What Are Jupiter's Spots?

While watching two large red storms pass each other in 2008, a third storm made a surprise appearance, giving scientists even more to study in Hubble Space Telescope data.

Three red spots on Jupiter Jupiter’s Red spots (and many of the round white spots) are massive high pressure storms powered by warm air rising in their centers. The "Great Red Spot", observed by telescopes for over 150 years, is the largest anticyclone known in the solar system. It is an anticyclone because it rotates counter clockwise and is a high pressure system; the exact opposite of a southern hemisphere hurricane.

The second red spot formed as three white storms merged together between 1998 and 2000. The single remaining storm became strong enough to dredge up material from below that perhaps chemically reacts with sunlight to turn red. A third red spot showed up west of the Great Red Spot earlier in 2008.

Wind speeds in Red Spot Jr. are estimated to be around 400 mph and have been tracked as fast as 650 kilometers an hour. Scientists are able to calculate wind speeds by tracking small features observed in the storms over time.

As the storms passed by each other in 2008, the smallest storm passed south of the Great Red Spot, and around to the east. Part of it was pulled into the Great Red Spot, while some remnants of it continued on slowly to the east. These interactions with very small storms may also help power the Great Red Spot by feeding their energy into it.