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What’s the time unit in Kepler’s third law?

A planet or celestial body’s period (T), also expressed as (P). In the third law, (T) represents the time it takes a given orbital body to complete one revolution around the sun. Kepler used the earth’s own orbit as a guide when describing his laws, and the orbital period is expressed in earth years. For example, Halley’s comet has a period of 75.3 years.

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