SIOUX CENTER—Channon Visscher, associate professor of chemistry and planetary sciences at Dordt University, was selected to fulfill a NASA proposal through the Space Science Institute for a project titled, “Coupled Tropospheric-Stratospheric Seasonal Photochemical Model for Saturn.”
This project is funded by the NASA Solar Systems Workings Program. Visscher will work in partnership with Space Science Institute principal investigator Julianne Moses to explore changes in the chemistry of Saturn’s atmosphere caused by shifting seasons over its 30-year orbit.
“I think what is compelling about this type of research is that it gets at one of the fundamental driving questions in planetary science: ‘Why does the creation around me—in this case, Saturn—look the way it does?’” Visscher said.
Saturn experiences strong seasonal changes throughout its orbit, producing effects that can be seen in clouds and hazes and in the color of the atmosphere. Visscher and Moses will use computer models that simulate chemistry and physics in Saturn’s troposphere and stratosphere, exploring some of the underlying causes for the changes, specifically looking at sunlight-driven photochemistry. Visscher’s role will focus on processes in the troposphere, while Moses will focus on processes in Saturn’s stratosphere and how both regions interact.
“Through all these different chemical and dynamical interactions, it’s fascinating to see how the changing of seasons expresses itself on other worlds,” he said.
One year for Saturn is the equivalent to 29.5 years for Earth, which means summer and winter seasons last several years, causing long periods of complete darkness or constant sunlight near its polar regions. Additionally, the shadow-casting effects of Saturn’s rings have to be incorporated into simulations of the planet’s winter season. This project provides the opportunity to incorporate observations from various spacecraft missions over the past few decades, as photos from each mission capture the fluctuations that occur as Saturn’s seasons change.
This project received $349,000 in funding and will take place over a three-year period, ending in 2022. Visscher holds a joint appointment as a research scientist with the Space Science Institute.