While Jupiter is primarily composed of gas, it's not just a simple "ball." It's a complex and dynamic planet with a layered structure. Here's a breakdown:

* Gaseous outer layers: The visible part of Jupiter is made up of mostly hydrogen and helium, forming a thick atmosphere with swirling clouds.

* Liquid metallic hydrogen: Beneath the gaseous layer lies a vast ocean of liquid hydrogen, compressed to such an extent that it acts like a metal, conducting electricity. This is what creates Jupiter's powerful magnetic field.

* Rocky core: Scientists believe that at the center of Jupiter is a solid, rocky core, about 10 to 15 times the mass of Earth.

So, while Jupiter is mostly gas, it's not just a floating cloud. It has a complex internal structure, including a rocky core, a liquid metallic hydrogen layer, and a gaseous outer layer. This makes it a fascinating and mysterious planet, and one that scientists are still working to understand.