Uranus's satellites
Uranus is orbited by 17 satellites, nearly as many as Saturn which has 18. Uranus also has 9 rings. The table below provides some information on the dimensions and orbital characteristics of Uranus' satellites (Illingworth, 1994; and other sources).
| Satellite | Year of Discovery |
Diameter (Km) |
Orbital Radius (Km) |
Eccentricity | Orbital Period (days) |
Inclination (°) |
|---|---|---|---|---|---|---|
| Cordelia | 1986 | 26 | 50 000 | < 0.001 | 0.34 | 0.10 |
| Ophelia | 1986 | 30 | 54 000 | 0.010 | 0.38 | 0.10 |
| Bianca | 1986 | 42 | 59 000 | < 0.001 | 0.43 | 0.20 |
| Cressida | 1986 | 62 | 62 000 | < 0.001 | 0.46 | 0.00 |
| Desdemona | 1986 | 54 | 63 000 | < 0.001 | 0.47 | 0.20 |
| Juliet | 1986 | 84 | 64 000 | < 0.001 | 0.49 | 0.10 |
| Portia | 1986 | 108 | 66 000 | < 0.001 | 0.51 | 0.10 |
| Rosalind | 1986 | 54 | 70 000 | < 0.001 | 0.56 | 0.30 |
| Belinda | 1986 | 66 | 75 000 | < 0.001 | 0.62 | 0.00 |
| Puck | 1985 | 154 | 86 000 | < 0.001 | 0.76 | 0.31 |
| Miranda | 1948 | 472 | 129 000 | 0.003 | 1.41 | 4.20 |
| Ariel | 1851 | 1 158 | 191 000 | 0.003 | 2.52 | 0.30 |
| Umbriel | 1851 | 1 172 | 266 000 | 0.005 | 4.14 | 0.36 |
| Titania | 1787 | 1 580 | 436 000 | 0.002 | 8.71 | 0.14 |
| Oberon | 1787 | 1 524 | 583 000 | 0.001 | 13.46 | 0.10 |
| Caliban | 1997 | 37 - 60 | 7 200 000 | nearly circular | 1.6y R | 40 |
| Sycorax | 1997 | 60 - 120 | 6 - 18 000 000 | very high | 3.5y R | high |
Caliban and Sycorax
On 31st October 1997, Philip Nicholson, Joseph Burns, Brett Gladman and J.J. Kavelaars announced that they had discovered two new satellites of Uranus, which were officially named Caliban and Sycorax by the IAU (after the suggestions were put forward by the discoverers) in April or May 1998. The two satellites are listed in the table above. They are both small, irregularly shaped, and pinkish in colour (probably due to solar ultra-violet radiation converting the methane-rich icy surfaces to slightly darker pink hydrocarbons).