Sister Moon

Do  you see it rise and fall from the sky
rise in the night
fall in the day.
 
Opposite from the Sun in every trait
how you shine in every way
sister,sister,sister moon
come home today
and never go away. 

What Am I?

One side is light one side is black.I float in the sky circling 2 things again and again.Nothing can stop my rotation.What am I?See if you can figure it out.If you do post it.I`ll look in a few days ,so post.Please! :] 😉