Why is the weight of an object on the moon its weight on the earth?
The weight of an object on the moon would be given by
where MM is the mass of the moon, m is mass of the body, rM is the radius of the moon and G is the gravitational constant.
The weight of an object on the Earth would be given by
where ME and rE are the mass and radius of the earth respectively.
The above ratio is approximately equal to 1/6 and this is why the weight of an object on the moon (1/6)th of its weight on the earth