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.
So, the sidereal rotation period is the TRUE ROTATION PERIOD of a celestial body. As in how much time elapses from when any distant star of interest rises to when same distant star rises again. It was later confirmed by inertial measurements, that without even looking outside Earth's atmosphere, we could measure its true rotation period.