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ORBONIX · NEPTUNE SYSTEM

TRITON

Neptune's largest moon, a frozen world with a remarkable retrograde orbit, nitrogen ice and active geysers.
Triton — Voyager 2
2,706 km
DIAMETER
5.88 DAYS
ORBITAL PERIOD
−235°C
APPROX. SURFACE TEMPERATURE
355,000 km
AVERAGE DISTANCE FROM NEPTUNE
RETROGRADE
ORBIT DIRECTION
1846
DISCOVERED
THE FROZEN WORLD
Triton is the largest moon of Neptune and the seventh-largest moon in the Solar System. Unlike almost all large moons, Triton moves around its planet in a retrograde direction. This unusual orbit strongly suggests that Triton was captured by Neptune rather than forming alongside the planet. Its surface is covered with nitrogen, methane and water ice. Voyager 2 revealed a surprisingly active world, including dark plumes rising from the surface. Triton is one of the coldest known objects in the Solar System, yet its surface shows evidence of geological activity.
RETROGRADE ORBIT
Triton orbits Neptune in the opposite direction to Neptune's rotation and most of its other moons.
ICE GEYSERS
Voyager 2 observed dark plumes rising several kilometres above Triton's surface.
CAPTURED WORLD
Its unusual orbit suggests Triton was once an independent Kuiper Belt object captured by Neptune.
DID YOU KNOW?
Triton is larger than the dwarf planet Pluto and is believed to have originated in the Kuiper Belt.
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IMAGE: NASA / JPL / VOYAGER 2
IMAGE VIA WIKIMEDIA COMMONS