Sponsored by the Institute of Physics   Planets   Mercury   Venus   Earth   Mars   Jupiter   Saturn   Uranus   Neptune     Rings     Naiad     Thalassa     Despina     Galatea     Larissa     Proteus     Triton     Nereid   Pluto Asteroids Comets Constellations Sunrise and Sunset Times Moon Phases SI Units Symbols   Printer Version Astronomy Planets - Neptune - Proteus Bulk Parameters Orbital Parameters Bulk Parameters Mass Radius 218 km × 208 km × 201 km Mean Density Visual Geometric Albedo 0.06 Orbital Parameters Semimajor Axis 117.647 × 103 km Period 1.122 315 days Orbital Inclination 0.55 ° Orbital Eccentricity 0.0   [ H O M E ] [ S C I E N C E ] [ M A T H S ] [ A S T R O N O M Y ] Download | Shop | Contact | About   Page compiled: Wed Sep 05 18:38:01 GMT+01:00 2001