Overview

Ophelia is one of Uranus's inner satellites. Cataloged as S/1986 U 8 at discovery and also designated Uranus VII, it is a small, dark moon that orbits close to the planet. Like many inner moons it is irregular in shape and very faint when seen from Earth-based telescopes. Its modest size and low reflectivity mean detailed information about its surface and composition remains limited.

Discovery and name

Ophelia was identified in images taken by the Voyager 2 spacecraft on January 20, 1986. Subsequent observations with the Hubble Space Telescope confirmed and tracked the object again in 2003. The moon's name comes from literature: it honors Ophelia, daughter of Polonius in a play by William Shakespeare, specifically Hamlet.

Physical characteristics

Available measurements indicate a radius of roughly 23 km and a low geometric albedo near 0.08, making Ophelia dark compared with many icy satellites. Images from Voyager 2 show an elongated object whose long axis points approximately toward Uranus, a shape consistent with tidal deformation expected for small, tidally locked moons. Beyond these basic properties — size, brightness and apparent elongation — little is firmly known about its geology, composition or internal structure.

Orbit and role in Uranus's rings

Ophelia orbits within the inner satellite system of Uranus and is associated with the planet's ring system. It is regarded as an outer shepherd for the bright ε (epsilon) ring, helping to confine ring particles through gravitational interactions. As with other close satellites, Ophelia is believed to be tidally locked so the same face always points toward Uranus.

Observations and open questions

After its discovery by Voyager 2, Ophelia was difficult to detect from Earth until the improved imaging of Hubble in the early 21st century. The moon's small size and low reflectivity make follow-up observations challenging, so many aspects remain uncertain: surface composition, detailed shape, rotational dynamics, and whether it bears impact craters or regolith layers. Future missions or improved ground-based and space telescopes could reveal more.

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