Oberon is Uranus' fifteenth known moon. It is also the outermost large moon and is the second largest after Titania. Oberon's orbit is about 362,520 miles from Uranus and has a diameter of 946 miles. The name Oberon comes from the King of the Fairies and husband of Titania in Shakespeare's Midsummer-Night's Dream. Titania was discovered in 1787 by Herschel. Titania has a mass of 3.49e21 kilograms.