The two Voyager spacecraft made a number of important discoveries about Jupiter and its satellites. The most surprising was the existence of sulfur volcanoes on Io, which had not been observed from the ground or by Pioneer 10 or 11.
The spacecraft went on to visit Saturn. Voyager 1's Saturn flyby occurred in November 1980, with the closest approach on November 12. The craft detected complex structures in Saturn's rings, and studied the atmospheres of Saturn and Titan. Its orbit, designed to allow close study of Titan, took it out of the plane of the ecliptic, thus ending its planetary science mission. As it heads for interstellar space, its instruments continue to study the solar system; Jet Propulsion Laboratory scientists are using the plasma wave experiments aboard Voyager 1 and 2 to look for the heliopause.
As of March 2002, Voyager 1 was at a distance of 12.4 billion kilometers (84 Astronomical) from the Sun. Voyager 1 is escaping the solar system at a speed of about 3.6 AU per year.
See also: Voyager program for more information about the spacecraft