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.
Using the Celestial Sphere as the reference is called Sidereal Time. A Sidereal Year would be the time it takes for the same reference star to be in the same position overhead at the Vernal Equinox A Sideral Year is slightly longer than a normal year (a Solar Year) it takes approximately 365.2465 days.