Close up of Saturn and its rings, photographed by Voyager 2, 1981.

Clear ring structure as well as a distinct gap between the rings can be seen in this photograph of Saturn taken by Voyager 2. The characteristic banded cloud formations in the gas giant planet's atmosphere are also clearly visible. The origin and formation of the rings, which are composed of ice and ice-coated dust and rock, are not precisely understood, but it seems that tidal effects caused by some of Saturn's moons play a role in maintaining their structure. The two Voyager spacecraft were launched by NASA in 1977 to explore the planets in the outer solar system. After first visiting Jupiter, Voyager 2 pased Saturn in August 1981, before continuing on to Uranus and Neptune.