The moons of Uranus possess a unique naming convention, drawing almost exclusively from English literature rather than the standard pantheon of Greek and Roman mythology. This distinction sets Uranus apart from every other major planet in the Solar System. The vast majority of its 27 known satellites are named after characters from the plays of William Shakespeare, with a small exception drawn from the work of Alexander Pope. This literary theme was established early and has been maintained by astronomers for over 170 years.
The Rationale Behind Literary Naming
The convention began with the discoveries of the first two moons by William Herschel in 1787, though he referred to them only numerically. It was his son, the prominent astronomer Sir John Herschel, who officially established the tradition in 1852 when four moons were known. Sir John Herschel chose names that represented “magical spirits in English literature” rather than following the common practice of selecting mythological figures. He was likely influenced by the fact that Uranus, named after the Greek god of the sky, did not neatly fit into the Roman-deity naming tradition of the other planets.
Sir John Herschel’s initial selections included characters from both Shakespeare and his contemporary, Alexander Pope. This choice broadened the naming pool beyond mythology to include a distinct literary source. When William Lassell later discovered two more moons, he sought Sir John Herschel’s advice on nomenclature, solidifying the idea to use English literary spirits. This decision ensured that all subsequent moons of Uranus would continue to be named after characters from the works of these two celebrated writers.
Uranus’s Major Shakespearean Satellites
The five largest moons of Uranus—Titania, Oberon, Umbriel, Ariel, and Miranda—form the core of the system and are the most recognizable satellites. Titania and Oberon, the largest and second-largest, were named after the King and Queen of the Fairies in Shakespeare’s comedy, A Midsummer Night’s Dream. Their names, assigned by John Herschel, evoke a sense of magical authority appropriate for the largest bodies orbiting the planet. Titania has a diameter of 1,578 kilometers, making it the eighth-largest moon in the Solar System.
Ariel and Umbriel were the next two moons to be named, discovered by William Lassell in 1851. Ariel is a character from Shakespeare’s The Tempest, referring to an airy spirit serving the magician Prospero. Ariel’s name is also found in Alexander Pope’s poem, The Rape of the Lock, where it describes a sylph. Umbriel is named exclusively after a melancholy, dark gnome character from Pope’s poem, representing a deviation from the purely Shakespearean theme.
The fifth major moon, Miranda, was discovered much later in 1948 by Gerard Kuiper. Kuiper continued the tradition by naming it after the heroine from The Tempest. Miranda is known for its highly unusual, fractured surface, which hints at a complex geological past.
Expanding the List: The Smaller Moons
The tradition of literary naming was upheld as more moons were discovered. The moon Puck, the first satellite discovered by Voyager 2 in 1986, is named after the mischievous sprite from A Midsummer Night’s Dream. The smaller, inner moons are named after characters almost exclusively from Shakespeare’s comedies and tragedies.
The inner system features a collection of moons named after female characters from various plays:
- Juliet
- Cressida
- Portia
- Rosalind
- Desdemona
- Bianca
These names, originating from plays such as Romeo and Juliet and The Merchant of Venice, maintain the theme of literary figures from Shakespeare’s work. The discovery of these smaller bodies confirmed the commitment of the International Astronomical Union to the established naming rule.
The literary scope was broadened with the inclusion of Belinda, another name drawn from Alexander Pope’s mock-epic poem, The Rape of the Lock. Belinda, along with Umbriel and one interpretation of Ariel, accounts for the few non-Shakespearean names in the Uranian system. This blend of names from Shakespeare and Pope creates a unique celestial reference to two giants of English literature.