Kepler's Third Law
Kepler's Third Law states that the square of a planet's orbital period (P) is proportional to the cube of its average distance from the Sun (a), or its semi-major axis. Mathematically:
P² = a³
Units
* P: Orbital period (measured in Earth years)
* a: Semi-major axis (measured in astronomical units, AU)
Calculations
1. Given: a = 19.2 AU
2. Substitute: P² = (19.2)³
3. Calculate: P² = 7077.888
4. Find P: P = √7077.888 ≈ 84.1 years
Answer:
The orbital period of a planet 19.2 astronomical units from the Sun is approximately 84.1 Earth years.
