Have you ever noticed how the night sky looks different every single day? This is because we are constantly moving in space so our view changes. The Earth spins on its axis once a day and travels around the Sun once a year. Additionally, the Sun and our entire Solar System moves around the centre of our galaxy. The time of year affects the night sky that we see. What we see also depends on where we are in the world – the southern and northern hemispheres see very different night skies and constellations.
Planispheres, also known as star wheels, have been used by astronomers for hundreds of years to help them understand what they can see in the sky at any given time. These tools allow us to see the fraction of the sky above us for a specific month, date, and time.
This activity will guide you through making your own star wheel, which you can use to help find your way around the night sky. Keep in mind, this star wheel is designed to work in the northern hemisphere, specifically in the UK and Ireland. If you live elsewhere in the world, the night sky will look different for you.
By the end of this resource you will:
- Have made your own star wheel.
- Know how to set your star wheel for today's time and date.
- Be able to use the star wheel to locate the north star and which constellations are visible to you.
To complete this resource you will need:
- The planisphere/star wheel template
- 2 sheets of card
- Scissors or crafting knife
- Sticky tape or glue
IT Equipment:
- A printer
Credit: The Schools' Observatory
Have a go!
First, make sure you have all the things you need to complete this activity from the list above. Then, read through the safety advice below. Once you have done that, you are ready to follow the instructions and make your own star wheel (there is a printable version of the instructions you can download and print if you prefer).
Safety advice
Take care when using the scissors or crafting knife to cut through the card.
Instructions
1. Print off the planisphere template either directly on to card, or print it on paper and then glue the paper to a piece of card.
2. Carefully cut out the star wheel holder on page 1 of the template. Make sure you remove the oval shape from the centre (white region).
3. Fold the template back along the dashed lines at each side and along the bottom.
4. Use glue or sticky tape to secure the folded flaps back. Make sure to leave a pocket in the back that you can slide the star chart into.
5. Cut around the star chart on page 2 of the template.
6. Slide the star chart into the grey template frame.
Using the Star Wheel
1. Spin the star chart circle until you see the current month at the top of the star wheel.
2. Rotate the inside wheel around so that the today's date lines up with the arrow that matches the current time.
3. The star wheel will then show you what stars and constellations are visible now.
4. This will help you pick out the constellations which you can see in the night sky.
5. You can rotate the star wheel to another time or date to help you plan future observations of the night sky.
Important notes:
This planisphere is for the northern hemisphere, specifically centred on the UK. If you live at a different latitude, the sky you see will be different. You should always use a star wheel that has been made for your location.
Polaris is one of the most important stars to recognise because it will help you navigate the night sky. Two stars in Ursa Major (the Great Bear) point towards Polaris.