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  1. Home
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  3. Celestial Sphere
Observational Astronomy

Celestial Sphere

Definition

An imaginary sphere of arbitrarily large radius centered on Earth, upon which all celestial objects are projected. Useful for locating objects using coordinates like right ascension and declination, though objects are at vastly different actual distances.

Related Terms

Constellation

A group of stars forming a recognizable pattern traditionally named after its apparent form or a mythological figure. Th...

Zodiac

A belt-shaped sky region extending about 8 degrees north and south of the ecliptic. It includes the constellations throu...

Eclipse

An astronomical event when one celestial body moves into the shadow of another. Solar eclipses occur when the Moon passe...

Explore Related Topics

Dive deeper into celestial sphere and related concepts on Cosmos Observatory.

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Visible planets, moon phase, and sunrise times.

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Full Glossary

Browse all 66+ space and astronomy terms.

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