MARY LOUISE KELLY, HOST:
This is ALL THINGS CONSIDERED from NPR News. I'm Mary Louise Kelly.
SCOTT DETROW, HOST:
And I'm Scott Detrow here with another edition of Spacing Out with our friends from Short Wave and the science desk. We've got host Regina Barber here. Hey there.
REGINA BARBER, BYLINE: Hey.
DETROW: And we're joined by NPR correspondent Katia Riddle. Katia, welcome to our nerd club.
KATIA RIDDLE, BYLINE: Oh, my gosh. It's such an honor, guys.
BARBER: I will say you're going to have to learn a secret handshake by the end of the day.
RIDDLE: I'm ready.
DETROW: You do.
RIDDLE: I'm ready for it.
DETROW: I'm sorry if we didn't tell you that beforehand...
RIDDLE: (Laughter).
DETROW: But that is reality, and you just have to deal with it.
BARBER: It is. Yep.
DETROW: In addition to that, we're going to talk about two new areas of research that would not be possible without this cool, new, amazing telescope called the James Webb Space Telescope from NASA.
BARBER: Yep.
DETROW: We're going to start with one of our prettiest planets, Neptune.
RIDDLE: Yeah, and specifically where one of its moons came from.
BARBER: Then I'm here to tell you both about a hot Jupiter-like planet orbiting a star far, far away.
RIDDLE: And I believe, Gina, you're going to remind us about how awesome the northern lights are, right?
BARBER: That's what I do. That's what I'm here for.
DETROW: All right, so let's start with the farthest planet from our sun, Neptune.
RIDDLE: Yeah. So I don't know if you know this, Scott, but Neptune has 16 moons. And there's been questions about one specifically, called Nereid. For decades, researchers have been wondering whether this moon was formed right in Neptune's orbit or if it's an interloper from elsewhere.
DETROW: What makes them think that could be the case?
RIDDLE: Well, for starters, Nereid has a 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 look more closely at Nereid'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.
DETROW: What is going on with this smooshed orbit shape, then?
RIDDLE: 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 Nereid, and it turned out it's kind of a bully.
DETROW: (Laughter).
BARBER: I actually kind of like Triton, but - OK, but when you have 16 moons, things are going to be very competitive.
RIDDLE: Yeah, exactly. Our moon is lucky. It doesn't have to compete for real estate around Earth. I talked to Matthew Belyakov from the California Institute of Technology. He's the lead researcher on a new paper out about this in the journal Science Advances.
MATTHEW BELYAKOV: I think there's a lot of value to having a new understanding of Nereid. It's a time capsule.
BARBER: So what does he mean by time capsule?
RIDDLE: 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.
BELYAKOV: It's pretty important to understand how the early solar system transpired because that tells us something about our formation here on Earth.
DETROW: I'm moving past the fact - I'm just, like, really dwelling on 16 moons jostling for space and moons swapping in and out.
BARBER: Yeah.
DETROW: 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?
RIDDLE: 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.
DETROW: OK, so let's switch gears here. Let's go from a cold planet to a hot planet, and let's...
BARBER: Yes.
DETROW: ...Go from our solar system to another solar system. Gina, you're going to talk to us about a hot Jupiter-like planet orbiting another star.
BARBER: 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.
DETROW: Mmm.
ELIZA KEMPTON: We can see things like storms in Jupiter, but planets orbiting other stars? What's their weather like?
BARBER: 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.
DETROW: That is super close.
BARBER: It's so close.
DETROW: What else makes this interesting for scientists to study and learn more about?
BARBER: 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 tidally locked with that star.
DETROW: Huh.
BARBER: And that star is about 700 light years from Earth.
RIDDLE: And that affects the weather.
BARBER: Yes. So astrophysicists 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-94 A b.
DETROW: That's a catchy name.
BARBER: 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 day side, the clouds get burned off. So there are clear skies on the day side of the exoplanet and clouds at the dawn and dusk parts.
DETROW: Wow. And then based on the way that it's tidally locked, does that mean that these are, like, semipermanent weather patterns?
BARBER: Yeah. So I talked to Sagnick 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...
SAGNICK MUKHERJEE: There's this huge temperature difference. What it does is it sets off really fast winds.
DETROW: One other thing I want to know, one of my questions I've always had about WASP-94 A b...
BARBER: Right, right.
DETROW: ...You know, going back...
BARBER: Since you've learned about it, yeah.
DETROW: Yeah, yeah. What are the clouds made of?
BARBER: Scott, I'm so glad you asked that. So the clouds are not made of water, like on Earth.
DETROW: OK.
BARBER: Here's Maria Steinrueck 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...
MARIA STEINRUECK: These planets are so hot that gemstones are clouds.
BARBER: Yeah, so the clouds are made of dust and bits of rock, and this...
DETROW: Amazing.
BARBER: ...Is possible 'cause it's just so hot.
DETROW: 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?
RIDDLE: Yeah. It's more space weather, Scott.
DETROW: Yes. Let's do it.
BARBER: Yep. Very true, Katia. 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 as Atlanta. I don't know if you all remember this.
DETROW: And this is - it's fair to say the bigger the solar storm is, the further south we see the aurora borealis, right?
BARBER: 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.
DETROW: Wow.
BARBER: Yeah.
RIDDLE: But nothing like that has happened this year or last.
BARBER: No, no, no, thankfully. All of the solar storms NOAA 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 NOAA's website and check out predictions on when and where you're going to see northern lights.
DETROW: That is Regina Barber of NPR's science podcast Short Wave and science correspondent Katia Riddle. Thanks to both of you.
BARBER: Thank you.
RIDDLE: Any time.
(SOUNDBITE OF FLUME SONG, "SPACE CADET (FT. GHOSTFACE KILLAH & AUTRE NE VEUT)") Transcript provided by NPR, Copyright NPR.
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