Gravity is the force that keeps our feet on the ground and holds the planets in orbit around the Sun. When discussing a celestial body, surface gravity describes the acceleration an object experiences while standing on its surface. Among the eight major planets in our solar system, Jupiter has the most powerful surface gravity.
The Planet with the Strongest Surface Gravity
Jupiter, the largest planet, possesses the highest surface gravity of any planet in the solar system, measuring about 2.53 times that of Earth’s gravity. This acceleration due to gravity is approximately 24.79 meters per second squared (m/s²).
To put this in perspective, an object weighing 100 pounds on Earth would weigh about 253 pounds on Jupiter. As a gas giant, Jupiter lacks a solid, well-defined surface like Earth. Its surface gravity is calculated at the point in its atmosphere where the pressure equals 1 bar, which is the same atmospheric pressure found at sea level on Earth. The immense size and mass of this colossal planet are the reasons for its dominant gravitational pull.
What Determines a Planet’s Surface Gravity?
A planet’s surface gravity is determined by two primary factors: its mass and its radius. Gravity is directly proportional to mass, meaning a more massive planet will have a stronger gravitational pull. However, the force weakens rapidly as the distance from the center of mass increases.
The calculation for surface gravity involves dividing the planet’s mass by the square of its radius. This relationship creates a trade-off where a planet’s enormous mass may be partially offset by its large size. For instance, Jupiter is over 300 times more massive than Earth.
However, Jupiter’s radius is also about eleven times greater than Earth’s, spreading that mass out over a much larger volume. Since the distance from the center of mass is squared in the gravity calculation, this large radius significantly reduces the final surface gravity value.
Gravity’s Scale Across the Solar System
Earth serves as the baseline for comparison, with a surface gravity of 1 g, or 9.8 m/s². The gas giants generally have higher gravity than the rocky planets. Neptune, for example, has a surface gravity of about 1.14 g, making it the second strongest planet in the solar system.
Saturn, despite being the second-largest planet, has a surface gravity of only about 1.07 g, which is slightly stronger than Earth’s pull. This relatively low value is due to its low density, as it is composed primarily of hydrogen and helium.
The smallest rocky planets, Mercury and Mars, possess the weakest gravitational fields among the eight planets. Both Mercury and Mars have a surface gravity of approximately 0.38 g. Standing on either of these worlds, a 100-pound person would weigh only about 38 pounds. Venus, which is close in size to Earth, is a near-match with a surface gravity of about 0.91 g.