Gemstone Clouds, a Bullied Moon, and a Storm That Lit Up Cuba: This Week in Space Got Weird
Picture a planet where the clouds aren't made of water vapor — they're made of gemstones and rock dust. That's not science fiction. That's one of three stories in this month's space roundup from Short Wave, "Spacing Out with Gina," hosted by Regina Barber (call her Gina) with science correspondent Katia Riddle and All Things Considered host Scott Detrow. Three stories, each stranger than the last: a Neptune moon whose big-brother neighbor shoved it into an oddball orbit, an exoplanet with weather made of literal gemstones, and the 1859 solar storm so bright that campers in the middle of the night thought the sun was coming up. Barber opens with a tease that Riddle will "have a secret handshake by the end of the day" — Riddle's ready, and the bit pays off later. Let's get into it.
Neptune Has 16 Moons, and One Got Bullied Into a Weird Orbit
Quick quiz: how many moons does Neptune have? Even the other two hosts didn't know — the answer is 16. That's a lot of moons crowded around one planet, and as Barber puts it, "when you have 16 moons, things are going to be very competitive." (Side note: Riddle jokes that she grew up learning Pluto was a full-fledged planet, before it got "kicked out of the major planet guild" — old news the hosts still haven't fully made peace with.)
One of Neptune's 16, called Nereid, has puzzled scientists for decades. Did it form right there in Neptune's orbit, or get captured from somewhere else? The clue that fueled the mystery was Nereid's orbit — stretched into a long, lopsided oval, while moons that form in place usually settle into neat, circular paths.
New research flips the question around. Instead of just staring at the orbit's shape, scientists took a close look at what Nereid is actually made of — and the composition points to a moon that formed right there around Neptune, not one that wandered in from elsewhere. So what bent its orbit into that weird oval? Blame another moon: Triton, roughly eight times bigger than Nereid, apparently shoved it there long ago. Riddle's verdict on Triton: "it's kind of a bully."
Matthew Belyakov of Caltech led the study, published in the journal Science Advances, and calls Nereid "a time capsule" — possibly the only intact survivor from Neptune's original set of moons. As he put it: "It's pretty important to understand how the early solar system transpired because that tells us something about our formation here on Earth."
None of this would have been possible without one particular piece of equipment: the James Webb Space Telescope. Riddle relays that for scientists in this field, work is split into two eras — "really like before the James Webb Space Telescope and after the telescope." Before JWST, researchers could only guess a moon's origin from its orbit shape. Now they can check its actual composition and get a real answer.
Same Telescope, New Trick: Clouds Made of Gemstones
That same telescope is the hero of story number two — except this time it's not pointed at a moon next door. It's pointed at a planet orbiting a completely different star.
The planet is called WASP-94 A b, and University of Chicago astronomer Eliza Kempton sums up why it matters: "We can see things like storms in Jupiter. But planets orbiting other stars, what's their weather like?"
WASP-94 A b is a "hot Jupiter" — roughly Jupiter-sized, but orbiting its star 18 times closer than Earth orbits the sun. Its star sits about 700 light-years away.
Quick decode: planets that orbit this close to their star often get tidally locked — their spin gets frozen in place by the star's gravity, the same way the moon always shows Earth the same face. That means WASP-94 A b has one side stuck in permanent daylight and one side permanently dark, with a fixed boundary between them instead of a normal day-night cycle.
Astrophysicists at Johns Hopkins University pointed the James Webb Space Telescope at this planet's atmosphere and found something backwards from what you'd expect: clouds pile up along the dawn-and-dusk boundary between day and night, but as you travel deeper into the permanently sunlit side, the clouds burn off completely, leaving clear skies. Lead author Sagnick Mukherjee explains what's driving it: "There's this huge temperature difference. What it does is it sets off really fast winds."
But the real jaw-dropper is what the clouds are made of. Maria Steinrueck, a University of Chicago astrophysicist who wasn't involved in the study, put it best: "These planets are so hot, the gemstones are clouds." These aren't water-vapor clouds like Earth's — they're dust and bits of rock, floating the way water vapor does here, because it's simply hot enough to vaporize rock into the sky.
The Storm That Made Cuba Glow
Last story, and it brings things back down to Earth: the Northern Lights.
The sun runs through activity cycles, and the past couple of years have brought strong auroras to a lot of US states. A big solar storm last fall reportedly let people see the Northern Lights as far south as Atlanta. The general rule holds: the stronger the solar storm, the farther south the aurora reaches.
But Barber's favorite space fact goes back to 1859, when the strongest solar storm on record pushed the Northern Lights all the way south to Cuba — and it was so bright that campers thought the sun was rising in the middle of the night. Nothing NOAA or NASA has tracked recently comes close to that scale. Right now, people living along the US-Canada border have the best odds of catching an aurora, and NOAA's website posts predictions on when and where to look.
The hosts trade their own aurora stories, too: Detrow says he's gotten his hopes up every time one was forecast, only to remember he lives in a city and it's never going to happen; Riddle says the same; Barber thinks she once saw a "foggy green" aurora but can't confirm it. Naturally, they joke about all flying to Alaska together and taking the show on the road.
Before signing off, Barber asks Riddle to rate the segment. Riddle doesn't hesitate: "Five out of five stars. I'm game to nerd out any time on space stuff, guys." And that secret handshake Barber promised at the top of the show? Delivered, right on schedule.
So, what's the actual story here?
On the surface, these are three unrelated stories — a moon's backstory, a planet's weather, an old solar storm. But look closer and they share a thread: the more clearly we can see, the stranger the universe turns out to be. The same telescope that nailed down a Neptune moon's origin also caught a planet growing clouds out of gemstones. And an 1859 storm bright enough to wake campers out of their tents is a reminder that even the sky right over our own heads still has surprises left. Next time you look up at the stars, remember: somewhere out there, a telescope might be turning a decades-old mystery into tonight's answer.