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Joni Mitchell looked at clouds from both sides.

But what song might be written about a 10-sided storm? As reported by NASA, observations with the Hubble Space Telescope have revealed a giant atmospheric decagon.

a ten-sided wave encircling Saturn's south pole.

The feature remarkably appears similar to Saturn's famous hexagon at its northern pole, but also distinctly different, suggesting scientists may be witnessing a new atmospheric phenomenon develop on the gas giant planet with the famous rings.

By piecing together many Hubble observations going back to 2023, researchers found subtle hints of the structure beginning to emerge before it became a clearly defined pattern.

The observations were taken as part of Hubble's Outer Planet Atmospheres Legacy Program, which has photographed the outer planets annually for more than a decade.

The discovery was possible because Saturn's changing seasons gradually brought the planet's south pole back into view from Earth, where astronomers who collectively analyze images of Saturn from ground-based observations first identified it.

The hints of the pattern were first detected by the Planetary Virtual Observatory Laboratory, a website managed by the University of the Basque Country in Spain.

Observers all around the world contribute to that website, They're ground-based images of planets in our solar system.

In 2024, scientists and amateur astronomers noticed a subtle undulating band along Saturn's southern pole, and more observations were made as it developed.

Images from NASA's Cassini spacecraft, which orbited Saturn between 2004 and 2017, showed no hint of this pattern, but the Hubble telescope's later observations clearly confirmed the presence of this new pattern.

The wave sits within one of Saturn's powerful jet streams and extends through multiple layers of the atmosphere, indicating it is not just a cloud-level feature, but a vertically extended atmospheric structure.

The decagon's apparent position shifts slightly when viewed at different wavelengths.

Those different wavelengths probe at different altitudes in Saturn's atmosphere.

The results were published last week in the journal Science Advances.