Ask A Scientist© Astronomy Archive

Author:      John
Where does the Sun get its fuel?

Response #:  1 of 1
Author:      asmith
The Sun runs on hydrogen, which is what it is made of - it is very gradually
consuming itself!  Because the fusion reactions it uses create so much
energy, the Sun will continue to shine for a long time - probably another 5
billion years.  The fusion (converting hydrogen into helium) occurs only in
the very deepest part of the Sun, which is extremely hot (millions of
degrees), and this heat gradually filters out to the outer layers which are
only a few thousand degrees, and this heat is then radiated into space as
light.