How does the same gravitational force explain falling objects and the Moon’s orbit?

Sir Isaac Newton unified celestial and terrestrial physics by demonstrating that the same gravitational force governs both falling objects on Earth and the motion of the Moon.12

According to Newton’s laws of motion, an object in motion tends to travel in a straight line unless acted upon by an external force. For a falling object, gravity provides the downward force that causes acceleration toward Earth’s center. Similarly, the Moon is constantly "falling" toward Earth; without the inward pull of gravity, the Moon would obey the law of inertia and fly off into space in a straight line.231

Newton realized that this gravitational attraction diminishes with the square of the distance between two bodies. By comparing the acceleration of a falling object at Earth's surface to the Moon's centripetal acceleration in its orbit, he confirmed that the Moon’s acceleration is reduced by the same inverse-square ratio of their respective distances from Earth's center. Thus, an orbiting planet or moon is essentially a freely falling body, continuously deflected from a straight path by the same gravity that pulls objects to the ground.143