The Jupiter of Pioneers 10 and 11 was quite unlike the planet seen by Voyager 1. At the time of the Pioneer exploration, the Great Red Spot, embedded in a huge white zone, was more uniformly colored, and pale brown bands circled the northern hemisphere. In the intervening years, the south temperate latitudes have changed completely, developing the complex turbulent clouds seen around the Red Spot by Voyager 1. Yet, even between the two Voyagers, Jupiter appeared to be undergoing a dynamic “facelift.” At a quick glance, Voyager 2 photographs showed the visage that had been familiar since early in 1979, but a closer look showed that it is not quite the same. The white band below the Great Red Spot, fairly broad during the first flyby, had become a thin white ribbon where it rims the southern edge of the Spot. The turbulence to the west of the Red Spot had stretched out and become “blander” than it was before. Small rotating clouds seemed to be forming out of the waves in this region. The cloud structure that had been east of the Red Spot during the Voyager 1 flyby spread out, covering the northern boundary and preventing small clouds from circling the huge red oval. The Red Spot itself also changed. Its northern boundary seemed—at least visually—to be more set off from the clouds that surround it, and the feature appeared to be more uniform in color, perhaps reverting back to the personality it had in Pioneer days. [Illustration: Jupiter’s cloud patterns changed significantly in the few months between the two Voyager flybys. Most of the changes are the result of differential rotation, in which the prevailing winds at different latitudes shift long-lived features with respect to those north or south. Thus, for example, the three large white ovals shifted nearly 90 degrees in longitude, relative to the Great Red Spot, between March and July. [P-21599]] [Illustration: Cloud patterns from Voyager 2.]