Discovery of the thin rings of Uranus

Discovery of the thin rings of Uranus

. Astronomers recording the light of a star that was expected to disappear behind Uranus, on 10 March 1977, unexpectedly recorded short dips in the starlight before the star passed behind the planet (top). The same pattern was repeated when the star reappeared (bottom), indicating that Uranus is surrounded by narrow rings that briefly block out the light at the same distance on opposite sides of the planet. The strong and abrupt absorption of starlight indicates that the narrow rings are quite opaque and have well-defined edges. (Courtesy of James L. Elliot.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University