File:Saturn hubble.jpg

Hubble found a number of small atmospheric storms. These are transient features that appear to come and go with each yearly Hubble observation. The banding in the northern hemisphere remains pronounced from Hubble???s 2019 observations, with several bands slightly changing color from year to year. The ringed planet???s atmosphere is mostly hydrogen and helium with traces of ammonia, methane, water vapor, and hydrocarbons that give it a yellowish-brown color.

Hubble photographed a slight reddish haze over the northern hemisphere in this color composite. This may be due to heating from increased sunlight, which could either change the atmospheric circulation, or perhaps remove ices from aerosols in the atmosphere. Another theory is that the increased sunlight in the summer months is changing the amounts of photochemical haze produced. ???It???s amazing that even over a few years, we???re seeing seasonal changes on Saturn,??? said lead investigator Amy Simon of NASA???s Goddard Space Flight Center in Greenbelt, Maryland. Conversely, the just now visible south pole has a blue hue, reflecting changes in Saturn???s winter hemisphere.

Hubble???s sharp view resolves the finely etched concentric ring structure. The rings are mostly made of pieces of ice, with sizes ranging from tiny grains to giant boulders. Just how and when the rings formed remains one of our solar system???s biggest mysteries. Conventional wisdom is that they are as old as the planet, over 4 billion years. But because the rings are so bright ??? like freshly fallen snow ??? a competing theory is that they may have formed during the age of the dinosaurs. However, many astronomers agree that there is no satisfactory theory that explains how rings could have formed within just the past few hundred million years.

This image is taken as part of the Outer Planets Atmospheres Legacy (OPAL) project. OPAL is helping scientists understand the atmospheric dynamics and evolution of our solar system???s gas giant planets. In Saturn???s case, astronomers continue tracking shifting weather patterns and storms.