The Sun is a glowing hot ball of gas with immense temperatures in its interior. It is made up of different layers. Nuclear reactions take place in its core and the energy produced is transported through the radiative and the convection_zone to the surface, from where it radiates into space. The part that is visible to us is called the photosphere. Above this lie the chromosphere and the corona, where huge eruptions of gas, called prominences, occur. Another clearly visible feature are the sunspots. These are dark areas in the photosphere with temperatures much lower than their surroundings. A period of increased sunspot activity occurs every eleven years. Sunspots are associated with magnetic_fields. Solar wind is a type of radiation that streams out from the Sun in all directions. A solar_eclipse is a particularly spectacular event. It occurs when the Sun is located directly between the Earth and the Sun. This causes the disc of the Sun to be completely occluded.
Today, the energy of the Sun can be utilized directly using photovoltaic cells and solar collectors.
