Utah Skies: Saturn Seasons

Sep 8, 2021

Saturn sits against the backdrop of a dark sky.
Credit Dell Vance

As the sky darkens tonight, you can easily see Jupiter to the East. Looking a little further to the Southeast the next bright object is Saturn. Saturn is one of my favorite objects to observe. The rings make it spectacular to see. Saturn orbits the sun every 29 years. Saturn is the second largest planet in our solar system and is about one-third less massive than Jupiter. It is about 850 million miles away from earth. Saturn has 82 identified moons, which means that it has more identified moons than any other planet in our solar system. The largest moon is Titan. Titan is larger than the planet Mercury.


Saturn has a 27˚ tilt that allows it to have seasons. Each season is a little more than seven years. The lowest levels of Saturn are composed of water clouds, ammonium hydrosulfide, and frozen ammonia. The upper levels contain hydrogen, helium, small amounts of methane, and photochemical smog. The smog contributes to the color and formations that are visible in the belts and zones. Every 29 years the season is such that there appears to be a bluish tint to the southern hemisphere that is angled away from the sun. This lasts for the season and can be seen through very large telescopes. Under the right conditions it can be seen through telescopes that are ten inches and larger. The last time the southern hemisphere exhibited this bluish tint was in 1992 to 1997. We are right on the beginning of this season and may be able to observe this tint for the next few years. In 2004, the Cassini spacecraft imaged Saturn, and there is a bluish haze over the northern hemisphere. There is an article in the September 2021 issue of the Sky and Telescope Magazine about this phenomenon, by Tom Dobbins. It may be available in your local library.

I imaged Saturn through my eleven inch Schmidt Cassegrain Telescope on August 25, 2021.  There was some smoke in the air that night. I was not able to see a blue tint, but I will try again when we have clearer skies here in Utah.