On Saturn, a super storm rips through the planet every Saturnian year (about 30 Earth years). The latest storm began in 2010, and is one of the largest ever observed on Saturn, reaching almost 9,300 miles across the planet's surface. Now, new data collected by NASA's Cassini mission has made a discovery about this storm: it's stirring up water and ammonia ice from Saturn's depths.
Using infrared spectral measurements, Cassini analyzed the color signatures of the storm to make this finding. Clouds from the storm are made up of three substances: water ice, ammonia ice, and a third substance that scientists believe to be ammonium hydrosulfide. This would mark the first time that ice composed of water has ever been seen on Saturn. Lawrence Sromovsky, a senior scientist at UW-Madison and an expert on planetary atmospheres said:
“We think this huge thunderstorm is driving these cloud particles upward, sort of like a volcano bringing up material from the depths and making it visible from outside the atmosphere. The upper haze is so optically pretty thick that it is only in the stormy regions where the haze is penetrated by powerful updrafts that you can see evidence for the ammonia ice and the water ice. Those storm particles have an infrared color signature that is very different from the haze particles in the surrounding atmosphere.”
The storm has stirred up the atmosphere of Saturn, which is usually neatly organized into layers. The bottom layers — water, ammonium hydrosulfide and ammonia — are churned up by the storm, bringing those components above Saturn's troposphere. Think of it like yogurt: the fruit on the bottom layer would be the water and ammonia ice. Stir up the yogurt with a spoon (or in Saturn's case, a storm) and the fruit gets mixed up with the rest of the mixture, some of it ending up on top.
Thanks to this new data, scientists are getting a better idea of the chemical components that make up Saturn, as well as what lies underneath what we have previously observed.