Why is Jupiter denser than Saturn
Although many people may feel that size plays an important role in determining how dense a planet is (with smaller planets of pure rock generally being considered the densest) the largest planet in our solar system, Jupiter, is actually more dense than its nearby neighbor Saturn. This is due to the fact that, contrary to what people may initially believe, Jupiter’s overall mass generates a larger gravitational well than Saturn and as such attracts more solid mass than its smaller neighbor.
The overall density of Jupiter being greater than that of Saturn lies in a number of factors, the two most prominent of which are its relatively larger gravitation field through its sheer mass and rotational pressures as well as its denser core of rocks and other minerals. Each Jovian planet (gas giant) such as Jupiter and Saturn, contrary to popular belief, contains a solid mass at its core that dictates its overall gravitational pull and mass – with Jupiter being considered to have a larger one of these formed throughout the years.
Remaining closer to the “frost line” that divides where Jovian and Terrestrial planets form (the inside of which, being closer to the sun, attracts heavier metals and thus generates denser Terrestrial planets), Jupiter formed a stronger interior core than Saturn. This allowed it to obtain a stronger rotational pull and attract various moons, formulating many of them into Terrestrial satellites despite the fact that it could not generate enough of a core mass to form into a Terrestrial body itself.
The density pressure within Jovian planets such as Saturn and Jupiter can be so intense, in fact, that the gaseous hydrogen exterior actually becomes so compact towards its core that the planet forms liquid and then metallic hydrogen before reaching the solid metallic core. While smaller Jovian planets such as Uranus and Neptune can not do this due to their lower pressure thresholds Saturn and Jupiter can do this with ease. Both actually do so considerably well – enough to generate roughly twice as much heat than they take in from the sun and thus provide their own source of energy. This is generally considered to occur in Jupiter as a result of internal fission from continual contraction of the planet while Saturn is seen to be caused by differentiation or the sinking of minerals, a testament to Jupiter’s heavier and ever increasing density.