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.
In other words, a solar day is how long it takes Earth to rotate once â and then some. A sidereal day â 23 hours 56 minutes and 4.1 seconds â is the amount of time needed to complete one rotation.In this system, the stars always appear at the same place in the sky at the same time each sidereal day. sidereal day â 23 hours 56 minutes and 4.1 seconds â is the amount of time needed to complete one rotation. In this system, the stars always appear at the same place in the sky at the same time each sidereal day.