This is what you see in this image:
- Upper atmosphere, top clouds.
- Atmosphere consisting of hydrogen, helium, and methane gas.
- Mantle consisting of water, ammonia, and methane ices.
- Core consisting of rock (silicates and nickel-iron).
I have taken this information straight from the source (link below).
I still can’t fathom sometimes, how on Earth – as it were – we know all of this. This is the inside of the outermost planet in the solar system. I mean, like, huh?!?!!
Image credits: FILNASA; Pbroks13 (redraw)