Evidence of giant rings in Venus’s atmosphere uncovered in archived observations

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Scientists discover evidence of giant rings in Venus's atmosphere
Venus as observed in total flux F (left) and polarized flux U (right) through the Hα continuum filter (see Table 1). Due to Venus’s orientation, the planetary scattering plane makes an angle of about 45° with ExPo’s optical plane (the two orthogonal directions along which ExPo measured U are indicated below the image). The spatial resolution is approximately 775 km at the subobserver point on Venus’s disk. Credit: The Planetary Science Journal (2026). DOI: 10.3847/psj/ae7e6f

In 2010, scientists waiting to use the William Herschel Telescope in the Canary Islands captured a brief 36 minutes of images of Venus. They were waiting for the sun to set so they could look at distant stars and dust disks around young stars. Consequently, little attention was paid to the data, which was filed away in the archives.

Hidden in the archives
Fast-forward more than a decade, and researchers from the Netherlands decided to look at the old observations. What they discovered, hidden in the data, was a series of faint, planetwide concentric rings in the upper atmosphere. Their findings are published in a paper in The Planetary Science Journal.

The team analyzed images captured with ExPo, a highly sensitive instrument designed to measure polarized light. They compared ordinary images with polarized images taken through several visible-light filters to search for patterns that might reveal hidden atmospheric features.

They discovered a faint ring pattern in three of the observations. The rings were completely invisible in the normal images, but they showed up when the researchers isolated the polarized light.

Simulating Venus’s atmosphere
But what were the rings doing, and why were they there? To get some answers, the research team ran several computer simulations that modeled how sunlight scatters through the gas layer above Venus’s clouds. These virtual models allowed the scientists to test how different atmospheric conditions alter light. The calculations showed that small changes in gas density of 5% to 10% would create ring patterns matching those seen in the data.
“Our simulations also show that such density variations would not show up in total flux observations,” wrote the study team in their paper.

Based on these results, the authors suggest that these density variations are massive atmospheric waves. Specifically, they could be giant, planetwide gravity waves, a type of wave that creates ripple-like patterns in gas layers, much like ripples on the surface of water.

A candidate detection
Although the rings are a direct observation, the atmospheric waves are inferred from the data, so the team stresses that their work is a candidate detection rather than confirmation of a new Venusian phenomenon. And since the ExPo instrument has been dismantled, the archived data remaains the only dataset available. As the researchers write: “We are therefore careful in claiming the detection of a new atmospheric phenomenon on Venus.” https://phys.org/news/2026-07-evidence-giant-venus-atmosphere-uncovered.html

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