The force of attraction, F, that exists between all bodies. For any two bodies, it is directly proportional to the product of the two masses and inversely proportional to the square of the distance between them. The constant of proportionality is G, the universal gravitational constant. Expressed in mathematical form, F = Gm1m2/d2, where m1 and m2 are the two masses and d is their distance apart.
Subjects: Astronomy and Astrophysics.