I'm still hoping that Arthur C Clarke was right and that the temperature and pressure in the core is so intense that it has fused into one incredibly rigid molecular structure. A diamond. Ah well.
I'm hoping for metalic hydrogen.
More likely a lump of (molten) rock from all the asteroids it has absorbed.
would it be doable with today's technology to do radar scans to see if inside of the gas hull there is a rigid body planet bigger than earth?