Learn more by clicking the Google or Facebook button below. Population Demographics for Tonasket, Washington in 2016 and 2017. Other Counties and Cities in Washington.
Sidereal Period versus Synodic Period. 1  Measuring the motion of the Moon around the Earth relative to the distant stars leads us to what is called the sidereal period. 2  Measuring the motion of the Moon around the Earth relative to the Sun leads us to what is called the synodic (pronounced si-nod-ik) period.
The Moon's orbital period in a non-rotating frame of reference is 27.32 days (27 days, 7 hours, 43 minutes, 11.6 seconds). This is the sidereal month. It is measured by observing how long it takes the Moon to pass a fixed star.