P-21741 BW Range: 2.6 million kilometers (1.6 million miles) This picture of Io, taken by Voyager 1, shows the region of the Jovian moon which will be monitored for volcanic eruptions by Voyager 2 during the 'Io movie' sequence. The white and orange patches probably are deposits of sulphur compounds and other volcanic materials. The Voyager 2 pictures of this region will be much more detailed. ARC-1979-A79-7076

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."