What did Planetary Synodic Periods look like?

Not a physical object — accumulated long-term astronomical observation data. Planetary positions and dates recorded on excavated bamboo-slip and silk manuscripts.

How did Planetary Synodic Periods work?

Long-term continuous observation and recording of each planet's motion → marking each moment when a planet rises or sets with the Sun → the interval between successive conjunctions is the synodic period → centuries of accumulated data yield highly precise values.

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五星会合周期

Planetary Synodic Periods

Precisely measured synodic periods of the five planets (Mercury, Venus, Mars, Jupiter, Saturn) — the time interval between successive conjunctions with the Sun — measurements that closely match modern values.

五星会合

Scientific Principle

Synodic period: 1/P_syn = |1/P_earth - 1/P_planet|. The reciprocal difference between Earth's and the planet's orbital periods equals the synodic frequency.

五星会合周期

Planetary Synodic Periods

Scientific Principle

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