Moons of Saturn{1}

name numerical designation ****mean distance from

***centre of planet

***(orbital radius) orbital period (sidereal period; Earth days){5} inclination of orbit to planet's equator (degrees) eccentricity

of orbit rotation period (Earth days){7} radius or radial dimensions (km) mass (kg) mean* density (g/cm³)

00000km Saturn

radii0

Pan XVIII 133,583 2.216 0.575 about 0 about 0 10

Atlas XV 137,666 2.284 0.602 about 0 about 0 19 × 17 × 14

Prometheus XVI 139,377 2.313 0.613 0 0.0024 70 × 50 × 34

Pandora XVII 141,713 2.351 0.629 0 0.0042 55 × 44 × 31

Epimetheus{2} XI 151,415 2.512 0.694 0.34 0.009 sync. 69 × 55 × 55

Janus{2} X 151,417 2.512 0.695 0.14 0.007 sync. 99 × 96 × 76

Mimas I 185,520 3.078 0.942 1.53 0.0202 sync. 199 3.60 × 10¹⁹ 1.10

Enceladus II 238,020 3.949 1.370 0.02 0.0045 sync. 249 8.53 × 10¹⁹ 1.30

Telesto{3} XIII 294,600 4.888 1.888 about 0 about 0 15 × 13 × 8

Calypso{3} XIV 294,600 4.888 1.888 about 0 about 0 15 × 8 × 8

Tethys III 294,660 4.889 1.888 1.09 0.0000 sync. 530 6.03 × 10²⁰ 1.00

Dione IV 377,400 6.262 2.737 0.02 0.0022 sync. 560 1.12 × 10²¹ 1.50

Helene{4} XII 377,400 6.262 2.737 0.2 0.005 16

Polydeuces{4} XXXIV 377,400 6.262 2.737 6.5

------------------------------------------------------------------------------------------------ known outer extent of ring system ------------------------------------------------------------------------------------------------

Rhea V 527,040 8.745 4.518 0.35 0.0010 sync. 764 2.46 × 10²¹ 1.30

Titan VI 1,221,850 20.274 15.940 0.33 0.0292 sync. 2,575 1.35 × 10²³ 1.88

Hyperion VII 1,481,100 24.575 21.280 0.43 0.1042 chaotic 185 × 140 × 113 5.5 × 10¹⁸ 0.50

Iapetus VIII 3,561,300 59.091 79.330 15{6} 0.0283 sync. 718 1.59 × 10²¹ 1.00

Phoebe IX 12,952,000 214.907 550.4 R0 175.3 0.163 0.4 110 8.3 × 10¹⁸ 1.60

{1}Beginning in 2000, about 40 additional moons were discovered with electronic detectors in Earth-based observations or in spacecraft images. Most have large orbital radii, eccentricities, and inclinations, and more than half have retrograde orbits. A small number orbit in a prograde direction within a few Saturn radii of the planet. Rough size estimates based on brightness place them between 3 and 20 km in radius. They were assigned provisional numerical designations on discovery; many have received official names.

{2}Co-orbital moons; certain values are variable owing to orbital exchange.

{3}"Trojan" moons: Telesto precedes Tethys in its orbit by 60°; Calypso follows Tethys by 60°.

{4}"Trojan" moons: Helene precedes Dione in its orbit by 60°; Polydeuces follows Dione by 60° on average, but with wide variations.

{5}R following the quantity indicates a retrograde orbit.

{6}Average value. The inclination oscillates about this value by 7.5° (plus or minus) over a 3,000-year period.

{7}Sync. = synchronous rotation; the rotation and orbital periods are the same.