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This is an image of Triton, Neptune's largest moon. The image was taken by the Voyager 2 spacecraft in August 1989.
Click on image for full size
NASA

Neptune's Moons and Rings

Neptune has moons. As is the case with all of the gas giant planets in our Solar System, it also has a series of rings.

Neptune's ring system is very different from the ring system found at Saturn. Neptune's rings are much darker than Saturn's bright rings. Saturn's rings are mostly composed of ice, whereas Neptune's appear to be made of small rocks and dust.

Neptune has one very large moon named Triton. Triton is one of the coldest places in the Solar System. However, Triton appears to be geologically active. It has active geysers, similar to those found at Yellowstone Park on Earth, but Triton's geysers spew out ice instead of steam. Triton may also have a water environment like that of Earth's north pole. This liquid environment might be suitable for the existence of life. This icy moon has a very thin atmosphere and an interior which may be active.

The rest of Neptune's moons are much smaller than Triton. Nereid was discovered by Gerard Kuiper in 1949. Despina, Galatea, Larissa, Naiad, Proteus and Thalassa were discovered by the Voyager 2 spacecraft in 1989. Five more small moons have been discovered recently; three in 2002 and two more in 2003. The most recently discovered moons don't yet have official names.




The Moons of Neptune

Ordered by Size

Name
Size
(diameter or dimensions)
Triton
2,706.8 km
Proteus
220 x 208 x 202 km
Nereid
340 km
Larissa
108 x 102 x 84 km
Galatea
102 x 92 x 72 km
Despina
90 x 74 x 64 km
Thalassa
54 x 50 x 26 km
Naiad
48 x 30 x 26 km
S/2002 N4
60 km
S/2002 N1
48 km
S/2002 N2
48 km
S/2002 N3
48 km
S/2003 N1
28 km

Ordered by
Distance from Neptune

Name
Average Distance
from Neptune's center
Naiad
48,227 km
Thalassa
50,075 km
Despina
52,526 km
Galatea
61,953 km
Larissa
73,548 km
Proteus
117,647 km
Triton
354,760 km
Nereid
5,513,400 km
S/2002 N1
15,686,000 km
S/2002 N2
22,452,000 km
S/2002 N3
22,580,000 km
S/2002 N4
46,570,000 km
S/2003 N1
46,738,000 km
Last modified April 22, 2009 by Randy Russell.

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