The Moon is the natural ruler of Cancer. The Moon is really not a planet but a satellite of the earth. It is considered as the second most important body after the Sun. The Moon takes 27 days, 7 hours and 43 minutes to complete one rotation around the earth. It is a feminine planet and rules emotions, fertility, marriage and motherhood. A well-placed moon can show a sensitive, caring and emotional person, while a poorly placed Moon may denote an unstable mind, weakness and confusion. The Moon rules the breasts and the womb.