Everyone is familiar with storms on Jupiter, particularly the Great Red Spot, which scientists believe is over 300 years old! Less is known about storms on Saturn. The planet has a region where storm intensity has been severe since the Cassini mission first began to photograph Saturn in early 2004.

Storm Alley on Saturn

Photo Credit: NASA/JPL/Space Science Institute
This picture taken May 19 of this year shows that region of intense storm activity on Saturn called “Storm Alley” by scientists.  The interesting part of the picture are the dark vortices. One can imagine winds running at hundreds of miles per hour, as the winds on Saturn’s are known to be among the swiftest in the solar system.  Voyager measured winds at 1,800 km/h or about 1,200 miles/hour during its flyby of the planet.

Saturn’s winds are banded much like Jupiter’s but are fainter and wider, especially near the equator.  Otherwise Saturn’s storms are a bit bland. The planet does have an interesting “Great White Spot”. In 1990, Hubble spotted an enormous white cloud near Saturn’s equator not present during the Voyager flybys. In 1994, another smaller storm was observed. The 1990 storm was an example of a Great White Spot. This is a unique but short-lived phenomenon which occurs once every Saturn year, or about every 30 Earth years. Great White Spots were observed in 1876, 1903, 1933, and 1960, with the 1933 storm being the most famous. If the patterns holds, another storm will occur in about 2020.