Weight on Other Planets – Same Mass, Different Weight

What it shows

Mass is the amount of matter in an object and is measured in kilograms; it is the same everywhere. Weight is the gravitational force on the object, W = m·g, measured in newtons with a spring balance. The surface gravity g differs from world to world: 1.62 m/s² on the Moon, 9.8 m/s² on Earth, 24.8 m/s² at Jupiter's cloud tops. The simulation uses NASA surface gravity data for 11 bodies and ignores air resistance. It assumes the same take-off speed on every world, so jump height is v²/2g and fall time is √(2h/g).

How to use

Choose a body in the list, click a row of the table or tap a bar of the g chart. Move the Mass m slider and compare the spring balance reading (the green mark shows Earth) with the beam balance, which always stays level. Set the Jump speed and Drop height, then press Jump and drop again to watch the astronaut and the ball next to Earth on the same clock. Use Slow ×¼ for fast worlds such as the Sun, and Reset to go back to the start values.

Parameters you can change

• Body Sun, Mercury, Venus, Earth, Moon, Mars, Jupiter, Saturn, Uranus, Neptune, Pluto
• Mass of the object 0.1–20 kg
• Jump take-off speed 1–4 m/s
• Drop height 0.5–20 m
• Compare side by side with Earth

Questions to explore

1. If you take a 2 kg bag of rice to the Moon, what happens to its mass and to its weight?
2. On which body does the astronaut jump highest, and why does g explain this?
3. How many times higher is a jump on the Moon than on Earth, compared with the ratio of their g values?