The Sun
The Sun provides all the light and energy that the living things need on planet Earth. It does this by converting 4 million tonnes of hydrogen into helium every second! The surface temperature of the Sun is around 6000 degrees Centigrade and this energy radiates throughout the Solar System.
Our Sun is a fairly small star but it is still an enormous nuclear fusion reactor. The temperature on the surface of the Sun is approximately 6000oC.
Despite our Sun being a fairly small star and burning four million tonnes of hydrogen per second, it is estimated that the Sun will take 7 billion years to use up all the hydrogen within it!
So you can begin to imagine what the estimated 200 billion to 400 billion stars contained within our galaxy alone are generating in heat and light. Now multiply this by the other 125 billion galaxies in our Universe!!
click images to expand them
our sun image in public domain Source: NASA |
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Sunrise image in public domain Source: NASA |
Sunset image in public domain Source: NASA |
When the energy from the Sun reaches planet Earth, about one third is radiated back into space. Earth itself radiates back as much energy as it receives, thus maintaining a balance in incoming and outgoing energy.