# Sun, Moon and Earth

Observe the Moon and you will soon discover one of her rhythms she moves past the fixed stars quite rapidly, taking about an hour to move her own diameter. In one day, she covers thirteen degrees, thereby taking slightly less than 28 days to return to the same stars. This is the sidereal month of 27.322 days. Three principal rotations are now defined the day SunEarth, the sidereal month MoonEarthstars and the year SunEarthstars. All three are shown opposite. But there is a fourth rotation, the lunar phases or lunation cycle, the time between full moons, which is truly Sun, Moon and Earth. Because the lunar phases are visible all over the Earth the lunation cycle is the prime lunar rhythm. It is also called the synodic month or, more simply, the lunar month. The lunation cycle takes 29.53059 days to complete. These two rhythms resemble a clock face. The 2.21 day catch up difference becomes one period five minutes in the clock. Imagine the centre of the clock is the Earth. If the minute hand is made to represent the position of the Moon and the hour hand that of the Sun, then one rotation of the Moon takes twelve periods sidereal month whereas the hands meet after every thirteen periods the lunation or new Moon. This 1213 rhythm is a fundamental Earth rhythm see picture opposite contents page. In fact there are 13.368 sidereal months and 12.368 synodic months in the year. The fractional part is very close to seven nineteenths. 14 the moonS tWo rhythmS sidereal and synodic months 15 the three key heavenly rotations Day, Month and Year the synodic lunar month is two days longer than the sidereal lunar month