Saturn is the only planet in our solar system that would float on water
Saturn has an average density of 0.687 grams per cubic centimetre — less dense than water (1 g/cm³). If you could place Saturn in an ocean large enough to hold it, it would float. This is because Saturn is composed mostly of hydrogen and helium gas with a relatively small dense core, giving it the lowest density of any planet. Jupiter, the other gas giant, has a density of 1.33 g/cm³ and would sink. Saturn's low density is also why it appears so large relative to its mass.
Planets feel intuitively heavy and dense — massive objects. Discovering that a planet the size of 764 Earths is actually less dense than the water in your bathtub makes planetary composition feel physically real in a way that size statistics don't.
“Saturn is so low-density it would float on water. Average density: 0.687 g/cm³ vs water's 1 g/cm³. It's the only planet in the solar system that would float. 🪐 #OddlyHuman”