The Uranian system contains several smaller, irregular moons that we know very little about. These satellites are extremely small, and many were not discovered until the Voyager 2 encounter with Uranus or by astronomers using the Hubble space telescope. Because of their small size, it is possible that some of these moons may be captured asteroids or comets. These recent discoveries bring the total number of Uranian moons to 27. Below is a listing of some of the largest of these moons in the order of their distance from Uranus. Images that appear on this page are the best available at this time. You may access information on one of the moons directly by clicking on its name below.
Cordelia | Ophelia | Bianca | Cressida | Desdemona | Juliet | Portia | Rosalind | Belinda | Puck | Caliban | Sycorax
Cordelia
Cordelia [kor-DEEL-ee-uh] is the innermost of Uranus' moons. With a diameter of only 9 miles (15 km), it is one of the smallest moons in the Solar System. It was named after the daughter of Lear in Shakespeare's King Lear. Cordelia was discovered by Voyager 2 in 1986. Not much is known about Cordelia except that it appears to be the inner shepherd satellite for the epsilon ring of Uranus. It is also one of two moons that orbit inside the synchronous orbit radius of Uranus.
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Voyager 2 Image of Cordelia
(NASA / JPL) |
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Statistics for Cordelia |
Discovered by
Year of Discovery
Approximate Diameter
Mean Distance from Uranus
Rotational Period
Orbital Period
Orbital Eccentricity
Orbital Inclination
Apparent Magnitude |
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Voyager 2
1986
16.1 miles (26 km)
30,905 miles (49,750 km)
unknown
0.335 days
0
0.14 degrees
24.1 |
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Ophelia
Ophelia [oh-FEEL-ee-uh] is the second of Uranus' moons. It was named after the daughter of Polonius in Shakespeare's play, Hamlet. Ophelia was discovered by Voyager 2 in 1986. Not much is known about this moon except that it appears to be the shepherd satellite of Uranus' epsilon ring. It is the second of two moons that orbit inside the synchronous orbit radius of Uranus.
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Voyager 2 Image of Ophelia
(NASA/JPL/Space Science Institute) |
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Statistics for Ophelia |
Discovered by
Year of Discovery
Approximate Diameter
Mean Distance from Uranus
Rotational Period
Orbital Period
Orbital Eccentricity
Orbital Inclination
Apparent Magnitude |
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Voyager 2
1986
19.8 miles (32 km)
33,396 miles (57,760 km)
unknown
0.376 days
0.001
0.09 degrees
23.8 |
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Bianca
Bianca [bee-ANG-kuh] is the third of Uranus' moons. It was named after the sister of Katherine in Shakespeare's play, The Taming of the Shrew. Bianca was discovered in 1986 by the Voyager 2 spacecraft. Very little is known about Bianca.
Statistics for Bianca |
Discovered by
Year of Discovery
Approximate Diameter
Mean Distance from Uranus
Rotational Period
Orbital Period
Orbital Eccentricity
Orbital Inclination
Apparent Magnitude |
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Voyager 2
1986
27.3 miles (44 km)
36,750 miles (59,160 km)
unknown
0.435 days
0.001
0.16 degrees
23.0
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Cressida
Cressida [KRES-id-uh] is the fourth moon of Uranus. It was named after the daughter of Calchas in Shakespeare's play, Troilus and Cressida. Cressida was discovered by Voyager 2 in 1986. Not much is known about Cressida at this time.
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Voyager 2 Image of Cressida
(NASA/JPL/Space Science Institute) |
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Statistics for Cressida |
Discovered by
Year of Discovery
Approximate Diameter
Mean Distance from Uranus
Rotational Period
Orbital Period
Orbital Eccentricity
Orbital Inclination
Apparent Magnitude |
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Voyager 2
1986
40.9 miles (66 km)
38,372 miles (61,770 km)
unknown
0.464 days
0.0
1.04 degrees
22.2
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Desdemona
Desdemona [dez-de-MOH-nuh] is the fifth of Uranus' known moons. It was named after the wife of Othello in Shakespeare's play, Othello. This moon was discovered by the Voyager 2 spacecraft in 1986. Little else is known about Othello.
Statistics for Desdemona |
Discovered by
Year of Discovery
Approximate Diameter
Mean Distance from Uranus
Rotational Period
Orbital Period
Orbital Eccentricity
Orbital Inclination
Apparent Magnitude |
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Voyager 2
1986
36 miles (58 km)
38,925 miles (62,660 km)
unknown
0.474 days
0.0
0.16 degrees
22.5
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Juliet
Juliet [JOO-lee-et] is the sixth moon of Uranus. It was named after the famous and tragic heroine in Shakespeare's play, Romeo and Juliet. Juliet was discovered in 1986 by Voyager 2. Not much else is known about Juliet at this time.
Statistics for Juliet |
Discovered by
Year of Discovery
Approximate Diameter
Mean Distance from Uranus
Rotational Period
Orbital Period
Orbital Eccentricity
Orbital Inclination
Apparent Magnitude |
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Voyager 2
1986
52.2 miles (84 km)
39,981 miles (64,360 km)
unknown
0.493 days
0.001
0.06 degrees
21.5
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Portia
Portia [POR-shuh] is the seventh of Uranus' moons. It was named after a rich heiress in Shakespeare's play, Merchant of Venice. Portia was one of several new moons discovered by Voyager 2 in 1986. Very little is known about Portia.
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Voyager 2 Image of Portia
(NASA/JPL/Space Science Institute) |
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Statistics for Portia |
Discovered by
Year of Discovery
Approximate Diameter
Mean Distance from Uranus
Rotational Period
Orbital Period
Orbital Eccentricity
Orbital Inclination
Apparent Magnitude |
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Voyager 2
1986
68.3 miles (110 km)
41,062 miles (66,100 km)
unknown
0.513 days
0.0
0.09 degrees
21.0
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Rosalind
Rosalind [ROZ-uh-lind] is the eighth moon of Uranus. It was named after the daughter of the banished Duke in Shakespeare's play, As You Like It. Rosalind was discovered by the Voyager 2 spacecraft in 1986. Not much is known about Rosalind.
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Voyager 2 Image of Rosalind
(NASA/JPL/Space Science Institute) |
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Statistics for Rosalind |
Discovered by
Year of Discovery
Approximate Diameter
Mean Distance from Uranus
Rotational Period
Orbital Period
Orbital Eccentricity
Orbital Inclination
Apparent Magnitude |
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Voyager 2
1986
33.5 miles (54 km)
43,441 miles (69,930 km)
unknown
0.559 days
0.0
0.28 degrees
22.5
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Belinda
Belinda [bel-LIN-duh] is the ninth of Uranus' known moons. It was named after the heroine in Alexander Pope's The Rape of the Lock. Belinda was another of the moons discovered by Voyager 2 in 1986. We know very little about Belinda.
Statistics for Belinda |
Discovered by
Year of Discovery
Approximate Diameter
Mean Distance from Uranus
Rotational Period
Orbital Period
Orbital Eccentricity
Orbital Inclination
Apparent Magnitude |
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Voyager 2
1986
42.2 miles (68 km)
46,752 miles (75,260 km)
unknown
0.624 days
0.0
0.03 degrees
22.1
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Puck
Puck [PUK] is the tenth moon of Uranus. It was named after a mischievous fairy in Shakespeare's play, Midsummer Night's Dream. Puck was discovered in 1986 by the Voyager 2 spacecraft. It was the only new moon discovered early enough in the mission that the observation schedule could be changed in order to get pictures. With an albedo of less than 0.1, Puck is extremely dark. Little else is known about this small moon.
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Voyager 2 Image of Puck
(NASA/JPL/Space Science Institute) |
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Statistics for Puck |
Discovered by
Year of Discovery
Approximate Diameter
Mean Distance from Uranus
Rotational Period
Orbital Period
Orbital Eccentricity
Orbital Inclination
Apparent Magnitude |
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Stephen Synnott
1985
95.6 miles (154 km)
53,430 miles (86,010 km)
unknown
0.762 days
0.0
0.31 degrees
20.2
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Caliban
Caliban [KAL-i-ban] is the sixteenth of Uranus' known moons. It is the smaller of the two moons that have just recently been discovered. The official designation of this moon is Uranus XVI (S/1997 U 1). The name Caliban was chosen by the discoverers and will most likely be accepted by the International Astronomical Union (IAU). It was named after the savage and deformed slave of the magician Prospero in Shakespeare's The Tempest. Caliban was discovered in 1997 by Brett Gladman, Phil Nicholson, Joseph Burns, and JJ Kavelaars using the 200-inch Hale Telescope. It is one of the dimmest moons to have ever been discovered by a ground-based telescope. Very little is known about this moon, due to the recent nature of its discovery. What we do know is that it is about 38 miles (60 km) in diameter and orbits Uranus at a distance of about 4.4 million miles (7.2 million kilometers). Its orbit appears to be retrograde. Astronomers believe that Caliban is probably an asteroid that was captured by the gravity of Uranus. It is probably composed of a mixture of rock and ice. The picture below shows the original image from which Caliban was discovered.
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Discovery Image of Caliban
(Brett Gladman, Canadian Institute
for Theoretical Astrophysics) |
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Statistics for Caliban |
Discovered by
Year of Discovery
Approximate Diameter
Mean Distance from Uranus
Rotational Period
Orbital Period
Orbital Eccentricity
Orbital Inclination
Apparent Magnitude |
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...... |
Gladman, Nicholson, Burns,
& Kavelaars
1997
37.2 miles (60 km)
4,470,000 miles (7,200,000 km)
unknown
579.7 days
0.159
140.9 degrees
22.4
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Sycorax
Sycorax [SIK-or-aks] is the seventeenth and outermost of Uranus' known moons. It is the larger of the two moons that have just recently been discovered. The official designation of this moon is Uranus XVII (S/1997 U 2). The name Sycorax was chosen by the discoverers and will most likely be accepted by the International Astronomical Union (IAU). It was named after Caliban's mother, a witch in Shakespeare's The Tempest. In the story, she imprisoned the fairy Ariel for disobedience. Sycorax was discovered in 1997 by Brett Gladman, Phil Nicholson, Joseph Burns, and JJ Kavelaars using the 200-inch Hale Telescope. It is one of the dimmest moons to have ever been discovered by a ground-based telescope. Very little is known about this moon, due to the recent nature of its discovery. What we do know is that it is about 75 miles (120 km) in diameter and orbits Uranus at a distance of about 7.6 million miles (12.2 million kilometers). Its orbit appears to be retrograde. Astronomers believe that Sycorax is probably a captured asteroid. It is thought to be composed of a mixture of rock and ice. The picture below shows the original image from which Sycorax was discovered.
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Discovery Image of Sycorax
(Brett Gladman, Canadian Institute
for Theoretical Astrophysics) |
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Statistics for Caliban |
Discovered by
Year of Discovery
Approximate Diameter
Mean Distance from Uranus
Rotational Period
Orbital Period
Orbital Eccentricity
Orbital Inclination
Apparent Magnitude |
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Gladman, Nicholson, Burns,
& Kavelaars
1997
75 miles (120 km)
7,580,000 miles (12,200,000 km)
unknown
1288.3
0.522
159.4 degrees
20.8
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