All nine of the "pre-Voyager" rings are visible in this image taken on January 22, 1986. The gray background is visible because the rings are so dark that the light level on the camera had to be extremely sensitive.
Voyager 2 and the Hubble Space Telescope later confirmed the presence of 15 Uranian rings.
This view of Uranus and its rings was acquired by the Hubble Space Telescope in 2007.
The Discovery of Uranus' Rings
On March 10, 1977, astronomers on board the Kuiper Airborne Observatory, a modified C-141 jet transport, discovered the rings of Uranus. While scientists were waiting for Uranus to occult (pass in front of) the star SAO 158687, they observed that the star's light dimmed repeatedly as the dark rings of Uranus passed between the star and the observatory.