The solar system contains two vastly different classes of worlds: small, dense terrestrial planets like Earth and colossal, low-density gas giants. Comparing the familiar scale of our home planet to the immense dimensions of the outer solar system quickly reveals the incredible size difference between these planetary types. Jupiter, the largest planet orbiting our Sun, dwarfs every other object in its neighborhood.
Calculating the Scale: The Earth-Jupiter Ratio
Jupiter’s sheer magnitude becomes clear when its diameter is compared to Earth’s. The giant planet is more than 11 times wider than Earth; approximately 11 Earths could be lined up side-by-side across Jupiter’s equator. However, this measurement only accounts for a single dimension and can be misleading when trying to grasp the planet’s true volume.
To understand how many Earths could fit inside Jupiter, the comparison must use volume, which measures three-dimensional space. Jupiter’s volume is roughly 1,321 times that of Earth. This means over 1,300 Earth-sized spheres could be contained within its boundaries, often illustrated by imagining Jupiter as a hollow shell requiring 1,300 Earths to completely fill it.
What Makes Jupiter So Large?
Jupiter’s size is a direct consequence of its composition and the massive amount of material it captured during the solar system’s formation. Composed primarily of hydrogen and helium, similar to the Sun, it is classified as a gas giant. Unlike a rocky planet, Jupiter lacks a solid surface; its atmosphere simply grows denser as it extends inward toward the core.
The planet’s immense gravitational pressure compresses the interior into exotic states of matter not seen on Earth. Deep within, hydrogen gas is squeezed so tightly that it behaves like a liquid, forming a vast ocean of liquid hydrogen. Further down, the extreme pressure strips hydrogen atoms of their electrons, creating a layer of liquid metallic hydrogen that conducts electricity.
This layer of metallic hydrogen is thought to be the source of Jupiter’s powerful magnetic field, which is 14 to 54 times stronger than Earth’s. The planet’s volume is dictated by a balance between its mass and the density of these compressed layers. Scientists estimate that if Jupiter accumulated significantly more mass, its increased gravity would simply compress the planet further, causing it to shrink rather than expand.
Putting Jupiter’s Size in Context
Jupiter’s dominance extends beyond its comparison with Earth. It is the most massive planet by a wide margin, holding approximately 2.5 times the mass of all the other planets combined. Because of this overwhelming mass, Jupiter is the second most gravitationally influential body in the solar system, after the Sun.
Even with its gargantuan size, Jupiter is still tiny compared to the Sun. The Sun’s diameter is about ten times wider than Jupiter’s, and its volume is so vast that approximately 1,000 Jupiters could fit inside it. The Sun contains about 99.86% of the total mass of the solar system, reinforcing that Jupiter and the Sun are in entirely different categories of celestial objects. Jupiter would need to be 75 to 80 times more massive to have the gravitational compression necessary to ignite nuclear fusion and become a true star.