Work out how much you'd weigh on Mars, the Moon or other celestial bodies, based on their gravity compared to Earth's.
It's important to distinguish between mass and weight. Your mass is constant no matter where in the universe you are — it tells you how much matter your body consists of. Weight, on the other hand, is the force gravity pulls you with, and it changes from place to place.
Different celestial bodies have different mass and radius, which together determine the surface gravity. Earth has a gravitational acceleration of 9.81 m/s², while the Moon, for example, has only about 1.66 m/s² — which is why you weigh so much less there, even though your mass hasn't changed at all.
Because it's mass, not weight, that describes how much matter your body consists of. Weight is the force gravity pulls you with, and since the Moon has much weaker surface gravity than Earth (about 1.66 m/s² versus 9.81 m/s²), this force — and so your weight — is much lower there, even though your mass is exactly the same.
Surface gravity depends on both mass and radius. A celestial body with a large radius spreads its mass over a bigger area, which can give lower surface gravity than the mass alone would suggest. Uranus has a large radius relative to its mass, while Jupiter has an enormous mass that more than compensates for its own large radius — which is why Jupiter ends up with higher surface gravity.
The Sun has an enormous mass — more than 300,000 times Earth's mass — which far outweighs the extra distance its radius provides. This makes the surface gravity on the Sun nearly 28 times as strong as on Earth, far higher than on any of the planets in the solar system.