What is Triton (moon)?
{{Infobox planet | name = Triton | note = yes | mpc_name = Neptune I | pronounced = {{IPAc-en|ˈ|t|r|aɪ|t|ən}} | adjectives = Tritonian | named_after = [[Triton (mythology)|Τρίτων]] ''Trītōn'' | image = Triton moon mosaic Voyager 2 (large).jpg | image_size = 300px | caption = {{longitem|''[[Voyager 2]]'' photomosaic of Triton's sub-Neptunian hemisphere|style=padding: 4px 0;}} | discoverer = [[William Lassell]] | discovered = October 10, 1846 | semimajor = {{val|354759|u=km|fmt=commas}} | eccentricity = {{val|0.000016|fmt=none}} | period = {{val|5.876854|u=d|fmt=none}}<br/>([[Retrograde and direct motion|retrograde]]) | avg_speed = 4.39 km/s | inclination = 129.812° (to the [[ecliptic]])<br/>156.885° (to Neptune's equator)<br/>129.608° (to Neptune's orbit) | satellite_of = [[Neptune]] | mean_radius = {{val|1353.4|0.9|u=km|fmt=commas}} | surface_area = {{val|23018000|u=km2|fmt=commas}} | volume = {{val|10384000000|u=km3|fmt=commas}} | mass = {{val|2.1390|0.0028|e=22|u=kg}}<br/>({{val|0.00359|u=Earths|fmt=none}}) | density = {{val|2.061|u=g/cm3}} | surface_grav = {{val|0.779|ul=m/s2}} ({{val|0.0794|u=[[G-force|''g'']]}}) (0.48 Moons) | escape_velocity = {{val|1.455|u=km/s}} | sidereal_day = 5 d, 21 h, 2&nbsp;min, 53 s | rotation = [[Synchronous rotation|synchronous]] | axial_tilt = 0 | albedo = 0.76 | magnitude = 13.47 | abs_magnitude = −1.2 | single_temperature = {{cvt|38|K|C}} | atmosphere = yes | surface_pressure = {{convert|1.4 to 1.9|Pa|atm|sigfig=3|abbr=on}} | atmosphere_composition = [[nitrogen]]; [[methane]] traces }} [[File:William Lassell.jpg|thumb|274x274px|William Lassell, the discoverer of Triton]] [[File:Retrogradeorbit.gif |thumb |180px |Retrograde orbit: the satellite (red) orbits in the direction opposite to the rotation of it