Apparent Motions of Celestial Objects

An apparent motion is a motion that an object appears to make. Apparent motions can be real or illusions. When you observe a person spinning around, that motion is real. However, when the spinning person sees the room as spinning that is an illusion and not a real motion. It has always been difficult for people looking into space to distinguish real motions of celestial objects from illusions. For example, the stars appear to move across the sky from east to west. However, this apparent motion is caused by Earth’s rotation.