Triton
Triton
Moon
Pisces
Visible
Level 6
Professional/Research - Timing dependent
Properties
Magnitude
13.5
Angular Size
0.1 arcmin
Type: Moon
Distance: 0.002 AU
Orbital Period: 5.9 days
Diameter: 2,707 km
Atmosphere: Thin nitrogen
Features: Cantaloupe terrain, nitrogen geysers, polar caps
Largest moon of Neptune; retrograde orbit suggests it was captured from the Kuiper Belt. Nitrogen geysers observed by Voyager 2. Requires 10 inch telescope at high magnification.
Position & Identifiers
RA
00h 08m 08.7s
Dec
-00° 32' 41.1"
Constellation
Pisces
Catalog
Triton
Physical Properties
Diameter
2,707 km
(0.21× Earth)
Mass
2.14e22 kg
Albedo
0.76
(76% reflected)
Temperature
-240°C to -235°C
Rotation
5.9 days
Atmosphere
Thin nitrogen
Surface
Cantaloupe terrain, nitrogen geysers, polar caps
Angular Size
0.1″ (current)
Orbital Properties
Semi-major Axis
0.0024 AU
(354,697 km)
Eccentricity
0.0000
Inclination
156.90°
Orbital Period
5.9 days
Distance
30.875 AU
(4.28 light-hours)
Elongation
4.8°
Near Sun
Observing Tips
Best Months
August
, September
, October
Visibility
Telescope
Where to Look
Near Neptune
Notes
Largest moon of Neptune; retrograde orbit suggests it was captured from the Kuiper Belt. Nitrogen geysers observed by Voyager 2. Requires 10 inch telescope at high magnification.
Parent Body
Discovery
Discovered by
William Lassell
Date
1846-10-10
Current Ephemeris
30.875
AU from Earth
4.62B
km
0.1″
Angular Size
5°
Elongation
Visibility
Set a location in User Settings to see visibility data.
Community Photos (1)
Credit: Michael T. Bland, U.S. Geological Survey (USGS). License: CC BY 4.0. (Wikimedia Commons)
Skybred Feb 28, 2026