Uranus Moons (27)

Uranus has currently 27 known moons.

1. Ariel	2. Umbriel	3. Titania	4. Oberon	5. Miranda	6. Cordelia
7. Ophelia	8. Bianca	9. Cressida	10. Desdemona	11. Juliet	12. Portia
13. Rosalind	14. Belinda	15. Puck	16. Caliban	17. Sycorax	18. Prospero
19. Setebos	20. Stephano	21. Trinculo	22. Francisco	23. Margaret	24. Ferdinand
25. Perdita	26. Mab	27. Cupid

Name	Ariel
Discovery date	1851 (W. Lassell)
Semi-major axis	190 900 km
Diameter	1158 km
Orbital period (Length of a year)	2.520 Earth days

Ariel taken by Voyager 2 on January 24, 1986. Photo: NASA

Name	Umbriel
Discovery date	1851 (W. Lassell)
Semi-major axis	266 000 km
Diameter	1169 km
Orbital period (Length of a year)	4.14 Earth days

Umbriel taken by Voyager 2 on January 24, 1986. Photo: NASA

Name	Titania
Discovery date	1787 (W. Herschel)
Semi-major axis	436 300 km
Diameter	1578 km
Orbital period (Length of a year)	8.70 Earth days

Titania taken by Voyager 2 on January 24, 1986. Photo: NASA

Name	Oberon
Discovery date	1787 (W. Herschel)
Semi-major axis	583 500 km
Diameter	1523 km
Orbital period (Length of a year)	13.46 Earth days

Oberon taken by Voyager 2 on January 24, 1986. Photo: NASA

Name	Miranda
Discovery date	1948 (G. Kuiper)
Semi-major axis	129 900 km
Diameter	472 km
Orbital period (Length of a year)	1.41 Earth days

Miranda taken by Voyager 2 on January 24, 1986. Photo: NASA

Name	Cordelia
Discovery date	1986 (R. Terrile, Voyager 2)
Semi-major axis	49 800 km
Diameter	40 km
Orbital period (Length of a year)	0.335 Earth days

Voyager 2 discovered two Uranus moons – Cordelia (1986U7) and Ophelia (1986U8) – associated with the rings of Uranus. This picture was taken on January 21, 1986. Photo: NASA/JPL

Name	Ophelia
Discovery date	1986 (R. Terrile, Voyager 2)
Semi-major axis	53 800 km
Diameter	42 km
Orbital period (Length of a year)	0.376 Earth days

Name	Bianca
Discovery date	1986 (Voyager 2)
Semi-major axis	59 200 km
Diameter	51 km
Orbital period (Length of a year)	0.435 Earth days

During his first look at Uranus, the near-infrared camera and the Hubble Space Telescope’s multi-object spectrometer (NICMOS) also captured 8 moons on July 28, 1997. This pictures were taken at a time interval of 90 minutes. NASA/JPL/ STScI

Name	Cressida
Discovery date	1986 (Voyager 2)
Semi-major axis	61 800 km
Diameter	80 km
Orbital period (Length of a year)	0.464 Earth days

Name	Desdemona
Discovery date	1986 (S. Synnott, Voyager 2)
Semi-major axis	62 700 km
Diameter	64 km
Orbital period (Length of a year)	0.474 Earth days

Name	Juliet
Discovery date	1986 (S. Synnott, Voyager 2)
Semi-major axis	64 400 km
Diameter	94 km
Orbital period (Length of a year)	0.493 Earth days

Name	Portia
Discovery date	1986 (S. Synnott, Voyager 2)
Semi-major axis	66 100 km
Diameter	135 km
Orbital period (Length of a year)	0.513 Earth days

Name	Rosalind
Discovery date	1986 (S. Synnott, Voyager 2)
Semi-major axis	69 900 km
Diameter	72 km
Orbital period (Length of a year)	0.558 Earth days

Name	Belinda
Discovery date	1986 (S. Synnott, Voyager 2)
Semi-major axis	75 255 km
Diameter	81 km
Orbital period (Length of a year)	0.624 Earth days

Name	Puck
Discovery date	1986 (S. Synnott, Voyager 2)
Semi-major axis	86 000 km
Diameter	162 km
Orbital period (Length of a year)	0.762 Earth days

Puck taken by Voyager 2 on January 24, 1986. Photo: NASA

Name	Caliban
Discovery date	1997 (B. J. Gladman, P. D. Nicholson, J. A. Burns, J. J. Kavelaars)
Semi-major axis	7 164 900 km
Diameter	72 km
Orbital period (Length of a year)	579.39 Earth days

Caliban (circled) was discovered with a ground-based telescope in 1997. Photo: Palomar Observatory

Name	Sycorax
Discovery date	1997 (B. J. Gladman, P. D. Nicholson, J. A. Burns, J. J. Kavelaars)
Semi-major axis	12 175 560 km
Diameter	150 km
Orbital period (Length of a year)	1283.48 Earth days

Name	Prospero
Discovery date	1999 (M. Holman, J. J. Kavelaars, B. Gladman, J.-M. Petit, H. Scholl)
Semi-major axis	16 256 000 km
Diameter	50 km
Orbital period (Length of a year)	1962.95 Earth days

Name	Setebos
Discovery date	1999 (B. J. Gladman, P. D. Nicholson, J. A. Burns, J. J. Kavelaars)
Semi-major axis	17 420 000 km
Diameter	47 km
Orbital period (Length of a year)	2196.35 Earth days

Name	Stephano
Discovery date	1999 (B. J. Gladman, M. Holman, J. J. Kavelaars, J.-M. Petit, H. Scholl)
Semi-major axis	7 952 320 km
Diameter	32 km
Orbital period (Length of a year)	677.48 Earth days

Name	Trinculo
Discovery date	2001 (M. Holman, J. J. Kavelaars, D. Milisavljevic)
Semi-major axis	8 501 260 km
Diameter	18 km
Orbital period (Length of a year)	748.83 Earth days

Name	Francisco
Discovery date	2001 (M. Holman et al., B. Gladman et al.)
Semi-major axis	4 276 000 km
Diameter	22 km
Orbital period (Length of a year)	267.12 Earth days

Name	Margaret
Discovery date	2003 (S. S. Sheppard)
Semi-major axis	14 345 000 km
Diameter	20 km
Orbital period (Length of a year)	1694.8 Earth days

Name	Ferdinand
Discovery date	2001 (M. Holman et al., B. Gladman et al.)
Semi-major axis	14 345 000 km
Diameter	21 km
Orbital period (Length of a year)	2805.50 Earth days

Name	Perdita
Discovery date	1999 (E. Karkoschka, Voyager 2)
Semi-major axis	76 420 km
Diameter	30 km
Orbital period (Length of a year)	0.638 Earth days

Perdita (S/1986 U10) was discovered in 1999, but could not be found in subsequent searches. The Hubble Space Telescope found it again in 2003, making it a confirmed moon. Photo: NASA /STScI

Name	Mab
Discovery date	2003 (M. R. Showalter, J. J. Lissauer)
Semi-major axis	97 736 km
Diameter	16 km
Orbital period (Length of a year)	0.923 Earth days

Diagram of the Uranus system with the two moons Mab and Cupid discovered on August 25, 2003. Graphics: NASA, ESA and A. Feild (STScI)

Name	Cupid
Discovery date	2003 (M. R. Showalter, J. J. Lissauer)
Semi-major axis	74 390 km
Diameter	18 km
Orbital period (Length of a year)	0.618 Earth days