Loading today’s stories
Science7 distinct publishers3 min readPublished Updated
Saturn's northern hexagon has looked the same for more than 40 years, so a second polygon that only shows up in images from 2023 onward hands atmospheric modellers a formation they can watch happen rather than a finished structure to explain.
The Scientist · Science desk
Compiled by The ScientistSomething wrong?How this is made
Calling the decagon new rests on a negative result, and a negative result is only as strong as the coverage behind it. Cassini's tour spanned 13 years [21], and its images showed no inkling of a long-lived formation at the south pole [8]. The OPAL program, meanwhile, has photographed the outer planets annually for more than a decade [3], so the empty stretch of the record is a sampled gap rather than an unwatched one. The weaker leg is the ground-based one: the south pole was only coming back into view from Earth as Saturn's seasons turned [9], and Hubble's edge over ground observers is precisely that it images full rotations at high spatial resolution without smearing by Earth's atmosphere [10].
Who noticed it first depends on which account you read. NASA, ESA and phys.org tell it as a ground-up find, with Agustin Sanchez-Lavega of the University of the Basque Country [7] and amateur observers Trevor Barry and Jean-Paul Oger picking out a subtle undulating band in images contributed to his university's Planetary Virtual Observatory Laboratory in 2024, and 2025 frames making the shape more convincing [6]. Discover magazine leads with the telescope, reporting that the first signs turned up in red-filtered Hubble frames in October 2023, with 2024 and 2025 observations clarifying them [5]. Both can be true of the same archive, and the sequence matters for how much the 2023 images prove, because a pattern recognised once you know its shape is weaker evidence than one found without a prior.
Mechanism is at the candidate stage. The team ran shallow-water simulations, a deliberately thin stand-in for Saturn's troposphere [15], and came out with two plausible drivers: a spatially periodic disturbance in a zonal jet stream, or a swirling vortex that may sit near a Red Spot slightly to the north [16]. The simulations show that a ten-lobed wave is dynamically available in a simplified model, without pinning down which disturbance actually grew this one. The wave's apparent position also shifts with observing wavelength, since each wavelength probes a different altitude [12], so any model-to-image comparison has to fix a height before it can claim agreement.
The census is the number to hold on to. Saturn's inventory of regular polar jet polygons goes from one to two with this paper [22], the first being the hexagon that Voyager photographed during its 1980 and 1981 flybys and that has persisted for over 40 years without substantial change [17], which leaves two examples on record, too small a sample to call a trend. Amy Simon's own framing is a question rather than a finding, which is why it suddenly formed now when nothing like it had been seen before [13]. Mike Wong's remark about OPAL is the operational lesson here, that its discoveries rest on years of repeat imaging rather than any single observation [18].
None of this transfers to terrestrial weather. Saturn can hold a geometric jet because it has no solid surface and a far more uniform composition, while Earth receives nearly 100 times more sunlight and has mountains standing in the flow [20].
Ranked by verification strength, evidence, and original report placement.
Hubble observations revealed a giant, evolving, 10-sided atmospheric wave encircling Saturn's south pole, the first time a large, regular-sided jet pattern has been observed in the planet's southern hemisphere.
The Hubble observations, dating back to 2023, were taken as part of the Outer Planet Atmospheres Legacy (OPAL) program, which has photographed the outer planets annually for more than a decade.
Amy Simon, OPAL principal investigator at NASA's Goddard Space Flight Center and a study co-author, said the northern hexagon has been there every time they looked for more than 40 years, while the new feature appears to be strengthening, giving a rare opportunity to watch a giant atmospheric pattern develop.
In October 2023, researchers saw the first signs of the decagon wave in red-filtered images taken by the Hubble Space Telescope; further observations in 2024 and 2025 gave a clear picture of the pattern.
It was in ground-based images contributed to the University of the Basque Country's Planetary Virtual Observatory Laboratory website, first in 2024, that Sanchez-Lavega and amateur astronomers Trevor Barry and Jean-Paul Oger noticed a subtle undulating band along the southern pole; additional 2025 ground-based imagery hinted more strongly at the decagon structure.
Agustin Sanchez-Lavega, lead author of the new study, is a researcher at the University of the Basque Country in Spain.
Follow any of these and your For You feed starts watching them — no settings page required.
product
Roman's 100x field is a pipeline bill, and August 30 is when it comes due1 distinct publisher
science
The Milky Way's Oldest Known Meal: 39 Globular Clusters Push Its Merger Record Back 1.8 Billion Years3 distinct publishers
product
NASA is flying Roman's coronagraph to learn what still breaks in orbit1 distinct publisher
science
A spiral galaxy at redshift 2 suggests Webb's little red dots are partly a resolution problem1 distinct publisher
Distinct publishers with included, body-backed reporting in this cluster.
discovermagazine.com
1 article · September 2, 2026
esa.int
1 article · September 2, 2026
nasa.gov
1 article · September 2, 2026
newscientist.com
1 article · September 2, 2026
phys.org
1 article · September 2, 2026
Evidence-backed comparisons of source perspectives and observed adoption signals. Read the methodology
Which Builder, Operator, and Investor concerns the observed source mix emphasized—not a truth score.
Evidence, demonstrated adoption, hype gap, incentives, and confidence are assessed independently, each on its own current evidence. How these are measured.
Two imaging streams, peer-reviewed, but blind before 2023
The finding rests on more than one team's assertion: amateur frames in a public archive flagged the band in 2024, a multi-year Hubble series resolved it, and the result carries a Science Advances DOI that Phys.org prints in full. What is missing is any view of Saturn's south pole before 2023 — Cassini departed in 2017 and the pole was tilted away from Earth from 2012 — so the archive cannot say when the wave began, only when it became visible.
One team, one instrument, follow-ups still queued
Independent eyes on this feature remain thin. The amateur network that spotted it and the OPAL team that confirmed it overlap in the same lead author; Webb has not looked yet and, as New Scientist notes, the time is contested; the nearest real test is the Hubble revisit Simon mentions for later in the month. Outside scientists — Kang at MIT, Ingersoll at Caltech — comment on significance in the reporting without having examined the data.
'Just formed' outruns the record
The overstatement is narrow but real and it sits in one word: recently. Simon's framing of a pattern that 'seems to have just formed', reproduced by NASA and ESA and echoed in headlines about baffled scientists, describes when the south pole became visible rather than when the wave appeared — a distinction only Science News makes explicitly. Everything else in the coverage is unusually restrained: the mechanism is openly unresolved, and the lead author volunteers that no single model fits.
A discovery that argues for its own programme
The two texts that most of this coverage descends from are issued by the agencies that operate the telescope, and they read that way: OPAL's annual cadence, Hubble's three decades of service, Wong's 'years and years of data', and NASA's closing roll-call of Goddard, Lockheed Martin and the Space Telescope Science Institute. None of that makes the decagon less real, but the framing of a rare chance to watch a giant pattern develop is also a case for keeping the observing series funded. The independently reported pieces carry no comparable stake.
Solid on what was seen, weak on when it started
Seven accounts agree on the observation, the geometry, the journal and the people, and the disagreements are about interpretation rather than fact. Confidence stops short of high because the single most quoted inference — that this thing is new — depends on a decade-long blind spot that only one outlet in our coverage names.
sciencenews.org
1 article · September 2, 2026
scientificamerican.com
1 article · September 2, 2026