The density of Saturn is so low that if you were to put it in a giant glass of water it would float.
Saturn Would Float in Water (If You Had a Big Enough Tub)
Imagine filling a bathtub so massive it could hold an entire planet. Now drop Saturn in. What happens? It floats. This isn't science fiction—it's real physics. Saturn's density is just 0.687 grams per cubic centimeter, making it the only planet in our solar system less dense than water.
Why is Saturn so light? The ringed giant is essentially a cosmic balloon filled with hydrogen and helium, the two lightest elements in the universe. Unlike rocky planets like Earth, Saturn has no solid surface—it's a gas giant held together by its own gravity. All that fluffy gas makes for one very buoyant planet.
The Math Checks Out
Archimedes figured this out over 2,000 years ago: objects less dense than a liquid will float in it. Water has a density of 1.0 g/cm³. Saturn clocks in at 0.687 g/cm³. By the numbers, Saturn absolutely would bob on the surface like a celestial beach ball.
To put this in perspective:
- Earth's density: 5.52 g/cm³ (would sink like a rock)
- Jupiter's density: 1.33 g/cm³ (would sink, but just barely)
- Saturn's density: 0.687 g/cm³ (the only floater)
Reality Crashes the Party
Here's where the thought experiment hits a wall. To float Saturn, you'd need an ocean so absurdly massive that the physics at the bottom would be apocalyptic. The pressure would be so intense that water could no longer exist as a liquid. In fact, you'd likely trigger nuclear fusion at those depths.
Saturn itself wouldn't cooperate. Unlike a rubber duck with a rigid structure, Saturn is held together by gravity alone. Its hydrogen and helium aren't contained by anything—they're just sitting there because the planet's mass keeps them around. Plop it in water and things would get... complicated.
The Coolest Impossible Thing
So yes, Saturn would float on water—in theory. The math is sound, the physics is real, and it's a perfect demonstration of density and buoyancy. But could you actually do it? Not unless you want to accidentally create a small sun in your cosmic swimming pool.
Still, it's a brilliant reminder of just how strange and wonderful our solar system is. Saturn, that magnificent giant with its stunning rings, is essentially lighter than air—or at least lighter than water. It's a gas bag on a planetary scale, and we're all just lucky enough to watch it drift through space.