Question

Explain the main reason why the position of the moon in the sky changes over the course of a single night. In other words why is the moon in a different position in the sky at 11:00 than it was as 9:00?
Explain why the position of the moon in the sky changes from night to night, so that at 9:00 tomorrow it will be at a different position in the sky than it was at 9:00 today.

Answer 1

Explanation:  The moon changes its visual position relative to the earth during one night because the earth revolves around its axis. As the earth revolves around its axis it means that within a few hours an observer at a certain point on earth will, due to the earth's rotation, change the angle at which he sees the moon.

The fact that the moon also moves, that is, rotates around the earth, and that it takes about a month for a full rotation around the earth, is why we will see the moon in a different position in the sky at the same time next night.