Free Sidereal-to-Synodic Converter
Convert a planet's sidereal period to its synodic period relative to Earth.
days
days
Synodic Period
583.93 days
Synodic Period (years)1.5987 yr
Synodic Period vs Planet Sidereal Period
Sidereal and Synodic Periods
A planet's sidereal period is its true orbital period. Its synodic period is how long between repeated alignments as viewed from Earth.
Formula
1/P_syn = 1/P_planet - 1/P_Earth
Example Calculation
Venus has a sidereal period of 224.7 days.
- 011/P_syn = |1/224.7 - 1/365.25|
- 02= |0.004451 - 0.002738| = 0.001713
- 03P_syn = 1/0.001713 ≈ 583.9 days