Small amounts of compounds such as methane, ammonia, hydrogen sulfide, and water have also been detected. It is the mixture of these chemical compounds and elements that have contributed to the colorful layers of clouds as seen from earthbound telescopes.
Clouds of ammonia, which are visible on the planet’s surface, form a collection of parallel bands. Dark bands called belts alternate with the light-colored ones, which are known as zones. It is the zones that are believed to be made of ammonia. It is not known what causes the the dark bands though.
You may have noticed dots and circles within these bands; the largest of which being the Great Red Spot. These circles are vortices and storms that continue to rage in the Jupiter’s highly unstable atmosphere. The vortices can be either cyclonic or anticyclonic. Cyclonic vortices typically have centers that have lower pressures than their surroundings. Anticyclonic ones, on the other hand, have centers with higher pressures than their surroundings.
The Great Red Spot is of the anticyclonic type and since we have been seeing it even in the earliest images of Jupiter, continues to persist through time. It is so huge that it can be observed even from earthbound telescopes. Scientists have yet to discover what causes its reddish color.
Another large red spot, which was first seen in 2000, is steadily increasing. Like the Great Red Spot (GRS), it is also reddish and anticyclonic. Because of its similarities with GRS, this red spot (which bears the official name Oval BA) is often called “Red Spot Jr”, “Red Jr”, or “The Little Red Spot”.
Unlike the vortices, which persist for longer durations, storms are more short-lived. Many of them can exist for months but, on the average, they can only last for about 4 days. The occurrence of storms in the atmosphere of jupiter have been observed to reach a climax every 15-17 years. That means, the storms are strongest at the end of these periods.
These storms are accompanied by lightnings, much like here on Earth. Interestingly, like here on Earth too, Jupiter also exhibits polar lightning, i.e., lightnings that strike at the poles. No other planet is known to have this characteristic.
We have some articles in Universe Today that are related to Jupiter’s atmosphere. Here are two of them:
Jupiter atmosphere articles brought to you by NASA, here are the links:
Tired eyes? Let your ears help you learn for a change. Here are some episodes from Astronomy Cast that just might suit your taste: