Jupiter is not merely the biggest planet in the solar system; it is in a category of its own. The giant is more than twice as massive as every other planet combined, meaning that if the other seven worlds were gathered onto one side of a cosmic scale and Jupiter placed on the other, Jupiter would still win with mass to spare. By volume it is larger still, roomy enough to hold more than 1,300 Earths.
More than twice everything else combined
The mass comparison is the fact that anchors Jupiter’s reputation. Add up Saturn, Neptune, Uranus, Earth, Venus, Mars, and Mercury, and the total still comes to less than half of Jupiter alone. The planet holds roughly two and a half times the mass of all the others put together, a dominance that no simple size illustration fully captures. Mass, not just width, is what makes Jupiter the true heavyweight of the Sun’s family.
That figure is well established in NASA’s planetary data. The agency notes that Jupiter has taken on more than twice the combined material of everything else orbiting the Sun, a summary reflected on its Jupiter fact page. The number reflects the planet’s enormous store of hydrogen and helium, the same light gases that make up the Sun.
Room for 1,300 Earths
Volume tells the other half of the story. Jupiter is about 11 times as wide as Earth, and because volume grows with the cube of that width, the difference balloons: more than 1,300 Earths could fit inside the planet if it were a hollow shell. The Great Red Spot alone, a storm that has raged for centuries, is wide enough to swallow the entire Earth. Standing beside images of the other planets, Jupiter dwarfs them so thoroughly that the rest of the solar system looks like an afterthought around it.
The headline claim that every other planet could fit inside Jupiter is grounded in that volume gap. The combined bulk of the seven other worlds occupies far less space than Jupiter’s interior, so packing them in would indeed leave the giant with room to spare. Its sheer physical scale is documented alongside its mass in NASA’s profile of Jupiter.
Why Jupiter grabbed so much material
Jupiter’s dominance traces back to the solar system’s birth. After the Sun ignited at the center of a collapsing cloud of gas and dust, a great deal of leftover material remained in the surrounding disk. Jupiter formed early and in a rich neighborhood, and its growing gravity let it sweep up hydrogen and helium far faster than the smaller worlds forming closer to the Sun or farther out. It essentially got first pick of the leftovers and grew into a gas giant while the inner planets were left assembling from a thinner supply of rock and metal.
Once large enough, the planet’s gravity accelerated its own growth, pulling in still more gas until the supply ran short. The outcome is a world that never became a star, lacking the mass to ignite fusion in its core, yet still hoarding more raw material than all its planetary siblings together.
A giant that shapes the whole neighborhood
All that mass gives Jupiter influence far beyond its own orbit. Its gravity helps corral the asteroid belt, nudges the paths of comets, and has shaped the long-term architecture of the solar system. Some researchers argue that Jupiter acts as a partial shield, deflecting or capturing objects that might otherwise strike the inner planets, though the picture is more complicated than a simple guardian role. What is clear is that a body this massive cannot help but steer everything around it.
The planet also generates the most powerful magnetic field of any planet, a vast structure that traps intense radiation and drives brilliant auroras at its poles. That field is another consequence of Jupiter’s scale, produced by the churning of metallic hydrogen deep in its interior, where pressures are high enough to force hydrogen into a liquid that conducts electricity.
How the mass was weighed
Weighing a planet cannot be done with a scale, so scientists read Jupiter’s mass from its gravity. The orbits of its many moons, the paths of passing spacecraft, and precise tracking of probes like Galileo and the ongoing Juno mission all respond to the planet’s pull, and that response reveals the mass with high precision. Juno, in particular, has mapped Jupiter’s gravity field in fine detail since arriving in 2016, sharpening estimates of how mass is distributed inside the planet.
Those measurements confirm the headline: Jupiter outweighs the combined total of every other planet by a wide margin and could contain them all within its volume. It is the anchor of the outer solar system, a near-miss star that instead became the largest and most massive planet circling the Sun, and the numbers behind that status are measured, cross-checked, and secure.
This article was produced with the assistance of AI and reviewed by Morning Overview editors prior to publication.
More from Morning Overview
