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Universe in the Classroom

The Welsh Government funding for Universe in the Classroom ended in June 2018. We have left this site available as an archive of the project.

Build Your Own Star Map

A planisphere is a circular star map of the night sky, showing the location of the brightest stars and constellations visible from Earth from various longitudes and latitudes through the year. This activity shows you how to make a rotating a planisphere at home using a simply template and how it can be used to explore the night sky and learn to recognise stars and constellations.

Build Your Own Star Map: Teacher Guide

Star Map Template

Full Instructions

Learning Objectives
  • Learn how a planisphere can be used to navigate the night sky and discover our place in the Universe
  • Practise coordination skills while building a usable planisphere
Materials
Background Science

A planisphere is a circular star map of the night sky. The star map contains the brightest stars and constellations visible from Earth. The composition of the night sky depends on whether the observer is on the Northern or Southern Hemisphere and on their latitude and longitude.

A planisphere is constructed to freely rotate about a common pivot point at its centre. Planispheres usually have transparent windows designed for a particular latitude and longitude to show only that part of the sky visible from a given latitude; stars below the horizon are not included.

A full twelve months of calendar dates are marked on the rim of the star map. A complete 24-hour time cycle is marked on the rim of the overlay. The window is marked to show the direction of the eastern and western horizons.

Step-by-Step
  1. Hand each student a printed copy of the Planisphere Template (Appendix 16) and a pair of scissors. Lead them through the instructions below.

  2. Begin by cutting out the Star Map (outside) shapes on the first two pages, leaving only the coloured sections.

Note: Make sure you cut out the white inner sections (see image below).

Planisphere Scrn 2

  1. Next cut out the Southern Hemisphere Star Map and the Northern Hemisphere Star Map circles on the third and fourth pages of the template.

  2. Stick the circles together, back-to-back with the drawings on the outside. Ensure that the months are lined up on both sides. Once done, put the inner circle to one side.

Planisphere Scrn 4

  1. Back to the Star Map (outside), there is a flap on the left side of each. Fold these flaps along the gold line.

Planisphere Scrn 3

  1. Next, line-up the two sides of the Star Map Outside (coloured sides facing outwards) and glue the flaps to stick both sides together.

  2. Once the Star Map Outside is complete, insert the inner star map and align the two. You should see the months above the Star Map Outside. (See image on the left.)

  3. Once aligned, pierce a hole through the centre of the cross bar using a sharp pencil. Insert a spit pin through all layers and open the pin to hold your planisphere together.

Note: For best results turn to the Northern Hemisphere side and push your pin directly through the North Star. This is a slightly larger star at the centre of the wheel, in the constellation Ursa Minor.

  1. You should now have a rotating star map that can be used to find out which constellations and objects can be seen in the night sky throughout the year, in both the Northern and Southern Hemispheres!

Planisphere Scrn

  1. To use the planisphere you will first need to choose a date, let’s start with today’s date. Find the date on the outer circle (each month has marks representing days).

  2. Next choose a time. You will probably want to choose a time after the sun sets. The time is marked on the inner circle (using the 24-hour clock).

  3. Rotate the star map to line up your chosen date with your chosen time.

  4. Remember to read the correct side of your planisphere. E.g. If you live on the Northern Hemisphere look at the Northern Hemisphere side.

  5. Once done you will see the constellations and stars visible at your chosen time and date through the window!

Note: Those living on the Northern Hemisphere side are lucky to have the North Star sitting directly above the North Pole. This can make it much easier to begin navigating the stars. The North Pole is a very bright star that can even be seen inside most towns on a clear night.

Finding the North Star

  1. Allow your students to familiarise themselves with their star maps and ensure they are confident they know how to read them. To check they understand what they are seeing, discuss the following questions with your class:
  • What does the edge of the spy window represent? (The horizon)
  • Why does our view of the night sky change? (Rotation of the Earth and movement of Earth through its orbit around the Sun).
  • Which constellations will be easiest to see? (The brightest constellations will be more visible, although the brightness is not displayed on the star map. The answer we’re looking for is ‘those closest to the centre of the spy window — furthest from the horizon — these will be highest in the sky and therefore less likely to be blocked by light pollution, building etc.)
Conclusion

Now that the students have a tool to navigate the night sky at any time or day, invite them to explore the night sky beyond the naked eye using robotic telescopes.

KS2 Art and Design in the Welsh National Curriculum, Making: “Design and make three-dimensional objects and artefacts using a range of various materials for a variety of purposes”.