Moon
Proteus
TypeMoon
Mass4.4 × 10¹⁹ kg
Diameter420 km
Orbital Radius117,650 km
Orbital Period1.122 days
Rotation Period26.9 hours
Known Moons0
Surface Gravity0.07 m/s²
Average Temp-220 °C
AtmosphereNone
Discovered ByVoyager 2 team
Discovery Year1989
About Proteus
About as large as an object can be while staying lumpy rather than round. Extremely dark, reflecting about 6 percent of sunlight. Discovered in Voyager 2 images after eluding ground telescopes for years. Its biggest crater, Pharos, is 230 km wide.
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