Saturn is the second-largest planet in our solar system, a gas giant, while Earth is a relatively small, rocky world. This size disparity hints at fundamental differences in how the two worlds formed and what they are made of.
Comparing Dimensions: Diameter and Volume
Saturn’s diameter is roughly 9.5 times greater than Earth’s diameter at the equator. Nearly ten Earths lined up side-by-side would stretch across the gas giant’s width.
The volume, which measures the total space occupied, provides a more dramatic comparison. Because volume scales with the cube of the radius, Saturn’s volume is approximately 764 times that of Earth. Saturn could physically contain over 760 Earth-sized planets packed inside it.
Mass Versus Volume: Understanding Density
Despite being over 760 times larger in volume, Saturn is not 760 times heavier than Earth; it is only about 95 times the mass. This surprising discrepancy between size and weight is due to the planet’s extremely low density. Density is defined as mass per unit volume, and Saturn’s value is the lowest of any planet in the solar system.
Saturn is classified as a gas giant, composed overwhelmingly of light elements, primarily hydrogen (about 96%) and helium (about 3%). Earth, by contrast, is a rocky, terrestrial planet with a dense core of iron and nickel, giving it the highest average density of any planet.
The average density of Saturn is so low—less than that of water—that it would float if placed in a large enough body of water. The light, gaseous composition of Saturn explains how it can be so physically large without being proportionally massive, illustrating the difference between a world of rock and a world of gas.
Visualizing the Scale
Translating these astronomical ratios into everyday images helps to grasp the sheer scale of the size difference. The volume ratio, which shows that 764 Earths could fit inside Saturn, is a powerful visualization of the planet’s internal capacity.
Furthermore, the rings of Saturn add another layer to its immense size, spanning a distance of up to 175,000 miles (282,000 kilometers) from the planet’s surface. The width of Saturn’s main ring system is actually wider than the average distance between Earth and its Moon, which is about 239,000 miles (384,400 kilometers).
If the Earth were placed at the center of the ring system, the rings would extend far past the orbit of our own Moon. Therefore, Saturn is not only physically enormous, but the span of its iconic ring system adds a truly breathtaking dimension to its overall presence.