... Uranus's Moon Oberon: Impact World . ... Uranus's Moon Umbriel: A Mysterious Dark World . ... This dark moon reflects only half the light of other Uranus' moons such as Ariel. ... Tonight's full moon would normally washout the spectacle of Comet Hyakutake's lovely tail, even for those far from light polluted skies. ... As the Sun floods Comet Hyakutake with ultraviolet light gases in the coma scatter the radiation and fluoresce making the comet a bright source in the ultraviolet sky. ...