The gravity of an astronomical object, such as a planet or a moon, depends primarily on its mass. The greater the mass of an object, the stronger its gravitational pull.
The Earth is significantly more massive than the Moon, which is why Earth's gravity is about six times stronger than the Moon's gravity. The mass of the Earth is approximately 5.97 x 10^24 kilograms, while the mass of the Moon is about 7.35 x 10^22 kilograms. The large difference in mass between the two bodies results in a substantial difference in gravitational pull.
The gravitational force between two objects is given by Newton's law of universal gravitation, which states that the force is directly proportional to the product of their masses and inversely proportional to the square of the distance between them. Since the mass of the Earth is much greater than that of the Moon, the gravitational force exerted by the Earth is significantly stronger.
It's important to note that the gravitational pull of an object decreases as you move farther away from it. This means that even though the Moon's gravity is weaker compared to Earth's, it is still sufficient to keep objects and the Moon's own atmosphere and surface features intact. Astronauts on the Moon, for example, experience about one-sixth of the gravity they would experience on Earth due to the Moon's lower mass and gravitational pull.
In summary, the difference in the masses of the Earth and the Moon leads to a significant difference in their gravitational pulls, with Earth's gravity being approximately six times stronger than the Moon's gravity.