These four pictures of Jupiter's Great Red Spot were taken Feb. 2 and 3, 1979, when Voyager 1 was about 31 million kilometers (19.4 million miles) from Jupiter. The pictures were taken one Jupiter rotation apart, and that together they depict four days in the life of the centuries-old Red Spot. The pictures clearly demonstrate changes in circulation around the Red Spot during the 40-hour period. The photos were taken through a blue filter. Jet Propulsion Laboratory manages the Voyager project for NASA's Office of Space Science. (JPL ref. No. P-21148) ARC-1979-AC79-7008

In 1977, Voyager 1 and 2 started their one-way journey to the end of the solar system and beyond, now traveling a million miles a day. Jimmy Carter was president when NASA launched two probes from Cape Canaveral. Voyager 1 and its twin, Voyager 2, were initially meant to explore Jupiter, Saturn, and their moons. They did that. But then they kept going at a rate of 35,000 miles per hour. Each craft bears an object that is a record, both dubbed the Golden Records. They were the product of Carl Sagan and his team who produced a record that would, if discovered by aliens, represent humanity and "communicate a story of our world to extraterrestrials."