Which spacecraft discovered Saturn's F ring in 1979?

Pioneer 11 discovered Saturn’s F ring in 1979.

The spacecraft reached Saturn after launching in 1973 and made its close encounter on September 1, 1979. Its cameras revealed a narrow ring outside the A Ring, which became known as the F Ring. Pioneer 11 also discovered a previously unknown moon and gathered important measurements of Saturn’s magnetic environment and radiation belts.

The F Ring is exceptionally thin and active. It lies outside the A Ring and is shaped by the gravity of nearby moons, especially Prometheus and Pandora. Later observations showed its intricate knots, kinks, strands, and braided-looking structure in much greater detail.

A common mix-up is crediting Voyager, because Voyager 1 and Voyager 2 produced spectacular close-up images and helped explain the F Ring’s complicated appearance. They did not make the original discovery. Pioneer 11 was the first spacecraft to visit Saturn, while Voyager’s later flybys transformed the initial discovery into a detailed study of the ring system.