Step on a scale on Earth and it tells you your weight. But that number isn’t fixed — it depends on gravity. Travel to another planet, and you wouldn’t suddenly gain or lose mass, but your weight would change depending on the planet’s pull.

Gravity isn’t the same everywhere. It depends on two things: a planet’s mass and its size (radius). The combination determines how strong gravity feels at the surface. Let’s take a tour of the solar system to see how you’d weigh if you hopped from one world to another.

A Quick Refresher: Mass vs. Weight

• Mass: How much matter you’re made of. Always the same, whether on Earth, Mars, or floating in space.
• Weight: The force of gravity acting on your mass. Changes depending on where you are.

On Earth, gravity is about 9.8 m/s². That sets the weight we’re familiar with. On other planets, the pull is stronger or weaker.

Mercury: The Lightest Tug

• Gravity: ~38% of Earth’s
• What it feels like: If you weigh 150 lbs on Earth, you’d weigh about 57 lbs on Mercury.

Mercury is small and dense, but its low mass means weaker gravity. You could leap twice as high, but the scorching days and freezing nights might distract you from testing it out.

Venus: Earth’s Twin, Almost

• Gravity: ~90% of Earth’s
• What it feels like: A 150-lb person would weigh about 135 lbs.

Venus is nearly the same size and mass as Earth, so gravity feels familiar. Unfortunately, you’d also be standing under crushing atmospheric pressure and 460°C heat. Best to leave this experiment to the imagination.

Mars: The Low-Gravity Frontier

• Gravity: ~38% of Earth’s (same as Mercury)
• What it feels like: A 150-lb person would weigh only 57 lbs.

Mars is the darling of space exploration, and its weaker gravity makes it attractive for exploration. You could jump much higher and carry heavy loads more easily. But over the long term, scientists worry low gravity could harm bones and muscles.

Jupiter: The Giant’s Grip

• Gravity: ~2.5 times Earth’s
• What it feels like: A 150-lb person would weigh about 375 lbs.

Jupiter is massive, but because it’s also enormous in size, surface gravity isn’t as extreme as you might guess. Still, you’d feel like you were being pressed into the ground. Not that you could stand there anyway — Jupiter is a gas giant with no solid surface.

Saturn: Lighter Than You’d Expect

• Gravity: ~1.1 times Earth’s
• What it feels like: A 150-lb person would weigh about 165 lbs.

Despite being huge, Saturn’s lower density (it’s mostly hydrogen and helium) means gravity at its cloud tops isn’t much stronger than Earth’s. In fact, Saturn is the only planet less dense than water — if you had a cosmic bathtub big enough, Saturn would float!

Uranus: A Subtle Squeeze

• Gravity: ~0.9 times Earth’s
• What it feels like: 150 lbs becomes about 135 lbs.

Uranus is an ice giant with odd tilts and seasons, but gravity there is surprisingly close to Earth’s. You wouldn’t notice much difference stepping on a scale.

Neptune: Strong but Familiar

• Gravity: ~1.1 times Earth’s
• What it feels like: 150 lbs becomes about 165 lbs.

Neptune, like Uranus, is an ice giant. Its stronger mass balances its size, so surface gravity ends up close to ours. But the 1,600 km/h winds might keep you too busy holding on to check your weight.

Pluto: The Featherweight World

• Gravity: ~6% of Earth’s
• What it feels like: 150 lbs shrinks to just 9 lbs.

Pluto isn’t officially a planet anymore, but it’s too fun to leave out. With such weak gravity, you could bound in giant leaps, like moving in slow motion.

The Moon: Earth’s Companion

• Gravity: ~16% of Earth’s
• What it feels like: 150 lbs becomes 24 lbs.

Apollo astronauts experienced this firsthand, bouncing lightly across the lunar surface. The footage looks playful, but low gravity also made simple tasks awkward and tiring.

Why Gravity Shapes Planets and People

Gravity isn’t just about your weight. It shapes everything:

• Atmospheres: Strong gravity holds thick atmospheres (like Jupiter). Weak gravity lets them escape (like Mars).
• Mountains: Higher gravity limits how tall mountains can grow. Olympus Mons on Mars towers 3 times higher than Everest because gravity is weaker.
• Life: On Earth, evolution shaped bones and muscles for 1 g. Living long-term on Mars or the Moon could change human physiology.

Gravity is the invisible hand sculpting worlds — and us.

Awe in the Pull

Stand on Earth, Mars, or Jupiter, and gravity changes how heavy you feel. But it’s always the same force — the warping of spacetime pulling you down.

The next time you step on a scale, imagine how different that number would be on another planet. Gravity may weigh us down, but it also binds us to worlds, shapes stars, and keeps the cosmos together.