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.