While your physical body remains unchanged no matter where you are in the universe, the downward pull you experience can vary significantly. This perceived heaviness, or weight, is directly influenced by the gravitational force of the celestial body you stand upon.
Weight Versus Mass
Understanding how your perceived heaviness changes across the cosmos begins with distinguishing between mass and weight. Mass refers to the amount of matter an object contains. This intrinsic property remains constant, whether on Earth or Jupiter; a bag of sugar, for instance, contains the same amount of sugar molecules regardless of its location.
Weight, in contrast, is a measure of the force of gravity acting on that mass. Your weight is dependent on the gravitational pull of the celestial body you are on, meaning it is a dynamic measurement that changes with your location. For example, a bag of sugar would feel lighter on the Moon than on Earth due to the Moon’s weaker gravitational pull.
How Gravity Shapes Your Weight
The gravitational pull exerted by a celestial body, which directly influences your weight, is determined by two primary factors: its mass and its radius. A planet with greater mass possesses more material, creating a stronger gravitational field that pulls objects towards its center with more force. This explains why giant planets like Jupiter exert a much stronger gravitational pull than smaller, less massive planets.
The second factor is the celestial body’s radius, or its size. For a given mass, a smaller, more compact planet will have stronger surface gravity than a larger, more spread-out one. This occurs because you are physically closer to the planet’s center of mass on a denser body. The combination of a planet’s total mass and how densely that mass is packed within its volume dictates the strength of its surface gravity.
Your Weight Across the Solar System
If you weigh 150 pounds (68 kilograms) on Earth, your weight would change dramatically across the solar system due to varying gravitational pulls. On the Moon, with roughly one-sixth of Earth’s gravity, you would weigh approximately 25 pounds (11.3 kg).
Moving to the planets, Mercury, the smallest planet, has a surface gravity of about 38% of Earth’s. This means a 150-pound person would weigh around 57 pounds (25.8 kg) on Mercury. Mars also has a similar surface gravity, at about 38% of Earth’s, so you would weigh approximately 57 pounds (25.8 kg) there as well. This lighter gravity would allow for higher jumps and easier movement compared to Earth.
Venus has a surface gravity that is 90% or 91% of Earth’s. A 150-pound individual would weigh around 135 to 136.5 pounds (61.2 to 61.9 kg) on Venus. Uranus has a surface gravity of around 86% or 89%, resulting in a weight of approximately 129 to 133.5 pounds (58.5 to 60.5 kg).
For the gas giants, “surface gravity” is typically measured at the 1-bar pressure level in their atmospheres since they lack solid surfaces. Jupiter, the largest planet, has a gravitational pull about 2.4 to 2.6 times that of Earth. On Jupiter, a 150-pound person would weigh 360 to 390 pounds (163.3 to 176.9 kg).
Saturn’s gravity is about 107% or 108% of Earth’s. This means you would weigh approximately 160.5 to 162 pounds (72.8 to 73.5 kg) on Saturn. Neptune’s surface gravity is around 110% or 114%. A 150-pound person would weigh about 165 to 171 pounds (74.8 to 77.5 kg) on Neptune.