From the perspective of a viewer standing on Earth's surface, the sun, the moon and the stars appear to be fixed (so to speak) onto a large celestial sphere which is rotating around the earth once per day. This gives the sense of the sun, the moon and the stars rising in the east and setting in the west day after day. But the -orientation- of this rotating sphere depends on where one is standing on the surface of the earth. For example, for observers in Milwaukee: the north star---which acts as one of the poles of the celestial sphere---lies about 45 degrees above the northern horizon. While for observers in Quito, Ecuador (near Earth's equator): the north star lies very close to the northern horizon.

свернуть