One of the most common fun Saturn facts that kids learn about Saturn is that it would be able to float in a giant bathtub if given the opportunity. This is based on the calculation that Saturn’s makeup is much less dense than standard liquid water. That means, in theory, Saturn would float on water if given the chance. But is that true? Can Saturn actually float on water?
In theory, Saturn could float on water but in practice, it probably would not. Saturn is much less dense than water, about 30% lighter, meaning that it would float if the conditions were right. The problem is, there are a whole host of issues with this thought experiment, not the least of which being that there is no conceivable situation in which anyone could test this theory. There is not enough water in the solar system to be able to hold Saturn.
The other problem is, Saturn is not a solid body. It is a giant ball of gas, ice, liquids, and other materials all held together by gravity. If Saturn were to be placed in a giant bathtub, it might break up and not float at all. Similar to something like a bath bomb, the planet might not be able to hold together properly in water and dissolve into different parts. The hydrogen and helium would instantly rise to the surface like bubbles in a cup of soda. But the denser parts would still probably sink since there is nothing holding Saturn together other than gravity.
While Saturn’s entire density is lighter than water, it still holds individual components that are much heavier than water. Most people focus on the overall density rather than studying Saturn’s complete makeup. If Saturn were a solid cohesive object which was able to retain its size, shape, and density and then be placed into a bathtub, it probably would float.
The other thing to consider is Saturn’s overall shape. Things such as boats or rafts are designed to displace water effectively but without solid features or artificial design, Saturn’s shape might not be conducive to floating. Even balls that are lighter than water might bob or spin when dropped into the liquid. That sort of effect on a planet is something that strains the models and the brain.
However, despite all of the talk about Saturn being able to float, those conditions would never be possible to create in actuality. So the entire idea of Saturn floating in a gigantic bathtub like a rubber ducky is simply conjecture and fantasy. It is fun to think about and it is fascinating that something as massive as Saturn could have a density that is so much lower than water. But, you will never see Saturn floating on water, sad to say.
So, this fact has had cold water poured on it a little here. Next time you get out your best telescope for planets to view Saturn you will have much more knowledge. If you like this post you will love our post about How Big Is Saturn Compared to Earth.