Moons of Uranus

Last updated
Uranus and its six largest moons compared at their proper relative sizes and relative positions. From left to right: Puck, Miranda, Ariel, Umbriel, Titania, and Oberon Uranus moons.jpg
Uranus and its six largest moons compared at their proper relative sizes and relative positions. From left to right: Puck, Miranda, Ariel, Umbriel, Titania, and Oberon

Uranus, the seventh planet of the Solar System, has 27 known moons, all of which are named after characters from the works of William Shakespeare and Alexander Pope. [1] Uranus's moons are divided into three groups: thirteen inner moons, five major moons, and nine irregular moons. The inner moons are small dark bodies that share common properties and origins with Uranus's rings. The five major moons are massive enough to have reached hydrostatic equilibrium, and four of them show signs of internally driven processes such as canyon formation and volcanism on their surfaces. [2] The largest of these five, Titania, is 1,578 km in diameter and the eighth-largest moon in the Solar System, and about one-twentieth the mass the Earth's Moon. The orbits of the regular moons are nearly coplanar with Uranus's equator, which is tilted 97.77° to its orbit. Uranus's irregular moons have elliptical and strongly inclined (mostly retrograde) orbits at large distances from the planet. [3]

Uranus Seventh planet from the Sun in the Solar System

Uranus is the seventh planet from the Sun. It has the third-largest planetary radius and fourth-largest planetary mass in the Solar System. Uranus is similar in composition to Neptune, and both have bulk chemical compositions which differ from that of the larger gas giants Jupiter and Saturn. For this reason, scientists often classify Uranus and Neptune as "ice giants" to distinguish them from the gas giants. Uranus' atmosphere is similar to Jupiter's and Saturn's in its primary composition of hydrogen and helium, but it contains more "ices" such as water, ammonia, and methane, along with traces of other hydrocarbons. It is the coldest planetary atmosphere in the Solar System, with a minimum temperature of 49 K, and has a complex, layered cloud structure with water thought to make up the lowest clouds and methane the uppermost layer of clouds. The interior of Uranus is mainly composed of ices and rock.

Solar System planetary system of the Sun

The Solar System is the gravitationally bound planetary system of the Sun and the objects that orbit it, either directly or indirectly. Of the objects that orbit the Sun directly, the largest are the eight planets, with the remainder being smaller objects, such as the five dwarf planets and small Solar System bodies. Of the objects that orbit the Sun indirectly—the moons—two are larger than the smallest planet, Mercury.

Natural satellite astronomical body that orbits a planet

A natural satellite or moon is, in the most common usage, an astronomical body that orbits a planet or minor planet.

Contents

William Herschel discovered the first two moons, Titania and Oberon, in 1787, and the other three ellipsoidal moons were discovered in 1851 by William Lassell (Ariel and Umbriel) and in 1948 by Gerard Kuiper (Miranda). [1] These five have planetary mass, and so would be considered (dwarf) planets if they were in direct orbit about the Sun. The remaining moons were discovered after 1985, either during the Voyager 2 flyby mission or with the aid of advanced Earth-based telescopes. [2] [3]

William Herschel 18th and 19th-century German-born British astronomer and composer

Frederick William Herschel, was a German-born British astronomer, composer and brother of fellow astronomer Caroline Herschel, with whom he worked. Born in the Electorate of Hanover, Herschel followed his father into the Military Band of Hanover, before migrating to Great Britain in 1757 at the age of nineteen.

Titania (moon) The largest moon of Uranus

Titania is the largest of the moons of Uranus and the eighth largest moon in the Solar System at a diameter of 1,578 kilometres (981 mi). Discovered by William Herschel in 1787, Titania is named after the queen of the fairies in Shakespeare's A Midsummer Night's Dream. Its orbit lies inside Uranus's magnetosphere.

Oberon (moon) moon of Uranus

Oberon, also designated Uranus IV, is the outermost major moon of the planet Uranus. It is the second-largest and second most massive of the Uranian moons, and the ninth most massive moon in the Solar System. Discovered by William Herschel in 1787, Oberon is named after the mythical king of the fairies who appears as a character in Shakespeare's A Midsummer Night's Dream. Its orbit lies partially outside Uranus's magnetosphere.

Discovery

The first two moons to be discovered were Titania and Oberon, which were spotted by Sir William Herschel on January 11, 1787, six years after he had discovered the planet itself. Later, Herschel thought he had discovered up to six moons (see below) and perhaps even a ring. For nearly 50 years, Herschel's instrument was the only one with which the moons had been seen. [4] In the 1840s, better instruments and a more favorable position of Uranus in the sky led to sporadic indications of satellites additional to Titania and Oberon. Eventually, the next two moons, Ariel and Umbriel, were discovered by William Lassell in 1851. [5] The Roman numbering scheme of Uranus's moons was in a state of flux for a considerable time, and publications hesitated between Herschel's designations (where Titania and Oberon are Uranus II and IV) and William Lassell's (where they are sometimes I and II). [6] With the confirmation of Ariel and Umbriel, Lassell numbered the moons I through IV from Uranus outward, and this finally stuck. [7] In 1852, Herschel's son John Herschel gave the four then-known moons their names. [8]

Ariel (moon) fourth-largest moon of Uranus

Ariel is the fourth-largest of the 27 known moons of Uranus. Ariel orbits and rotates in the equatorial plane of Uranus, which is almost perpendicular to the orbit of Uranus and so has an extreme seasonal cycle.

Umbriel (moon) moon of Uranus

Umbriel is a moon of Uranus discovered on October 24, 1851, by William Lassell. It was discovered at the same time as Ariel and named after a character in Alexander Pope's poem The Rape of the Lock. Umbriel consists mainly of ice with a substantial fraction of rock, and may be differentiated into a rocky core and an icy mantle. The surface is the darkest among Uranian moons, and appears to have been shaped primarily by impacts. However, the presence of canyons suggests early endogenic processes, and the moon may have undergone an early endogenically driven resurfacing event that obliterated its older surface.

William Lassell British astronomer

William Lassell, was an English merchant and astronomer. He is remembered for his improvements to the reflecting telescope and his ensuing discoveries of four planetary satellites.

No other discoveries were made for almost another century. In 1948, Gerard Kuiper at the McDonald Observatory discovered the smallest and the last of the five large, spherical moons, Miranda. [8] [9] Decades later, the flyby of the Voyager 2 space probe in January 1986 led to the discovery of ten further inner moons. [2] Another satellite, Perdita, was discovered in 1999 [10] after studying old Voyager photographs. [11]

Gerard Kuiper Netherlands-born American astronomer

Gerard Peter Kuiper was a Dutch–American astronomer, planetary scientist, selenographer, author and professor. He is the eponymous namesake of the Kuiper belt. Kuiper is considered by many to be the father of modern planetary science. As professor at the University of Chicago, he was dissertation advisor to Carl Sagan. In 1958, the two worked on the classified military Project A119, the secret Air Force plan to detonate a nuclear warhead on the Moon.

McDonald Observatory astronomical observatory in Texas

The McDonald Observatory is an astronomical observatory located near the unincorporated community of Fort Davis in Jeff Davis County, Texas, United States. The facility is located on Mount Locke in the Davis Mountains of West Texas, with additional facilities on Mount Fowlkes, approximately 1.3 kilometers (0.81 mi) to the northeast. The observatory is part of the University of Texas at Austin. It is an organized research unit of the College of Natural Sciences.

Miranda (moon) smallest moon of Uranus

Miranda, also designated Uranus V, is the smallest and innermost of Uranus's five round satellites. It was discovered by Gerard Kuiper on 16 February 1948 at McDonald Observatory, and named after Miranda from William Shakespeare's play The Tempest. Like the other large moons of Uranus, Miranda orbits close to its planet's equatorial plane. Because Uranus orbits the Sun on its side, Miranda's orbit is perpendicular to the ecliptic and shares Uranus's extreme seasonal cycle.

Uranus was the last giant planet without any known irregular moons, but since 1997 nine distant irregular moons have been identified using ground-based telescopes. [3] Two more small inner moons, Cupid and Mab, were discovered using the Hubble Space Telescope in 2003. [12] As of 2016, the moon Margaret was the last Uranian moon discovered, and its characteristics were published in October 2003. [13]

Irregular moon natural satellite following a distant, inclined, and often eccentric and retrograde orbit

In astronomy, an irregular moon, irregular satellite or irregular natural satellite is a natural satellite following a distant, inclined, and often eccentric and retrograde orbit. They have been captured by their parent planet, unlike regular satellites, which formed in orbit around them.

Cupid (moon) moon of Uranus

Cupid is an inner satellite of Uranus. It was discovered by Mark R. Showalter and Jack J. Lissauer in 2003 using the Hubble Space Telescope. It was named after a character in William Shakespeare's play Timon of Athens.

Mab (moon) moon of Uranus

Mab, or Uranus XXVI (26), is an inner satellite of Uranus. It was discovered by Mark R. Showalter and Jack J. Lissauer in 2003 using the Hubble Space Telescope. It was named after Queen Mab, a fairy queen from English folklore who is mentioned in William Shakespeare's play Romeo and Juliet.

The number of moons known for each of the four outer planets up to July 2018. Uranus currently has 27 known satellites. Outer planet moons.png
The number of moons known for each of the four outer planets up to July 2018. Uranus currently has 27 known satellites.

Spurious moons

After Herschel discovered Titania and Oberon on January 11, 1787, he subsequently believed that he had observed four other moons: two on January 18 and February 9, 1790, and two more on February 28 and March 26, 1794. It was thus believed for many decades thereafter that Uranus had a system of six satellites, though the four latter moons were never confirmed by any other astronomer. Lassell's observations of 1851, in which he discovered Ariel and Umbriel, however, failed to support Herschel's observations; Ariel and Umbriel, which Herschel certainly ought to have seen if he had seen any satellites beside Titania and Oberon, did not correspond to any of Herschel's four additional satellites in orbital characteristics. Herschel's four spurious satellites were thought to have sidereal periods of 5.89 days (interior to Titania), 10.96 days (between Titania and Oberon), 38.08 days, and 107.69 days (exterior to Oberon). [14] It was therefore concluded that Herschel's four satellites were spurious, probably arising from the misidentification of faint stars in the vicinity of Uranus as satellites, and the credit for the discovery of Ariel and Umbriel was given to Lassell. [15]

Names

Although the first two Uranian moons were discovered in 1787, they were not named until 1852, a year after two more moons had been discovered. The responsibility for naming was taken by John Herschel, son of the discoverer of Uranus. Herschel, instead of assigning names from Greek mythology, named the moons after magical spirits in English literature: the fairies Oberon and Titania from William Shakespeare's A Midsummer Night's Dream , and the sylph Ariel and gnome Umbriel from Alexander Pope's The Rape of the Lock (Ariel is also a sprite in Shakespeare's The Tempest ). The reasoning was presumably that Uranus, as god of the sky and air, would be attended by spirits of the air. [16]

Subsequent names, rather than continuing the airy spirits theme (only Puck and Mab continued the trend), have focused on Herschel's source material. In 1949, the fifth moon, Miranda, was named by its discoverer Gerard Kuiper after a thoroughly mortal character in Shakespeare's The Tempest . The current IAU practice is to name moons after characters from Shakespeare's plays and The Rape of the Lock (although at present only Ariel, Umbriel, and Belinda have names drawn from the latter; all the rest are from Shakespeare). At first, the outermost moons were all named after characters from one play, The Tempest; but with Margaret being named from Much Ado About Nothing that trend has ended. [8]

The relative masses of the Uranian moons. The five rounded moons vary from Miranda at 0.7% to Titania at almost 40% of the total mass. The other moons collectively constitute 0.1%, and are barely visible at this scale. Masses of Uranian moons-en.svg
The relative masses of the Uranian moons. The five rounded moons vary from Miranda at 0.7% to Titania at almost 40% of the total mass. The other moons collectively constitute 0.1%, and are barely visible at this scale.

Some asteroids share names with moons of Uranus: 171 Ophelia, 218 Bianca, 593 Titania, 666 Desdemona, 763 Cupido, and 2758 Cordelia.

Characteristics and groups

Schematic of the Uranian moon-ring system Uranian rings scheme.png
Schematic of the Uranian moon–ring system

The Uranian satellite system is the least massive among those of the giant planets. Indeed, the combined mass of the five major satellites is less than half that of Triton (the seventh-largest moon in the Solar System) alone. [lower-alpha 1] The largest of the satellites, Titania, has a radius of 788.9 km, [18] or less than half that of the Moon, but slightly more than that of Rhea, the second-largest moon of Saturn, making Titania the eighth-largest moon in the Solar System. Uranus is about 10,000 times more massive than its moons. [lower-alpha 2]

Inner moons

As of 2016, Uranus is known to have 13 inner moons. [12] Their orbits lie inside that of Miranda. All inner moons are intimately connected with the rings of Uranus, which probably resulted from the fragmentation of one or several small inner moons. [19] The two innermost moons (Cordelia and Ophelia) are shepherds of Uranus's ε ring, whereas the small moon Mab is a source of Uranus's outermost μ ring. [12] There may be two additional small (2–7 km in radius) undiscovered shepherd moons located about 100 km exterior to Uranus' α and β rings. [20]

At 162 km, Puck is the largest of the inner moons of Uranus and the only one imaged by Voyager 2 in any detail. Puck and Mab are the two outermost inner satellites of Uranus. All inner moons are dark objects; their geometrical albedo is less than 10%. [21] They are composed of water ice contaminated with a dark material, probably radiation-processed organics. [22]

The small inner moons constantly perturb each other. The system is chaotic and apparently unstable. Simulations show that the moons may perturb each other into crossing orbits, which may eventually result in collisions between the moons. [12] Desdemona may collide with either Cressida or Juliet within the next 100 million years. [23]

The five largest moons of Uranus compared at their proper relative sizes and brightnesses. From left to right (in order of increasing distance from Uranus): Miranda, Ariel, Umbriel, Titania, and Oberon. Uranian moon montage.jpg
The five largest moons of Uranus compared at their proper relative sizes and brightnesses. From left to right (in order of increasing distance from Uranus): Miranda, Ariel, Umbriel, Titania, and Oberon.

Large moons

Uranus has five major moons: Miranda, Ariel, Umbriel, Titania, and Oberon. They range in diameter from 472 km for Miranda to 1578 km for Titania. [18] All these moons are relatively dark objects: their geometrical albedo varies between 30 and 50%, whereas their Bond albedo is between 10 and 23%. [21] Umbriel is the darkest moon and Ariel the brightest. The masses of the moons range from 6.7 × 1019 kg (Miranda) to 3.5 × 1021 kg (Titania). For comparison, the Moon has a mass of 7.5 × 1022 kg. [24] The major moons of Uranus are thought to have formed in the accretion disc, which existed around Uranus for some time after its formation or resulted from a large impact suffered by Uranus early in its history. [25] [26]

Artist's conception of the Sun's path in the summer sky of a major moon of Uranus (which shares Uranus's axial tilt) Uranusmoonsummer.jpg
Artist's conception of the Sun's path in the summer sky of a major moon of Uranus (which shares Uranus's axial tilt)

All major moons comprise approximately equal amounts rock and ice, except Miranda, which is made primarily of ice. [27] The ice component may include ammonia and carbon dioxide. [28] Their surfaces are heavily cratered, though all of them (except Umbriel) show signs of endogenic resurfacing in the form of lineaments (canyons) and, in the case of Miranda, ovoid race-track like structures called coronae. [2] Extensional processes associated with upwelling diapirs are likely responsible for the origin of the coronae. [29] Ariel appears to have the youngest surface with the fewest impact craters, while Umbriel's appears oldest. [2] A past 3:1 orbital resonance between Miranda and Umbriel and a past 4:1 resonance between Ariel and Titania are thought to be responsible for the heating that caused substantial endogenic activity on Miranda and Ariel. [30] [31] One piece of evidence for such a past resonance is Miranda's unusually high orbital inclination (4.34°) for a body so close to the planet. [32] [33] The largest Uranian moons may be internally differentiated, with rocky cores at their centers surrounded by ice mantles. [27] Titania and Oberon may harbor liquid water oceans at the core/mantle boundary. [27] The major moons of Uranus are airless bodies. For instance, Titania was shown to possess no atmosphere at a pressure larger than 10–20 nanobar. [34]

The path of the Sun in the local sky over the course of a local day during Uranus's and its major moons' summer solstice is quite different from that seen on most other Solar System worlds. The major moons have almost exactly the same rotational axial tilt as Uranus (their axes are parallel to that of Uranus). [2] The Sun would appear to follow a circular path around Uranus's celestial pole in the sky, at the closest about 7 degrees from it. [lower-alpha 3] Near the equator, it would be seen nearly due north or due south (depending on the season). At latitudes higher than 7°, the Sun would trace a circular path about 15 degrees in diameter in the sky, and never set.

Irregular moons of Uranus. The X axis is labeled in Gm (million km) and in the fraction of the Hill sphere's radius. The eccentricity is represented by the yellow segments (extending from the pericentre to the apocentre) with the inclination represented on the Y axis. TheIrregulars URANUS.svg
Irregular moons of Uranus. The X axis is labeled in Gm (million km) and in the fraction of the Hill sphere's radius. The eccentricity is represented by the yellow segments (extending from the pericentre to the apocentre) with the inclination represented on the Y axis.

Irregular moons

As of 2005 Uranus is known to have nine irregular moons, which orbit it at a distance much greater than that of Oberon, the furthest of the large moons. All the irregular moons are probably captured objects that were trapped by Uranus soon after its formation. [3] The diagram illustrates the orbits of those irregular moons discovered so far. The moons above the X axis are prograde, those beneath are retrograde. The radius of the Uranian Hill sphere is approximately 73 million km. [3]

Uranus's irregular moons range in size from 120–200 km (Sycorax) to about 20 km (Trinculo). [3] Unlike Jupiter's irregulars, Uranus's show no correlation of axis with inclination. Instead, the retrograde moons can be divided into two groups based on axis/orbital eccentricity. The inner group includes those satellites closer to Uranus (a < 0.15 rH) and moderately eccentric (~0.2), namely Francisco, Caliban, Stephano, and Trinculo. [3] The outer group (a > 0.15 rH) includes satellites with high eccentricity (~0.5): Sycorax, Prospero, Setebos, and Ferdinand. [3]

The intermediate inclinations 60° < i < 140° are devoid of known moons due to the Kozai instability. [3] In this instability region, solar perturbations at apoapse cause the moons to acquire large eccentricities that lead to collisions with inner satellites or ejection. The lifetime of moons in the instability region is from 10 million to a billion years. [3]

Margaret is the only known irregular prograde moon of Uranus, and it currently has the most eccentric orbit of any moon in the Solar System, though Neptune's moon Nereid has a higher mean eccentricity. As of 2008, Margaret's eccentricity is 0.7979. [35]

List

The Uranian moons are listed here by orbital period, from shortest to longest. Moons massive enough for their surfaces to have collapsed into a spheroid are highlighted in light blue and bolded. Irregular moons with retrograde orbits are shown in dark grey. Margaret, the only known irregular moon of Uranus with a prograde orbit, is shown in light grey.

Uranian moons
Order
[lower-alpha 4]
Label
[lower-alpha 5]
NamePronunciation
(key)
Image Diameter
(km) [lower-alpha 6]
Mass
(×1018 kg) [lower-alpha 7]
Semi-major axis
(km) [37]
Orbital period
(d) [37] [lower-alpha 8]
Inclination
(°) [37] [lower-alpha 9]
Eccentricity
[38]
Discovery
year
[1]
Discoverer
[1]
1VI¡ Cordelia /kɔːrˈdliə/ Cordeliamoon.png 40 ± 6
(50 × 36)
0.044497700.3350340.08479°0.000261986 Terrile
(Voyager 2)
2VII¡ Ophelia /ˈfliə/ Opheliamoon.png 43 ± 8
(54 × 38)
0.053537900.3764000.1036°0.009921986 Terrile
(Voyager 2)
3VIII¡ Bianca /biˈɑːŋkə/ Biancamoon.png 51 ± 4
(64 × 46)
0.092591700.4345790.193°0.000921986 Smith
(Voyager 2)
4IX¡ Cressida /ˈkrɛsɪdə/ Cressida.png 80 ± 4
(92 × 74)
0.34617800.4635700.006°0.000361986 Synnott
(Voyager 2)
5X¡ Desdemona /ˌdɛzdɪˈmnə/ Desdemonamoon.png 64 ± 8
(90 × 54)
0.18626800.4736500.11125°0.000131986 Synnott
(Voyager 2)
6XI¡ Juliet /ˈliət/ Julietmoon.png 94 ± 8
(150 × 74)
0.56643500.4930650.065°0.000661986 Synnott
(Voyager 2)
7XII¡ Portia /ˈpɔːrʃə/ Uranus-Portia-Cressida-Ophelia-NASA.gif 135 ± 8
(156 × 126)
1.70660900.5131960.059°0.000051986 Synnott
(Voyager 2)
8XIII¡ Rosalind /ˈrɒzəlɪnd/ Rosalindmoon.png 72 ± 120.25699400.5584600.279°0.000111986 Synnott
(Voyager 2)
9XXVII¡ Cupid /ˈkjuːpɪd/ Cupidmoon.png ≈ 180.0038748000.6180.1°0.00132003 Showalter and
Lissauer
10XIV¡ Belinda /bɪˈlɪndə/
Belinda.gif
90 ± 16
(128 × 64)
0.49752600.6235270.031°0.000071986 Synnott
(Voyager 2)
11XXV¡ Perdita /ˈpɜːrdɪtə/ Perditamoon.png 30 ± 60.018764000.6380.0°0.00121999 Karkoschka
(Voyager 2)
12XV¡ Puck /ˈpʌk/
Puck.png
162 ± 42.90860100.7618330.3192°0.000121985 Synnott
(Voyager 2)
13XXVI¡ Mab /ˈmæb/
Mabmoon.png
≈ 250.01977000.9230.1335°0.00252003Showalter and
Lissauer
14V Miranda /mɪˈrændə/
PIA18185 Miranda's Icy Face.jpg
471.6 ± 1.4
(481 × 468 × 466)
65.9±7.51293901.4134794.232°0.00131948 Kuiper
15I Ariel /ˈɛəriəl/
Ariel (moon).jpg
1157.8±1.2
(1162 × 1156 × 1155)
1353±1201910202.5203790.260°0.00121851 Lassell
16II Umbriel /ˈʌmbriəl/
PIA00040 Umbrielx2.47.jpg
1169.4±5.61172±1352663004.1441770.205°0.00391851 Lassell
17III Titania /tɪˈtniə/
Titania (moon) color cropped.jpg
1576.8±1.23527±904359108.7058720.340°0.00111787 Herschel
18IV Oberon /ˈbərɒn/
Voyager 2 picture of Oberon.jpg
1522.8±5.23014±7558352013.4632390.058°0.00141787 Herschel
19XXII Francisco /frænˈsɪsk/ Uranus moon 021002 02.jpg ≈ 220.00724276000−266.56147.459°0.14592003 [lower-alpha 10] Holman et al.
20XVI Caliban /ˈkælɪbæn/ Caliban feat.png ≈ 720.257230000−579.50139.885°0.15871997 Gladman et al.
21XX Stephano /ˈstɛfən/ Stephano - Uranus moon.jpg ≈ 320.0228002000−676.50141.873°0.22921999 Gladman et al.
22XXI Trinculo /ˈtrɪŋkjʊl/ ≈ 180.00398571000−758.10166.252°0.22002001 Holman et al.
23XVII Sycorax /ˈsɪkəræks/ Sycorax.jpg 165+36
−42
2.3012179000−1283.4152.456°0.52241997 Nicholson et al.
24XXIII± Margaret /ˈmɑːrɡərɪt/ ≈ 200.0054143450001694.851.455°0.66082003 Sheppard and
Jewitt
25XVIII Prospero /ˈprɒspər/ Prospero discovery image.gif ≈ 500.08516418000−1992.8146.017°0.44481999 Holman et al.
26XIX Setebos /ˈsɛtɪbʌs/ Uranus - Setebos image.jpg ≈ 480.07517459000−2202.3145.883°0.59141999 Kavelaars et al.
27XXIV Ferdinand /ˈfɜːrdɪnænd/ Ferdinand - Uranus moon.gif ≈ 200.005420900000−2823.4167.346°0.36822003 [lower-alpha 10] Holman et al.
Key
¡
Inner moons
 

Major moons
 

Irregular moons (retrograde)
±
Irregular moon (prograde)

Sources: NASA/NSSDC, [37] Sheppard, et al. 2005. [3] For the recently discovered outer irregular moons (Francisco through Ferdinand) the most accurate orbital data can be generated with the Natural Satellites Ephemeris Service. [35] The irregulars are significantly perturbed by the Sun. [3]

Notes

  1. The mass of Triton is about 2.14 × 1022 kg, [17] whereas the combined mass of the Uranian moons is about 0.92 × 1022 kg.
  2. Uranus mass of 8.681 × 1025 kg / Mass of Uranian moons of 0.93 × 1022 kg
  3. The axial tilt of Uranus is 97°. [2]
  4. Order refers to the position among other moons with respect to their average distance from Uranus.
  5. Label refers to the Roman numeral attributed to each moon in order of their discovery. [1]
  6. Diameters with multiple entries such as "60 × 40 × 34" reflect that the body is not a perfect spheroid and that each of its dimensions have been measured well enough. The diameters and dimensions of Miranda, Ariel, Umbriel, and Oberon were taken from Thomas, 1988. [18] The diameter of Titania is from Widemann, 2009. [34] The dimensions and radii of the inner moons are from Karkoschka, 2001, [11] except for Cupid and Mab, which were taken from Showalter, 2006. [12] The radii of outer moons except Sycorax were taken from Sheppard, 2005. [3] The diameter of Sycorax is from Lellouch, 2013. [36]
  7. Masses of Miranda, Ariel, Umbriel, Titania, and Oberon were taken from Jacobson, 1992. [24] Masses of all other moons were calculated assuming a density of 1.3 g/cm3 and using given radii.
  8. Negative orbital periods indicate a retrograde orbit around Uranus (opposite to the planet's rotation).
  9. Inclination measures the angle between the moon's orbital plane and the plane defined by Uranus's equator.
  10. 1 2 Detected in 2001, published in 2003.

Related Research Articles

Nereid (moon) moon of Neptune

Nereid is the third-largest moon of Neptune. It has a highly eccentric orbit. It was the second moon of Neptune to be discovered, by Gerard Kuiper in 1949.

Puck (moon) moon of Uranus

Puck is an inner moon of Uranus. It was discovered in December 1985 by the Voyager 2 spacecraft. The name Puck follows the convention of naming Uranus's moons after characters from Shakespeare. The orbit of Puck lies between the rings of Uranus and the first of Uranus's large moons, Miranda. Puck is approximately spherical in shape and has diameter of about 162 km. It has a dark, heavily cratered surface, which shows spectral signs of water ice.

Cordelia (moon) moon of Uranus

Cordelia is the innermost known moon of Uranus. It was discovered from the images taken by Voyager 2 on January 20, 1986, and was given the temporary designation S/1986 U 7. It was not detected again until the Hubble Space Telescope observed it in 1997. Cordelia takes its name from the youngest daughter of Lear in William Shakespeare's King Lear. It is also designated Uranus VI.

Ophelia (moon) moon of Uranus

Ophelia is a moon of Uranus. It was discovered from the images taken by Voyager 2 on January 20, 1986, and was given the temporary designation S/1986 U 8. It was not seen until the Hubble Space Telescope recovered it in 2003. Ophelia was named after the daughter of Polonius, Ophelia, in William Shakespeare's play Hamlet. It is also designated Uranus VII.

Bianca (moon) moon of Uranus

Bianca is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on January 23, 1986, and was given the temporary designation S/1986 U 9. It was named after the sister of Katherine in Shakespeare's play The Taming of the Shrew. It is also designated Uranus VIII.

Cressida (moon) moon of Uranus

Cressida is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on 9 January 1986, and was given the temporary designation S/1986 U 3. It was named after Cressida, the Trojan daughter of Calchas, a tragic heroine who appears in William Shakespeare's play Troilus and Cressida. It is also designated Uranus IX.

Desdemona (moon) moon of Uranus

Desdemona is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on 13 January 1986, and was given the temporary designation S/1986 U 6. Desdemona is named after the wife of Othello in William Shakespeare's play Othello. It is also designated Uranus X.

Juliet (moon) moon of Uranus

Juliet is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on 3 January 1986, and was given the temporary designation S/1986 U 2. It is named after the heroine of William Shakespeare's play Romeo and Juliet. It is also designated Uranus XI.

Rosalind (moon) moon of Uranus

Rosalind is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on 13 January 1986, and was given the temporary designation S/1986 U 4. It was named after the daughter of the banished Duke in William Shakespeare's play As You Like It. It is also designated Uranus XIII.

Belinda (moon) moon of Uranus

Belinda is an inner satellite of the planet Uranus. Belinda was discovered from the images taken by Voyager 2 on 13 January 1986 and was given the temporary designation S/1986 U 5. It is named after the heroine of Alexander Pope's The Rape of the Lock. It is also designated Uranus XIV.

Portia (moon) moon of Uranus

Portia is an inner satellite of Uranus. It was discovered from the images taken by Voyager 2 on 3 January 1986, and was given the temporary designation S/1986 U 1. The moon is named after Portia, the heroine of William Shakespeare's play The Merchant of Venice. It is also designated Uranus XII.

Sycorax (moon) moon of Uranus

Sycorax is the largest retrograde irregular satellite of Uranus. Sycorax was discovered on 6 September 1997 by Brett J. Gladman, Philip D. Nicholson, Joseph A. Burns, and John J. Kavelaars using the 200-inch Hale telescope, together with Caliban, and given the temporary designation S/1997 U 2.

Wunda (crater) crater on the surface of Uranus moon Umbriel

Wunda is a large crater on the surface of Uranus' moon Umbriel. It is 131 km in diameter and is located near the equator of Umbriel. The crater is named after Wunda, a dark spirit of Australian aboriginal mythology.

The naming of moons has been the responsibility of the International Astronomical Union's committee for Planetary System Nomenclature since 1973. That committee is known today as the Working Group for Planetary System Nomenclature (WGPSN).

References

  1. 1 2 3 4 5 "Planet and Satellite Names and Discoverers". Gazetteer of Planetary Nomenclature. USGS Astrogeology. July 21, 2006. Retrieved 2006-08-06.
  2. 1 2 3 4 5 6 7 Smith, B. A.; Soderblom, L. A.; Beebe, A.; Bliss, D.; Boyce, J. M.; Brahic, A.; Briggs, G. A.; Brown, R. H.; Collins, S. A. (4 July 1986). "Voyager 2 in the Uranian System: Imaging Science Results". Science. 233 (4759): 43–64. Bibcode:1986Sci...233...43S. doi:10.1126/science.233.4759.43. PMID   17812889.
  3. 1 2 3 4 5 6 7 8 9 10 11 12 13 Sheppard, S. S.; Jewitt, D.; Kleyna, J. (2005). "An Ultradeep Survey for Irregular Satellites of Uranus: Limits to Completeness". The Astronomical Journal. 129: 518–525. arXiv: astro-ph/0410059 . Bibcode:2005AJ....129..518S. doi:10.1086/426329.
  4. Herschel, John (1834). "On the Satellites of Uranus". Monthly Notices of the Royal Astronomical Society . 3 (5): 35–36. Bibcode:1834MNRAS...3...35H. doi:10.1093/mnras/3.5.35.
  5. Lassell, W. (1851). "On the interior satellites of Uranus". Monthly Notices of the Royal Astronomical Society. 12: 15–17. Bibcode:1851MNRAS..12...15L. doi:10.1093/mnras/12.1.15.
  6. Lassell, W. (1848). "Observations of Satellites of Uranus". Monthly Notices of the Royal Astronomical Society. 8 (3): 43–44. Bibcode:1848MNRAS...8...43L. doi:10.1093/mnras/8.3.43.
  7. Lassell, William (December 1851). "Letter from William Lassell, Esq., to the Editor". Astronomical Journal. 2 (33): 70. Bibcode:1851AJ......2...70L. doi:10.1086/100198.
  8. 1 2 3 Kuiper, G. P. (1949). "The Fifth Satellite of Uranus". Publications of the Astronomical Society of the Pacific. 61 (360): 129. Bibcode:1949PASP...61..129K. doi:10.1086/126146.
  9. Kaempffert, Waldemar (December 26, 1948). "Science in Review: Research Work in Astronomy and Cancer Lead Year's List of Scientific Developments". The New York Times (Late City ed.). p. 87. ISSN   0362-4331.
  10. Karkoschka, Erich (May 18, 1999). "S/1986 U 10". IAU Circular. 7171. ISSN   0081-0304 . Retrieved 2011-11-02.
  11. 1 2 Karkoschka, Erich (2001). "Voyager's Eleventh Discovery of a Satellite of Uranus and Photometry and the First Size Measurements of Nine Satellites". Icarus. 151 (1): 69–77. Bibcode:2001Icar..151...69K. doi:10.1006/icar.2001.6597.
  12. 1 2 3 4 5 Showalter, Mark R.; Lissauer, Jack J. (2006-02-17). "The Second Ring-Moon System of Uranus: Discovery and Dynamics". Science. 311 (5763): 973–977. Bibcode:2006Sci...311..973S. doi:10.1126/science.1122882. PMID   16373533.
  13. Sheppard, Scott S.; Jewitt, D. C. (2003-10-09). "S/2003 U 3". IAU Circular. 8217. ISSN   0081-0304 . Retrieved 2011-11-02.
  14. Hughes, D. W. (1994). "The Historical Unravelling of the Diameters of the First Four Asteroids". R.A.S. Quarterly Journal. 35 (3): 334–344. Bibcode:1994QJRAS..35..331H.
  15. Denning, W.F. (October 22, 1881). "The centenary of the discovery of Uranus". Scientific American Supplement (303). Archived from the original on January 12, 2009.
  16. William Lassell (1852). "Beobachtungen der Uranus-Satelliten". Astronomische Nachrichten. 34: 325. Bibcode:1852AN.....34..325. Retrieved 18 December 2008.
  17. Tyler, G.L.; Sweetnam, D.L.; et al. (1989). "Voyager radio science observations of Neptune and Triton". Science. 246 (4936): 1466–73. Bibcode:1989Sci...246.1466T. doi:10.1126/science.246.4936.1466. PMID   17756001.
  18. 1 2 3 Thomas, P. C. (1988). "Radii, shapes, and topography of the satellites of Uranus from limb coordinates". Icarus. 73 (3): 427–441. Bibcode:1988Icar...73..427T. doi:10.1016/0019-1035(88)90054-1.
  19. Esposito, L. W. (2002). "Planetary rings". Reports on Progress in Physics. 65 (12): 1741–1783. Bibcode:2002RPPh...65.1741E. doi:10.1088/0034-4885/65/12/201.
  20. Chancia, R.O.; Hedman, M.M. (2016). "Are there moonlets near Uranus' alpha and beta rings?". The Astronomical Journal. arXiv: 1610.02376 . Bibcode:2016AJ....152..211C. doi:10.3847/0004-6256/152/6/211.
  21. 1 2 Karkoschka, Erich (2001). "Comprehensive Photometry of the Rings and 16 Satellites of Uranus with the Hubble Space Telescope". Icarus. 151 (1): 51–68. Bibcode:2001Icar..151...51K. doi:10.1006/icar.2001.6596.
  22. Dumas, Christophe; Smith, Bradford A.; Terrile, Richard J. (2003). "Hubble Space Telescope NICMOS Multiband Photometry of Proteus and Puck". The Astronomical Journal . 126 (2): 1080–1085. Bibcode:2003AJ....126.1080D. doi:10.1086/375909.
  23. Duncan, Martin J.; Lissauer, Jack J. (1997). "Orbital Stability of the Uranian Satellite System". Icarus. 125 (1): 1–12. Bibcode:1997Icar..125....1D. doi:10.1006/icar.1996.5568.
  24. 1 2 Jacobson, R. A.; Campbell, J. K.; Taylor, A. H.; Synnott, S. P. (June 1992). "The masses of Uranus and its major satellites from Voyager tracking data and earth-based Uranian satellite data". The Astronomical Journal. 103 (6): 2068–2078. Bibcode:1992AJ....103.2068J. doi:10.1086/116211.
  25. Mousis, O. (2004). "Modeling the thermodynamical conditions in the Uranian subnebula – Implications for regular satellite composition". Astronomy & Astrophysics. 413: 373–380. Bibcode:2004A&A...413..373M. doi:10.1051/0004-6361:20031515.
  26. Hunt, Garry E.; Patrick Moore (1989). Atlas of Uranus. Cambridge University Press. pp. 78–85. ISBN   0-521-34323-2.
  27. 1 2 3 Hussmann, Hauke; Sohl, Frank; Spohn, Tilman (November 2006). "Subsurface oceans and deep interiors of medium-sized outer planet satellites and large trans-neptunian objects". Icarus . 185 (1): 258–273. Bibcode:2006Icar..185..258H. doi:10.1016/j.icarus.2006.06.005.
  28. Grundy, W. M.; Young, L. A.; Spencer, J. R.; Johnson, R. E.; Young, E. F.; Buie, M. W. (October 2006). "Distributions of H2O and CO2 ices on Ariel, Umbriel, Titania, and Oberon from IRTF/SpeX observations". Icarus. 184 (2): 543–555. arXiv: 0704.1525 . Bibcode:2006Icar..184..543G. doi:10.1016/j.icarus.2006.04.016.
  29. Pappalardo, R. T.; Reynolds, S. J.; Greeley, R. (1996). "Extensional tilt blocks on Miranda: Evidence for an upwelling origin of Arden Corona". Journal of Geophysical Research. 102 (E6): 13, 369–13, 380. Bibcode:1997JGR...10213369P. doi:10.1029/97JE00802.
  30. Tittemore, William C.; Wisdom, Jack (June 1990). "Tidal evolution of the Uranian satellites: III. Evolution through the Miranda-Umbriel 3:1, Miranda-Ariel 5:3, and Ariel-Umbriel 2:1 mean-motion commensurabilities". Icarus. 85 (2): 394–443. Bibcode:1990Icar...85..394T. doi:10.1016/0019-1035(90)90125-S.
  31. Tittemore, W. C. (September 1990). "Tidal heating of Ariel". Icarus. 87 (1): 110–139. Bibcode:1990Icar...87..110T. doi:10.1016/0019-1035(90)90024-4.
  32. Tittemore, W. C.; Wisdom, J. (1989). "Tidal Evolution of the Uranian Satellites II. An Explanation of the Anomalously High Orbital Inclination of Miranda" (PDF). Icarus. 78 (1): 63–89. Bibcode:1989Icar...78...63T. doi:10.1016/0019-1035(89)90070-5.
  33. Malhotra, R.; Dermott, S. F. (1990). "The Role of Secondary Resonances in the Orbital History of Miranda". Icarus. 85 (2): 444–480. Bibcode:1990Icar...85..444M. doi:10.1016/0019-1035(90)90126-T.
  34. 1 2 Widemann, T.; Sicardy, B.; Dusser, R.; Martinez, C.; Beisker, W.; Bredner, E.; Dunham, D.; Maley, P.; Lellouch, E.; Arlot, J. -E.; Berthier, J.; Colas, F.; Hubbard, W. B.; Hill, R.; Lecacheux, J.; Lecampion, J. -F.; Pau, S.; Rapaport, M.; Roques, F.; Thuillot, W.; Hills, C. R.; Elliott, A. J.; Miles, R.; Platt, T.; Cremaschini, C.; Dubreuil, P.; Cavadore, C.; Demeautis, C.; Henriquet, P.; Labrevoir, O. (February 2009). "Titania's radius and an upper limit on its atmosphere from the September 8, 2001 stellar occultation" (PDF). Icarus. 199 (2): 458–476. Bibcode:2009Icar..199..458W. doi:10.1016/j.icarus.2008.09.011.
  35. 1 2 "Natural Satellites Ephemeris Service". IAU: Minor Planet Center. Retrieved 2011-01-08.
  36. Lellouch, E.; Santos-Sanz, P.; Lacerda, P.; Mommert, M.; Duffard, R.; Ortiz, J. L.; Müller, T. G.; Fornasier, S.; Stansberry, J.; Kiss, Cs.; Vilenius, E.; Mueller, M.; Peixinho, N.; Moreno, R.; Groussin, O.; Delsanti, A.; Harris, A. W. (September 2013). ""TNOs are Cool": A survey of the trans-Neptunian region. IX. Thermal properties of Kuiper belt objects and Centaurs from combined Herschel and Spitzer observations" (PDF). Astronomy & Astrophysics. 557: A60. Bibcode:2013A&A...557A..60L. doi:10.1051/0004-6361/201322047 . Retrieved 7 November 2014.
  37. 1 2 3 4 Williams, Dr. David R. (2007-11-23). "Uranian Satellite Fact Sheet". NASA (National Space Science Data Center). Archived from the original on 2010-01-18. Retrieved 2008-12-20.
  38. Jacobson, R. A. (1998). "The Orbits of the Inner Uranian Satellites From Hubble Space Telescope and Voyager 2 Observations". The Astronomical Journal. 115 (3): 1195–1199. Bibcode:1998AJ....115.1195J. doi:10.1086/300263.