The date of each photograph and the distance of the spacecraft from the planet or satellite are included with each picture. [Illustration: 2/5/79 28.4 million km (17.6 million mi) Jupiter is the largest planet in our solar system, with a diameter 11 times that of Earth. Jupiter rotates very quickly, making one full rotation in just under ten hours. Composed primarily of hydrogen and helium, Jupiter’s colorfully banded atmosphere displays complex patterns highlighted by the Great Red Spot, a large, circulating atmospheric disturbance. Three of Jupiter’s 13 known satellites are also visible in this Voyager 1 photograph. The innermost large satellite, Io, can be seen in front of Jupiter and is distinguished by its bright, orange surface. To the right of Jupiter is Europa, also very bright but with fainter surface markings. Callisto is barely visible beneath Jupiter. These satellites orbit Jupiter in the equatorial plane and appear in their present position because Voyager is above the plane.] [Illustration: Jupiter’s atmosphere is undergoing constant change, presenting an ever-shifting face to observers. The Great Red Spot has undergone three major periods of activity in the last 15 years. These images of Jupiter, taken by Voyager 1 (top) and Voyager 2 (bottom) almost four months apart, show that cloud movement in the Jovian atmosphere is not uniform because wind speeds vary at different latitudes. For example, the white ovals which appear below the Great Red Spot dramatically shifted between January and May, the time interval between these two pictures. The bright “tongue” extending upward from the Great Red Spot interacted with a thin, bright cloud above it that had traveled twice around Jupiter in four months. Eddy patterns to the left of the Great Red Spot, which have been observed since 1975, appear to be breaking up.] [Illustration: 1/24/79 40 million km (25 million mi)] [Illustration: 5/9/79 46.3 million km (28.7 million mi)] [Illustration: 2/25/79 9.2 million km (5.7 million mi) The Great Red Spot on Jupiter is a tremendous atmospheric storm, twice the size of Earth, that has been observed for centuries. The Great Red Spot rotates counterclockwise with one revolution every six days. Wind currents on the top flow east to west, and currents on the bottom flow west to east. This Voyager 1 picture shows the complex flow and turbulent patterns that result from the Great Red Spot’s interactions with these flows. The large white oval is a similar, but smaller, storm center that has existed for about 40 years.] [Illustration: 7/3/79 6 million km (3.72 million mi)