| Name |
Diameter(s) (km) |
Mean Distance From Planet (×103 km) |
Rotational Period (days) |
Orbital Period (days) |
Orbital Inclination |
Orbital Eccentricity |
Albedo (%) |
| Naiad | 58 | 48.227 | 0.294396 | 4.74° | 0.000 | 6 | |
| Thalassa | 80 | 50.075 | 0.311485 | 0.21° | 0.000 | 6 | |
| Despina | 148 | 52.526 | 0.334655 | 0.07° | 0.000 | 6 | |
| Galatea | 158 | 61.953 | 0.428745 | 0.05° | 0.000 | 6 | |
| Larissa | 208 × 178 | 73.548 | 0.554654 | 0.20° | 0.00139 | 6 | |
| Proteus | 436 × 416 × 402 | 117.647 | 1.122315 | 0.55° | 0.0004 | 6 | |
| Triton | 2,705.2 | 354.76 | 5.876854 | -5.876854 | 157.345° | 0.000016 | 77 |
| Nereid | 340 | 5,513.4 | 360.13619 | 7.23° | 0.7512 | 40 |
Name
Diameter
Mean Distance From Planet
Rotational and Orbital Periods
As seen from above the north pole of the Earth, most of the planets and satellites revolve in an anticlockwise direction. This is called Direct Rotation. Some satellites revolve in a clockwise sense. This is called Retrograde Rotation. Only Triton revolves in the retrograde direction, the only large satellite in the Solar System to do so.
Orbital Inclination
Orbital Eccentricity
Albedo
The satellites of Neptune have Greek and Roman names associated with Neptune, the god of the sea.
Triton is by far Neptune's largest satellite. The rest are small bodies.
The satellites are all fairly evenly spaced out apart from the very distant Nereid.
Triton rotates in the same period as it revolves around the planet. This is caused by the strong tidal forces exerted by the planet on the satellite. A planet's outer satellites are less affected by tidal forces.
This is the angle of inclination of the satellite orbits compared to the planet's equatorial plane. Most of Neptune's satellites orbit very close to the planet's equator. Triton has the most inclined orbit for a large satellite in the Solar System.
The orbits of most of Neptune's satellites are nearly circular. The exception is Nereid, which has the most eccentric orbit of a satellite in the Solar System.
This is the percentage of sunlight that is reflected by the satellites. Most of Neptune's satellites are dark bodies. Triton, with its surface covered with frozen Nitrogen, is very reflective.