MOONS OF NEPTUNE
Neptune has 11 moons, 6 of which
were discovered by Voyager 2. The largest, Triton, orbits Neptune in a direction opposite
to the planet's rotation direction, and is gradually getting closer until it will collide
with the planet in about 10 - 100 million years. And this will form vast rings around
Neptune that will rival or exceed Saturn's extensive ring system.
| Moon | Diameter | Time to orbit Neptune | Distance from Neptune | Position | Characteristic features |
| Naiad | 54 | 7h 6min | 23,200 | close to Neptune's equatorial plane | irregularly shaped and shows no sign of any geological modification |
| Thalassa | 80 | 7h 30min | 25,200 | - | --||-- |
| Despina | 150 | 8h | 27,700 | --||-- | --||-- |
| Galatea | 180 | 10h 18min | 37,200 | --||-- | --||-- |
| Larissa | 190 | 13h 18min | 48,800 | --||-- | --||-- |
| Proteus | 400 | 26h 54min | 92,800 | --||-- | --||-- |
| Triton | 2,700 | - | - | - | The largest among Neptune's moons |
| Nereid | 340 | 360days | from 1,353,600 to 9,623,700 km | The most distant among the moons | The most eccentric orbit in the Solar System |
Naiad, Thalassa, Despina, Galatea, Larissa and Proteus circle Neptune in the same direction as it rotates. Only Triton, the largest among all moons, circles the planet in a retrograde direction.
Triton was discovered by William Lassel a month after the "blue" planet's discovery in 1846. The temperature of its surface is -235°C and the atmosphere is extremely thin. This is not only the coldest of all bodies in the Solar System, but also one of the three objects (The Earth, Triton and Saturn's giant moon, Titan) whose atmosphere is saturated with N2 (nitrogen).
Nereid was discovered in 1949 by Gerard Kuiper. Its surface reflects about 14% of the sunlight that strikes it. Nereid's orbit is the most eccentric of any moon in the Solar System - the distance between Nereid and Neptune ranges from about 1,353,600 kilometers to 9.623,700 kilometers.
Proteus is one of the darkest objects in the Solar System because it reflects only 6% of the sunlight that strikes it.
Three More Moons for Neptune!!!
To find the moons, Holman and Kavelaars took multiple exposures of the sky surrounding Neptune while tracking the planet as it moved across the sky. While stars showed up in composite images as streaks, the moons appeared as points of light. To find the moons, Holman and Kavelaars took multiple exposures of the sky surrounding Neptune while tracking the planet as it moved across the sky. While stars showed up in composite images as streaks, the moons appeared as points of light.