The term 'Night Sky' can be broken down into two crossword solutions: ETHER (5 letters) and Night (5 letters). ETHER is a term used in physics to describe a medium that fills the universe and transmits electromagnetic waves. It is also known as the 'aether' or 'QUINTESSENCE'. Night is the period of darkness between sunset and sunrise, when the sun is below the horizon. The night sky is the view of the stars, planets, and other celestial bodies that can be seen in the night sky.