Our Sun

 The sun and us    Formation of the solar system    The sun's surface     Links
The sun and us

We depend on the sun in the following ways.  
  
  

Even so, the sun is just an average star.
  • for light and heat
  • to provide energy for photosynthesis
  • to control the world's weather
  • the earths tilted orbit around the sun provides us with our seasons
One theory of the formation of the solar system 

A rotating disc of dust and gas (mostly hydrogen and a little bit of helium) forms the primitive solar nebula
The Sun, and the giant gas-rich planets begin to form.  
The new star is called a protostar.  
The temperature and pressure of the young sun become high enough for nuclear fusion to occur.  
Hydrogen nuclei fuse together to form helium, and to release energy.  
 
Strong solar winds from the young sun sweep gas from the system, while the planetisimals form from the dust. This takes about 1 million years.  
 
The inner planets form from the planetesimals. This takes about 100 million years. The remaining gas is swept from the system, or accumulates on the gas giants. 
 

 
 
The sun's surface 

The sun's surface consists of churning gas clouds, which gives off charged particles and energy which spreads out far into space
Links
The birth of the sun