Clouds of Jupiter Made of Hydrogen and Helium
The first thing you see when you look at the atmosphere of Jupiter is the bands of dark and light clouds as well as swirls, waves and oval spots. The patterns are mezmerizing! So what causes this complex mixture of colors and shapes?
Let’s start with the composition of the atmosphere itself. Jupiter’s atmosphere is made of mostly hydrogen and helium in a mixture that closely resembles that of the sun. Gasses such as oxygen and nitrogen are present along with compounds including methane, ammonia, hydrogen sulfide and water.
The clouds visible on the surface of the atmosphere (the part that we can see) are made up of ammonia and are arranged in a dozen or so zonal bands. These bands seem to alternate between light and dark and have distinct boundries. They run parallel to the equator. The difference in colors is thought to be caused by the composition of the ammonia itself. The lighter bands or zones as they are called, have a higher concentration of ammonia ice and are opaque at high altitudes. The darker bands or belts are thinner and lie a a lower altitude. Why there is so much difference in color is not entirely known.
The cool thing about the Jovian atmosphere is that it is a very active, violent place. The belts and zones are bounded by atmospheric jets. The wind sheer between these areas causes the beautiful swirls or vortices that dance across the surface. There are also enormous storms in the atmosphere. The best known example of a Jovian storm is the Great Red Spot. The Great Red Spot is an old storm. It has lasted for at least 180 years and possibly as long as 345 years! It is large enough to contain three planets the size of Earth. Did you know that there is also a “Little Red Spot” called Oval BA that was first seen in 2000 after the collision of three smaller white storms. Who knows, maybe Oval BA will become the next Great Red Spot…in another hundred years or so!