The Motion of the Moon

As the Earth rotates the Moon, like the Sun, rises in the east and sets in the west. It follows a path quite close to the ecliptic.

As the Moon also rotates around the Earth every 27.3 days it will also move eastwards by about 13 degrees (360 / 27.3) every night. This means that if you observe the Moon at a certain time on a particular night in a certain place then at the same time the following night it will be about 13 degrees east of where it was.

This works out to about 1/2 a degree, or one Moon diameter, per hour relative to the starry background.

Different phases of the Moon rise and set at different times of day. A full moon, for example, rises at about 6 a.m., culminates at about midnight then sets at about 6 p.m.

Other phases rise, culminate and set at other times which we can figure out using similar diagrams. I have shown the first quarter and waxing crescent phases below.

                      

You should be able to draw similar diagrams for all the phases of the Moon and so calculate their rising and setting times.

 

New moon

Waxing crescent

First quarter

Waxing gibbous

Full moon

Waning gibbous

Third quarter

Waning crescent

Rises in East

6 a.m.

3 a.m

midnight

9 p.m

6 p.m.

3 p.m

midday

9 a.m.

Culminates

midday

9 a.m.

6 a.m.

3 a.m.

midnight

9 p.m.

6 p.m.

3 p.m.

Sets in West

6 p.m.

3 p.m.

midday

9 a.m.

6 a.m.

3 a.m.

midnight

9 p.m