# As planets orbit around the Sun, does the force of gravity due to the Sun remain constant?

I know that the force of gravity is:

$$F = GMm/R^2$$

Where $G$ is gravitational constant, $M$ is mass of sun, $m$ is mass of the orbiting planet and $R$ is the distance between the center of their masses.

Would I be right to assume that the gravitational pull on the planet due to the sun, changes because the distance between the sun and the planet changes over time?

• absolutely right. – user108787 May 22 '16 at 19:53
• It is, in principle, possible for a body to have a perfectly circular orbit, in which case the force remains constant. – WhatRoughBeast May 22 '16 at 21:34