AFTER a 14-year search the Hubble Space Telescope has found two tiny moons
orbiting Uranus only previously seen by a planetary probe. The find supports a
theory that the moons—one inside Uranus’s main ring and one
outside—act as “shepherds”, keeping the ring from dispersing.
The Voyager 2 spacecraft discovered the moons, named Cordelia and Ophelia, as
it whizzed passed the planet in January 1986. But researchers could not get a
precise fix on their orbits. Even though astronomers immediately began training
their telescopes on Uranus, light from the main ring blotted out the moons.
However, Philip Nicholson of…
