Hubble tracks new decagon encircling Saturn’s south pole

What happened

Decagon on Saturn’s south pole (colour image) By piecing together several years of Hubble observations dating back to 2023, researchers found subtle hints of the structure beginning to emerge before it became a clearly defined pattern. Recent observations with the NASA/ESA Hubble Space Telescope have revealed a giant, evolving 10-sided atmospheric wave encircling Saturn’s south pole.

This discovery marks the first time a large regular-sided jet pattern has been observed in the planet’s southern hemisphere. Those observations were taken as part of Hubble’s OPAL ( Outer Planet Atmospheres Legacy ) programme, which has photographed the outer planets annually for more than a decade.

Decagon on Saturn’s south pole (single filter image) Agustín Sánchez-Lavega, lead author of the new study, is a researcher at the University of the Basque Country in Spain. It was in those images, first in 2024, that Agustín and amateur astronomers Trevor Barry and Jean-Paul Oger noticed a subtle undulating band along the southern pole.

Key facts

• Decagon on Saturn’s south pole (colour image) By piecing together several years of Hubble observations dating back to 2023, researchers — found: subtle hints of the structure beginning to emerge before it became a clearly defined pattern