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This is a picture of Triton, Neptune's largest moon. The picture 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. It also has rings, but its rings are different from Saturn's.

Neptune's largest moon is named Triton. Triton is much larger than any of the planet's other moons. Triton is a very cold place, so the moon is covered with ice. Even though Triton is cold there is a lot going on there. It has geysers like the ones at Yellowstone Park on Earth. The geysers shoot ice 8 km (5 miles) high into Triton's thin atmosphere! There may be water under the ice at Triton. It is even possible that there might be life in that water. The interior of Triton is probably geologically 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 found by the Voyager 2 spacecraft in 1989. Five more small moons have been found recently. Three of those were discovered in 2002 and two more were found in 2003. The newest moons don't have official names yet.

Neptune's rings are much darker than Saturn's bright rings. Saturn's rings are made of ice, which reflects lots of light. Neptune's rings are probably made of rocks and dust. Rocks and dust don't reflect as much light.


The Moons of Neptune

Listed by Size
(Largest to Smallest)

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

In Order of
Distance from Neptune

Name
Average Distance
from the Center of Neptune
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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