 A major finding of the flyby , announced on March 6 , 2003 , was of Jupiter 's atmospheric circulation . Dark belts alternate with light zones in the atmosphere , and the zones , with their pale clouds , had previously been considered by scientists to be areas of <unk> air , partly because on Earth clouds tend to be formed by rising air . Analysis of Cassini imagery showed that the dark belts contain individual storm cells of <unk> bright @-@ white clouds , too small to see from Earth . Anthony Del <unk> of NASA 's Goddard Institute for Space Studies said that " the belts must be the areas of net @-@ rising atmospheric motion on Jupiter , [ so ] the net motion in the zones has to be sinking " . 
