天球在天文学上的用途极广。夜晚,当我们向上仰望天空,可以看到天上的星星和月亮似乎都分布在一个球面上。这个以我们为中心的球面就是天球。不同的天体,在天球上的位置各不相同。随着日夜交替以及四季更换 The celestial sphere has a wide range of uses in astronomy. At night, when we look up at the sky, we can see that the stars and moon in the sky seem to be on a sphere. This sphere centered on us is the celestial sphere. Different celestial bodies have different positions on the celestial sphere. With the change of day and night and four seasons