Astronomy & Space
Intermediate

Synodic Period

Time between repeated alignments of two orbiting bodies.

Formula

1S=∣1P1−1P2∣\frac{1}{S} = \left|\frac{1}{P_1} - \frac{1}{P_2}\right|

Variables

P_1,P_2Orbital periods
SSynodic period

Example

Earth (1 yr) & Mars (1.88 yr) ⇒ S ≈ 2.14 yr

Did You Know?

The Earth–Mars synodic period is why launch windows to Mars open only about every 26 months.

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