View your list of saved words. (You can log in using Facebook.)
Time required for a celestial body in the solar system to complete one revolution with respect to the fixed stars (as observed from a fixed point outside the system). A planet's sidereal period can be calculated from its synodic period. The sidereal period of the Moon or an artificial satellite of Earth is the time it takes to return to the same position against the background of stars. See alsoday.
This entry comes from Encyclopædia Britannica Concise. For the full entry on sidereal period, visit Britannica.com.
Seen & Heard
What made you look up sidereal period? Please tell us what you were reading, watching or discussing that led you here.