What natural law did Newton use to explain the movement of objects on Earth and in space?

 Sir Isaac Newton used his law of universal gravitation to explain the movement of objects both on Earth and in space. This law states that every point mass attracts every other point mass by a force directed along the line intersecting both points. The force is proportional to the product of their masses and inversely proportional to the square of the distance between the points (centers of mass). Mathematically, it can be expressed as:

F = G * (m1*m2) / r^2

Where F is the force of attraction between two bodies, G is the gravitational constant, m1 and m2 are the masses of the two bodies, and r is the distance between the centers of the two masses.

Using this law, Newton was able to explain not only why objects fall to the ground on Earth, but also the motion of planets and other celestial objects. For example, it was this law that allowed him to show that the orbits of the planets around the Sun are elliptical, as earlier described by Kepler's laws of planetary motion.