Jupiter Globe.
Moons of Jupiter. Magnetosphere of Jupiter. Jupiter Rise & Set Times. Jupiter Retrogrades. ScienceCasts: What Lies Inside Jupiter Jupiter. Jupiter. Structure Jupiter is composed primarily of gaseous and liquid matter.
It is the largest of four gas giants as well as the largest planet in the Solar System with a diameter of 142,984 km (88,846 mi) at its equator. The density of Jupiter, 1.326 g/cm3, is the second highest of the gas giants, but lower than for any of the four terrestrial planets. Composition Jupiter's upper atmosphere is composed of about 88–92% hydrogen and 8–12% helium by percent volume or fraction of gas molecules.