Does Jupiter have a solid surface? We do not yet know if a solid surface exists on Jupiter. Jupiter's clouds are thought to be about 30 miles (50 km) thick. Below this there is a 13,000 mile (21,000 km) thick layer of hydrogen and helium which changes from gas to liquid as the depth and pressure increase. Beneath the liquid hydrogen layer is a 25,000 mile (40,000 km) deep sea of liquid metallic hydrogen. Beneath this, there might be a solid core which is about one and a half times the size of Earth, but thirty times more massive. The temperature here would be about 55,000 Fahrenheit (30,000 Celsius) and the pressure would be tremendous because of the weight of the atmosphere above.