Range : 4.2 million km. ( 2.6 million miles ) Jupiter's moon Europa, the size of earth's moon, is apparently covered by water ice, as indicated by ground spectrometers and its brightness. In this view, global scale dark sreaks discovered by Voyager 1 that criss-cross the the satelite are becoming visible. Bright rayed impact craters, which are abundant on Ganymede and Callisto, would be easily visible at this range, suggesting that Europa's surface is young and that the streaks are reflections of currently active internal dynamic processes. ARC-1979-A79-7103

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."