GALAXIES.

                       GALAXIES.

The milky way.                                              
Our sun is one of a hundred thousand million other stars which make up the milky way, A giant whirlpool of stars 100,000 light years across. On a clear summer night, the milky way appears as a misty band of light in the sky. The crowds of the stars there are so thick and far away that they blur
away into each other. Clouds of dust in space make the shape of the milky way difficult to see. However dust cannot blot out the invincible rays we call radio waves, so astronomers have been able to use radio telescopes to find out that the milky way is shaped like a spiral.                                                            There many more galaxies in the universe. Some are way bigger than the milky way and some are smaller. And others the same size of our own. There are spiral galaxies like our milky way,and elliptical galaxies which are more oval or round in shape. Astronomers think that spiral galaxies were spinning fast when they formed and that elliptical galaxies were spinning slowly. 
                  The stars in each galaxy are held together by the force of gravity. Each star has its own fixed path around the center. It takes 230 million years for the sun to circle once around the centre of the milky way.

Galaxy M81.       
                                                                                                             astronomers call this galaxy M81. It looks very much as our own milky way.  The blue stars along the spiral arms are the youngest ones, the red ones are older.                                                                    







Elliptical Galaxy :-   
                                   
Spiral Galaxy:-      
               

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