What's Small Angle Approximation???
 
     
   
206,265...It's the Magic Number
  
 

How would you like to use your hands to figure out how large an celestial object is?  The following web sites will show you how.  Go through each one and then come back here to take a quick review quiz.

1)  http://www.astro.washington.edu/astro211/smanAA/smangleA.html
2)  http://www.geocities.com/angolano/Astronomy/PIinSky.html

    
 

1)  What does an angle of less than 5 degrees allow us to approximate and why?

2)  Where does the number 206,265 come from?  Explain it in words instead of just math.

3)  Why do we use radians?

3)  Would small angle approximation work if you wanted to find the distance between two objects that are 30 degrees apart in the night sky?  Why or why not?
       

Now that you have an understanding of small angle approximation and the magic number, lets put you knowledge to use.  Let's see which is bigger, the moon or the sun.  Click here.

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