Jupiter is the largest planet in the Solar System: if it were hollow, more than 1300 Earth could fit inside.
Scientists describe Jupiter as a "gaseous giant" since it is mainly composed of hydrogen.The fast planet rotation (it takes only 10 hours to complete a full rotation) breaks up the surface layers of gaseous hydrogen into whirling clouds.
Under the clouds, there is no solid material but a wide ocean of hot liquid hydrogen. At greater depths, hydrogen becomes metallic.
Astronomers think the planet core is a sphere of melted rock, six times hotter than the Sun surface.
