The answer to ”does Jupiter have a solid core” is that the planet has a core that contains some rock and hydrogen metals. Scientists are not sure if deep within the planet there is a solid core or not. All that they can do is gather gravitational measurements, compare them with Earth’s, and make the best educated guesses possible based on those measurements. Those measurements make them think that the core is a thick, super hot soup.
Jupiter’s composition is by-and-large a mystery. Generally accepted theory holds that it consists of a dense core made of a mixture of elements, the core is thought to be surrounded by a layer of liquid metallic hydrogen and helium, then the outer layer is proposed to be dominated by molecular hydrogen. The core is often speculated to be rocky. It wasn’t until 1997 that the existence of the core was even theorized. Gravitational measurements were taken, which indicated a mass of from 12 to 45 times the Earth’s mass. That would mean that the Jovian core accounts for about 3–15% of the total mass of the planet. The presence of a planetary core follows accepted knowledge of planetary formation. According to this knowledge base, Jupiter would have had to form a rocky or icy core with enough mass in order to capture such a high percentage of gasses from the early solar nebula. Scientists admit that the planet may lack a core at this time due to the high heat and as hot liquid metallic hydrogen mixed with the molten core, carrying it to higher levels of the planet’s interior.
Current theory holds that the core region is surrounded by dense metallic hydrogen. The layer extends to the 78th percentile of the planet’s radius. Just above the layer of metallic hydrogen is an interior atmosphere of hydrogen. The hydrogen at this point is at a temperature where there are no distinct liquid and gas phases, so the hydrogen is in a supercritical fluid state. The temperature and pressure increase steadily toward the core. In the region where hydrogen becomes metallic, it is believed the temperature is 10,000 K and the pressure is 200GPa. The temperature at the core boundary is estimated to be 36,000 K with a corresponding pressure of 3,000 to 4,500 Gpa.
The JUNO space mission is scheduled to be launched on August, 5, 2011 and should arrive in orbit around Jupiter in 2016. The purpose of the mission is to orbit the poles and clear up some of the mysteries surrounding the question “does Jupiter have a solid core?”
We’ve also recorded an episode of Astronomy Cast just about Jupiter. Listen here, Episode 56: Jupiter.