Newton's Universal Law of Gravitation states that
Any two objects exert a gravitational force of attraction on each other.
The direction of the force is along the line joining the objects.
The magnitude of the force is proportional to the product of the gravitational masses of the objects and inversely proportional to the square of the distance between them.
F=GMmr2">F
=GMm/r^2
where F">F represents the force in Newtons,
M">M and m">m represent the two masses in kilograms,
and r">r represents the separation in meters.
G">G represents the gravitational constant, which has a value of 6.674⋅10−11N(m/kg)2">6.674*10^−11N(m/kg)^2.
Because of the magnitude of G">G, the gravitational force is very small unless large masses are involved.