paid homage to the Sun by giving it prominent roles in their religions and mythologies.
Solar energy, radiant light and heat from the Sun, has been harnessed by humans since ancient times using a range of ever-evolving technologies. Solar radiation, along with secondary solar-powered resources such as wind and wave power, hydroelectricity and biomass, account for most of the available renewable energy on Earth. Only a minuscule fraction of the available solar energy is used.
A Solar Deity (also Sun God(dess)) is a deity who represents the sun, or an aspect of it, usually by its perceived power and strength. Solar deities and sun worship can be found through-out most of recorded history in various forms. Hence, many beliefs have formed around this worship, such as the "missing sun" found in many cultures.
Sun-Earth Day is a celebration established in 2000 by NASA and ESA. The purpose of the holiday is to popularize the knowledge about the Sun, and the way it influences life on the Earth.
Source: Wikipedia (All text is available under the terms of the GNU Free Documentation License and Creative Commons Attribution-ShareAlike License.)