The Sun consists almost exclusively of hydrogen and helium, the simplest and lightest of the elements. The core of the Sun
is a plasma burning at a temperature of 15 million degrees under enormous pressure. Here, hydrogen atoms combine to synthesize
helium in a fusion reaction much like that in a hydrogen bomb. In the Sun, fusion goes on continuously, and every second,
400 million tons of hydrogen are converted to helium.
Fusion releases energy in enormous quantities. Photons, ultraviolet light, X-Rays, microwaves and radiation in many other
forms emanate from the core of the Sun toward its surface. At the surface, the temperature is “only” 5000 degrees Celsius.
Just above the surface there is a thick layer of hot, glowing gasses called the corona. In the corona the temperature rises
again, to between one and two million degrees.
Photons and other particles from the interior of the Sun continue out into space. Protons and neutrons make up the solar wind
and photons make up the sunshine that we see with the naked eye. Some of the radiation and the solar wind fall upon the Earth.
The Earth’s magnetic field deflects the solar wind toward the poles, where it causes the visible Aurora. Most of the radiation
falling upon the upper atmosphere provides the light (from photons) and heat (from infrared radiation) that we call sunshine.
How the Sun works
Like most stars, the Sun derives its energy from nuclear fusion in which hydrogen “burns” to form helium.
