A planisphere, also called a Star Chart or, sometimes, a Star Wheel is a flat multi-part chart that displays the stars visible from a particular location for any time and date. A planisphere is one of the fundamental pieces of equipment used by astronomers of every type; it will help you learn to find the constellations in the night sky as well as become your guide for finding any other objects you may find referenced in an atlas or observing list. It will also help you plan your observing time by showing you when a particular object of interest will be visible from your location and where to find it.
When you look up at the night sky you see the stars from a perspective as if you were inside a giant sphere looking out. The portion of the sphere you can see depends on the location and position of the earth. Our observing platform, the Earth, travels around the Sun once each year giving us a slightly different view of this celestial sphere each night. Our platform is also spinning, once per day so just as the Sun appears to cross the sky each day, the portion of the celestial sphere we can see travels across the sky each night. This means that as the hours of the night pass we will see different things rising in the East and setting in the West.
The Night Sky planisphere is designed to help you keep track of all this motion and will show you what objects are in what position in the sky for any time and andy day of the year. It will never go out of date and will always be in synch with the night sky above. Our unique design minimizes distortion meaning that the sky above will look just like what you see on your map dial making The Night Sky the easiest to use planisphere on the market.