An imaginary sphere of infinite extent with the earth at its center on which the stars, planets, and other heavenly bodies appear to be located.
An imaginary sphere of infinite extent with the earth at its center on which the stars, planets, and other heavenly bodies appear to be located.
以地球球心为中央，且拥有很大半径的假想圆球。设想中，一切天体都附着在天球上。