The Earth and Moon exert gravitational forces on one another as they orbit the Sun. As a result, the path they follow is not the simple circular orbit you would expect if either one orbited the Sun alone. Occasionally you will see a suggestion that the Moon follows a path like a sine wave centered on a circular path, as in the upper part of FIGURE 12-32. This is incorrect. The Moon's path is qualitatively like that shown in the lower part of Figure 12-32. Explain. (Refer to Conceptual Question 11.)

This is not the path of the Moon Path of Earth-Moon center of mass Path of Earth-Moon Path of the Moon center of mass