The answer
The weaker a world's gravity, the higher and longer you jump: about 6 times higher on the Moon, 2.6 times on Mars, and only about 40% as high on Jupiter's cloud tops.
When you jump, your legs launch you upward at a certain speed. Gravity then slows you down until you stop and fall back. The weaker the gravity, the longer it takes to slow you down, so you go higher.
Jump height is inversely proportional to gravity: half the gravity, twice the height. Time in the air grows the same way, since you rise and fall more slowly.
The Moon's gravity is about 1.62 m/s², about one sixth of Earth's 9.81. A jump that reaches 50 cm on Earth would reach about 3 metres there. On Mars, at 3.71 m/s², it would reach about 1.3 metres. On tiny Pluto, at 0.62 m/s², about 8 metres.
Jupiter has no solid surface: it's a giant ball of gas that gets thicker and hotter deeper down. But if you could stand at its cloud tops, its gravity of about 24.8 m/s² would hold you to a 20 cm hop, and you'd feel two and a half times heavier.
What we know and what we don't
What physics tells us
- For the same push, jump height and time in the air are inversely proportional to surface gravity.
- Surface gravities: Earth 9.81, Moon 1.62, Mars 3.71, Pluto 0.62, Jupiter (at the cloud tops) 24.8 m/s².
Scientists aren't sure
- Real jumps would also depend on spacesuits, footing and how your body adapts, so these are ideal numbers.
Go deeper
Why? Why does gravity differ from world to world?
Surface gravity depends on a world's mass and its size. More mass pulls harder, but being bigger puts you farther from the centre, which weakens the pull. The Moon has about 1% of Earth's mass, so even though it's smaller, its pull is much weaker.
Why? Why did Apollo astronauts hop instead of walk?
In low gravity, a normal step launches you up and forward, and you come down slowly. Hopping like a kangaroo turned out to be an easier way to move in their stiff spacesuits.
Why? Could you jump off a small asteroid?
On a very small asteroid, yes. Some are so small that a good jump would carry you faster than the speed needed to escape, and you'd float off into space.
Keep wondering
Sources
- Planetary Fact Sheet, NASA Goddard (NSSDCA)
- Pluto Fact Sheet, NASA Goddard (NSSDCA)