Why does your mass stay the same if you go to the moon?

Mass is not the same as weight. Your weight will be less on the Moon; your mass can informally be considered as the "amount of substance" you have. Since you won't lose or gain a significant amount of atoms when you go to the Moon, your mass will stay the same - except for any insignificant change if you eat or breathe on your trip to the Moon, or an even more insignificant effect due to the General Theory of Relativity.

Mass is not the same as weight. Your weight will be less on the Moon; your mass can informally be considered as the "amount of substance" you have. Since you won't lose or gain a significant amount of atoms when you go to the Moon, your mass will stay the same - except for any insignificant change if you eat or breathe on your trip to the Moon, or an even more insignificant effect due to the General Theory of Relativity.

Mass is not the same as weight. Your weight will be less on the Moon; your mass can informally be considered as the "amount of substance" you have. Since you won't lose or gain a significant amount of atoms when you go to the Moon, your mass will stay the same - except for any insignificant change if you eat or breathe on your trip to the Moon, or an even more insignificant effect due to the General Theory of Relativity.

Mass is not the same as weight. Your weight will be less on the Moon; your mass can informally be considered as the "amount of substance" you have. Since you won't lose or gain a significant amount of atoms when you go to the Moon, your mass will stay the same - except for any insignificant change if you eat or breathe on your trip to the Moon, or an even more insignificant effect due to the General Theory of Relativity.