uranus' natural satellites

Uranus has 27 known moons. The first two moons (Titania and Oberon) were discovered by William Herschel on March 13, 1787. Two more moons (Ariel and Umbriel) were discovered by William Lassell in 1851. In 1852, Herschel's son John Herschel gave the four then-known moons their names. In 1948 Gerard Kuiper discovered the moon Miranda. The flyby of the Voyager 2 space probe in January 1986 led to the discovery of a further 10 moons, and another satellite S/1986 U 10 was later found after studying old Voyager photographs. Eleven additional moons have since been identified using telescopes. All moons of Uranus are named after characters from the works of Shakespeare and Alexander Pope.

The natural satellites

lign=bottom style="text-align:left; padding:0.5em;" \| Notes: * Awaiting confirmation and naming; ** Negative orbital periods indicate a retrograde orbit around Uranus (opposite to the planet's rotation).
colspan="3" style="background:#efefef;"\| Name (Pronunciation key)	style="background:#efefef;"\| Diameter (km)	style="background:#efefef;"\| Mass (kg)	style="background:#efefef;"\| Mean orbital radius (km)	style="background:#efefef;"\| Orbital period	style="background:#efefef;"\| Discovery date
Uranus VI	Cordelia	kor-dee'-lee-a	40	4.5 × 10¹⁶ ?	49,770	0.335034 days	1986
Uranus VII	Ophelia	oh-fee'-lee-a	42	5.4 × 10¹⁶ ?	53,790	0.376400 days	1986
Uranus VIII	Bianca	bee-ahng'-ka	51	9.3 × 10¹⁶ ?	59,170	0.434579 days	1986
Uranus IX	Cressida	kres'-i-da	80	3.43 × 10¹⁷ ?	61,780	0.463570 days	1986
Uranus X	Desdemona	dez'-di-moh'-na	64	1.78 × 10¹⁷ ?	62,680	0.473650 days	1986
Uranus XI	Juliet	jew'-lee-et'	93	5.57 × 10¹⁷ ?	64,350	0.493065 days	1986
Uranus XII	Portia	por'-sha	135	1.68 × 10¹⁸ ?	66,090	0.513196 days	1986
Uranus XIII	Rosalind	roz'-a-lind	72	2.54 × 10¹⁷ ?	69,940	0.558460 days	1986
colspan="3" \| S/2003 U 2^*	10	Unknown	74,800	0.618 days	2003
Uranus XIV	Belinda	be-lin'-da	80	3.57 × 10¹⁷ ?	75,260	0.623527 days	1986
colspan="3" \| S/1986 U 10^*	20	Unknown	76,420	0.638 days	1986
Uranus XV	Puck	puk'	162	2.89 × 10¹⁸ ?	86,010	0.761833 days	1986
colspan="3" \| S/2003 U 1^*	10	Unknown	97,734	0.923 days	2003
Uranus V	Miranda	mi-ran'-da	472	6.6 × 10¹⁹	129,390	1.413479 days	1948
Uranus I	Ariel	air'-ee-ul	1158	1.35 × 10²¹	191,020	2.520379 days	1851
Uranus II	Umbriel	um'-bree-ul	1170	1.17 × 10²¹	266,300	4.144177 days	1851
Uranus III	Titania	ti-tahn'-ya	1578	3.52 × 10²¹	435,910	8.705872 days	1787
Uranus IV	Oberon	oh'-bur-on	1523	3.01 × 10²¹	583,520	13.463239 days	1787
colspan="3" \| S/2001 U 3^*	12	Unknown	4,276,000	-266.6 days^**	2001
Uranus XVI	Caliban	kal'-i-ban	98	7.3 × 10¹⁷ ?	7,231,000	-579.7 days^**	1997
Uranus XX	Stephano	stef'-a-noh	20	6 × 10¹⁵ ?	8,004,000	-677.4 days^**	1999
Uranus XXI	Trinculo	tring'-kew-loh	10	Unknown	8,504,000	-759.0 days^**	2001
Uranus XVII	Sycorax	sik'-or-aks	190	5.4 × 10¹⁸ ?	12,179,000	-1288.3 days^**	1997
colspan="3" \| S/2003 U 3^*	11	Unknown	14,345,000	1694.8 days	2003
Uranus XVIII	Prospero	pros'-pur-oh	30	2.1 × 10¹⁶ ?	16,256,000	-1977.3 days^**	1999
Uranus XIX	Setebos	set'-e-bus	30	2.1 × 10¹⁶ ?	17,418,000	-2234.8 days^**	1999
colspan="3" \| S/2001 U 2^*	12	Unknown	20,901,000	-2823.4 days^**	2001

Sources: NASA/NSSDC and University of Hawaii. These sources give no information on the masses for the small satellites; some data have changed greatly so it is unlikely that these old values are correct. Pronunciations are from the Royal Shakespeare Company.

Naming notes

Some asteroids share the same names as moons of Uranus: 171 Ophelia, 218 Bianca, 593 Titania, 666 Desdemona and 2758 Cordelia.

Uranus' Natural Satellites

The natural satellites

Naming notes

See also