How much difference is there between the astronaut's mass on Earth and on the moon?
1 Answer
The astronaut's weight changes, not their mass.
Explanation:
It's important to remember that mass and weight are not the same thing. Mass is the amount of matter that makes up a person or object. One way to measure mass is through its interaction with gravity. Any time you have two objects with mass, gravity will pull those two objects together. Newton quantified this attraction with his law of universal gravitation.
Looking at this equation, we can see that the force of gravity increases as the mass of the objects increases. We feel this attraction as weight. The Earth is much more massive than the moon, so the astronaut's weight would be greater on the Earth than on the moon.
This leads to the common misconception that mass changes in space, but really it is just the gravitational interactions between masses that change. Since mass is what makes up everything, it doesn't change just by moving an object.
