The Sun is important to study because it provides the Earth with energy in the form of both light and heat. The various layers of the Sun - the core, the radiative zone, the convective zone, the photosphere, the chromosphere, and the corona - all serve important functions in the production of light and energy. Without the Sun and the process of nuclear fusion in its core, there could not be life on planet Earth. The Sun will continue to produce energy through fusion and provide the Earth with the energy to survive until all of the hydrogen has turned into heavier elements.