On other planets of the solar system, your weight is different from what it is on Earth, as you can see on the platform scale in this Demonstration. The length of a day (one rotation of the planet around its axis) varies too. The clock will run slower or faster than it would on Earth, depending on the rotation period of each planet. If the clock doesn't seem to move, it is because the rotation period of the planet shown is very large. Weight (measured in newtons) is the mass (measured in kilograms) multiplied by the acceleration due to gravity for each planet. An ordinary platform scale measures weight, but it is calibrated according to its mass on Earth. Mass, the amount of matter, is the same in all places, but weight varies.