Why is the weight of an object on the moon 1/6th its weight on the earth?
The weight of an object depends on ‘g’ acceleration due to gravity, and the value of ‘g’ on earth: and moon is not same. The mass and radius of the earth is more than the mass and radius of the moon. As  the weight of a body on the earth is 6 times more than the weight of a same body on moon.