densities comparable to a nice blob of shaving foam
In a constellation named for a flying fish, astronomers have found two Jupiter-sized worlds so insubstantial they rival the density of shaving foam — a discovery that quietly expands our sense of what a planet can be. Located 1,110 light-years away and detected through a decade of satellite data, these so-called super-puffs are the lightest planets of their size ever confirmed. Their existence invites us to reconsider the boundaries of planetary formation, reminding us that the universe routinely exceeds the limits of our imagination.
- Two giant planets have been confirmed with densities so low they defy intuition — Jupiter-sized in mass, yet lighter than cotton candy.
- Their improbability creates a genuine scientific tension: objects this large should collapse inward under gravity, not drift like cosmic foam.
- Researchers at Oxford, drawing on NASA's Tess satellite data and ground-based telescopes, worked to precisely measure orbits and calculate densities across more than a millennium of light-travel distance.
- Of nearly 6,300 confirmed exoplanets, fewer than 40 qualify as super-puffs, making each discovery a rare and meaningful addition to the catalog.
- NASA's James Webb Space Telescope is now positioned to follow up, with the goal of confirming the planets' chemical makeup and illuminating how such ethereal worlds come to exist.
Somewhere in the southern sky, in a constellation named for a flying fish, two planets orbit a distant star with a property so improbable it seems almost whimsical: they weigh less than cotton candy. Announced this week in Monthly Notices of the Royal Astronomical Society, the discovery was led by George Dransfield of the University of Oxford. The planets lie 1,110 light-years away, yet researchers used ground-based telescopes and a decade of data from NASA's Tess satellite to measure their orbits precisely enough to calculate their density — and the result was striking. These are the largest planets yet found to be lighter than cotton candy.
To grasp the strangeness, consider that Jupiter is roughly 35 times denser than either of these worlds. A planet of that size should be a compressed, roiling sphere of gas. Yet these two seem almost to float. Dransfield suspects they are likely white or blue in appearance, their bulk composed mostly of hydrogen and helium — the lightest elements in existence. Astronomers believe super-puffs form in the gas-rich disks surrounding young stars, then gradually shed their substance over time, growing ever more ethereal.
What makes the find especially notable is its rarity. Fewer than 40 of the nearly 6,300 confirmed exoplanets qualify as super-puffs. Each one offers a clue to the astonishing diversity of planetary systems beyond our own. Follow-up observations by NASA's James Webb Space Telescope are expected to confirm the planets' composition and deepen understanding of how such improbable worlds come to be — adding another piece, as Dransfield put it, to the puzzle of planet formation and our place in the cosmos.
Somewhere in the southern sky, in a constellation named for a flying fish, two planets orbit a distant star with a property so improbable it seems almost whimsical: they weigh less than cotton candy. Astronomers announced this week that they have identified a pair of these so-called super-puffs, worlds as massive as Jupiter but so insubstantial that their density rivals the foam you'd find in a freshly opened can of shaving cream.
The discovery, reported Wednesday in Monthly Notices of the Royal Astronomical Society, represents a significant find in the growing catalog of exotic planetary systems. George Dransfield, an astronomer at the University of Oxford, led the research team that characterized these two featherweight giants. They orbit a star 1,110 light-years away—a distance so vast that light itself takes more than a millennium to bridge the gap. Yet from Earth, using ground-based telescopes and data collected over the past decade by NASA's Tess satellite, researchers were able to measure the planets' orbits with enough precision to calculate their density. The result was striking: these are the largest planets yet discovered to be lighter than cotton candy.
To grasp the strangeness of this, consider Jupiter, the heavyweight champion of our own solar system. Jupiter is roughly 35 times denser than either of these two distant worlds. A Jupiter-sized object should be crushing under its own gravity, a sphere of roiling gases and compressed matter. Yet here are two planets of comparable size that seem almost to float, their bulk distributed so thinly that they would barely register on a scale.
Dransfield suspects the planets are probably white or blue, their appearance determined by whether clouds shroud their surfaces. Their composition is likely dominated by hydrogen and helium—the lightest elements in the periodic table—though confirmation will require follow-up observations from NASA's James Webb Space Telescope. The mechanism that produces such improbable worlds remains an active area of study. Astronomers believe super-puffs form in the swirling disk of gas and dust that surrounds young stars, in regions where gas vastly outweighs solid material. Over time, these planets shed much of their substance, becoming progressively more ethereal.
These discoveries are rare enough to merit attention. Of the nearly 6,300 confirmed exoplanets cataloged to date, fewer than 40 are classified as super-puffs. Each one offers a clue to the vast diversity of planetary systems that exist beyond our own. Dransfield emphasized that studying such exotic worlds helps astronomers understand the fundamental processes by which planets form and evolve. "By studying exotic systems containing rare planet types, we add further pieces to the puzzle of planet formation and learn more about our place in the cosmos," she wrote. The two planets orbiting in the constellation Volans represent another piece of that puzzle—a reminder that the universe contains wonders that defy easy intuition.
Citações Notáveis
These two planets have densities comparable to a nice blob of shaving foam, fresh from the can.— George Dransfield, University of Oxford
By studying exotic systems containing rare planet types, we add further pieces to the puzzle of planet formation and learn more about our place in the cosmos.— George Dransfield
A Conversa do Hearth Outra perspectiva sobre a história
When you say these planets are lighter than cotton candy, are you being literal or is that just a catchy comparison?
It's literal. Cotton candy has a density of roughly 0.05 grams per cubic centimeter. These planets have densities comparable to shaving foam fresh from the can—they're genuinely less dense than spun sugar.
How is that even possible? Doesn't gravity crush everything into something denser?
Gravity does pull inward, but it's balanced by the outward pressure of the gas itself. These planets are mostly hydrogen and helium, the lightest elements. The gas pressure from within holds the shape, even though the overall mass is enormous.
So they're mostly empty space?
In a sense, yes. Imagine a Jupiter-sized balloon made of the thinnest possible material. The volume is immense, but the stuff filling it weighs almost nothing.
Why are they so rare if they form naturally?
We don't fully understand that yet. They seem to form in young star systems where gas vastly outweighs dust, then shed material over time. But something about the process is uncommon—fewer than 40 are known out of 6,300 exoplanets.
What happens next with these two?
The Webb Space Telescope will observe them to confirm their chemical composition. That data will help astronomers refine their models of how planets form and why some end up so impossibly light.