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.
Earth's rotation period relative to the precessing or moving mean vernal equinox, its sidereal day, is 86164.090 530 832 88 seconds of mean solar time (UT1) (23 56 4.090 530 832 88). Thus the sidereal day is shorter than the stellar day by about 8.4 ms.