10 March 1977

Astronomers discover the rings of Uranus.

The rings of Uranus are a system of narrow, dark rings encircling the planet Uranus. They were first discovered in 1977 by astronomers James L. Elliot, Edward W. Dunham, and Douglas J. Mink using the Kuiper Airborne Observatory. At that time, the rings were observed as faint lines passing in front of a star as Uranus occulted it.

Astronomers have identified 13 distinct rings around Uranus, which are named in order of their discovery. The rings are primarily composed of dark particles, likely made up of water ice, dust, and rocky debris. These particles range in size from micrometers to a few meters across.

The rings of Uranus are much darker than those of Saturn, for example, which are predominantly made up of bright ice particles. This darkness is believed to be due to the presence of organic compounds, possibly formed from the bombardment of the rings by charged particles from the Sun and Uranus’s magnetosphere.

The rings of Uranus are thought to be relatively young compared to those of other gas giants like Saturn. They may have formed from the breakup of one or more small moons or from the collision of larger bodies in Uranus’s system. The exact mechanisms of their formation and evolution are still topics of ongoing research.

Observations from space probes like Voyager 2, which flew by Uranus in 1986, have provided valuable insights into the rings’ characteristics and structure. Future missions to Uranus, such as the proposed Uranus Orbiter and Probe mission, could further enhance our understanding of these enigmatic rings.