Here's why:
* Mass is a fundamental property of matter and represents the amount of "stuff" in an object. It's a constant value regardless of location.
* Weight is the force exerted on an object due to gravity. In space, where gravity is much weaker, the car would be weightless, but its mass would still be the same.
Think of it this way: If you took a scale to space, the car would appear to have zero weight. But its mass, which is the amount of matter it contains, would be unchanged.
