Vital Statistics for Neptune’s Rings

Rings of Neptune

Feature Middle Boundary (km) Width Optical Depth Type Associated Moons Footnotes Comments
Galle 42,000 2,000 10^-4 Faint, wide   3 A faint and poorly understood ring.
Le Verrier 53,200 <100 0.003 Narrow Despina 2,3 A narrow, axisymmetric ring.
Lassell 55,200 4,000 10^-4 Wide, diffuse   3 A uniform, faint ring extending outward from Le Verrier.
Arago 57,200     Faint, wide   3 A brightness enhancement at the outer edge of Lassell.
Unnamed 61,953     Narrow Galatea 3 A ring of dust in the orbit of Galatea.
Adams 62,933 15 0.003 to 0.1 Narrow Galatea 3 A narrow ring containing the arcs. It shows radial wiggles due to perturbations from nearby Galatea.
Fraternite 62,933 ~15 ~0.1 Narrow Galatea 3 The brightest of five ring arcs embedded in the Adams Ring, Fraternite is the trailing arc.
“Egalite 1,2” 62,933 ~15 ~0.1 Narrow Galatea 3 Double arc in the Adams ring. Egalite 2 is located 10.7 deg ahead of Fraternite.
Liberte 62,933 ~15 ~0.1 Narrow Galatea 3 Ring arc in the Adams Ring. Located between Egalite and Courage arcs and is 12 degrees ahead of Egalite 1.
Courage 62,933 ~15 ~0.1 Narrow Galatea 3 The dimmest of five ring arcs embedded in the Adams Ring. Courage is about 7.3 degrees ahead of Liberte in longitude.

The table of Neptune’s inner satellites can be found here.


  1. Murray, C.D., and S.F. Dermott 1999. Solar System Dynamics, Cambridge University Press. DOI:10.1017/CBO9781139174817

  2. Porco, al. 1995. Neptune’s ring system. In D.P. Cruikshank (ed.), Neptune and Triton, University of Arizona Press, 703-804. ISBN: 978-0-8165-1525-7

  3. De Pater, I., et al. 2018. The rings of Neptune. In M.S. Tiscareno and C.D. Murray (eds.), Planetary Ring Systems. Cambridge University Press, 112-124. 10.1017/9781316286791.005