The Sun, a massive star, and Jupiter, the largest planet, are the two most dominant objects in our solar system. The Sun is a fiery ball of plasma generating its own energy, while Jupiter is a cold, gas giant that orbits it. Understanding the difference in their physical dimensions provides a clear perspective on the scale of our local cosmos.
The Direct Size Comparison
The Sun is larger than Jupiter in every geometric measure. The Sun’s diameter measures approximately 1.39 million kilometers (864,000 miles), compared to Jupiter’s diameter of about 143,000 kilometers (89,000 miles) at its equator. This means the Sun is roughly ten times wider than Jupiter. If you placed Jupiter side-by-side, you would need ten Jupiters to span the Sun’s diameter.
The difference in volume is even more dramatic. The Sun’s volume is so immense that it could contain over 1,000 planets the size of Jupiter inside it. Some estimates place the precise number closer to 984 Jupiters, indicating the star’s sheer capacity.
Mass, Density, and Composition Differences
The size comparison only tells part of the story, as the objects differ in mass and internal structure. The Sun contains about 99.8% of the entire mass of the solar system, making it nearly a thousand times more massive than Jupiter. Jupiter accounts for only a small fraction of the remaining mass, though it is still \(2.5\) times more massive than all the other planets combined.
This vast difference in mass relative to size is explained by the objects’ densities and compositions. The Sun is a sphere of superheated plasma composed of about 74% hydrogen and 25% helium by mass. Its tremendous mass creates gravity that compresses its core to an extreme density of about 150 grams per cubic centimeter, over 100 times the density of water. This pressure and temperature, reaching 15 million Kelvin, allow for sustained nuclear fusion, which defines the Sun as a star.
Jupiter’s composition is also mostly hydrogen and helium, similar to the Sun’s outer layers, but it lacks the necessary mass to initiate fusion. The planet’s average density is only about 1.33 grams per cubic centimeter, slightly denser than water. While Jupiter’s interior has massive pressure, it is not enough to sustain the stellar nuclear reaction, so its hydrogen remains in a liquid metallic state.
Visualizing the Scale of Difference
To grasp the scale difference, it helps to use common objects for comparison. If the Sun were scaled down to the size of a standard 65-centimeter exercise ball, Jupiter would be about the size of a tennis ball. In this same model, Earth would be scaled down to the size of a sesame seed.
Another way to visualize the scale is by considering the Earth as the reference point. Jupiter’s diameter is approximately 11 times that of Earth. The Sun, however, has a diameter about 109 times greater than Earth’s, which means 109 Earths could be lined up across the Sun’s face.