Saturn Could Float In Water

The famous thought experiment about the ringed planet floating in a cosmic-sized bathtub isn't just a quirky mental image; it perfectly illustrates Saturn's unique composition. The planet's incredibly low average density is a direct result of what it's made of: primarily hydrogen and helium, the two lightest and most abundant elements in the universe. While Earth is a dense ball of rock and metal, Saturn is a gas giant. This means that despite having a mass over 95 times that of Earth, its volume is so immense that its material is very spread out, making it the only planet in our solar system less dense than water.

This low density becomes even more fascinating when compared to its larger neighbor, Jupiter. Though also a gas giant made of hydrogen and helium, Jupiter is so much more massive that its immense gravity compresses its own gases, making it more than twice as dense as Saturn. Saturn simply doesn't have enough mass to crush its interior with the same force, allowing its gaseous layers to remain more "fluffy." So while Saturn does have a small, dense core of rock and ice, the vast, lightweight atmosphere surrounding it brings its overall average density down, securing its title as the solar system's most buoyant planet.