hter than Saturn. At oppositions when the rings are edge-on, as in 1980, the magnitude is as low as +0.08, though even at these times Saturn is still prominent.The equatorial zone appears creamy, sometimes almost white. The polar regions are almost always less brilliant. The belts, unlike those of Jupiter, do not show obvious colors. Well-defined spots on Saturn are rare. The most prominent example sighted during the present century was that discovered on August 3, 1933, by the English amateur W.T. Hay, using a six-inch refractor. The spot took the form of a large white oval patch in the equatorial zone, about one-fifth of the planet’s diameter in length, and with both ends well defined. During the next few weeks it lengthened rapidly, until by mid-September it had spread out so much that it could no longer be called a spot.Pioneer 11 was the first unmanned space probe to meet with Saturn in September 1979. It had already passed by Jupiter, which had been its main objective, but valuable information about Saturn was obtained. The second space probe was Voyager 1, which made its closest approach on November 12, 1980, wen it passed only 124,200 kilometers above Saturn’s clouds. Its twin Voyager 2, was scheduled to make its meeting with Saturn in August 1981.Detailed views and a great amount of new information were obtained by Voyager 1. Though Saturn’s disk is blander than that of Jupiter because of a greater amount of overlying “haze,” much detail was shown. A red spot was detected in the southern hemisphere, with brownish ovals in the northern hemisphere. Measurements of the locations of individual features at different times yielded data concerning the speed of the winds, and it seems that Saturn’s circulation is different from that of Jupiter. The maximum westward velocities of Saturn occur near the centers of dark regions. In the polar latitudes, the large-scale light and dark bands break down int...
