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.
More specifically, our rotation period (the time elapsed for one rotation) with respect to the stars is called a sidereal day. A sidereal day is 24 sidereal hours, or 23 hours and 56 minutes on a normal clock. Our clock time is based on the earth's rotation with respect to the sun from solar noon to solar noon.arth's Rotation and the Apparent Daily Motion of the Sky. The earth rotates about an imaginary line that passes through the North and South Poles of the planet. This line is called the axis of rotation. Earth rotates about this axis once each day (approximately 24 hours).