| Mass (1020 kg) |
Radius (km) |
Mean density (kg/m3) |
Visual geometric albedo |
|
|---|---|---|---|---|
| Naiad (NIII) | 0.002 | 48 x 30 x 26 | 0.07 | |
| Thalassa (NIV) | 0.004 | 54 x 50 x 26 | 0.09 | |
| Despina (NV) | 0.02 | 90 x 74 x 64 | 0.09 | |
| Galatea (NVI) | 0.04 | 102 x 92 x 72 | 0.08 | |
| Larissa (NVII) | 0.05 | 108 x 102 x 84 | 0.09 | |
| Hippocamp (S/2004 N1) | 0.0003 | 17 | 0.10 | |
| Proteus (NVIII) | 0.5 | 220 x 208 x 202 | 0.10 | |
| Triton (NI) | 214. | 1,353.4 | 2,050 | 0.72 |
| Nereid (NII) | 0.3 | 170 | 0.16 | |
| Halimede (NIX, S/2002 N1) | 0.002 | 30 | 0.04 | |
| Sao (NXI, S/2002 N2) | 0.001 | 20 | 0.04 | |
| S/2002 N5 | 12 | |||
| Laomedeia (NXII, S/2002 N3) | 0.001 | 20 | 0.04 | |
| Psamathe (NX, S/2003 N1) | 0.0002 | 20 | 0.04 | |
| Neso (NXIII, S/2002 N4) | 0.002 | 30 | 0.04 | |
| S/2021 N1 | 7 | |||
| Orbital | Rotation | |||||
|---|---|---|---|---|---|---|
| Semimajor axis | Period * | Period | Inclination | Eccentricity | ||
| (103 km) | (Neptune Radii) | (days) | (days) | (degrees) | ||
| Naiad (NIII) | 48.227 | 1.948 | 0.294396 | 4.74 | 0.0003 | |
| Thalassa (NIV) | 50.075 | 2.022 | 0.311485 | 0.21 | 0.0002 | |
| Despina (NV) | 52.526 | 2.121 | 0.334655 | 0.07 | 0.0001 | |
| Galatea (NVI) | 61.953 | 2.502 | 0.428745 | 0.05 | 0.0001 | |
| Larissa (NVII) | 73.548 | 2.970 | 0.554654 | 0.20 | 0.0014 | |
| Hippocamp (S/2004 N1) | 105.300 | 4.252 | 0.950 | 0.00 | 0.0000 | |
| Proteus (NVIII) | 117.647 | 4.751 | 1.122315 | 0.04 | 0.0004 | |
| Triton (NI) | 354.76 | 14.328 | 5.876854R | S | 157.345 | 0.000016 |
| Nereid (NII) | 5,513.4 | 222.67 | 360.13619 | 7.23 | 0.7512 | |
| Halimede (NIX, S/2002 N1) | 15730. | 635.2 | 1879.7R | 134.1 | 0.571 | |
| Sao (NXI, S/2002 N2) | 22420. | 905.3 | 2914.1 | 48.5 | 0.293 | |
| S/2002 N5 | 23400. | 944.9 | 3141.1 | 42.1 | 0.548 | |
| Laomedeia (NXII, S/2002 N3) | 23570. | 951.8 | 3167.9 | 34.7 | 0.424 | |
| Psamathe (NX, S/2003 N1) | 46700. | 1885.8 | 9115.9R | 137.4 | 0.450 | |
| Neso (NXIII, S/2002 N4) | 48390. | 1954.0 | 9374.0R | 132.6 | 0.495 | |
| S/2021 N1 | 50760. | 2049.7 | 10018.8R | 134.5 | 0.44 | |
Neptune's Known Satellites
- Carnegie Institution, DTM
Neptune Fact Sheet
Neptune Home Page
Notes on the Factsheets
Directory to other Planetary Fact Sheets
Author/Curator: