This photo of Jupiter's Great Red Spot was taken by Voyager 1 in early March 1979. Distance from top to bottom of the picture is 15,000 miles (24,000 kilometers). Smallest features visible are about 20 miles (30 kilometers) across. The white feature below the Great Red Spot is one of several white ovals that were observed to form about 40 years ago; they move around Jupiter at a different velocity from the Red Spot. During the Voyager 1 encounter period, material was observed to revolve around the center of the spot with a period of six days. The Voyager project is managed for NASA's Office of Space Science by the Jet Propulsion Laboratory.