10 March
1977: On 10 March 1977, the rings of Uranus were discovered from Earth.
This was done with stellar occultation experiments made when Uranus occulted (passed in front of) a star and it was noticed that there were dips in the brightness of the star before and after it passed behind the body of Uranus.
These data suggest that Uranus was surrounded by at least five rings. Four more rings were suggested by subsequent occultation measurements from Earth, and two additional ones were found by Voyager 2, bringing the total to 11.
Direct observations of the rings from Earth had not been possible, because the rings are lost in the planet's glare as seen through terrestrial optical telescopes. Most of the rings are not quite circular, and most are not exactly in the plane of the planet's equator.
