The hottest temperature on Saturn is estimated to be 11,700 degrees Celsius at its core. Saturn's core is composed of liquid metallic hydrogen that is formed by the compression forces surrounding the core. The energy that radiates from the planet is twice what it receives from the Sun.
Apart from the gravitational compression, scientists hypothesize that heat is produced by the friction created by helium sinking into the core of the planet. Hydrogen and helium form a thick layer around the core of Saturn, creating strong compression forces. As the liquefied hydrogen moves away from the core, it gradually becomes non-metallic and transforms into a gaseous form.