celestial sphere
Imaginary stellar backdrop
The celestial sphere is an imaginary sphere of infinite radius surrounding Earth, on which all celestial objects appear to be projected.
Astronomers use it as a reference frame for mapping star positions and describing the apparent motion of heavenly bodies across the sky.
Ancient peoples conceived of the night sky as an actual dome or sphere enclosing the world.
The arching sky above
- PtolemaicEarth-centered astronomical system
- geocentricTreating our planet as center
- AristotelianOf ancient systematic philosophy
- crystal spheresTransparent orbs for scrying
empyrean · harmony of the spheres · quintessence · ether · epicycles · deferent · spheres · heavens
Celestial expanse overhead
- firmamentThe arching sky above
- domeRounded vault forming roof
- OlympusSacred Greek mountain
- AsgardNorse divine realm
empyrean · cosmic ocean · world egg · axis mundi · divine · ethereal · transcendent · shamanic
Angular distance from equator
- eclipticSun's apparent annual path
- zenithPoint straight overhead
- nadirLowest possible point
- azimuthHorizontal directional angle
altitude · hour angle · meridian · equinox · solstice · precession · epoch · sidereal
Named pattern of celestial bodies
- fixed starsStars appearing motionless
- magnitudeSize or scale
- stargazingObserving celestial bodies
- naked eyeVision without optical instruments
telescope · observatory · planetarium · star chart · night sky · zodiac · asterism · circumpolar
Mechanical solar system model
- demonstrationPublic display of opinion
- educationalPromoting knowledge or skill
- replicaFaithful scaled reproduction
- mechanismMeans by which something operates
clockwork · projection · Mercator · stereographic · mapping · representation · teaching · visualization
firmament
The arching sky above
- PtolemaicEarth-centered astronomical system
- geocentricTreating our planet as center
- AristotelianOf ancient systematic philosophy
crystal spheres · empyrean · harmony of the spheres · quintessence · ether · epicycles · deferent · spheres · heavens · cosmology
heavens
Celestial expanse overhead
Asgard · empyrean · cosmic ocean · world egg · axis mundi · divine · ethereal · transcendent · shamanic · afterlife
declination
Angular distance from equator
azimuth · altitude · hour angle · meridian · equinox · solstice · precession · epoch · sidereal · horizon
constellation
Named pattern of celestial bodies
- fixed starsStars appearing motionless
- magnitudeSize or scale
- stargazingObserving celestial bodies
naked eye · telescope · observatory · planetarium · star chart · night sky · zodiac · asterism · circumpolar · rising
orrery
Mechanical solar system model
- demonstrationPublic display of opinion
- educationalPromoting knowledge or skill
- replicaFaithful scaled reproduction
mechanism · clockwork · projection · Mercator · stereographic · mapping · representation · teaching · visualization
- astronomystars, moon, sun, planet, planets
- night skystars, moon, constellations, shooting stars, constellation
- spacespace, sun, moon, stars, star
- astronomy termseclipse, solar eclipse, lunar eclipse, star, meteor shower
- celestialsun, moon, stars, planet, planets
- stargazingtelescope, stargazing guides, night sky, stars, constellation
celestial sphereEarth
Our world
earthly realm · terra firma · geosphere · mortal realm · underworld
sphere, atmosphere, celestial, spherical, hemisphere, spheroid, biosphere, stratosphere, lithosphere