Phoebe

E45105

Phoebe is an irregular, retrograde moon of Saturn believed to be a captured object from the outer Solar System.


Statements (47)
Predicate Object
instanceOf irregular satellite
moon of Saturn
natural satellite
retrograde satellite
albedo low geometric albedo
atmosphere no substantial atmosphere detected
axialTilt small relative to its orbit
belongsTo Saturnian system
Solar System
belongsToGroup Norse group of Saturnian moons
catalogCode S/1899 S 1
contributesTo Phoebe ring of Saturn
density_g_per_cm3 approximately 1.6
designation Saturn IX
discoveredBy William Henry Pickering
discoveryMethod telescopic observation
discoveryYear 1899
eccentricity high orbital eccentricity
escapeVelocity_m_per_s approximately 100
firstOuterMoonOfSaturnDiscovered true
flybyDate 2004
gravitationalInfluence affects dust distribution in outer Saturnian system
gravity very low surface gravity
imagedBy Cassini imaging system
inclination high inclination relative to Saturn’s equator
likelyOrigin outer Solar System
meanDiameter_km approximately 213
meanRadius_km approximately 106.5
namedAfter Phoebe (Titaness from Greek mythology)
orbitalClass irregular
orbitalDirection retrograde
orbitalPeriod_days approximately 550
orbits Saturn
possibleOrigin captured Kuiper belt object
captured centaur-like body
ringAssociation source of material for Saturn’s outer Phoebe ring
rotationPeriod_hours approximately 9.27
rotationState not tidally locked
scientificInterest clues to early outer Solar System conditions
semiMajorAxis_km approximately 12,952,000
shape roughly spherical but irregular
spectralType C-type or D-type asteroid–like
surfaceColor dark
surfaceComposition water ice mixed with dark material
surfaceFeatures heavily cratered
large impact basins
visitedBy Cassini–Huygens spacecraft

Referenced by (3)
Subject (surface form when different) Predicate
Phoebe Adele Gates
givenName
Titans
includes
Iapetus
sibling

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