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Encyclopedia > Neptune > Satellites > Triton

TRITON : SATELLITE I OF NEPTUNE



Credit : NASA/JPL
Triton as seen by Voyager 2

Triton (Neptune I) is the first satellite of Neptune, by far the largest, discovered by Lassell in 1846. 

The probe space Voyager detected some geological activity on its surface similar to geysers phenomena.

Click here for an animation showing the flyby of Triton by Voyager.Credit : NASA.


Characteristics Values
Semi-major axis in km  354 759 
Revolution period  5.877 days 
Rotation period  5.877 days
Orbital velocity 4 km/s
Inclination on the equator of Neptune 156.3°
Eccentricity of the orbit 0.00002
Equatorial diameter (Earth=1)  0.21
Equatorial diameter 2705 km
Visual magnitude at the opposition 13.7
Flattening  0 
Mass (Neptune=1)  2/10 000 
Density (Water=1)  2.1 
Escpape velocity 1450 m/s
Reflectivity (geometric albedo) 0.7
The highest peak   ? 
Deepest pit   ? 
Atmosphere tenuously : 
nitrogen, traces of methane

Origin of the name : click here.