The brightness cycle, the perigee-apogee cycle, and the lunar standstill cycle are three lunar cycles that occur throughout the moon's 27.3-day voyage around the Earth. During its orbit, the Earth's natural satellite's location in regard to the sun varies, resulting in the typical brightness cycle between the new and full moon every 29.5 days. The moon's gravitational attraction changes when it swings from perigee, the closest point on the loop around Earth, to apogee, the farthest point on the loop around Earth, every 27.5 days. This orbit is also inclined in regard to the Earth's axis, resulting in different gravitational impacts on the Southern and Northern hemispheres throughout the 27.3-day moon standstill cycle.