Figure 7-3 The internal Structures of Jupiter and Saturn These diagrams of the interiors of Jupiter and Saturn are drawn to the same scale. Each planet’s rocky core is surrounded by an outer core of liquid “ices,” a layer of helium and liquid metallic hydrogen, and a layer of helium and ordinary molecular hydrogen (H2). Saturn’s rocky core contains a larger fraction of the planet’s mass than Jupiter’s core, while Saturn has a smaller relative volume of liquid metallic hydrogen than Jupiter.