The truth is that nobody as yet knows. Jupiter is by far the largest planet in our solar system (some 1100 times bigger than Earth by volume) and is designated a 'gas giant'. This means that its atmosphere is hundreds (if not thousands) of kilometres deep, and probes which have been launched into it, such as that from the Galileo mission, were crushed under the intense pressure long before they reached the planetary surface. It has even been speculated, that the core of Jupiter is one enormously massive diamond, but of course it will be a very long time before the veracity of this is proved or disproved.
