Proteus

E118790

Proteus is one of Neptune’s largest irregularly shaped moons, known for its dark surface and heavily cratered, ancient terrain.

All labels observed (2)

Label Occurrences
Proteus canonical 2
Proteus (mythology) 1

How this entity was disambiguated

Statements (45)

Predicate Object
instanceOf irregularly shaped moon
moon of Neptune
natural satellite
albedo low
alternativeName Neptune VIII
surface form: Neptune VIII Proteus
axialTilt approximately zero relative to its orbit
belongsTo Neptune’s natural satellites
belongsToPlanetarySystem Neptune
surface form: Neptunian system
catalogDesignation Neptune VIII
craterCharacteristic many large impact craters
density about 1.3 g/cm³
diameter about 420 km
discoveredOn 1989-07-07
discoverer Voyager 2
discoveryContext Voyager 2 flyby of Neptune in 1989
discoveryMethod spacecraft imaging
eccentricity low orbital eccentricity
escapeVelocity about 0.23 km/s
gravitationalBinding insufficient to form a perfect sphere
hasAtmosphere no significant atmosphere detected
imagedBy Voyager 2
inclination small inclination relative to Neptune’s equator
largerOnlyThan Triton
largestCraterDiameter about 230 km
largestCraterName Lighthouse of Alexandria
surface form: Pharos
likelyOrigin accreted from a debris disk around Neptune
locatedIn outer Solar System
meanRadius about 210 km
namedAfter Proteus self-linksurface differs
surface form: Proteus (mythology)
orbitalPeriod about 1.122 days
about 27 hours
orbits Neptune
orbitsWithin Neptune’s inner regular satellite system
rankBySizeAroundNeptune second largest moon of Neptune
rotation synchronous with Neptune
rotationalPeriod about 1.122 days
semiMajorAxis about 117647 km
shape irregular
spectralType dark, neutral to slightly bluish
surfaceAge geologically old
surfaceBrightness very low
surfaceColor dark
surfaceComposition water ice and dark material (likely organics and silicates)
surfaceFeature ancient terrain
heavily cratered terrain

How these facts were elicited

Referenced by (3)

Full triples — surface form annotated when it differs from this entity's canonical label.

Neptune moon Proteus
Proteus namedAfter Proteus self-linksurface differs
subject surface form: Proteus (moon)
this entity surface form: Proteus (mythology)