There’s a cool new planet in town.

If Tuesday’s cute little newest cat ever discovered wasn’t geekily gorgeous enough for you, how about the youngest planet we’ve ever seen. Just look at its chubby cheeks! Who’s. beautiful bubba?

(First published on my Substack where you can get #NerdNews, marvellous maths and general geekery.)

(Elias 2-24 b artist’s impression: W. M. Keck Observatory / Adam Makarenko)

I don’t know which is cooler: discovering a new species of cat or discovering a new planet? Tuesday we got rightly excited about the Leopardus Tilcayo, but let’s be honest, something about the discovery of a new planet is particularly awesome.

And that’s certainly the case with Elias 2-24 b. A planet that’s not just new, it’s so new and so massive that it challenges our understanding of how planets themselves are formed.

What’s in a name?

The planet’s name is Elias 2-24 b.

J.H. Elias was an awesome astronomer who, in the 1970s, catalogued a series of “infrared sources” in a part of the night sky known as the Ophiuchus star-forming region — a nursery for the growth of young stars.

The region contains thick swathes of dust that block visible light and are much easier to see using infrared. Infrared also lets us see the young stars hiding in all that dust.

Elias 2-24 was one of those stars. The lowercase b denotes that Elias 2-24 b is the first planet detected around that star.

What a pleasant surprise.

For a long time, we’ve known that Elias 2-24 is surrounded by a disc of gas and dust. We’d even known there appeared to be a gap in that disc.

When this gap was first spotted, a lot of astronomers crossed their fingers and hoped it was a planet. But there were other possible suspects. It could, for example, have been caused by “snow lines”, where gases freeze onto dust grains and create ring-like gaps.

So it became a waiting game.

The first really encouraging sign was a faint point of light sitting right there in the gap. But other suspects still had to be ruled out. And they were, once data from the Keck Observatory was factored in.

(Actual Keck infrared observation of Elias 2-24 b. The central star is hidden behind a coronagraph to block its glare, allowing the much fainter planet to be detected.)

Put simply, this dot looked like a planet, smelt like a planet, moved like a planet.

“The planets should be found within the gaps, since they are carving them. And that’s exactly where we found Elias 2-24 b.” — Andrea Bernardi, lead author.

Welcome to the family, Elias 2-24 b.

What a big, beautiful baby.

The thing that’s got astronomers truly excited about Elias 2-24 b is its mass.

It’s massive.

We’re talking Jupiter-like massive, which is crazy for a system that’s less than a million years old. Models say a Jupiter-sized planet at roughly Jupiter’s distance from the Sun should take around five million years to form.

Elias 2-24 b is less than a million years old and orbits about 55 times farther from its star than Earth is from the Sun — roughly 10 times farther out than Jupiter.

Let me stress: this is the YOUNGEST PLANET of any type we’ve ever discovered.

Young planets, by the nature of how they form, are often still shrouded in a hard-to-see-through dusty disc — a stellar nursery. That’s the case with Elias 2-24 b, still cocooned in the gas and dust it was born from.

Which is why NASA describes catching it as being right at the limits of what current telescopes can do.

“Elias 2-24 b shows us that even our best planet-formation models are still missing some important processes.” — Lucas Cieza, study co-author.

So where to from here?

Scientists will keep tracking Elias 2-24 b’s orbit, watch how it interacts with the disc and see whether our models of planet formation need serious revision.

Doubtless, in years to come and with stronger telescopes, we’ll spot even younger planets.

“This is just the beginning of a new era of discovery.” — Lucas Cieza, study co-author.

But astronomy could well look back on the discovery of Elias 2-24 b as a turning point in our understanding of planet formation.

Further reading:

Andrea Bernardi et al. — Searching for Embedded Protoplanets with the Keck/NIRC2 Vortex Coronagraph: Confirmation of a Core-accretion Planet in the Narrow Gap of the Elias 2-24 Disk. The Astrophysical Journal Letters, 1009(1): L3, 2026. DOI: 10.3847/2041-8213/ae9bb6.

Ashley Balzer — Newfound ‘Baby’ Planet Smashes Record for Youngest Known World. NASA Science, 16 September 2026. NASA Science article