why do stars shimmer

When it's a dark night sky without a moon it's the
best time to look at the shimmering stars. Wait do
they really sparkle?

Stars don't actually flicker because the atmosphere's
  moisture blanket of air (wind) is moving and tricking
you. It's tricking you by wiggling around, the star
shifts and it's also just your eyes and it's just a
optical illusion,but they just seem to glimmer. 

I Samantha have read you writing I like how you 

 used Lots of vocab but i think you need more ideas.