The question of how much you would weigh on another planet reveals a fundamental aspect of physics and the diversity of our solar system. Weight is not a fixed characteristic; it is a measurement of force that changes depending on the gravitational pull of the celestial body you are standing on. If you were to travel throughout our cosmic neighborhood, the planet where you would weigh the most is the solar system’s largest world, Jupiter.
Weight vs. Mass: A Distinction
To understand why your weight changes from one planet to the next, it is necessary to distinguish between weight and mass. Mass is a measure of the amount of matter an object contains, and this quantity remains constant regardless of location. Your mass would be the same whether you were standing on Earth, the Moon, or floating in deep space.
Weight, conversely, is a measure of the force of gravity acting upon that mass. It is the pull exerted on your body by a celestial object, and because the gravitational pull varies, your weight changes as you travel. On Earth, where gravitational acceleration is standardized to one “g,” a 150-pound person has the same mass and weight, but this relationship only holds true for our home planet.
Jupiter: The Planet of Maximum Weight
The planet with the greatest gravitational force in the solar system, resulting in the maximum weight, is Jupiter. This enormous gas giant has a surface gravity approximately 2.4 to 2.5 times that of Earth. Since Jupiter has no solid surface, this measurement is taken at the point in its atmosphere where the pressure is comparable to Earth’s sea level, known as the one-bar pressure level.
This powerful gravitational field would make a person feel heavy compared to their Earth weight. For example, a person who weighs 150 pounds on Earth would weigh about 360 to 375 pounds on Jupiter. Jupiter’s mass, which is more than 300 times that of Earth, is responsible for this weight.
The Physics of Surface Gravity
The strength of gravity on a planet’s surface is determined by two properties: the planet’s total mass and its radius (the distance from the center to its surface). Gravitational force increases directly with mass, meaning a more massive planet pulls harder. However, gravity also follows an inverse square law, meaning the force decreases rapidly with the square of the distance from the center of the mass.
Jupiter’s immense mass is the primary reason for its high surface gravity, but its large radius works to lessen the effect. Even though Jupiter is over 300 times more massive than Earth, its radius is about 11 times larger, spreading the gravitational force over a greater distance. Because Jupiter is a gas giant with a much lower overall density, the surface gravity is about 2.5 times Earth’s.
Comparative Weights Across the Solar System
Applying these principles reveals a wide range of weights across the solar system. The rocky inner planets and smaller worlds have significantly lower surface gravity than Earth. For instance, on Mars and Mercury, a person would weigh less than 40% of their Earth weight. On the Moon, a person would weigh only about 16% of their Earth weight.
Even among the other large gas giants, only Neptune has a surface gravity slightly stronger than Earth’s, at about 1.1 times our planet’s pull. Saturn and Uranus, despite their massive size, have surface gravities nearly equal to or slightly less than Earth’s because their gaseous layers are more spread out. The smallest weight in the solar system would be experienced on low-mass bodies like the dwarf planet Pluto, where a person would weigh less than 10% of their Earth weight.