Vital Statistics for Saturn’s Rings and Inner Satellites

Rings of Saturn

Feature Inner Boundary (km) Outer Boundary (km) Optical Depth Type Associated Moons Footnotes Comments
D Ring 66,900 74,491 10-5 to 10-3 Tenuous, Broad   1,10 Contains narrow ringlets at 67,580 and 71,710 km.
C Ring 74,491 91,975 0.05 to 0.35 Dense, Broad   1,10 Contains isolated “plateaus” among a surrounding, fainter ring.
Colombo Gap 77,748 77,926 ~0 Gap   7  
Titan Ringlet 77,867 77,890 ~4 Dense, Narrow Titan 7 Ringlet that occupies outer third of Colombo Gap. Also known as Colombo Ringlet.
Maxwell Gap 87,343 87,610 ~0 Gap   7 Widest gap in the C Ring.
Maxwell Ringlet 87,480 87,539 1 to 3 Dense, Narrow   7 A narrow, eccentric ringlet inside a gap in the C Ring.
Bond Gap 88,686 88,723 ~0 Gap   7 Gap due to second-order resonance with Mimas.
Bond Ringlet 88,702 88,719 ~1 Dense, Narrow   7 A narrow, sharp-edged ringlet inside a gap in the C Ring.
Dawes Gap 90,200 90,221 ~0 Gap   7 Very narrow gap
Dawes Ringlet 90,138 90,200 0.2 to 1 Dense, Narrow   7 This feature has been referred to as ringlet, but it is not detached from the rest of the C ring.
B Ring 91,975 117,570 0.4 to 5 Dense, Broad   1,11 Contains fine structure on all scales. The most opaque of Saturn’s rings.
Region B1 91,975 99,000 1.1 to 1.5 Dense, Broad   9 Innermost region of B Ring. Characterized by undulations in optical depth and I/F.
Region B2 99,000 104,000 1.5 and >4 Dense   9 Central region of B Ring. Characterized by alternating zones of high and low optical depth.
Region B3 104,000 110,000 1 to 5 Dense   9 Central region of B Ring. Characterized by high optical depth. Median optical depth is 3.6, the highest of any region in the rings.
Region B4 110,000 116,500 2 to 3 Dense   9 Outer region of B Ring. Here the optical depth gradually decreases, but in an irregular way.
Region B5 116,500 117,500 0.5 to >5 Dense Mimas 9 Outermost region of B Ring, affected by its highly variable outer edge.
Cassini Division 117,500 122,050 0 to 0.2 Dense, Broad   10,11 The prominent gap between the A and B Rings. It contains several features of low optical depth.
Huygens Gap 117,500 117,930 ~0 Gap Mimas 8  
Huygens Ringlet 117,806 117,824 1 to 2 Dense, Narrow   8  
Strange Ringlet 117,907 117,909   Dense, Narrow   8  
Herschel Gap 118,188 118,284 ~0 Gap   8 Approximate boundaries based on Table 3 of Ref 8.
Herschel Ringlet 118,234 118,263 ~0.1 Dense, Narrow   8 A narrow, eccentric, inclined ringlet near the inner edge of the Cassini Division.
Russell Gap 118,590 118,628 ~0 Gap   8  
Jeffreys Gap 118,930 118,967 ~0 Gap   8  
Kuiper Gap 119,402 119,406 ~0 Gap   8  
Laplace Gap 119,845 120,086 ~0 Gap   8  
Laplace Ringlet 120,037 120,078 ~1 Dense, Narrow   8  
Bessel Gap 120,231 120,244 ~0 Gap   8  
Barnard Gap 120,304 120,316 ~0 Gap   8  
A Ring 122,050 136,770 0.4 to 1 Dense, Broad   10,12 A fairly uniform ring with many density and bending waves, especially near its outer edge.
Encke Gap 133,423 133,745 ~0 Gap Pan 10 A gap in the A Ring maintained by the embedded moon Pan. One or more faint ringlets are also present.
Keeler Gap 136,487 136,522 ~0 Gap Daphnis 10 A narrow gap in the outer A Ring maintained by the embedded moon Daphnis.
Roche Division 136,770 139,380 ~10-4 Tenuous, Broad Atlas, Prometheus 6 The separation between outer edge of A Ring and the F Ring.
F Ring 139,826 140,612 0.01 to 0.2 Narrow Prometheus, Pandora 1,13 A complex, narrow, eccentric, inclined ring with a denser core at a=140,224 km demonstrating a wide variety of quasi-stable and ephemeral structure.
Janus/Epimetheus Ring 149,000 154,000 10-7 Tenuous Janus, Epimetheus 2 A narrow, very faint ring in the region occuppied by Janus and Epimetheus.
G Ring 166,000 173,200 10-6 Tenuous Aegaeon 1 A faint, isolated dust ring.
E Ring 180,000 480,000 5x10-6 Tenuous Enceladus 1 A broad, faint dust ring encompassing the orbits of Mimas through Dione. Densest near the orbit of Enceladus. Up to ~30,000 km in vertical extent.
Methone Ring ~194,440   ~10-7 Tenuous Methone 3 A narrow, very faint ring in the the region occuppied by Methone.
Anthe Ring ~197,655   ~10-7 Tenuous Anthe 4 A narrow, very faint ring in the orbit of Anthe.
Pallene Ring ~212,280   ~10-7 Tenuous Pallene 2 A narrow, very faint ring in the region occuppied by Pallene.
Phoebe Ring 7,720,000 12,500,000 ~2x10-8 Tenuous Phoebe 5 A broad, faint ring in the orbit of Phoebe with a vertical extent of ~2,400,000 km.

Sources

  1. Murray, C.D., and S.F. Dermott 1999. Solar System Dynamics, Cambridge University Press. DOI:10.1017/CBO9781139174817
  2. Porco, C.C., and the Cassini Imaging Team 2006. Rings of Saturn (R/2006 S 1, R/2006 S 2, R/2006 S 3, R/2006 S 4). IAU Circulars 8759
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  6. The Gazetteer of Planetary Nomenclature, https://planetarynames.wr.usgs.gov/Page/Rings
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Regular Satellites of Saturn

Name Semimajor Axis Period Eccentricity Inclination Mean Diameter Mass Associated Ring Footnotes Comments
  (km) (days)   (deg) (km) (kg)      
Pan 133,584 0.575 0.00001 0.0001 28 4.95x1015 A ring, Encke gap 4,8,9  
Daphnis 136,504 0.594 0.00003 0.0036 7.6 7.70x1013 A ring, Keeler gap 3,10  
Atlas 137,666 0.602 0.0012 0.003 30.2 6.60x1015 A ring, Roche division 8,9  
Prometheus 139,378 0.613 0.0022 0.007 84.2 1.59x1017 F ring, Roche division 8,9 Prometheus and Pandora interact to produce chaotic orbit changes.
Pandora 141,713 0.629 0.0042 0.05 81.4 1.37x1017 F ring 8,9 Prometheus and Pandora interact to produce chaotic orbit changes.
Epimetheus 151,452 0.695 0.0097 0.352 116.2 5.27x1017 Janus/Epimetheus ring 8,9 Janus and Epimetheus are ?coorbital? and undergo orbit changes at approximately 4 year intervals. Semi-major axis and period given are averages.
Janus 151,452 0.695 0.0068 0.164 178 1.90x1018 Janus/Epimetheus ring 8,9 Janus and Epimetheus are ?coorbital? and undergo orbit changes at approximately 4 year intervals. Semi-major axis and period given are averages.
Aegaeon 167,494 0.808 0.00024 0.001     G ring 7 Embedded in the G Ring.
Mimas 185,537 0.942 0.0196 1.565 396 3.75x1019 B ring, Cassini division, Huygens gap 5,8  
Methone 194,230 1.01 0.01 0.01 2.8 3.92x1015 Methone ring 10  
Anthe 197,669 1.037 0.0010 0.159 2   Anthe ring 1,6  
Pallene 212,283 1.154 0.004 0.18 4.4 1.15x1016 Pallene ring 10  
Enceladus 238,037 1.37 0.0047 0.009 504 1.08x1020 E ring 5,8  
Tethys 294,672 1.888 0.0001 1.091 1066 6.17x1020   5,8  
Telesto 294,675 1.888 0.0002 1.2 25     10 Leading coorbital of Tethys.
Calypso 294,675 1.888 0.0005 1.5 20     10 Trailing coorbital of Tethys.
Dione 377,400 2.737 0.0022 0.028 1123 1.10x1021   5,8  
Helene 377,400 2.737 0.007 0.21 37     10 Leading coorbital of Dione.
Polydeuces 377,400 2.737 0.019 0.17 1.5     10 Trailing coorbital of Dione.
Rhea 527,070 4.518 0.001 0.36 1529 2.31x1021   5,8  
Titan 1,221,865 15.95 0.0288 0.312 5151 1.35x1023 Titan ringlet 5,8  
Hyperion 1,500,934 21.28 0.0232 0.615 266 5.58x1018   5,8  
Iapetus 3,560,851 79.33 0.0293 8.313 1471 1.81x1021   5,8  
Phoebe 12,948,000 548.02 0.1635 175.243 213 8.29x1018 Phoebe ring 5,11  

Sources

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