What concept explains why an object weighs less on the Moon than on Earth?

The reason an object weighs less on the Moon than on Earth is due to differences in gravitational field strength. Weight is the force experienced by an object due to gravity, and it is directly proportional to the local gravitational acceleration. The Moon has only about one-sixth the gravitational acceleration that Earth has, which is approximately 1.62 m/s² compared to Earth's 9.81 m/s². This lower gravitational strength on the Moon results in a smaller weight for any object when compared to its weight on Earth, even though the object's mass remains unchanged.

To provide additional context, the concept of gravitational field strength is fundamentally linked to the mass of the celestial body and the distance from its center. While the radius of the Moon is indeed smaller than that of Earth, it is the inherent gravitational pull generated by the Moon's mass that is the primary factor impacting weight. Additionally, the universal gravitational constant remains constant throughout the universe, so variations in its force do not apply in this scenario. Therefore, the key to understanding why objects weigh less on the Moon is recognizing that the strength of gravitational attraction is less on the Moon than it is on Earth.