Short Wave - This distant planet has wild weather and gemstone clouds

Episode Date: May 29, 2026

For many astronomers and astrophysicists there are two distinct, important periods: before the James Webb Space Telescope – and after. It has powered many scientific discoveries since it came online, including two at the heart of this episode: insights into one of Neptune’s moons and a “hot Jupiter” exoplanet orbiting another star. This exoplanet has a strange weather system with high winds and cloud coverage only on one side of the planet. Fill in some of the scientific gaps about our solar system and the universe beyond with us.Interested in more space science? Email us your question at [e-mail] to every episode of Short Wave sponsor-free and support our work at NPR by signing up for Short Wave+ at plus.npr.org/shortwave.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, Sheroivers, Regina Barbara here. It's time for my favorite monthly episode. Our space news segment, spacing out with Gina. We're here today with science correspondent Katie Riddle. Hey, Katie. Hey, Gina. I will say you're going to have to learn a secret handshake by the end of the day.

I'm ready. I'm ready for it. And Space Connoisseur and all things considered hosts, Scott Detrow. Welcome back, Scott. I like Space Connoisseur. I'm excited to be here. I'm excited here. what you will teach us this week. Yes, I actually did use to teach this stuff for like a dozen years.

But, Kadia, you're actually going to start us off, though, with a story about the furthest planet in our solar system. Exactly, which, you know, I grew up learning with Pluto, but unfortunately, it's since been kicked out of the major planet guild. There's a lot of beef, a lot of baggage. I'll be telling you about Neptune today and how one of its moons could help us fill in the gaps of our solar system's origin story. But I promise us. It'll still be fun. Can I rattle off the, like, slightly dated nemomic, pneumonic device? That is a hard word to say that I learned to sail the planets.

Do it. My very educated mother just served us nine pizzas. Just served us nothing. Yes, just nothing. Yeah, now it's nothing. Or like noodles. I don't know. Got to update it.

But Pluto aside, Neptune's cool too. That's not the only planet on our agenda today, though, right? Yes. So there's a planet that isn't in our solar system, an exoplanet. orbiting another star far, far away. And Gina, you're also telling us another reason that the northern lights are awesome. Yes. Have either of you seen the northern lights?

Honestly, I never have. All the times that it was coming low in recent years, I get excited and then it'd be like, oh, wait, I live in a city. Yeah. It's not going to happen. I think I kind of did once. It was like a foggy green, but I can't confirm it, right? So let's all pack our bags and let's all go to Alaska together.

I think so. It takes the show on the road. I'm there. Okay. Today on the show, we're traveling up and. and out from Earth's northern lights to the edges of our solar system and outside of it. You're listening to Shortwave, the science podcast from NPR. Okay, Gina, Scott, I'm sure you've heard a lot about Neptune, but I bet you don't know much about its moons.

Did you know that it has 16 of them? I definitely did not. No, you probably did. No, I did not. I knew it was a lot, but I didn't know it was like 16. Well, now we know. There's been questions about one specifically called Nariad for decades. researchers have been wondering whether this moon was formed right in Neptune's orbit or if it's an interloper from elsewhere.

What makes them think that could be the case? Well, for starters, Nariad has really unusual orbit. It's stretched into this elongated oval shape. For years, that highly eccentric orbit led researchers to speculate that it was not formed around Neptune. Moons that are born, so to speak, around a planet tend to travel in a kind of regular, circular path. But now we're able to be able to. to look more closely at Narad's composition and see evidence that despite this weird orbit, it is more consistent with a moon that formed around Neptune than one that was captured from elsewhere. What is going on with this smushed orbit shape, then? Yeah. The idea now is that it was shoved into this unusual orbit by another moon called Triton at an earlier point. Triton is big. It's about eight times bigger than Narriott. And it turned out as kind of a bully. I actually kind of like Triton. But, okay, but when you're you have 16 moons, things are going to be very competitive. Yeah, exactly. Our moon is lucky. It doesn't

have to compete for real estate around Earth. I talked to Matthew Beliakov from the California Institute of Technology. He's the lead researcher on a new paper out about this in the journal Science Advances. I think there's a lot of value to having a new understanding of Nariad. It's a time capsule. So what does he mean by time capsule? Well, this may be the only intact moon remaining from Neptune's original moons. Matthew says information like this leads to filling in other blanks around the solar system. It's pretty important to understand how the early solar system transpired, because that tells us something about our formation here on Earth. I'm moving past the, I'm just like really dwelling on 16 moods, jostling for space and moons swapping in and out.

Yeah. But I'm going to get past that. Like, I guess my one question here is that this is something scientists have been thinking about studying for a long time. How are we able to get this new information? Yeah, it all comes back to the James Webb talking to Matthew. He just underscored how much of a game changer this telescope has been. It's such a powerful tool. He says in his line of work, it's really like before the James Webb Space Telescope and after the telescope.

It's given us such a richer and more nuanced understanding of the universe. Okay, so let's switch gears here. Let's go from a cold planet to a hot planet. And let's go from our solar system to another solar system. Jita, you're going to talk to us about a hot, jukewarm. Jupiter-like planet orbiting another star? Yeah. So we're going to talk about an exoplanet.

So this is a planet around another star. And we're going to be talking about its weather. We can see things like storms in Jupiter. But planets orbiting other stars, what's their weather like? That's Eliza Kempton, an astronomer at the University of Chicago. I talked to her about a new study she didn't work on, but she was excited about. It looks at a specific exoplanet that's a hot, gas giant, so like Jupiter, but it's 18 times closer to its star than Earth is to the sun.

That is super close. It's so close. What else makes this interesting for scientists to study and learn more about? Yeah, so these planets are called hot Jupiters. It's not Jupiter, but it kind of is slightly bigger. It has a permanent day and a permanent night. This planet is always facing its star on one side. It's tidily locked with that star.

And that star is about 700 light years from Earth. And that affects the weather. Yes, so astrophysicist at Johns Hopkins University also used the new and very precise James Webb Space Telescope to look at the atmosphere of this exoplanet called WASP 94AB. That's a catchy name. Yeah, it is. And researchers looked at the morning part of the planet at the boundary separating the day and night side. And that's riddled with clouds. But then if you travel along the sunlit dayside, the clouds get burned off.

So there are clear skies on the dayside of the exoplanet and clouds at the dawn and dusk parts. Wow. And then based on the way that it's tidily locked, does that mean that these are like semi-permanent weather patterns? Yeah. So I talked to Shagnik Mukherjee about all of this. He's the lead author of a new paper about this in the journal Science. And he says having distinct night and day sides means there's also. There's this huge temperature difference. What it does is it sets off really fast winds. One other thing I want to know, one of my questions I've always had about WASP 94AB. Right, right. Going back.

Since you've learned about it. Yeah. Yeah. What are the clouds made of? Scott, I'm so glad you asked that. So the clouds are not made of water like on Earth. Okay. Here's Maria Steinrook of the University of Chicago also.

She's an astrophysicist who didn't work on the study, but she says her favorite part of the study and hot gas giants in general is... These planets are so hot. The gemstones are clouds. Yeah. So the clouds are made of dust and bits of rock. And this is possible because it's just so hot. Let's close this out by coming back to Earth, the Northern Lights. This is something we've talked a lot about lately because there's been so much activity.

These come from solar storms, right? Yeah, it's more space weather, Scott. Yes, let's do it. Yep. Very true, Katie. So the sun goes through these cycles. And this year and last, we saw strong auroras in a lot of the U.S. states. There was a big solar storm last fall where people claimed to see the Northern Lights as

south is Atlanta. I don't know if you all remember this. And this is, it's fair to say, the bigger the solar storm is, the further south we see the Aurora Borealis, right? Yeah. I mean, that's a pretty good general rule. Fun fact, this is actually one of my favorite stories. There was a massive solar storm in 1859. And you could see the northern lights as south as Cuba. And it was so bright that campers thought the sun was rising in the middle of the night. Wow. Yeah. But nothing like that has happened this year or last. No, no, no, thankfully. All of the solar storms, Noah and and NASA has tracked lately, have been smaller than that famous one. For the most part, people who live on the U.S.-Canada border have, like, the best chance to see Northern Lights.

But for any curious listeners, you should definitely go to Noah's website and check out predictions on when and where you're going to see Northern Lights. Katie, how would you rate your first time on spacing out with Gina? Five out of five stars. I'm game to nerd out any time on space stuff, guys. Aw, we hope you'll join our nerd club again sometime. only after you learn that handshake. I'm ready. I'm ready for it. If you like this episode, please share it with a friend. It really helps the show.

And hey, give us a follow on the NPR app or wherever you're listening from. This way, you'll never miss a new episode. This episode was produced by Arun Nair and Kai McNamee. It was edited by Christopher and Taliatta, Amina Khan, and our showrunner Rebecca Ramirez. Kadia, myself, and Tyler Jones check the facts. Jimmy Keely and Ted Mebain were the audio engineers.

I'm Regina Barber. Thank you for listening to Shortwave, the science podcast from NPR. See you Monday.