Jupiter’s rings were first discovered in 1979 by NASA’s Voyager 1 spacecraft. The discovery was unexpected because Jupiter’s rings are extremely faint and difficult to see from Earth, unlike Saturn’s bright, prominent ring system.
Voyager 1 photographed the rings during its Jupiter encounter in early 1979. Scientists found a narrow main ring, a halo-like inner ring, and a pair of much fainter outer rings. Later observations showed that the system is made mostly of dark dust, likely supplied when tiny meteoroids strike Jupiter’s small inner moons.
The year can be confused with other major Jupiter discoveries. Voyager 1 also revealed volcanic activity on Io in 1979, while NASA’s Galileo spacecraft entered Jupiter orbit in 1995. The rings were not discovered in 1980, although Voyager 1 reached Saturn that year and made important observations of Saturn’s much more conspicuous rings. Jupiter’s ring system remains far less visible than Saturn’s, even though both planets have rings.