Weight is a measurement of the force on a object caused by gravity trying to pull the object down. Mars has less gravity than Earth. Therefore if you were on Mars you'd weigh less because the force of gravity wouldn't be as strong as it is here on Earth. Does this mean you would suddenly be thinner on Mars? No. You would have the same amount of mass as you do on Earth. (Mass is the amount of stuff inside an object.) So, on Mars, your mass would be the same as it is here on Earth. But you'd weigh less because Mars has less gravity than Earth.

Click Professor Parsons to find out more about gravity, weight, and mass.