The edge of this window represents the horizon with appropriate north, south, east and west markings, and everything within it is the visible sky. Give everyone a set of templates. They should cut out the horizon templates for both hemispheres. They’ll need to cut out the shaded areas in the middle of each template to make the spy window. Just to the right of Polaris, you should see the Big Dipper in the constellation of Ursa Major on the planisphere. Now identify the Big Dipper in the sky. Get your orientation.

The bottom disk will have the months and dates printed around the edge. These will be used to set the planisphere to show us the sky as it will appear tonight. Tilt the chart to the right or left when you face East or West, so the word “East” or “West” ishorizontal.A planisphere is a circular star map that shows the brightest stars and constellations we can see from Earth. It helps you to name the constellations you can see, depending on where you are and what time of year it is. These stars are in constellations – these are just groups of stars that people have given names to, often because they look like something. The lines on the planisphere show how the stars are grouped together. For example, if you set up the Planisphere for March 25 at 9 pm, as shown in the photo, the window will show the sky for March 25 th at 9 pm. Now, face north and place Polaris in the rivet. Marked around the outside of this lower disc are the days and months. What does a planisphere show you? A planisphere is an astronomical tool that can help you navigate the night sky We also measure the Power with our systems which is essentially the error from the reference sphere to the test optic. The reference sphere we use on our system is a very high quality sphere so the closer to zero the Power, the less error between the 2 elements thus ensuring a higher quality optical surface.

Each planisphere is designed for a particular latitude shown in its title, but can also be used within ten degrees north and south of it with only minor discrepancies at the northern and southern horizons. When the Earth orbits the Sun, at certain times of year the Northern Hemisphere is tilted towards the Sun and the Southern Hemisphere is tilted away from it. For the other half of the year, the reverse happens. Also shown on the typical planisphere will be symbols for double stars and the brighter deep sky objects, DSOs, such as star clusters, nebulae, galaxies, globular clusters and other of deep sky objects. There should be a key printed on the planisphere to show you what each symbol represents.Above the horizon already at sunset and setting a couple of hours later, Venus and Jupiter will be all but unmissable as the bright points of light in the southwest in the early evening sky. Take a look for yourself! The stars visible in the oval window on your star map are the ones visible in the night sky at that time.