The Sun is the star at the center of the solar system. It is the Earth’s primary source of light and heat, and drives the Earth’s climate and weather. The Sun is a medium-sized star and is about halfway through its life. It has enough mass to maintain nuclear fusion in its core, producing energy that radiates into space as sunlight. The sun’s diameter is about 109 times that of Earth, and its mass is about 333,000 times that of Earth. About three quarters of the Sun’s mass consists of hydrogen; almost all of the rest is helium, with much smaller quantities of heavier elements such as oxygen, carbon, neon, and iron.
The value of the sun can be estimated in terms of its utility to humanity. The sun provides warmth and light essential for human life and growth; it also powers nearly all forms of renewable energy used on earth including wind power, hydroelectricity, solar thermal, photovoltaics etc. The direct use of sunlight (as opposed to indirect uses such as solar powered electricity) accounts for less than 1% global energy consumption but this number is growing rapidly as more efficient solar technology becomes available. In addition to