Question

What planet is so light it could float in water?

Answer 1

Hint: As a very first step, you may recall the physics behind the floating of objects. That is, firstly we have to find the physical quantity that determines whether a certain object will float or sink. Then, you could recall the value of the density of Saturn and then compare it with water’s density and hence find the answer.

Complete step-by-step solution:
In the question, we are asked to name the light-weighted planet that is so light that it might float in water.
Let us recall the factors that determine whether an object floats or not. Mainly, it is the density of the object that determines whether the given object will float or sink in water. Density of an object is defined as the ratio of the object’s mass to its volume. Also, the point to be noted here is that relative density matters. That is, the density of the object should be lesser than that of water for the object to float on water.
You may know that Saturn is the second biggest planet of our solar system. However, it is also known to be the lightest of these planets. The average density of the planet Saturn is found to be $0.7g/c{{m}^{3}}$ . You may recall that the density of water is known to be $1g/c{{m}^{3}}$. So, the density of Saturn is lower than that of water and hence it will float in water if that huge water source is available.

 Note: Saturn is known to be the gas giant being made up of different gases. It is also known to have over 60moons. Even a child would recognize the picture of the planet Saturn by the series of rings that surround it. One should know that these series of rings aren’t actually solid but consist of little rock pieces and ice particles orbiting Saturn at the same speed.