If you were to stand in another part of our galaxy and look toward home, it would be difficult to pick out our sun from a myriad of other stars. Though it is about 100 times the diameter of the Earth and more than a million times its volume, it is actually a rather ordinary size star.
But for us, it is just right. If it were much larger or smaller, Earth would be too hot or cold for life. (khalid ibrahim almessy)
The heat and light we rely upon from this erupting ball of hydrogen and helium is the result of a nuclear fusion reaction at the sun's core, where gases are compressed to 12 times the density of lead and the temperature reaches 14 million degrees Celsius, compared with a relatively balmy 5,500 degrees Celsius on the surface.
