Is it possible that the gas giants have a solid core?

Yet, can gas giants possible be all gas? Well, the answer is slightly complicated. there's no reason that the planets need a solid core to stay together — at their current mass, the gas giants in our solar system would have no trouble maintaining their own gravity without any heavier elements at the center. read more

Gas giants do have a solid core. Its mostly hard rock, and is surrounded by hydrogen and light gases. It is believed that due to the high pressure , the hydrogen near the core is metallic, but the exact physical composition is a mystery. read more

What this essentially means is that rather than being thoroughly solid, this core is most likely to be quite slushy with a consistency of both solid and liquid. A theory surrounding the formation of giant planets of gas suggests that there is almost definitely a core. This idea is called the bottom-up theory or core-accretion model. read more