Answer:
Gravity explains this.
Explanation:
Weights and mass are different terms .
Weight is defined as the force exerting on the surface due to the mass and gravity of acceleration.
Here mass is related to the density of the body. So as the density would be same mass woulnt vary.
Whereas the Gravity changes due to the property of the planet.
Gravity is different for different planets and hence moon and earth have two different values.
So the mass i.e density remains same on both planets but the g value always changes hence weight is different.