F = Gm₁m₂/r² — Newton's Universal Law of Gravitation. G = 6.674×10⁻¹¹ N·m²/kg².
Earth–Moon gravitational force: ~1.98 × 10²⁰ N — keeps the Moon in orbit.
Doubling the distance between objects reduces gravity to 1/4 (inverse square law).
F = Gm₁m₂/r². Gravitational force is proportional to the product of masses and inversely proportional to distance squared.