Online Astronomy eText: Satellites (Moons)
The Satellites (Moons) of Neptune: Triton Link for sharing this page on Facebook

Voyager 2 photomosaic of Triton showing large cracks in darker areas, ice volcanoes in lighter areas.
(All images by Voyager 2, 1989)

A closeup of the lower portion of the photomosaic above, showing nitrogen and dust plumes pushed downwind. The atmosphere is so thin that the plumes are the only evidence of an atmosphere in the Voyager 2 images.

A smooth "lake" presumably caused by ice volcanism.

Data for Triton

Discovered by William Lassell in 1846, shortly after Neptune's discovery
Named after Triton, the mythological son of Poseidon and Amphitrite
Orbital size 354,800 km (about 220,000 miles)
Orbital eccentricity 0
Orbital inclination 157 degrees = -23 degrees (retrograde revolution)
Orbital period -5.87685 days (retrograde revolution)
Rotational period -5.87685 days (synchronous rotation)
Mass 0.00358 Earth masses
Diameter about 2700 km (about 1675 miles)
Density 2.07 g/cc (implies substantial amounts of rock and ice)
Escape velocity 1.45 km/sec
Albedo (reflectivity) 70%
Mean surface temperature -235 Celsius (-390 Fahrenheit)