An object's mass remains the same regardless of its location, including on the Moon.

Here's why:

* Mass vs. Weight: Mass is the amount of matter in an object. Weight is the force of gravity acting on that mass.

* Gravity's Role: The Moon has a weaker gravitational pull than Earth. This means an object will weigh less on the Moon, but its mass will remain the same.

Therefore, if an object has a mass of 4.2 on Earth, it will also have a mass of 4.2 on the Moon.