Decagon on Saturn’s South Pole (Color)

Two views of Saturn from NASA’s Hubble Space Telescope reveal a giant, evolving 10-sided atmospheric wave encircling the planet’s south pole. The feature, called a decagon, is the first large, persistent, regular-sided pattern observed at Saturn’s southern hemisphere.

By comparing observations taken over several years, researchers found that the pattern has become increasingly distinct since 2023, suggesting they may be witnessing a new atmospheric phenomenon develop on the gas giant. The observations, captured by Hubble's Wide Field Camera 3 , were made as part of Hubble’s Outer Planet Atmosphere’s Legacy (OPAL) program, which has monitored the Jupiter, Saturn, Uranus, and Neptune for more than a decade.

The “X” and dashed circle in the image on the right represent where data was not captured by Hubble.

About the colours

These images were acquired by the WFC3/UVIS instrument on Hubble. The color results from assigning different hues (colors) to a monochromatic (grayscale) image. In this case, the assigned colors are: Blue: F395N, Green: F502N, Red: F631N

About the data

These images were created with Hubble data from proposal: 17843 (A. Simon).