Here's why:
* Newton's Law of Universal Gravitation: This law states that the force of gravity between two objects is directly proportional to the product of their masses and inversely proportional to the square of the distance between their centers.
* Inverse Square Law: The "inversely proportional to the square of the distance" part is crucial. This means that if you double the distance between the objects, the gravitational force between them becomes four times weaker (2 squared = 4). If you triple the distance, the force becomes nine times weaker (3 squared = 9).
In summary: As the distance between two objects increases, the force of gravity between them decreases rapidly.