planetoid
Small celestial body
A planetoid is a small celestial body orbiting the sun—essentially a minor planet or large asteroid.
The term emphasizes that these objects share characteristics with planets but lack sufficient size or gravitational dominance to qualify as full planets: Ceres was reclassified from asteroid to dwarf planet, though planetoid still applies.
The word is somewhat dated in technical astronomy but persists in general usage.
Sun-orbiting rocky mass
- trans-NeptunianBeyond the eighth planet
- centaurHalf-human, half-equine being
- scattered discDistant, inclined orbital population
- resonantDeeply vibrating with sound
classical · detached · binary · rubble pile · protoplanet
Distant ring of frozen objects
- Oort cloudTheoretical cometary halo
- asteroid beltPlanetary rubble orbit zone
- scattered discDistant, inclined orbital population
- NeptuneEighth planet or sea deity
Goddess of crops and growth
Covered with stones
- icyFrozen or unfriendly
- metallicResembling ore-based elements
- silicateOxygen-bound crystal compound
- carbonaceousContaining or composed of carbon
basaltic · regolith · volatile · primitive · differentiated · undifferentiated · hydrated · anhydrous
Oval-shaped or indirect
- perihelionOrbital point nearest sun
- aphelionFarthest point from sun
- eccentricityUnconventional behavior or nature
- inclinationDisposition toward something
revolution · trajectory · gravitational · retrograde · prograde · resonance · perturbation · barycenter
Close pass without landing
- rendezvousScheduled meeting at agreed location
- DawnProper name suggesting beginning
- New HorizonsUndiscovered opportunities ahead
- HayabusaAsteroid-sampling space probe
Rosetta · Lucy · landing · imagery · spectroscopy · mapping · crater · surface features
asteroid
Sun-orbiting rocky mass
- trans-NeptunianBeyond the eighth planet
- centaurHalf-human, half-equine being
- scattered discDistant, inclined orbital population
resonant · classical · detached · binary · rubble pile · protoplanet
Kuiper belt
Distant ring of frozen objects
- Oort cloudTheoretical cometary halo
- asteroid beltPlanetary rubble orbit zone
- scattered discDistant, inclined orbital population
Neptune · Jupiter · ecliptic · heliosphere
Ceres
Goddess of crops and growth
rocky
Covered with stones
carbonaceous · basaltic · regolith · volatile · primitive · differentiated · undifferentiated · hydrated · anhydrous · albedo
elliptical
Oval-shaped or indirect
- perihelionOrbital point nearest sun
- aphelionFarthest point from sun
- eccentricityUnconventional behavior or nature
inclination · revolution · trajectory · gravitational · retrograde · prograde · resonance · perturbation · barycenter · heliocentric
flyby
Close pass without landing
- rendezvousScheduled meeting at agreed location
- DawnProper name suggesting beginning
- New HorizonsUndiscovered opportunities ahead
Hayabusa · Rosetta · Lucy · landing · imagery · spectroscopy · mapping · crater · surface features · rotation
- solar systemsun, Earth, Mars, Jupiter, Saturn
- space objectsgalaxy, star cluster, nebula, quasar, star
- space rocksasteroid, asteroids, meteorites, meteorite, meteors
- Exoplanetsocean world, super-Jupiter
- planetary formationplanetesimals, protoplanet, solar nebula, planetesimal, snow line
- TNOsPluto, Eris, Sedna, Charon, Albion