Kepler's Third Law
Kepler's Third Law of Planetary Motion states that the square of a planet's orbital period (P) is proportional to the cube of its average distance from the star (a). We can write this as:
P² = a³
Units
* a (average distance): Measured in Astronomical Units (AU) – 1 AU is the average distance between the Earth and the Sun.
* P (orbital period): Measured in Earth years.
Calculation
1. Substitute the average distance: a = 10 AU
2. Apply Kepler's Third Law:
P² = (10 AU)³ = 1000
3. Solve for P:
P = √1000 ≈ 31.62 years
Therefore, a planet with an average distance of 10 AU from its star would have an orbital period of approximately 31.62 Earth years.
