πͺ Orbital Period (Kepler's Third Law)
Bigger orbits take longer β predict a year anywhere with Kepler's law.
Results
- Orbital period
- 365.249 days
- In years
- 0.999996 years
- Earth check: ~365 days
How it works
T = 2Ο β(aΒ³ / GM)
Kepler found that the square of an orbital period is proportional to the cube of the orbit size. Newton showed why: gravity supplies the centripetal force. This one equation times moons, planets and exoplanets.
Assumptions: Circular orbit approximation, orbiting mass much smaller than central mass.
Reference: Kepler (1619); Newtonian derivation