The distance between the Moon and the Earth varies during the Moon's rotation around the Earth because the Moon's orbit around the Earth is not a perfect circle, but rather an ellipse. This means that the Moon is sometimes closer to the Earth (perigee) and sometimes farther away (apogee) during its rotation. The difference between the perigee and apogee distances is about 30,000 miles, which can result in noticeable differences in the Moon's appearance and gravitational pull on the Earth.