Salty Clouds aren’t the only strange thing about this object in space

Summary

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Podcast Summary: Short Wave (NPR)

Episode: Salty Clouds Aren’t the Only Strange Thing About This Object in Space

Date: June 26, 2026
Hosts: Regina Barber & Angela Zhang
Guest: Juana Summers (All Things Considered)

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Overview

In this biweekly science news roundup, Regina Barber and Angela Zhang, joined by Juana Summers, delve into three captivating scientific mysteries:

• An unusual object in space with clouds made of salt
• The possible discovery of a sex-specific burial among ancient human relatives
• How laughter in great apes reveals clues to the evolution of human communication

The trio balances scientific depth and creative humor, making complex research accessible and engaging.

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Segment 1: Salty Clouds on a Strange Space Object

Timestamps: [03:16]–[05:14]

Key Discussion Points

• The object in question, GJ504b, is about 25 times more massive than Jupiter. Its classification is debated: is it a planet, or a "failed star"?
• The distinction depends on whether the object is massive enough to ignite fusion—GJ504b is not, making it unusually dim and hard to study from Earth ([03:23]).
• The James Webb Space Telescope enabled astronomers to analyze light from the object and determine the composition of its atmosphere for the first time ([03:57]).
• Unlike Earth or Jupiter, GJ504b’s clouds are composed of salt (“salt clouds”), discovered through spectral analysis ([04:51]).

Scientific Context & Insights

• Planet or Star? “Stars need a lot of mass to ignite fusion and turn on. And without enough mass, the star doesn’t turn on. Basically it failed.” — Regina Barber ([03:43])
• Temperature Context: At 550°F (288°C) it's "hot to us, but that's pretty cool for other worlds like this." — Angela Zhang ([04:18])
• Cloud types in different worlds:
  • Some exoplanets have gemstone clouds due to extreme temperatures
  • Jupiter’s clouds are ammonia ice and water vapor ([04:33])

Notable Quotes

• “The study, modeling and this temperature all pointed towards, get this, salt clouds.” — Angela Zhang ([04:51])
• “There’s still a lot of questions astronomers...have.” — Regina Barber ([04:59])
• “So uncovering as much as possible can help astronomers make better models for how planets and stars are born.” — Regina Barber ([05:08])

Memorable Moment

• The trio jokes about their own preferred types of clouds, ranging from marshmallows to coffee and cotton candy, before revealing that GJ504b’s are much stranger ([00:32]–[01:20]).

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Segment 2: Sex-Specific Burial Among Ancient Human Relatives

Timestamps: [05:14]–[07:30]

Key Discussion Points

• In South Africa’s Rising Star cave system (2013), over 1,000 Homo naledi fossils were discovered; surprisingly, most skeletons appeared the same size, a rarity for primate species ([05:20]).
• Homo naledi: upright-walking, humanlike hands and feet, but small brains ([05:41]).
• Using dental analysis on 20 individuals, researchers found only females, suggesting a sex-specific burial ([05:52]–[06:15]).
• The odds of this being random are about one in a million.
• Such a practice, if confirmed, could reshape our understanding of burial rituals, which are typically associated with Homo sapiens ([06:30]).

Scientific Insights

• “The chances are about one in a million that all 20 would be female. So the team thinks this could have been an intentional sex-specific burial practice.” — Angela Zhang ([06:15])
• Burial behavior is extremely rare outside of humans, though observed in elephants and even naked mole rats.

Field Perspectives

• Charles Museiba (Duke University), not part of the study:

  “Could this be intentional sort of disposal of the bodies? The answer probably is yes. I like to see a little bit more evidence, but it sort of strongly suggests that way. And the biggest question is, where are the males?” ([07:01])

Memorable Moment

• Juana Summers humorously echoes the central mystery: “Where are the males? Indeed. Hopefully we’ll have you on later for an answer to this next mystery.” ([07:15])

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Segment 3: Great Apes’ Laughter and the Evolution of Human Communication

Timestamps: [07:30]–[10:04]

Key Discussion Points

• New research explores how laughter tempo in great apes sheds light on the evolution of human vocal communication ([07:30]).
• Laughter tempo in orangutans, gorillas, chimpanzees, bonobos, and human children was analyzed ([07:54]).
• All great apes and humans laugh at a steady, metronome-like rhythm, but only human children can modulate their laughter ([09:11]).
• As ape societies become more complex, laughter becomes more varied and flexible—a clue to evolving social structures ([08:17]).

Notable Quotes & Insights

• Chiara de Gregorio (Univ. of Warwick), study lead:

  • “Many non-human primates love being tickled, especially when they are like babies.” ([07:54])
  • “We go from orangutans that are solitary animals, and then you have gorillas, which have more of a family kind of group. Then you have chimpanzees and bonobo, which start to have a really complex social life… Then laughter becomes more variable, more flexible.” ([08:17])

• “And laughing like this requires a lot of vocal control, which is also how you learn to speak, which of course, also sets us apart from the great apes.” — Angela Zhang ([09:40])

Memorable Exchange

• On laughter’s flexibility:
  • “We can have a polite, small laugh in front of a, I don’t know, an important person, but then maybe you’re at the pub with friends and we laugh in a totally different way.” — Chiara de Gregorio ([09:29])
• Hosts model both polite and genuine laughter, then close with a “dad joke”:
  • “What is a monkey's favorite month?” ([09:50])
  • “April.” ([09:59])
  • “How's that for a polite, small laugh, y'?” — Juana Summers ([10:00])

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Conclusion & Credits

Timestamps: [10:11]–[10:41]

• Juana Summers playfully demands “more jokes and marshmallows.”
• The hosts encourage listeners to follow Short Wave for more science stories.

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Highlights & Takeaways

• GJ504b challenges planetary definitions and expands our concept of atmospheric weather—salt clouds are possible!
• The Homo naledi cave find may indicate the oldest known intentional, sex-specific burial practice, blurring the lines between human and non-human rituals.
• Great apes’ laughter showcases the roots of human social vocalization—the more social the animal, the more nuanced and flexible its laughter.
• Science communication can (and should) be fun and accessible, as evidenced by this lively, humor-filled conversation.

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Recommended for:
Science buffs, armchair anthropologists, evolution enthusiasts, and anyone who enjoys clever, digestible explorations of big questions in astronomy, anthropology, and biology—all delivered with wit and warmth.

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Transcript

[Announcer]

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[Regina Barber]

You're listening to Short Wave from NPR. Hey, Short Wavers. Regina Barber here and Angela Zhang with our bi weekly science news roundup featuring Juana Summers of All Things Considered. You're super fun. I'm glad you're back.

[Juana Summers]

Glad to be back with y'.

[Sponsor Announcer]

All.

[Regina Barber]

Okay, so this week we've got a few mysteries unraveling. First up, an object in space that might be a planet or might be a failed star and what new observations about its clouds can reveal about it. Juana? Yes, Angela? If you could have a cloud made of anything, what would it be?

[Juana Summers]

I mean, I feel like my brain automatically goes to marshmallows, which I feel like might be a cop out. But I'm also really hungry, so that might have something to do with this.

[Regina Barber]

Marshmallows will not quench that hunger though.

[Juana Summers]

But they taste really good.

[Regina Barber]

Yeah, that's true.

[Angela Zhang]

Oh, man. I had something a little bit more, you wouldn't want to be in it, but I'm kind of tired this morning and I was like, some coffee sounds great in a cloud. You know, coffee, cloudy clouds.

[Regina Barber]

That sounds awesome actually. And it like raining down and just open your mouth.

[Angela Zhang]

Exactly. And then you're caffeinated.

[Juana Summers]

Only if it's iced coffee that otherwise might be a little painful.

[Regina Barber]

It'll be a cold storm. It's fine. A cold front. I personally think instantly like cotton candy. Cotton candy is the first thing. But these clouds are none of those things.

[Angela Zhang]

Yeah. Stay tuned. Our second and third topics are a lot closer to home. The exciting possibility of a sex specific burial site of ancient human relatives. And what great apes laughter can tell us about the evolution for human communication.

[Regina Barber]

I don't have a fun question for this though.

[Juana Summers]

And yet I'm still intrigued.

[Angela Zhang]

We'll laugh a lot. That's all I can say.

[Regina Barber]

So today on the show we've got mysteries across space and time. You're listening to Shortwave, the science podcast from NPR Foreign.

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[Angela Zhang]

All right, Gina and Juana, we've got a lot to get into.

[Juana Summers]

I would love it if we could start in space. Tell me about the weather on another planet yet.

[Regina Barber]

This might not even be a planet that we're talking about here. There is a debate over this object, GJ504B. It's roughly 25 times larger than Jupiter and astronomers are uncertain how to define it. Is it a planet like Jupiter or is it a failed star?

[Juana Summers]

What do you mean by that? Like, they look the same to us from a telescope, but they're actually different things.

[Regina Barber]

Yeah, huge Jupiter like planets and a failed star, they do look super similar, but how they get there is different. So stars need a lot of mass to ignite fusion and turn on. And without enough mass, the star doesn't turn on. Basically, it failed.

[Angela Zhang]

And whichever one this object is, we know that it's really dim and couldn't be fully studied from ground telescopes until a study out this month in the astronomical journal about GJ 504b. Astronomers were finally able to analyze the light using the James Webb Space Telescope, and they got some information on what chemicals are in its atmosphere.

[Juana Summers]

So what can scientists say about it?

[Angela Zhang]

They could say something about the kind of clouds that were in the atmosphere. So this maybe, maybe not planet. It's about 550 degrees Fahrenheit. That's probably how hot your oven gets at home. And that might seem hot to us, but that's actually pretty cool for other worlds like this.

[Regina Barber]

Yeah. And that temperature affects what kind of weather it has. Like there are exoplanets that are so hot, the clouds are made up of gemstones. Yeah. And our Jupiter is so cold that the clouds are ammonia ice. And beneath that, water vapor.

[Juana Summers]

So what are these clouds made of? And how does knowing that help our understanding of space?

[Angela Zhang]

So the study modeling and this temperature all pointed towards get this, salt clouds. And there actually aren't a lot of objects in space like this one.

[Regina Barber]

Yeah. There's still a lot of questions astronomers like the lead author Anish Babaraj have.

[Juana Summers]

Like, we still don't know how big planets can get.

[Regina Barber]

So uncovering as much as possible can help astronomers make better models for how planets and stars are born.

[Juana Summers]

All right, up next, we've got a story about ancient human relatives. What did scientists find out that's so interesting?

[Regina Barber]

So, in 2013, archaeologists discovered more than 1,000 human like, fossils, so, like bones and teeth in the Rising Star cave system in South Africa. And one big thing jumped out. All the reconstructed skeletons looked oddly the same size, which surprised scientists because in most primate species, there's a clear difference in size between the sexes.

[Angela Zhang]

And this species called Homo naledi, they lived a few hundred thousand years ago. They walked upright and they had human like hands and feet, but their brains were much smaller than those of ancient humans.

[Regina Barber]

Yeah. And if you look them up, they look very Planet of the Apes, like, okay, okay. Anyway, a study out this week in the journal Cell may have solved the size mystery. An international team of researchers analyzed the teeth of 20 Homo naledi individuals spanning thousands of years to determine the sex.

[Angela Zhang]

All of the Homo naledi individuals that

[Chiara de Gregorio]

we looked at came back missing a male maca.

[Angela Zhang]

That's lead author and molecular scientist Palesa Madupe. She says the chances are about one in a million that all 20 would be female. So the team thinks this could have been an intentional sex specific burial practice.

[Juana Summers]

Oh, interesting. So how big of a deal would that be?

[Regina Barber]

If it's true, it could be a big deal because Homo naledi isn't in our direct lineage and burial practices are largely ascribed to humans, although other animals do it, like elephants and naked mole rats.

[Juana Summers]

Huh, Interesting. So how are other others in the field reacting to these findings?

[Angela Zhang]

They're pretty excited. Researchers have been puzzling over this for more than a decade. Actually, we talked to Charles Museiba. He's an evolutionary anthropologist at Duke University who wasn't a part of this study, though even with his excitement, he was also a little cautious.

[Announcer]

Could this be intentional sort of disposal of the bodies? The answer probably is yes. I like to see a little bit more evidence, but it sort of strongly suggests that way. And the biggest question is, where are the males?

[Juana Summers]

Where are the males? Indeed. Hopefully we'll have you on later for an answer to this next mystery. So let's move on here. For our last story, let's stay with these distant Relatives. There's new research that could tell us more about how humans evolved to communicate. And you said it's from studying primates?

[Regina Barber]

Yeah. So how humans evolved to communicate is not totally clear. I mean, we don't have recordings of our hominid ancestors, you know, talking, but we can study some distant relatives, the great apes. There are orangutans, gorillas, chimpanzees and bonobos. And so how they communicate and vocalize could give us clues about our own evolution.

[Angela Zhang]

And what do we have in common? We play and we laugh.

[Chiara de Gregorio]

Many non human primates love being tickled, especially when they are like babies.

[Angela Zhang]

That's primatologist Chiara de Gregorio from the University of Warwick. Her team measured the tempo of laughter in great apes and human children, and they just published their results in Communications Biology. They found that great apes like us laugh in a steady rhythm, almost like a metronome. And they found that the laughter actually changed over time.

[Chiara de Gregorio]

We go from orangutans that are solitary animals, and then you have gorillas, which have more a family kind of group. Then you have chimpanzees and bonobo, which start to have a really complex social live, Going towards more complex society. Then a laughter becomes more valuable, more flexible.

[Juana Summers]

It's so cool hearing all of those together. I mean, you can really hear how the chimpanzees and bonobos, the last two that we heard, do sort of sound like human laughter.

[Regina Barber]

Yeah, they basically made us laugh. Right. And we're actually more closely related to bonobos and chimpanzees, out of all the great apes. And our laughter is the most similar to theirs, like you said. So this study shows us that as a species becomes more social, maybe laughter gradually evolves.

[Juana Summers]

And what can that tell us about humans?

[Angela Zhang]

Well, as you heard, the great apes have a pretty cute laugh. They do, but it's also pretty regular, like that metronome. And they can't really change it, as you also heard, but humans can. The human children in the study were the only ones who could actually modulate or change how they laughed.

[Regina Barber]

And that laughter conveys really important information.

[Chiara de Gregorio]

We can have a polite, small laugh in front of a, I don't know, an important person, but then maybe you're at the pub with friends and we laugh in a totally different way.

[Angela Zhang]

You can totally imagine those scenarios, right? Oh, yeah, for sure, totally. And laughing like this requires a lot of vocal control, which is also how you learn to speak, which of course, also sets us apart from the great apes.

[Regina Barber]

So, Juana, with all this laughing in mind, we have a joke for you. What is a monkey's favorite month?

[Juana Summers]

Oh, gosh, I don't know.

[Angela Zhang]

April.

[Juana Summers]

Get it? How's that for a polite, small laugh, y'?

[Announcer]

All?

[Regina Barber]

You're like, yeah, that was rough. I liked it, though.

[Juana Summers]

Dad, jokes abound.

[Regina Barber]

Please come back anytime.

[Juana Summers]

Only if you bring me more jokes and marshmallows.

[Angela Zhang]

You got it. You can hear more of Juana Summers on consider this NPR's afternoon podcast about what the news means for you.

[Regina Barber]

And for more sign stories just like this one, follow Short Wave on whatever app you're listening to.

[Angela Zhang]

This episode was Produced by Burleigh McCoy and Jordan Marie Smith. It was edited by Rebecca Ramirez and Mallory Yu.

[Regina Barber]

Josephine Nyonai and Jimmy Keeley were the audio engineers. I'm Regina Barber.

[Angela Zhang]

And I'm Angela Zhang. Thanks for listening to Shortwave, the science podcast from npr.

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