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Moons of Uranus

May 04, 2024

Uranus, the seventh planet of the Solar System, has 28 confirmed moons. Most of them are named after characters that appear in, or are mentioned in, the works of William Shakespeare and Alexander Pope.[1] Uranus's moons are divided into three groups: thirteen inner moons, five major moons, and ten irregular moons. The inner and major moons all have prograde orbits and are cumulatively classified as regular moons. In contrast, the orbits of the irregular moons are distant, highly inclined, and mostly retrograde.

An updated image of the six largest moons and eight inner moons of Uranus as captured by the James Webb Space Telescope on September 4, 2023.

The inner moons are small dark bodies that share common properties and origins with Uranus's rings. The five major moons are ellipsoidal, indicating that they reached hydrostatic equilibrium at some point in their past (and may still be in 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, about one-twentieth the mass of 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]

William Herschel discovered the first two moons, Titania and Oberon, in 1787. 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 may be in hydrostatic equilibrium. 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]

Discovery edit

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]

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] by Erich Karkoschka after studying old Voyager photographs.[11]

Uranus was the last giant planet without any known irregular moons until 1997, when astronomers using ground-based telescopes discovered Sycorax and Caliban. From 1999 to 2003, astronomers continued searching for irregular moons of Uranus using more powerful ground-based telescopes, resulting in the discovery of seven more Uranian irregular moons.[3] In addition, two small inner moons, Cupid and Mab, were discovered using the Hubble Space Telescope in 2003.[12] No other discoveries were made until 2021 and 2023, when Scott Sheppard and colleagues discovered one more irregular moon of Uranus (and five more candidates waiting to be announced) using the Subaru Telescope at Mauna Kea, Hawaii.[13][14][15]

Spurious moons edit

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 besides 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).[16] 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.[17]

Discovery of outer planet moons

  Moons of Jupiter
  Moons of Saturn
  Moons of Uranus
  Moons of Neptune

Names edit

Main article: Naming of moons
See also: Name conflicts with minor planets

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.[18] It is uncertain if John Herschel was the originator of the names, or if it was instead William Lassell (who discovered Ariel and Umbriel) who chose the names and asked Herschel for permission.[19]

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.[8] 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). The outer retrograde moons are all named after characters from one play, The Tempest; the sole known outer prograde moon, Margaret, is named from Much Ado About Nothing.[19]

Some asteroids, also named after the same Shakespearean characters, share names with moons of Uranus: 171 Ophelia, 218 Bianca, 593 Titania, 666 Desdemona, 763 Cupido, and 2758 Cordelia.

Characteristics and groups edit

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.[a] The largest of the satellites, Titania, has a radius of 788.9 km,[21] 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.[b]

Inner moons edit

See also: Inner moon and Rings of Uranus
 
Schematic of the Uranian moon–ring system

As of 2024, Uranus is known to have 13 inner moons, whose orbits all lie inside that of Miranda.[12] The inner moons are classified into two groups based on similar orbital distances: these are the Portia group, which includes the six moons Bianca, Cressida, Desdemona, Juliet, Portia, and Rosalind; and the Belinda group, which includes the three moons Cupid, Belinda, and Perdita.[12][22] All of the inner moons are intimately connected with the rings of Uranus, which probably resulted from the fragmentation of one or several small inner moons.[23] 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's α and β rings.[24]

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%.[25] They are composed of water ice contaminated with a dark material, probably radiation-processed organics.[26]

The inner moons constantly perturb each other, especially within the closely-packed Portia and Belinda groups. The system is chaotic and apparently unstable.[27] 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 Cressida within the next million years,[28] and Cupid will likely collide with Belinda in the next 10 million years; Perdita and Juliet may be involved in later collisions.[29] Because of this, the rings and inner moons may be under constant flux, with moons colliding and re-accreting on short timescales.[29]

Large moons edit

 
Uranus and its six largest moons compared at their proper relative sizes and in the correct order. From left to right: Puck, Miranda, Ariel, Umbriel, Titania, and Oberon

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.[21] All these moons are relatively dark objects: their geometrical albedo varies between 30 and 50%, whereas their Bond albedo is between 10 and 23%.[25] 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.[30] 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.[31][32] This view is supported by their large thermal inertia, a surface property they share with dwarf planets like Pluto and Haumea.[33] It differs strongly from the thermal behaviour of the Uranian irregular moons that is comparable to classical trans-Neptunian objects.[34] This suggests a separate origin.

 
Moons (Ariel, Umbriel, Titania, Oberon, Miranda)
Modeling (4 May 2023)

All major moons comprise approximately equal amounts rock and ice, except Miranda, which is made primarily of ice.[35] The ice component may include ammonia and carbon dioxide.[36] 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.[37] 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.[38][39] 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.[40][41] The largest Uranian moons may be internally differentiated, with rocky cores at their centers surrounded by ice mantles.[35] Titania and Oberon may harbor liquid water oceans at the core/mantle boundary.[35] 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.[42]

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,[c] during the hemispheric summer. 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 during the hemispheric summer, moving to a position over the celestial equator during the Uranian equinox, and then invisible below the horizon during the hemispheric winter.

Irregular moons edit

See also: Irregular moon
 
Irregular satellites of Jupiter (red), Saturn (green), Uranus (magenta) and Neptune (blue; including Triton), plotted by distance from their planet (semi-major axis) in the horizontal axis and orbital inclination in the vertical axis. The semi-major axis values are expressed as a fraction of the planet's Hill sphere's radius, while the inclination is expressed in degrees from the ecliptic. The radius of the Uranian Hill sphere is approximately 73 million km.[3] The relative sizes of moons are indicated by the size of their symbols, and the Caliban group of Uranian moons is labeled. Data as of February 2024.

Uranus's irregular moons range in size from 120 to 200 km (Sycorax) to under 10 km (S/2023 U 1).[43] Due to the small number of known Uranian irregular moons, it is not yet clear which of them belong to groups with similar orbital characteristics. The only known group among Uranus's irregular moons is the Caliban group, which is clustered at orbital distances between 6–7 million km (3.7–4.3 million mi) and inclinations between 141°–144°.[14] The Caliban group includes three retrograde moons, which are Caliban, S/2023 U 1, Stephano.[14]

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 has one of the most eccentric orbits of any moon in the Solar System.

List edit

 
Orbital diagram of the orbital inclination and orbital distances for Uranus's rings and moon system at various scales. Open the image for full resolution.

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. The inner and major moons all have prograde orbits. 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. The orbits and mean distances of the irregular moons are variable over short timescales due to frequent planetary and solar perturbations, therefore the listed orbital elements of all irregular moons are averaged over a 8,000-year numerical integration by Brozović and Jacobson (2009). These may differ from osculating orbital elements provided by other sources.[44] The orbital elements of major moons listed here are based on the epoch of 1 January 2000,[45] while orbital elements of irregular satellites are based on the epoch of 1 January 2020.[46]

Key
 
Inner moons 		♠
Major moons 		†
Ungrouped prograde irregular moons 		‡
Ungrouped retrograde irregular moons 		♦
Caliban group
Uranian moons
Label
[d] 		Name Pronunciation
(key) 		Image Abs.
magn.[47] 		Diameter
(km)[e] 		Mass
(× 1016 kg)[f] 		Semi-major axis
(km)[g] 		Orbital period
(d)[g][h] 		Inclination
(°)[g][i] 		Eccentricity
[g] 		Discovery
year[50] 		Year announced Discoverer
[50] 		Group
VI Cordelia /kɔːrˈdiːliə/   10.3 40 ± 6
(50 × 36)		 ≈ 3.4 49800 +0.33457 0.2 0.000 1986 1986 Terrile
(Voyager 2)		 ε ring shepherd
VII Ophelia /oʊˈfiːliə/   10.2 43 ± 8
(54 × 38)		 ≈ 4.2 53800 +0.37686 0.1 0.011 1986 1986 Terrile
(Voyager 2)		 ε ring shepherd
VIII Bianca /biˈɑːŋkə/   9.8 51 ± 4
(64 × 46)		 ≈ 6.9 59200 +0.43501 0.1 0.001 1986 1986 Smith
(Voyager 2)		 Portia
IX Cressida /ˈkrɛsədə/   8.9 80 ± 4
(92 × 74)		 ≈ 27 61800 +0.46315 0.1 0.000 1986 1986 Synnott
(Voyager 2)		 Portia
X Desdemona /ˌdɛzdəˈmoʊnə/   9.3 64 ± 8
(90 × 54)		 ≈ 14 62700 +0.47323 0.1 0.000 1986 1986 Synnott
(Voyager 2)		 Portia
XI Juliet /ˈdʒuːliət/   8.5 94 ± 8
(150 × 74)		 ≈ 43 64400 +0.49348 0.0 0.001 1986 1986 Synnott
(Voyager 2)		 Portia
XII Portia /ˈpɔːrʃə/   7.7 135 ± 8
(156 × 126)		 ≈ 130 66100 +0.51320 0.0 0.000 1986 1986 Synnott
(Voyager 2)		 Portia
XIII Rosalind /ˈrɒzələnd/   9.1 72 ± 12 ≈ 20 69900 +0.55846 0.0 0.000 1986 1986 Synnott
(Voyager 2)		 Portia
XXVII Cupid /ˈkjuːpəd/   12.6 ≈ 18 ≈ 0.31 74400 +0.61317 0.1 0.005 2003 2003 Showalter and
Lissauer		 Belinda
XIV Belinda /bəˈlɪndə/
 
 8.8 90 ± 16
(128 × 64)		 ≈ 38 75300 +0.62353 0.0 0.000 1986 1986 Synnott
(Voyager 2)		 Belinda
XXV Perdita /ˈpɜːrdətə/   11.0 30 ± 6 ≈ 1.4 76400 +0.63841 0.0 0.002 1999 1999 Karkoschka
(Voyager 2)		 Belinda
XV Puck /ˈpʌk/
 
 7.3 162 ± 4 191±64 86005 +0.76148 0.3562 0.0002 1985 1986 Synnott
(Voyager 2)
XXVI Mab /ˈmæb/
 
 12.1 ≈ 18 ≈ 0.31 97700 +0.92329 0.1 0.003 2003 2003 Showalter and
Lissauer		 μ ring source
V Miranda♠ /məˈrændə/
 
 3.5 471.6 ± 1.4
(481 × 468 × 466)		 6293±300 129858 +1.4138 4.4072 0.0014 1948 1948 Kuiper
I Ariel♠ /ˈɛəriɛl/
 
 1.0 1157.8±1.2
(1162 × 1156 × 1155)		 123310±1800 190930 +2.5207 0.0167 0.0012 1851 1851 Lassell
II Umbriel♠ /ˈʌmbriəl/
 
 1.7 1169.4±5.6 128850±2250 265982 +4.1445 0.0796 0.0039 1851 1851 Lassell
III Titania♠ /təˈtɑːniə/
 
 0.8 1576.8±1.2 345500±5090 436282 +8.7064 0.1129 0.0012 1787 1787 Herschel
IV Oberon♠ /ˈoʊbərɒn/
 
 1.0 1522.8±5.2 311040±7490 583449 +13.464 0.1478 0.0014 1787 1787 Herschel
XXII Francisco‡ /frænˈsɪskoʊ/ 12.4 ≈ 22 ≈ 0.56 4275700 −267.11 146.8 0.144 2001 2003 Holman et al.
XVI Caliban♦ /ˈkælɪbæn/   9.1 42+20
−12		 ≈ 3.9 7167000 −579.76 141.4 0.200 1997 1997 Gladman et al. Caliban
XX Stephano♦ /ˈstɛfənoʊ/   9.7 ≈ 32 ≈ 1.7 7951400 −677.55 143.6 0.235 1999 1999 Gladman et al. Caliban
S/2023 U 1♦ 13.7 ≈ 8 ≈ 0.027 7976600 −680.78 143.9 0.250 2023 2024 Sheppard et al. Caliban
XXI Trinculo‡ /ˈtrɪŋkjʊloʊ/ 12.7 ≈ 18 ≈ 0.31 8502600 −749.40 167.1 0.220 2001 2002 Holman et al.
XVII Sycorax‡ /ˈsɪkəræks/   7.4 157+23
−15		 ≈ 200 12193200 −1288.40 157.0 0.520 1997 1997 Nicholson et al.
XXIII Margaret† /ˈmɑːrɡərət/   12.7 ≈ 20 ≈ 0.42 14425000 +1655.16 60.5 0.642 2003 2003 Sheppard and
Jewitt
XVIII Prospero‡ /ˈprɒspəroʊ/   10.5 ≈ 50 ≈ 6.5 16221000 −1979.41 149.4 0.441 1999 1999 Holman et al.
XIX Setebos‡ /ˈsɛtɛbʌs/   10.7 ≈ 47 ≈ 5.4 17519800 −2224.94 153.9 0.579 1999 1999 Kavelaars et al.
XXIV Ferdinand‡ /ˈfɜːrdənænd/   12.5 ≈ 21 ≈ 0.48 20421400 −2808.70 169.2 0.395 2001 2003 Holman et al.

See also edit

Notes edit

  1. ^ The mass of Triton is about 2.14 × 1022 kg,[20] 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. ^ Label refers to the Roman numeral attributed to each moon in order of their discovery.[1]
  5. ^ 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.[21] The diameter of Titania is from Widemann, 2009.[42] 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 and Caliban were taken from Sheppard's website.[43] The radii of Sycorax and Caliban are from Farkas-Takács et al., 2017.[48]
  6. ^ Masses of Puck, Miranda, Ariel, Umbriel, Titania, and Oberon were taken from Jacobson, 2023 as reported in French, 2024.[49] Masses of all other moons were calculated assuming a density of 1 g/cm3 and using given radii.
  7. ^ a b c d Mean orbits of irregular satellites are taken from JPL Small System Dynamics,[46] while mean orbits of the five major moons and Puck are taken from Jacobson (2014).[45]
  8. ^ Negative orbital periods indicate a retrograde orbit around Uranus (opposite to the planet's orbit).
  9. ^ For regular satellites, inclination measures the angle between the moon's orbital plane and the plane defined by Uranus's equator. For irregular satellites, inclination measures the angle between the moon's orbital plane and the ecliptic.

References edit

  1. ^ a b c "Planet and Satellite Names and Discoverers". Gazetteer of Planetary Nomenclature. USGS Astrogeology. July 21, 2006. Retrieved 2006-08-06.
  2. ^ a b c d e f g 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. S2CID 5895824.
  3. ^ a b c d e f Sheppard, S. S.; Jewitt, D.; Kleyna, J. (2005). "An Ultradeep Survey for Irregular Satellites of Uranus: Limits to Completeness". The Astronomical Journal. 129 (1): 518–525. arXiv:astro-ph/0410059. Bibcode:2005AJ....129..518S. doi:10.1086/426329. S2CID 18688556.
  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. ^ a b c 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. S2CID 119916925.
  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: 1. Bibcode:1999IAUC.7171....1K. ISSN 0081-0304. Retrieved 2011-11-02.
  11. ^ a b 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. ^ a b c d e f 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. S2CID 13240973.
  13. ^ "MPEC 2024-D113 : S/2023 U 1". Minor Planet Electronic Circular. Minor Planet Center. 23 February 2024. Retrieved 23 February 2024.
  14. ^ a b c "New Uranus and Neptune Moons". Earth & Planetary Laboratory. Carnegie Institution for Science. 23 February 2024. Retrieved 23 February 2024.
  15. ^ "Gemini Observatory Archive Search - Program GN-2021B-DD-104". Gemini Observatory. Retrieved 23 February 2024.
  16. ^ 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.
  17. ^ Denning, W.F. (October 22, 1881). . Scientific American Supplement (303). Archived from the original on January 12, 2009.
  18. ^ William Lassell (1852). "Beobachtungen der Uranus-Satelliten". Astronomische Nachrichten. 34: 325. Bibcode:1852AN.....34..325.
  19. ^ a b Paul, Richard (2014). "The Shakespearean Moons of Uranus". folger.edu. Folger Shakespeare Library. Retrieved 25 February 2024.
  20. ^ 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. S2CID 39920233.
  21. ^ a b c 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.
  22. ^ Ćuk, Matija; French, Robert S.; Showalter, Mark R.; Tiscareno, Matthew S.; El Moutamid, Maryame (August 2022). "Cupid is not Doomed Yet: On the Stability of the Inner Moons of Uranus". The Astronomical Journal. 164 (2): 8. arXiv:2205.14272. Bibcode:2022AJ....164...38C. doi:10.3847/1538-3881/ac745d. S2CID 249192192. 38.
  23. ^ 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. S2CID 250909885.
  24. ^ Chancia, R.O.; Hedman, M.M. (2016). "Are there moonlets near Uranus' alpha and beta rings?". The Astronomical Journal. 152 (6): 211. arXiv:1610.02376. Bibcode:2016AJ....152..211C. doi:10.3847/0004-6256/152/6/211. S2CID 85559054.
  25. ^ a b 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.
  26. ^ 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.
  27. ^ 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.
  28. ^ "Uranus's colliding moons". astronomy.com. 2017. from the original on 26 February 2021. Retrieved 23 September 2017.
  29. ^ a b French, Robert S.; Showalter, Mark R. (August 2012). "Cupid is doomed: An analysis of the stability of the inner uranian satellites". Icarus. 220 (2): 911–921. arXiv:1408.2543. Bibcode:2012Icar..220..911F. doi:10.1016/j.icarus.2012.06.031. S2CID 9708287.
  30. ^ 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.
  31. ^ 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.
  32. ^ Hunt, Garry E.; Patrick Moore (1989). Atlas of Uranus. Cambridge University Press. pp. 78–85. ISBN 0-521-34323-2.
  33. ^ Detre, Ö. H.; Müller, T. G.; Klaas, U.; Marton, G.; Linz, H.; Balog, Z. (2020). "Herschel -PACS photometry of the five major moons of Uranus". Astronomy & Astrophysics. 641: A76. arXiv:2006.09795. Bibcode:2020A&A...641A..76D. doi:10.1051/0004-6361/202037625. ISSN 0004-6361.
  34. ^ Farkas-Takács, A.; Kiss, Cs.; Pál, A.; Molnár, L.; Szabó, Gy. M.; Hanyecz, O.; Sárneczky, K.; Szabó, R.; Marton, G.; Mommert, M.; Szakáts, R. (2017-08-31). "Properties of the Irregular Satellite System around Uranus Inferred from K2 , Herschel , and Spitzer Observations". The Astronomical Journal. 154 (3): 119. arXiv:1706.06837. Bibcode:2017AJ....154..119F. doi:10.3847/1538-3881/aa8365. ISSN 1538-3881.
  35. ^ a b c 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.
  36. ^ 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. S2CID 12105236.
  37. ^ Pappalardo, R. T.; Reynolds, S. J.; Greeley, R. (1996). . Journal of Geophysical Research. 102 (E6): 13, 369–13, 380. Bibcode:1997JGR...10213369P. doi:10.1029/97JE00802. Archived from the original on 2008-03-02.
  38. ^ 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. hdl:1721.1/57632.
  39. ^ 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.
  40. ^ 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. hdl:1721.1/57632.
  41. ^ 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.
  42. ^ a b 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.; et al. (February 2009). (PDF). Icarus. 199 (2): 458–476. Bibcode:2009Icar..199..458W. doi:10.1016/j.icarus.2008.09.011. Archived from the original (PDF) on July 25, 2014. Retrieved September 4, 2015.
  43. ^ a b Sheppard, Scott S. "Moons of Uranus". Earth & Planets Laboratory. Carnegie Institution for Science. Retrieved 23 February 2024.
  44. ^ Brozović, Marina; Jacobson, Robert A. (April 2009). "The Orbits of the Outer Uranian Satellites". The Astronomical Journal. 137 (4): 3834–3842. Bibcode:2009AJ....137.3834B. doi:10.1088/0004-6256/137/4/3834.
  45. ^ a b Jacobson, Robert A. (November 2014). "The Orbits of the Uranian Satellites and Rings, the Gravity Field of the Uranian System, and the Orientation of the Pole of Uranus". The Astronomical Journal. 148 (5): 13. Bibcode:2014AJ....148...76J. doi:10.1088/0004-6256/148/5/76. S2CID 122457734. 76.
  46. ^ a b "Planetary Satellite Mean Elements". Jet Propulsion Laboratory. Retrieved 28 February 2024. Note: Orbital elements of regular satellites are with respect to the Laplace plane, while orbital elements of irregular satellites are with respect to the ecliptic. Inclinations greater than 90° are retrograde. Orbital periods of irregular satellites may not be consistent with their semi-major axes due to perturbations.
  47. ^ "Natural Satellites Ephemeris Service". IAU: Minor Planet Center. Retrieved 2011-01-08.
  48. ^ Farkas-Takács, A.; Kiss, Cs.; Pál, A.; Molnár, L.; Szabó, Gy. M.; Hanyecz, O.; et al. (September 2017). "Properties of the Irregular Satellite System around Uranus Inferred from K2, Herschel, and Spitzer Observations". The Astronomical Journal. 154 (3): 13. arXiv:1706.06837. Bibcode:2017AJ....154..119F. doi:10.3847/1538-3881/aa8365. S2CID 118869078. 119.
  49. ^ French, Richard G.; Hedman, Matthew M.; Nicholson, Philip D.; Longaretti, Pierre-Yves; McGhee-French, Colleen A. (March 2024). "The Uranus system from occultation observations (1977–2006): Rings, pole direction, gravity field, and masses of Cressida, Cordelia, and Ophelia". Icarus. 411: 115957. arXiv:2401.04634. doi:10.1016/j.icarus.2024.115957.
  50. ^ a b "Planetary Satellite Discovery Circumstances". JPL Solar System Dynamics. NASA. Retrieved 28 February 2024.

External links edit

 
Wikimedia Commons has media related to Moons of Uranus.
  • Scott S. Sheppard: Uranus Moons
  • . NASA's Solar System Exploration. Archived from the original on 21 October 2015. Retrieved 20 December 2008.
  • "NASA's Hubble Discovers New Rings and Moons Around Uranus". Space Telescope Science Institute. 22 December 2005. Retrieved 20 December 2008.
  • "Uranus Rings photos", James Webb Space Telescope, NASA, December 18, 2023, retrieved 19 December 2023

May 04, 2024
moons, uranus, uranus, seventh, planet, solar, system, confirmed, moons, most, them, named, after, characters, that, appear, mentioned, works, william, shakespeare, alexander, pope, uranus, moons, divided, into, three, groups, thirteen, inner, moons, five, maj. Uranus the seventh planet of the Solar System has 28 confirmed moons Most of them are named after characters that appear in or are mentioned in the works of William Shakespeare and Alexander Pope 1 Uranus s moons are divided into three groups thirteen inner moons five major moons and ten irregular moons The inner and major moons all have prograde orbits and are cumulatively classified as regular moons In contrast the orbits of the irregular moons are distant highly inclined and mostly retrograde An updated image of the six largest moons and eight inner moons of Uranus as captured by the James Webb Space Telescope on September 4 2023 The inner moons are small dark bodies that share common properties and origins with Uranus s rings The five major moons are ellipsoidal indicating that they reached hydrostatic equilibrium at some point in their past and may still be in 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 about one twentieth the mass of 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 William Herschel discovered the first two moons Titania and Oberon in 1787 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 may be in hydrostatic equilibrium 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 Contents 1 Discovery 1 1 Spurious moons 2 Names 3 Characteristics and groups 3 1 Inner moons 3 2 Large moons 3 3 Irregular moons 4 List 5 See also 6 Notes 7 References 8 External linksDiscovery editThe 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 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 by Erich Karkoschka after studying old Voyager photographs 11 Uranus was the last giant planet without any known irregular moons until 1997 when astronomers using ground based telescopes discovered Sycorax and Caliban From 1999 to 2003 astronomers continued searching for irregular moons of Uranus using more powerful ground based telescopes resulting in the discovery of seven more Uranian irregular moons 3 In addition two small inner moons Cupid and Mab were discovered using the Hubble Space Telescope in 2003 12 No other discoveries were made until 2021 and 2023 when Scott Sheppard and colleagues discovered one more irregular moon of Uranus and five more candidates waiting to be announced using the Subaru Telescope at Mauna Kea Hawaii 13 14 15 Spurious moons edit 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 besides 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 16 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 17 Discovery of outer planet moons Graphs are unavailable due to technical issues There is more info on Phabricator and on MediaWiki org Moons of Jupiter Moons of Saturn Moons of Uranus Moons of NeptuneNames editMain article Naming of moons See also Name conflicts with minor planets 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 18 It is uncertain if John Herschel was the originator of the names or if it was instead William Lassell who discovered Ariel and Umbriel who chose the names and asked Herschel for permission 19 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 8 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 The outer retrograde moons are all named after characters from one play The Tempest the sole known outer prograde moon Margaret is named from Much Ado About Nothing 19 Some asteroids also named after the same Shakespearean characters share names with moons of Uranus 171 Ophelia 218 Bianca 593 Titania 666 Desdemona 763 Cupido and 2758 Cordelia Characteristics and groups editThe 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 a The largest of the satellites Titania has a radius of 788 9 km 21 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 b Inner moons edit See also Inner moon and Rings of Uranus nbsp Schematic of the Uranian moon ring system As of 2024 Uranus is known to have 13 inner moons whose orbits all lie inside that of Miranda 12 The inner moons are classified into two groups based on similar orbital distances these are the Portia group which includes the six moons Bianca Cressida Desdemona Juliet Portia and Rosalind and the Belinda group which includes the three moons Cupid Belinda and Perdita 12 22 All of the inner moons are intimately connected with the rings of Uranus which probably resulted from the fragmentation of one or several small inner moons 23 The two innermost moons Cordelia and Ophelia are shepherds of Uranus s e ring whereas the small moon Mab is a source of Uranus s outermost m ring 12 There may be two additional small 2 7 km in radius undiscovered shepherd moons located about 100 km exterior to Uranus s a and b rings 24 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 25 They are composed of water ice contaminated with a dark material probably radiation processed organics 26 The inner moons constantly perturb each other especially within the closely packed Portia and Belinda groups The system is chaotic and apparently unstable 27 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 Cressida within the next million years 28 and Cupid will likely collide with Belinda in the next 10 million years Perdita and Juliet may be involved in later collisions 29 Because of this the rings and inner moons may be under constant flux with moons colliding and re accreting on short timescales 29 Large moons edit nbsp Uranus and its six largest moons compared at their proper relative sizes and in the correct order From left to right Puck Miranda Ariel Umbriel Titania and OberonUranus has five major moons Miranda Ariel Umbriel Titania and Oberon They range in diameter from 472 km for Miranda to 1578 km for Titania 21 All these moons are relatively dark objects their geometrical albedo varies between 30 and 50 whereas their Bond albedo is between 10 and 23 25 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 30 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 31 32 This view is supported by their large thermal inertia a surface property they share with dwarf planets like Pluto and Haumea 33 It differs strongly from the thermal behaviour of the Uranian irregular moons that is comparable to classical trans Neptunian objects 34 This suggests a separate origin nbsp Moons Ariel Umbriel Titania Oberon Miranda Modeling 4 May 2023 All major moons comprise approximately equal amounts rock and ice except Miranda which is made primarily of ice 35 The ice component may include ammonia and carbon dioxide 36 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 37 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 38 39 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 40 41 The largest Uranian moons may be internally differentiated with rocky cores at their centers surrounded by ice mantles 35 Titania and Oberon may harbor liquid water oceans at the core mantle boundary 35 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 42 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 c during the hemispheric summer 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 during the hemispheric summer moving to a position over the celestial equator during the Uranian equinox and then invisible below the horizon during the hemispheric winter Irregular moons edit See also Irregular moon nbsp Irregular satellites of Jupiter red Saturn green Uranus magenta and Neptune blue including Triton plotted by distance from their planet semi major axis in the horizontal axis and orbital inclination in the vertical axis The semi major axis values are expressed as a fraction of the planet s Hill sphere s radius while the inclination is expressed in degrees from the ecliptic The radius of the Uranian Hill sphere is approximately 73 million km 3 The relative sizes of moons are indicated by the size of their symbols and the Caliban group of Uranian moons is labeled Data as of February 2024 Uranus s irregular moons range in size from 120 to 200 km Sycorax to under 10 km S 2023 U 1 43 Due to the small number of known Uranian irregular moons it is not yet clear which of them belong to groups with similar orbital characteristics The only known group among Uranus s irregular moons is the Caliban group which is clustered at orbital distances between 6 7 million km 3 7 4 3 million mi and inclinations between 141 144 14 The Caliban group includes three retrograde moons which are Caliban S 2023 U 1 Stephano 14 The intermediate inclinations 60 lt i lt 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 has one of the most eccentric orbits of any moon in the Solar System List edit nbsp Orbital diagram of the orbital inclination and orbital distances for Uranus s rings and moon system at various scales Open the image for full resolution 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 The inner and major moons all have prograde orbits 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 The orbits and mean distances of the irregular moons are variable over short timescales due to frequent planetary and solar perturbations therefore the listed orbital elements of all irregular moons are averaged over a 8 000 year numerical integration by Brozovic and Jacobson 2009 These may differ from osculating orbital elements provided by other sources 44 The orbital elements of major moons listed here are based on the epoch of 1 January 2000 45 while orbital elements of irregular satellites are based on the epoch of 1 January 2020 46 Key Inner moons Major moons Ungrouped prograde irregular moons Ungrouped retrograde irregular moons Caliban group Uranian moons Label d Name Pronunciation key Image Abs magn 47 Diameter km e Mass 1016 kg f Semi major axis km g Orbital period d g h Inclination g i Eccentricity g Discovery year 50 Year announced Discoverer 50 Group VI Cordelia k ɔːr ˈ d iː l i e nbsp 10 3 40 6 50 36 3 4 49800 0 33457 0 2 0 000 1986 1986 Terrile Voyager 2 e ring shepherd VII Ophelia oʊ ˈ f iː l i e nbsp 10 2 43 8 54 38 4 2 53800 0 37686 0 1 0 011 1986 1986 Terrile Voyager 2 e ring shepherd VIII Bianca b i ˈ ɑː ŋ k e nbsp 9 8 51 4 64 46 6 9 59200 0 43501 0 1 0 001 1986 1986 Smith Voyager 2 Portia IX Cressida ˈ k r ɛ s e d e nbsp 8 9 80 4 92 74 27 61800 0 46315 0 1 0 000 1986 1986 Synnott Voyager 2 Portia X Desdemona ˌ d ɛ z d e ˈ m oʊ n e nbsp 9 3 64 8 90 54 14 62700 0 47323 0 1 0 000 1986 1986 Synnott Voyager 2 Portia XI Juliet ˈ dʒ uː l i e t nbsp 8 5 94 8 150 74 43 64400 0 49348 0 0 0 001 1986 1986 Synnott Voyager 2 Portia XII Portia ˈ p ɔːr ʃ e nbsp 7 7 135 8 156 126 130 66100 0 51320 0 0 0 000 1986 1986 Synnott Voyager 2 Portia XIII Rosalind ˈ r ɒ z e l e n d nbsp 9 1 72 12 20 69900 0 55846 0 0 0 000 1986 1986 Synnott Voyager 2 Portia XXVII Cupid ˈ k juː p e d nbsp 12 6 18 0 31 74400 0 61317 0 1 0 005 2003 2003 Showalter and Lissauer Belinda XIV Belinda b e ˈ l ɪ n d e nbsp 8 8 90 16 128 64 38 75300 0 62353 0 0 0 000 1986 1986 Synnott Voyager 2 Belinda XXV Perdita ˈ p ɜːr d e t e nbsp 11 0 30 6 1 4 76400 0 63841 0 0 0 002 1999 1999 Karkoschka Voyager 2 Belinda XV Puck ˈ p ʌ k nbsp 7 3 162 4 191 64 86005 0 76148 0 3562 0 0002 1985 1986 Synnott Voyager 2 XXVI Mab ˈ m ae b nbsp 12 1 18 0 31 97700 0 92329 0 1 0 003 2003 2003 Showalter and Lissauer m ring source V Miranda m e ˈ r ae n d e nbsp 3 5 471 6 1 4 481 468 466 6293 300 129858 1 4138 4 4072 0 0014 1948 1948 Kuiper I Ariel ˈ ɛer i ɛ l nbsp 1 0 1157 8 1 2 1162 1156 1155 123310 1800 190930 2 5207 0 0167 0 0012 1851 1851 Lassell II Umbriel ˈ ʌ m b r i e l nbsp 1 7 1169 4 5 6 128850 2250 265982 4 1445 0 0796 0 0039 1851 1851 Lassell III Titania t e ˈ t ɑː n i e nbsp 0 8 1576 8 1 2 345500 5090 436282 8 7064 0 1129 0 0012 1787 1787 Herschel IV Oberon ˈ oʊ b e r ɒ n nbsp 1 0 1522 8 5 2 311040 7490 583449 13 464 0 1478 0 0014 1787 1787 Herschel XXII Francisco f r ae n ˈ s ɪ s k oʊ 12 4 22 0 56 4275 700 267 11 146 8 0 144 2001 2003 Holman et al XVI Caliban ˈ k ae l ɪ b ae n nbsp 9 1 42 20 12 3 9 7167 000 579 76 141 4 0 200 1997 1997 Gladman et al Caliban XX Stephano ˈ s t ɛ f e n oʊ nbsp 9 7 32 1 7 7951 400 677 55 143 6 0 235 1999 1999 Gladman et al Caliban S 2023 U 1 13 7 8 0 027 7976 600 680 78 143 9 0 250 2023 2024 Sheppard et al Caliban XXI Trinculo ˈ t r ɪ ŋ k j ʊ l oʊ 12 7 18 0 31 8502 600 749 40 167 1 0 220 2001 2002 Holman et al XVII Sycorax ˈ s ɪ k e r ae k s nbsp 7 4 157 23 15 200 12193 200 1288 40 157 0 0 520 1997 1997 Nicholson et al XXIII Margaret ˈ m ɑːr ɡ er e t nbsp 12 7 20 0 42 14425 000 1655 16 60 5 0 642 2003 2003 Sheppard and Jewitt XVIII Prospero ˈ p r ɒ s p e r oʊ nbsp 10 5 50 6 5 16221 000 1979 41 149 4 0 441 1999 1999 Holman et al XIX Setebos ˈ s ɛ t ɛ b ʌ s nbsp 10 7 47 5 4 17519 800 2224 94 153 9 0 579 1999 1999 Kavelaars et al XXIV Ferdinand ˈ f ɜːr d e n ae n d nbsp 12 5 21 0 48 20421 400 2808 70 169 2 0 395 2001 2003 Holman et al See also editList of natural satellitesNotes edit The mass of Triton is about 2 14 1022 kg 20 whereas the combined mass of the Uranian moons is about 0 92 1022 kg Uranus mass of 8 681 1025 kg Mass of Uranian moons of 0 93 1022 kg The axial tilt of Uranus is 97 2 Label refers to the Roman numeral attributed to each moon in order of their discovery 1 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 21 The diameter of Titania is from Widemann 2009 42 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 and Caliban were taken from Sheppard s website 43 The radii of Sycorax and Caliban are from Farkas Takacs et al 2017 48 Masses of Puck Miranda Ariel Umbriel Titania and Oberon were taken from Jacobson 2023 as reported in French 2024 49 Masses of all other moons were calculated assuming a density of 1 g cm3 and using given radii a b c d Mean orbits of irregular satellites are taken from JPL Small System Dynamics 46 while mean orbits of the five major moons and Puck are taken from Jacobson 2014 45 Negative orbital periods indicate a retrograde orbit around Uranus opposite to the planet s orbit For regular satellites inclination measures the angle between the moon s orbital plane and the plane defined by Uranus s equator For irregular satellites inclination measures the angle between the moon s orbital plane and the ecliptic References edit a b c Planet and Satellite Names and Discoverers Gazetteer of Planetary Nomenclature USGS Astrogeology July 21 2006 Retrieved 2006 08 06 a b c d e f g 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 S2CID 5895824 a b c d e f Sheppard S S Jewitt D Kleyna J 2005 An Ultradeep Survey for Irregular Satellites of Uranus Limits to Completeness The Astronomical Journal 129 1 518 525 arXiv astro ph 0410059 Bibcode 2005AJ 129 518S doi 10 1086 426329 S2CID 18688556 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 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 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 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 a b c 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 S2CID 119916925 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 Karkoschka Erich May 18 1999 S 1986 U 10 IAU Circular 7171 1 Bibcode 1999IAUC 7171 1K ISSN 0081 0304 Retrieved 2011 11 02 a b 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 a b c d e f 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 S2CID 13240973 MPEC 2024 D113 S 2023 U 1 Minor Planet Electronic Circular Minor Planet Center 23 February 2024 Retrieved 23 February 2024 a b c New Uranus and Neptune Moons Earth amp Planetary Laboratory Carnegie Institution for Science 23 February 2024 Retrieved 23 February 2024 Gemini Observatory Archive Search Program GN 2021B DD 104 Gemini Observatory Retrieved 23 February 2024 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 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 William Lassell 1852 Beobachtungen der Uranus Satelliten Astronomische Nachrichten 34 325 Bibcode 1852AN 34 325 a b Paul Richard 2014 The Shakespearean Moons of Uranus folger edu Folger Shakespeare Library Retrieved 25 February 2024 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 S2CID 39920233 a b c 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 Cuk Matija French Robert S Showalter Mark R Tiscareno Matthew S El Moutamid Maryame August 2022 Cupid is not Doomed Yet On the Stability of the Inner Moons of Uranus The Astronomical Journal 164 2 8 arXiv 2205 14272 Bibcode 2022AJ 164 38C doi 10 3847 1538 3881 ac745d S2CID 249192192 38 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 S2CID 250909885 Chancia R O Hedman M M 2016 Are there moonlets near Uranus alpha and beta rings The Astronomical Journal 152 6 211 arXiv 1610 02376 Bibcode 2016AJ 152 211C doi 10 3847 0004 6256 152 6 211 S2CID 85559054 a b 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 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 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 Uranus s colliding moons astronomy com 2017 Archived from the original on 26 February 2021 Retrieved 23 September 2017 a b French Robert S Showalter Mark R August 2012 Cupid is doomed An analysis of the stability of the inner uranian satellites Icarus 220 2 911 921 arXiv 1408 2543 Bibcode 2012Icar 220 911F doi 10 1016 j icarus 2012 06 031 S2CID 9708287 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 Mousis O 2004 Modeling the thermodynamical conditions in the Uranian subnebula Implications for regular satellite composition Astronomy amp Astrophysics 413 373 380 Bibcode 2004A amp A 413 373M doi 10 1051 0004 6361 20031515 Hunt Garry E Patrick Moore 1989 Atlas of Uranus Cambridge University Press pp 78 85 ISBN 0 521 34323 2 Detre O H Muller T G Klaas U Marton G Linz H Balog Z 2020 Herschel PACS photometry of the five major moons of Uranus Astronomy amp Astrophysics 641 A76 arXiv 2006 09795 Bibcode 2020A amp A 641A 76D doi 10 1051 0004 6361 202037625 ISSN 0004 6361 Farkas Takacs A Kiss Cs Pal A Molnar L Szabo Gy M Hanyecz O Sarneczky K Szabo R Marton G Mommert M Szakats R 2017 08 31 Properties of the Irregular Satellite System around Uranus Inferred from K2 Herschel and Spitzer Observations The Astronomical Journal 154 3 119 arXiv 1706 06837 Bibcode 2017AJ 154 119F doi 10 3847 1538 3881 aa8365 ISSN 1538 3881 a b c 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 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 S2CID 12105236 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 Archived from the original on 2008 03 02 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 hdl 1721 1 57632 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 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 hdl 1721 1 57632 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 a b 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 et al 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 Archived from the original PDF on July 25 2014 Retrieved September 4 2015 a b Sheppard Scott S Moons of Uranus Earth amp Planets Laboratory Carnegie Institution for Science Retrieved 23 February 2024 Brozovic Marina Jacobson Robert A April 2009 The Orbits of the Outer Uranian Satellites The Astronomical Journal 137 4 3834 3842 Bibcode 2009AJ 137 3834B doi 10 1088 0004 6256 137 4 3834 a b Jacobson Robert A November 2014 The Orbits of the Uranian Satellites and Rings the Gravity Field of the Uranian System and the Orientation of the Pole of Uranus The Astronomical Journal 148 5 13 Bibcode 2014AJ 148 76J doi 10 1088 0004 6256 148 5 76 S2CID 122457734 76 a b Planetary Satellite Mean Elements Jet Propulsion Laboratory Retrieved 28 February 2024 Note Orbital elements of regular satellites are with respect to the Laplace plane while orbital elements of irregular satellites are with respect to the ecliptic Inclinations greater than 90 are retrograde Orbital periods of irregular satellites may not be consistent with their semi major axes due to perturbations Natural Satellites Ephemeris Service IAU Minor Planet Center Retrieved 2011 01 08 Farkas Takacs A Kiss Cs Pal A Molnar L Szabo Gy M Hanyecz O et al September 2017 Properties of the Irregular Satellite System around Uranus Inferred from K2 Herschel and Spitzer Observations The Astronomical Journal 154 3 13 arXiv 1706 06837 Bibcode 2017AJ 154 119F doi 10 3847 1538 3881 aa8365 S2CID 118869078 119 French Richard G Hedman Matthew M Nicholson Philip D Longaretti Pierre Yves McGhee French Colleen A March 2024 The Uranus system from occultation observations 1977 2006 Rings pole direction gravity field and masses of Cressida Cordelia and Ophelia Icarus 411 115957 arXiv 2401 04634 doi 10 1016 j icarus 2024 115957 a b Planetary Satellite Discovery Circumstances JPL Solar System Dynamics NASA Retrieved 28 February 2024 External links edit nbsp Wikimedia Commons has media related to Moons of Uranus Scott S Sheppard Uranus Moons Simulation Showing the location of Uranus s Moons Uranus Moons NASA s Solar System Exploration Archived from the original on 21 October 2015 Retrieved 20 December 2008 NASA s Hubble Discovers New Rings and Moons Around Uranus Space Telescope Science Institute 22 December 2005 Retrieved 20 December 2008 Gazetteer of Planetary Nomenclature Uranus USGS Uranus Rings photos James Webb Space Telescope NASA December 18 2023 retrieved 19 December 2023 Portals nbsp Science nbsp Stars nbsp Spaceflight nbsp Outer space Retrieved from https en wikipedia org w 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