. In fact, you've got to make sure you don't hop out of, out of orbit or something like that. So, yeah, I can see these things going to a number of places. We'll have transformers on various planets and asteroids eventually.

Okay, this was a really fun start. We need to shift to something much more existential, though, for all of us, and that is our ever-expanding universe. First of all, remind us what this debate has focused on over recent decades. Okay, so, Scott, almost 30 years ago, astronomers discovered that our universe is not only expanding, but that expansion is speeding up. But in the last few years, a group of scientists shook up that understanding by claiming that

the expansion isn't speeding up but slowing down. Now, a paper out last week in the journal, monthly notices of the Royal Astronomical Society pushes back and says the old framework still stands. Continuing the debate. So we're back to expanding. Expanding and accelerating. Okay. Okay.

So given that we're back to that point of view, what do the expansion? of the universe is slowing down folks say to that. The group of scientists at Yonsei University in South Korea stands by their work. They already posted a rebuttal to this paper, and they say that the standard way astrophysicists measure universe expansion now is fundamentally flawed. So for the non-astrophysicists out there, remind us how you measure this. I'm going to let Burley do this. Yeah, so astronomers basically measure the brightness of a special type of exploding star, a supernova,

and then correct for things like how long it explodes or how much dust is in the way. And the South Korean team has said astronomers, we haven't been including the age of the star's home galaxy in those corrections. So the math is off. And when you include that, the final answer is that the expansion of the universe is slowing down. Which would be a massive discovery if that were true? This is quite the big if true. Exactly. So, okay, so given all of that, though, what is the consensus?

among other astronomers. So the experts we spoke to were skeptical of the slowdown hypothesis. They say the community has been fine-tuning the supernova method for almost 30 years, and there are other methods that point to the universe's expansion speeding up. Yeah, we talked to Priamvada Natarajan, an astrophysicist from Yale University, who wasn't involved in this work, and she's still skeptical, but she says these kind of debates are what strengthens science. Scientists by nature are skeptical, and even for an idea that has been validated,

and accepted, right? If there is a new argument, we do take it seriously and we interrogate it. And it's a low stakes debate, right? Because it's only just like the fate of the universe that's a Yeah, instead of everything eventually drifting far apart from each other and dying

a cold death billions of years from now, the universe could simply implode what astronomers call the big crunch. Sadly, none of us are going to be around to see that. I'm team cold death. I don't know which one I prefer. Hard to choose, huh?

Yeah, non-issue for me, I guess. Something that is happening in our time spans, though. Yeah. Our favorite NASA program, Artemis, we've got to talk about it. Totally. The crew for the next mission, Artemis 3, was just selected. And this is the mission that will do lots of maneuvers in space in low Earth orbit. Scott, you spoke with one of the newly selected astronauts, right?

I did. The day he was selected, I talked with Andre Douglas. And one of the things he talked about was going on training missions. He was on the backup crew for Artemis II and he trained alongside them. And one of the things they did was go to Iceland. We did a 24 mile hike in two days in Iceland just to go through a hard challenge of land navigation as if we're, you know, learning how to be really good operators. And they do this, you know, as you know, because this mission is supposed to help prepare them for future lunar exploration. So they're looking for places on Earth that are kind of analog.

of the moon of lunar conditions. Yeah, and it's also about geology. Like the rocky terrain and the actual rock compositions are very similar between the moon and Iceland. Apollo astronauts actually trained in Iceland too way back when and said it was the closest thing they had seen to the moon's surface. Two NASA astronauts are going back there this July to train in Iceland. And this isn't just for lunar missions, right? They're actually NASA's, it's farther away, but they're trying to simulate Mars as well right now? Yeah. Yeah, so they've had astronaut hopefuls trek around the lava beds in Hawaii Volcano's National Park with big packs on their backs doing geological field work and dealing with very limited and very delayed communications from a simulated mission control.

It's all a way to make sure our astronauts are super well prepared when someday they are out in space doing the real thing. And Scott, there is a simulated Mars mission happening right now at NASA's Johnson Space Center in Houston. NASA has four researchers in this 3D printed habitat doing experiments as if they're living on Mars. They went in last October and they'll stay inside for a little over a year. And maybe, you know, we'll come back and talk about that when they emerge. Sounds great. I think we need a spacing out field trip to Iceland then. Let's do that.

Oh, my gosh. And then we can see the Northern Lights too, which we've always talked about. Yes, yes. Okay, remote show in Iceland. Done. Scott Burley, thank you for spacing out with me. I had a great time. My mind definitely feels spacing after that.

You know, contemplating the expansion of the universe will do that. It will. I enjoy it. If you like this episode, please share it with a friend. It really helps our show. And hey, give us a follow on the NPR app or wherever you're listening from. So you'll never miss a new episode from us. This episode was produced by Burley McCoy and Kahneman.

It was edited by Christopher and Taliyata and our showrunner Rebecca Ramirez. Tyler Jones checked the facts. Robert Rodriguez, Ted Mebane, and Hannah Glovena were the audio engineers. I'm Berley McCoy. And I'm Regina Barber. Thank you for listening to Shortwave. The Science Podcast from NPR. See you Monday.

I'm floating away. Accelerating or decelerating? Decelerating. He stopped.