Kepler’s second law is calculated for 18 planets and asteroids. It is shown that equal areas are swept in equal intervals of time only near the perihelion (P) and the aphelion (A).

# Kepler’s Second Law

The gravitational force of the Sun, based on observations, is derived as the product of the acceleration times the area of a circle with radius equal to the semimajor axis of revolution. This quantity is constant for all planets, asteroids, and artificial satellites; it is independent of the mass of the attracted body.