The Night Sky is a rotating star finder- or planisphere that allows the user to recognize the constellations for any time of night, any day of the year. The sky appears to rotate (due to the rotation and orbital motion of the earth), so to be successful recognizing the constellations a beginner needs to know which stars are above the horizon at any time. This is the full-sized version of The Night Sky suitable for the 40°-50° latitude zone (northern United States and parts of Europe).