Newton's law of universal gravitation states that every mass attracts every other mass in the universe. The strength of this attraction depends on two factors: the masses of the objects and the distance between them. Specifically, the force of gravity increases with greater mass and decreases as the distance increases. This law can be expressed mathematically with the formula F = G \fracm_1 m_2r^2 , where F is the gravitational force, G is the gravitational constant, m_1 and m_2 are the masses, and r is the distance between their centers. This principle helps explain the motion of planets, moons, and other celestial bodies in space.