The pictures below describes the movements of the Moon in the Mercator View.
The letters N, W, E, and S refers to North, West, East and South respectively.
The other sinusoidal line, beside the red line is the path of the moon.
The blue line is the horizon. The horizontal
line in the middle is the celestial equator. The red
line is the path of the sun. The Moon moves like the sun, in the
left direction but it completes it's cycle in one month. Here, in
this picture, the horizon has moved toward the left in its original position
as marked by the letters N, W, E and S.