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Encyclopedia > Numbers about the solar system X
Orbital elements of satellites: SATURN
The planet Saturn has rings and four families of satellites, orbiting around it (86 satellites of which 83 numbered on December 3, 2022).
- the rings are easily observable from Earth: the Cassini division between the rings is also visible from Earth and the space probe Voyager put into evidence the large number of rings surrounding Saturn.
- the inner satellites : these satellites are orbiting inside the orbit of Enceladus, and outside the A ring. Some are orbiting inside the external faint E, F, G rings seeming to "shepherd" these rings as described in the rings table. Because of the closeness of the planet, they are very difficult to observe. Infrared observations are necessary in order to decrease the contrast brightness between the planet and the satellites but, since the rings remain bright, it is easier to wait until the transit of the Earth in the plane of the rings to make observations. At that time, the rings seem to disappear, allowing observations of these faint satellites.
- the coorbital satellites: these satellites are orbiting on the same orbit than some main satellites: most of time they are at the lagrangian points with a strong libration around these points.
- the main satellites: these satellites are bright, similar to small planets, and easily observable even in a small telescope, except Mimas because of the closeness of Saturn and Hyperion which is the faintest. Their observations are easy to make and they present phenomena due to the closeness and the size of the planet Saturn.
- the outer irregular satellites: these satellites are orbiting outside the orbit of Iapetus, the farthest main satellite. They are very faint due to their small sizes and their orbits are neither circular, nor in the equatorial plane of Saturn as the inner and the main satellites (except Iapetus). They are observable as asteroids, independently of the planet Saturn far from them. Only their faintness is a difficulty for their observation. These satellites are distributed into two families: the direct orbits and the retrograde orbits (direct = inclination < 90°; retrograde = inclination > 90°).
The tables below provide the main characteristics of these satellites including orbital parameters. These data may change either because new data are more precise, or because some parameters are evoluting year after year. The year of the discovery is provided by the provisional name of the satellite. For some satellites, specific descriptive pages are available.
The rings
| Rings and inner satellites |
Distance from the beginning of the ring to the center of Saturn |
Width |
Thickness |
Albedo |
|---|---|---|---|---|
| D | 67 000 km | 7 500 km | ? | ? |
| C | 74 500 km | 17 500 km | ? | 0.25 |
| Maxwell division | 87 500 km | 270 km | - | - |
| B | 92 000 km | 25 500 km | 0.1 to 1 km | 0.65 |
| Cassini division | 117 500 km | 4 700 km | ? | 0.30 |
| A | 122 200 km | 14 600 km | 0.1 to 1 km | 0.60 |
| Division de Encke | 133 570 km | 325 km | - | - |
| Keeler division | 136 530 km | 35 km | - | - |
| satellite Daphnis (S-35) | 136 545 km | - | - | - |
| satellite Pan (S-18) | 136 600 km | - | - | - |
| satellite Atlas (S-15) | 137 670 km | - | - | - |
| satellite Prometheus (S-16) | 139 350 km | - | - | - |
| F ("shepherd" by Prometheus and Pandora) | 140 210 km | 30 to 500 km | ? | ? |
| satellite Pandora (S-17) | 141 700 km | - | - | - |
| Epimetheus (S-11) | 151 420 km | - | - | - |
| Janus (S-10) | 151 470 km | - | - | - |
| G | 165 800 km | 8 000 km | 100 to 1000 km | ? |
| E | 180 000 km | 300 000 km | 1000 km | ? |
The small inner satellites inside the orbit of Rhea, "shepherds of the rings" or "coorbital" (for comparison: the main satellites)
| satellites: | a en km | P in hr, mn, s or in days | excentricité | inclination on the equateur of Saturn | d in km | mv | ap in arcsec | coorbital: associated satellite |
|---|---|---|---|---|---|---|---|---|
| S/2009 S1 | 117 000 | 11h 21m | 0.0 | 0.0° | 0.3 | 26.8 | 21" | - |
| S/1981 S13 - Pan - S 18 | 133 600 | 13h 48m | 0.0 | 0.0° | 20 | 19 | 23" | - |
| S/2005 S1 - Daphnis - S 35 | 136 545 | 14h 15m | 0.0 | 0.0° | 7 | 24 | 24" | - |
| S/1980 S28 - Atlas - S 15 | 137 670 | 14h 27m | 0.002 | 0.3° | 37 x 35 x 27 | 18 | 24" | - |
| S/1980 S27 - Prometheus - S 16 | 139 350 | 14h 43m | 0.002 | 0.0° | 148 x 100 x 68 | 15 | 24" | - |
| S/1980 S26 - Pandora - S 17 | 141 700 | 15h 05m | 0.004 | 0.0° | 110 x 88 x 62 | 15.5 | 24" | - |
| S/1980 S3 - Epimetheus - S 11 | 151 420 | 16h 39.8m | 0.009 | 0.34° | 138 x 110 x 110 | 15 | 26" | - |
| S/1980 S1 - Janus - S 10 | 151 470 | 16h 40.3m | 0.007 | 0.14° | 194 x 190 x 154 | 14 | 26" | - |
| S/2008 S1 - Aegaeon - S 53 | 167 500 | 0.808d | 0.0002 | 0.001° | 0.5 | 26.5 | 29" | - |
| Mimas - S 1 | 185 540 | 0.942d | 0.019 | 1.56° | 418 x 392.4 x 383 | 12.9 | 32" | - |
| S/2004 S1 - Methone - S 32 | 194 000 | 1.01d | 0.0 | 0.0° | 3 | 25 | 34" | - |
| S/2007 S4 - Anthe - S 49 | 197 700 | 1.04d | 0.001 | 0.10° | 1 | 26 | 34" | - |
| S/2004 S2 - Pallene - S 33 | 211 000 | 1.14 d | 0.0 | 0.0° | 4 | 25 | 35" | - |
| Enceladus - S 2 | 238 200 | 1.37d | 0.005 | 0.03° | 512.6 x 494.6 x 489.2 | 11.7 | 41" | - |
| S/1980 S13 - Telesto - S 13 | 294 660 | 1.8878 d | 0.001 | 1.158° | 30 x 25 x 15 | 18 | 50" | Tethys |
| S/1980 S25 - Calypso - S 14 | 294 660 | 1.8878 d | 0.001 | 1.473° | 30 x 16 x 16 | 18.5 | 50" | Tethys |
| Tethys - S 3 | 294 992 | 1.8878 d | 0.0 | 1.10° | 1071.2 x 1056.4 x 1051.6 | 10.3 | 51" | - |
| S/2004 S5 Polydeuces - S 34 | 377 400 | 2.74 d | 0.0 | 0.0° | 4 | 25 | 65" | Dione |
| S/1980 S6 - Helene - S 12 | 377 400 | 2.74 d | 0.0 | 0.212 ° | 32 | 17 | 65" | Dione |
| Dione - S 4 | 377 654 | 2.74 d | 0.0022 | 0.01° | 1120 | 10.4 | 65" | - |
The main satellites
| Mimas S 1 |
Enceladus S 2 |
Tethys S 3 |
Dione S 4 |
Rhea S 5 |
Titan S 6 |
Hyperion S 7 |
Iapetus S 8 |
|
|---|---|---|---|---|---|---|---|---|
| semi-makor axis in km | 185 540 | 238 200 | 294 992 | 377 654 | 527 367 | 1 221 803 | 1 481 100 | 3 561 850 |
| period of revolution in days | 0.942 422 | 1.370 218 | 1.887 803 | 2 736 916 | 4.517 503 | 15.945 446 | 21.276 673 | 79.330 954 |
| eccentricity | 0.01905 | 0.0049 | 0.0 | 0.0022 | 0.0003 | 0.0291 | 0.1035 | 0.0283 |
| inclination on the equateur of Saturn | 1.56 ° | 0.03 ° | 1.10 ° | 0.01° | 0.35 ° | 0.30 ° | 0.64 ° | 18.5 ° |
| size in km | 418 x 392.4 x 383 | 512.6 x 494.6 x 489.2 | 1071.2 x 1056.4 x 1051.6 | 1120 | 1528 | 5150 | 360 x 280 x 225 | 1436 |
| mv | 12.9 | 11.7 | 10.3 | 10.4 | 9.7 | 8.3 | 14.19 | 10.2 to 11.9 |
| ap in arcsec | 32" | 41" | 51" | 65" | 90" | 209" | 254" | 610" |
The outer satellites
- The outer satellites present also two families of satellites :
- the "direct" satellites
- the "retrograde" satellites (including S 9 - Phoebe)
The variation of the osculating elements are given from 1975 to 2045.
The "direct" family (direct revolution):
| satellites |
a |
P in years |
eccentricity |
inclination on ecliptic |
d in km |
mv |
ap |
|---|---|---|---|---|---|---|---|
| S/2000 S5 - Kiviuq - S 24 | 11.27 to 11.34 | 1.23 | 0.141 to 0.181 | 48 to 50° | 14 | 22.1 | 0.54° |
| S/2000 S6 - Ijiraq - S 22 | 11.30 to 11.39 | 1.24 | 0.277 to 0.436 | 47 to 51° | 10 | 23.0 | 0.54° |
| S/2000 S2 - Paaliaq - S 20 | 14.85 to 15.15 | 1.88 | 0.283 to 0.595 | 39 to 51° | 18 | 21.6 | 0.71° |
| S/2000 S11 - Albiorix - S 26 | 16.09 to 16.63 | 2.17 | 0.397 to 0.631 | 33 to 45° | 21 | 20.3 | 0.78° |
| S/2004 S29 - S2428b | 16.78 to 17.42 | 2.35 | 0.332 to 0.665 | 32 to 47° | 4 | 24.9 | 0.82° |
| S/2004 S11 - Bebhionn - S 37 | 16.80 to 17.34 | 2.25 | 0.317 to 0.392 | 35 to 44° | 6 | 24.1 | 0.80° |
| S/2000 S10 - Erriapo - S 28 | 17.19 to 17.90 | 2.43 | 0.328 to 0.621 | 33 to 46° | 8 | 23.2 | 0.85° |
| S/2004 S31 - T522499 | 17.23 to 17.75 | 2.34 | 0.127 to 0.304 | 46 to 51° | 4 | 24.9 | 0.82° |
| S/2007 S1 - Tarqeq - S 52 | 17.50 to 18.00 | 2.45 | 0.044 to 0.169 | 48 to 52° | 7 | 23.9 | 0.84° |
| S/2000 S3 - Siarnaq - S 29 | 17.57 to 18.24 | 2.51 | 0.290 to 0.541 | 41 to 52° | 35 | 20.0 | 0.87° |
| S/2000 S4 - Tarvos - S 21 | 17.83 to 18.71 | 2.46 | 0.382 to 0.703 | 33 to 46° | 12 | 22.2 | 0.86° |
| S/2004 S24 - S8881b | 22.64 to 24.11 | 3.61 | 0.003 to 0.136 | 33 to 38° | 3 | 25.2 | 1.22° |
The "Phoebe" family (retrograde revolution):
| satellites |
a | P in years | eccentricity | inclination on the ecliptic | d in km | mv | ap |
|---|---|---|---|---|---|---|---|
| Phoebe - S 9 | 12.87 to 13.00 | 1.496 | 0.143 to 0.186 | 173 to 174° | 230 x 220 x 210 | 16.5 | 0.61° |
| S/2000 S8 - Skathi - S 27 | 15.45 to 15.73 | 1.97 | 0.193 to 0.330 | 147 to 151° | 6 | 24.0 | 0.74° |
| S/2004 S37 - S5605a2 | 15.78 to 16.13 | 2.06 | 0.412 to 0.550 | 158 to 164° | 4 | 25.1 | 0.76° |
| S/2007 S2 | 16.52 to 16.86 | 2.19 | 0.141 to 0.217 | 152 to 157° | 6 | 24.4 | 0.78° |
| S/2006 S8 - Skoll - S 47 | 17.40 to 17.94 | 2.38 | 0.365 to 0.525 | 152 to 157° | 6 | 24.5 | 0.82 |
| S/2004 S13 | 17.84 to 18.35 | 2.48 | 0.199 to 0.304 | 167 to 169° | 6 | 24.5 | 0.88° |
| S/2006 S4 - Grep - S 51 | 18.10 to 18.68 | 2.48 | 0.256 to 0.385 | 172 to 173° | 6 | 24.4 | 0.86° |
| S/2004 S19 - Hyrrokkin - S 44 | 18.10 to 18.63 | 2.50 | 0.331 to 0.484 | 150 to 155° | 8 | 23,5 | 0.87° |
| S/2000 S9 - Mundilfari - S 25 | 18.33 to 18.90 | 2.55 | 0.162 to 0.165 | 168 to 170° | 5 | 23.8 | 0.88° |
| S/2006 S1 | 18.48 to 18.98 | 2.66 | 0.088 to 0.181 | 153 to 155° | 6 | 24.6 | 0.90° |
| S/2004 S20 - S2423b | 18.96 to 19.59 | 2.71 | 0.141 to 0.253 | 162 to 164° | 4 | 25.0 | 0.91° |
| S/2006 S6 - Jarnsaxa - S 50 | 18.99 to 19.63 | 2.58 | 0.161 to 0.285 | 161 to 165° | 6 | 24.7 | 1.11° |
| S/2003 S1 - Narvi - S 31 | 18.99 to 19.64 | 2.71 | 0.236 to 0.446 | 136 to 142° | 4.9 | 23.9 | 0.91° |
| S/2004 S15 - Bergelmir - S 38 | 19.00 to 19.56 | 2.60 | 0.103 to 0.201 | 157 to 160° | 6 | 24.2 | 0.90° |
| S/2004 S17 | 19.07 to 19.70 | 2.50 | 0.133 to 0.228 | 166 to 169° | 4 | 25.2 | 0.89° |
| S/2000 S12 - Suttungr - S 23 | 19.10 to 19.70 | 2.72 | 0.078 to 0.158 | 174 to 175° | 6 | 23.8 | 0.91° |
| S/2004 S14 - Hati - S 43 | 19.35 to 20.13 | 2.96 | 0.283 to 0.443 | 160 to 165° | 6 | 24.4 | 0.95° |
| S/2007 S3 | 19.39 to 20.09 | 3.01 | 0.137 to 0.240 | 176 to 177° | 5 | 24.9 | 0.99° |
| S/2004 S12 | 19.44 to 20.18 | 2.87 | 0.273 to 0.419 | 162 to 164° | 5 | 24.8 | 0.95° |
| S/2004 S27 - S8576a | 19.52 to 20.22 | 2.83 | 0.105 to 0.203 | 166 to 168° | 4 | 24.5 | 0.95° |
| S/2000 S7 - Thrymr - S 30 | 19.91 to 20.88 | 2.88 | 0.372 to 0.564 | 174 to 175° | 6 | 23.5 | 0.95° |
| S/2004 S18 - Bestla - S 39 | 19.97 to 20.77 | 2.88 | 0.488 to 0.766 | 134 to 147° | 7 | 23.8 | 0.95° |
| S/2004 S9 - Farbauti - S 40 | 19.97 to 20.72 | 2.95 | 0.153 to 0.287 | 156 to 160° | 5 | 24.7 | 0.95° |
| S/2004 S10 - Aegir - S 36 | 20.28 to 21.13 | 2.81 | 0.187 to 0.331 | 167 to 169° | 6 | 24.4 | 0.94° |
| S/2004 S22 - S8637a | 20.21 to 21.02 | 2.96 | 0.157 to 0.284 | 177 to 178° | 3 | 25.3 | 0.97° |
| S/2004 S30 - S5612a2 | 20.34 to 21.09 | 2.97 | 0.060 to 0.145 | 156 to 158° | 3 | 25.4 | 0.97° |
| S/2004 S25 - S8631e | 20.45 to 20.61 | 3.00 | 0.410 to 0.422 | 171 to 175° | 3 | 25.2 | 0.98° |
| S/2004 S7 | 20.48 to 21.52 | 3.02 | 0.447 to 0.641 | 161 to 165° | 6 | 24.5 | 0.95° |
| S/2004 S32 - S64472 | 20.72 to 21.67 | 3.22 | 0.177 to 0.352 | 156 to 160° | 4 | 25.0 | 1.00° |
| S/2006 S3 | 20.74 to 21.82 | 3.13 | 0.321 to 0.513 | 151 to 156° | 6 | 24.6 | 1.00° |
| S/2004 S23 - S8630a | 20.94 to 22.16 | 3.19 | 0.330 to 0.533 | 175 to 179° | 4 | 24.8 | 0.99° |
| S/2004 S28 - S8386a | 21.39 to 22.38 | 3.28 | 0.100 to 0.222 | 169 to 171° | 4 | 24.9 | 1.02° |
| S/2006 S2 - Kari - S 45 | 21.45 to 22.80 | 3.41 | 0.315 to 0.546 | 144 to 154° | 7 | 23.9 | 1.10° |
| S/2004 S35 - S5801a2 | 21.48 to 22.60 | 3.21 | 0.162 to 0.314 | 176 to 178° | 4 | 24.6 | 1.04° |
| S/2004 S38 - S8568a | 21.64 to 23.05 | 3.55 | 0.381 to 0.662 | 149 to 161° | 4 | 25.1 | 1.10° |
| S/2004 S16 - Fenrir - S 41 | 21.86 to 22.88 | 3.48 | 0.083 to 0.201 | 162 to 165° | 4 | 25.0 | 1.09 |
| S/2006 S7 - Surtur - S 48 | 22.17 to 23.59 | 3.37 | 0.343 to 0.560 | 164 to 170° | 6 | 24.8 | 1.10° |
| S/2006 S5 - Loge - S 46 | 22.37 to 23.57 | 3.60 | 0.117 to 0.269 | 164 to 168° | 6 | 24.6 | 1.11° |
| S/2000 S1 - Ymir - S 19 | 22.36 to 23.72 | 3.64 | 0.242 to 0.437 | 172 to 174° | 15 | 22.3 | 1.11° |
| S/2004 S21 - S5602a | 22.50 to 23.95 | 3.74 | 0.247 to 0.538 | 151 to 159° | 3 | 25.4 | 1.13° |
| S/2004 S39 - S64454x | 22.64 to 23.81 | 3.50 | 0.050 to 0.165 | 165 to 169° | 2 | 25.5 | 1.10° |
| S/2004 S36 - S5593a2 | 22.67 to 24.36 | 3.71 | 0.457 to 0.797 | 143 to 159° | 3 | 25.3 | 1.13° |
| S/2004 S33 - T514042 | 22.86 to 24.66 | 3.73 | 0.348 to 0.652 | 155 to 165° | 4 | 25.0 | 1.22° |
| S/2004 S34 - S5613a2 | 23.46 to 25.04 | 3.87 | 0.180 to 0.379 | 164 to 168° | 3 | 25.3 | 1.18° |
| S/2004 S8 - Fornjot - S 42 | 24.20 to 25.86 | 3.71 | 0.132 to 0.303 | 166 to 169° | 6 | 24.6 | 1.09° |
| S/2004 S26 - S8353a | 25.20 to 27.09 | 4.45 | 0.071 to 0.237 | 170 to 174° | 4 | 25.0 | 1.22° |