Convertisseur Sidéral en Synodique
Convertissez les périodes sidérales en périodes synodiques.
days
days
Synodic Period
583.93 days
Synodic Period (years)1.5987 yr
Synodic Period vs Planet Sidereal Period
Formule
## 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|**
Exemple Résolu
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
Questions Fréquentes
Which planets have the longest synodic periods?
Planets whose sidereal periods are closest to Earth's. Mars (780 days) has a longer synodic period than Jupiter (399 days).
Can synodic be shorter than sidereal?
Yes. For distant planets the synodic period approaches one Earth year, shorter than the planet's sidereal period.
Why does this matter for observation?
The synodic period determines how often you get favourable viewing geometry like opposition or greatest elongation.