The timing offset experienced by Voyager 1 as a result of Jupiter’s intense radiation environment was not expected to be a problem on Voyager 2 for two reasons: Even at closest approach, Voyager 2 would still be more than twice as far from Jupiter as Voyager 1 had been, and the Voyager 2 computer was programmed to resynchronize the spacecraft’s timing systems automatically every hour. In this way, even if the radiation environment proved to be much higher than anticipated, the image smear that might occur from a timing offset would be prevented. [Illustration: Complex activity in the southern hemisphere of Jupiter continued during the Voyager 2 encounter, although changes had occurred in the region of the Great Red Spot. A white oval, different from the one observed in a similar position at the time of the Voyager 1 encounter, was situated south of the Red Spot. The region of white clouds extended from east of the Red Spot and around its northern boundary, preventing small cloud vortices from circling the feature. The disturbed region west of the Red Spot had also changed since the equivalent Voyager 1 image. The picture was taken on July 3 from a distance of 6 million kilometers. [P-21742C]] As a result of the discoveries made by Voyager 1, the project scientists decided to modify some of Voyager 2’s preplanned sequences. As early as April 1, the painstaking job of constructing new computer commands began. A ten-hour Io Volcano Watch was added to the spacecraft’s program, taking advantage of the fact that shortly after closest approach to Jupiter, the spacecraft would remain within about 1 million kilometers of Io for a long period, keeping nearly the same face in view. Provisions were also made to take extensive ultraviolet measurements of the emission from the glowing torus surrounding Jupiter near the orbit of Io. Further studies would be made of the dark side of Jupiter to search for lightning and auroral activity, and there was also the hope that the plasma wave instrument would be able to detect lightning whistlers (radio signals created by lightning bolts) as the Voyager 1 instrument had done. A high priority was given to observations of the newly discovered ring, which had not been in the original Voyager 2 sequence at all. The spacecraft would cross the ring plane twice, photographing the ring during both the inbound and the outbound passages.