Figure 1-9 Why Daily Motion Happens The apparent daily motion of the stars, Sun, and Moon from east to west across the sky is a consequence of Earth’s rotation. (a) This drawing shows Earth from a vantage point above the north pole, with very distant stars in the background. In this drawing, imagine the red dot is a person in California, the local time is 8:00 p.m., and the constellation Cygnus is visible high overhead. (b) Four hours later, Earth has made one-sixth of a complete rotation to the east. As seen from Earth, the entire sky appears to have rotated to the west by one-sixth of a complete rotation. It is now midnight in California, and the constellation high over the observer in California is now Andromeda.