Triton (moon)
largest moon of Neptune / From Wikipedia, the free encyclopedia
Triton, or Neptune I, is the largest moon of the planet Neptune.[1][2] It is the seventh-largest moon in the Solar System. Triton is slightly smaller than Earth's Moon. Triton has a complicated geological history: it is thought to have a young surface compared to the age of the Solar System itself.
Discovery | |
---|---|
Discovered by | William Lassell |
Discovery date | October 10, 1846 |
Designations | |
MPC designation | Neptune I |
Pronunciation | /ˈtraɪtən/ |
Named after | Τρίτων Trītōn |
Adjectives | Tritonian |
Orbital characteristics | |
354,759 km | |
Eccentricity | 0.000016 |
5.876854 d (retrograde) | |
Average orbital speed | 4.39 km/s |
Inclination | 129.812° (to the ecliptic) 156.885° (to Neptune's equator) 129.608° (to Neptune's orbit) |
Satellite of | Neptune |
Physical characteristics | |
Mean radius | 1,353.4±0.9 km |
23,018,000 km2 | |
Volume | 10,384,000,000 km3 |
Mass | (2.1390±0.0028)×1022 kg (0.00359 Earths) |
Mean density | 2.061 g/cm3 |
0.779 m/s2 (0.0794 g) (0.48 Moons) | |
1.455 km/s | |
synchronous | |
Sidereal rotation period | 5 d, 21 h, 2 min, 53 s |
0 | |
Albedo | 0.76 |
Temperature | 38 K (−235.2 °C) |
13.47 | |
−1.2 | |
Atmosphere | |
Surface pressure | 1.4 to 1.9 Pa (1.38×10−5 to 1.88×10−5 atm) |
Composition by volume | nitrogen; methane traces |
It was discovered by the British astronomer William Lassell on 10 October 1846, just 17 days after Neptune itself was discovered by the German astronomer Johann Gottfried Galle and Heinrich Louis d'Arrest.[1]
Triton is believed to be a captured Kuiper Belt object,[1] and is the coldest known body in the Solar System.[1] The surface temperature of Triton was recorded by Voyager 2 as -235 °C (-391 °F).[1] Triton has its own magnetic field and has a faint trace of an atmosphere.