Exploring the Planets

The Moons of Uranus

The image on the right is a composite of four images acquired by Voyager 2 in 1985 showing three moons of Uranus: Umbriel, lower left; Miranda, bottom right; Ariel, top right. At the time when this image was collected, only 5 moons of Uranus were known. Voyager 2 discovered 10 more moons in 1986, bringing the total to 15.

Since then scientists using the Hubble Space Telescope and powerful Earth-based telescopes have continued to discover more moons orbiting Uranus. In 1997, two moons [Uranus XVI (Caliban) and XVII (Sycorax)] were discovered using the 200-inch Hale telescope at the Palomar Observatory in California, USA. In 1999, another three moons were discovered: one was discovered while comparing images from Voyager 2 and two more were discovered by astronomers using the Canada-France-Hawaii Telescope at Mauna Kea. As of 2014, 27 moons are known to orbit Uranus.

Uranus

Uranian Satellites

(in order by distance from planet)

Name Discoverer Diameter Distance From
Uranus
Orbital
Period
(days)
Cordelia Voyager 2, 1986 40 km/25 mi 49,800 km/30,944 mi .34
Ophelia Voyager 2, 1986 43 km/27 mi 53,800 km/33,430 mi .38
Bianca Voyager 2, 1986 51 km/32 mi 59,200 km/36,785 mi .44
Cressida Voyager 2, 1986 80 km/50 mi 61,800 km/38,401 mi .46
Desdemona Voyager 2, 1986 64 km/40 mi 62,700 km/38,960 mi .47
Juliet Voyager 2, 1986 94 km/59 mi 64,400 km/40,016 mi .49
Portia Voyager 2, 1986 135 km/84 mi 66,100 km/41,073 mi .51
Rosalind Voyager 2, 1986 72 km/45 mi 69,900 km/43,434 mi .56
Cupid Showalter & Lissauer, 2003 36 km/22 mi 74,392 km/46,225 mi .61
Belinda Voyager 2, 1986 81 km/50 mi 75,300 km/46,789 mi .62
Perdita Voyager 2, 1986 30 km/18 mi 76,417 km/47,483 mi .64
Puck Voyager 2, 1986 162 km/101 mi 86,000 km/53,438 mi .76
Mab Showalter & Lissauer, 2003 48 km/30 mi 97,736 km/60,760 mi .92
Miranda Kuiper, 1948 472 km/293 mi 129,900 km/80,716 mi 1.41
Ariel Lassell, 1851 1,158 km/720 mi 190,900 km/118,600 mi 2.52
Umbriel Lassell, 1851 1,169 km/726 mi 266,000 km/165,285 mi 4.14
Titania Herschel, 1787 1,578 km/981 mi 436,300 km/271,104 mi 8.71
Oberon Herschel, 1787 1,523 km/946 mi 583,500 km/362,570 mi 13.46
Francisco Kavalaars, Holman, Milisavljevic & Grav, 2001 22 km/14 mi 4,282,900 km/2,661,271 mi

267.09

Caliban Gladman, Nicholson, 
Burns & Kavelaars, 1997
72 km/44.8 mi 7,231,100km/4,493,197 mi 579.73
Stephano Gladman, Holman, Kavelaars, Petit & Scholl, 1999 32 km/20 mi 8,007,400 km/4,975,568 mi 677.47
Trinculo

Holman, Kavelaars & Milisavljevic, 2001

18 km/11 mi 8,505,200 km/5,284,886 mi 749.4
Sycorax Nicholson, Gladman, Burns & Kavelaars, 1997 150 km/93 mi 12,179,400 km/7,567,928 mi 1288.38
Margaret Sheppard & Jewitt, 2003 20 km/12 mi 14,146,700 km/8,790,352 mi 1661

Prospero

Gladman, Petie, Scholl, Kavelaars, Holman, 1999 50km/31 mi 16,276,800 km/10,113,935 mi 1978.37
Setebos Kavelaars, Gladman, Holman, Petit & Scholl, 1999 48 km/30 mi 17,420,400 km/10,824,535 mi 2225.08
Ferdinand Milisavljevic, Holman, Kavelaars & Grav, 2001 20 km/12 mi 20,430,000 km/12,694,613 mi

2,970.03

 

Uranus & Satellites

Uranus and its five major moons are depicted in this montage of images acquired by the Voyager 2 spacecraft during its January 1986 flyby of the planet. The moons, counterclockwise from bottom right, are Ariel, Miranda, Titania, Oberon and Umbriel.

 

Uranus and it's 5 Major Moons

 

Miranda

Miranda

 

Miranda is the smallest of the five major satellites of Uranus, measuring just 480 kilometers (300 miles) in diameter. Voyager 2 passed between Miranda and Uranus during 1986, and returned this color composite of the moon.

The carved dark streaks on the surface of this icy moon turned out to be ridges and valleys in higher resolution images.

Miranda

This high resolution image of Miranda was taken from a distance of 31,000 kilometers (19,000 miles), and shows a cratered surface broken by cliffs up to 20 kilometers (12 miles) high. Such fractures and grooves in the satellite's surface indicate a complex geologic history.

Titania

Titania

 

Titania is the largest satellite of Uranus. This image of Titania is a composite of 2 images taken by Voyager 2 on January 24, 1986.



More Moons:

Before the 1986 Voyager encounter, Uranus was known to have five moons. Those farthest from the planet have the highest density, and may consist of a silicate core covered by a thin, ice-rich crust. The moons show increasingly complex surface features closer to the planet.

Ariel

Ariel

 

The next moon out from Miranda, Ariel, is the brightest of the Uranian moons, and has the highest density (1.65 g/cm3).

Umbriel

Umbriel

 

Umbriel is the darkest of the Uranian moons, and has an icy crust pockmarked by craters. The surface is uniform in reflectivity, with the exception of a bright ring (top), which may be an impact crater.

Oberon

Oberon

 

The outermost of the five major satellites, Oberon, appears much like the satellites. Oberon orbits Uranus at more than twice the distance of our own Moon from Earth.

Puck

Puck

 

Ten new moons of Uranus were discovered by Voyager in 1985 and 1986. Puck is only 150 kilometers (93 miles) across, and is the largest of the ten. These ten minor satellites all circle Uranus inside the orbit of Miranda.