Levenhuk M20 Large Planisphere Dimensions: 7.4x8.2 in / 19x21cm Levenhuk M20 Large Planisphere is a rotating star chart. It s a simple and fun way to model the real position of the stars in the sky at a particular date and time. The night sky as you know is constantly changing due to the Earth s rotation around the Sun and around its own axis. That s why our sky Planisphere will be irreplaceable if you want to easily and quickly locate a specific celestial object. On the star chart you can find stars brighter than third stellar magnitude. Levenhuk M20 Large Planisphere is very easy to use. Just align the date on the star chart and time on the disk and you will see the representation of the night sky through the disk s oval window. This Planisphere is designed for 45 -63 north latitude (Seattle is approximately 47 N Anchorage is approximately 61 N) that means that it shows you only the constellations that can be observed from these coordinates. Additional information: - Levenhuk M20 Large Planisphere shows the representation of the night sky at a particular date and time. - The North Pole is situated in the center of the chart with Polaris next to it. - On the star chart you can find stars brighter than third stellar magnitude. (The bigger the point the bigger the star.) - All components are laminated.