Why is Saturn so light?

Answer 1

Reflection of light: Saturn reflects a lot of light because it is so big and so pale in color.

The pale color is mainly because of clouds of ammonia in the upper atmosphere.

So, Saturn is "light" in that sense.

Density: Saturn is the least dense planet in the Solar System.

So it is "light" in that sense.

Saturn contains a lot of material of low density, such as gaseous hydrogen.

Its average density is less than water.

Because of internal heat Saturn expands until gravity halts its expansion.

That involves the principle of hydrostatic equilibrium [See related question].

Answer 2

Saturn is considered light because it has a low average density, primarily due to its composition of mostly hydrogen and helium gases. These gases make up the majority of its mass but are less dense than rocky materials. Additionally, Saturn's large volume and low density contribute to its overall lightness compared to other planets.

Answer 3

Any particle in the ring with an orbital tilt would collide with other ring particles, flattening its orbit.