You will need
- Pens or pencils
- Something to protect surfaces (for example, newspaper or tablecloths)
- A 1cm-wide concave lens, per group
- A 1.5 inch-wide convex lens, per group
- Two kitchen roll tubes, per group
- Craft materials, including scissors, glue, a craft knife, cardboard sheets and paint brushes
- Black electrical tape
- Black paint
- Decorative items, like stickers
Gather your materials
The sky we see at night is full of different things, from stars and planets to satellites, there is so much to be seen. The naked eye has a limit of what it can see and depending on where you live, other elements can reduce what you see such as lights from a town or city. To be able to see more, people and astronomers use telescopes of all different sizes. In groups create a telescope out of simple materials and use it to look at the stars from your meeting place.
- Before the session, encourage everyone to come to the meeting in clothes they don’t mind getting paint on.
- Find all the materials needed. Lenses can be bought cheaply online if needed. If you can re-purpose some from old reading glasses or magnifying glasses, even better.
- Set up tables and chairs for each group, with newspaper on the tables to protect them. Set out on each table all the materials the group will need.
Time to build
- Everyone should get into small groups. The number of groups will depend on the equipment available. Each group should sit at a table.
- Explain that everyone will be making telescopes for stargazing in their groups. Have everyone start by drawing two parallel lines, 1cm apart, from the top of one of the tubes to the bottom. With scissors, cut along the lines, so that a strip of the tube is removed.
- The tube with the strip missing should now be inserted into the other tube. Squeeze the tube with the strip missing together slightly to make it fit, then check that it slides back and forth up and down the inside of the tube, without catching on anything.
- Once the inner tube is a perfect fit, tape it back together with black tape. Try to place the tape evenly on the inside of the inner tube, so that it keeps its shape and doesn’t catch in the outer tube. Once taped up, test out the slide action again.
- Place the taped-up tube face-down on the sheet of card and draw around it with a pen or pencil. Then, with a ruler, draw a cross in the circle you’ve just drawn.
- Take the 1cm lens and place it in the centre of the circle you’ve just drawn. Draw around the lens.
- Cut out the larger circle from the card. Then, with a craft knife, carefully cut out the smaller circle from the centre.
- Brush some glue around the edges of the small hole in the circle. Take the 1cm lens and find the flat side. Push the lens into the hole so that it sticks there, with the flat side face-up. Wipe away any excess glue.
- Brush some glue around the edges of the taped-up tube. Take the circle containing the lens and push this into the tube so that it sticks there, with the flat side face-up. Leave this to dry lens-side-down, so the lens doesn’t drop out and break.
- When the glue has dried, carefully tape over any joins with the black tape, to keep any light out.
- Brush some glue around the edges of one end of the other tube. Take the 1.5 inch lens and insert it into the tube so that it sticks in that end. Leave this to dry lens-side-down, so the lens doesn’t drop out and break. Wipe away any excess glue.
- When the glue has dried, groups can decorate their tubes, if there’s time. They could make them look like real life telescopes, with complicated dials and panels, or come up with a new telescope design of their own.
Discover the stars
- When everyone is ready, take the telescopes outside and gather people in their groups.
- Allow them the time to look through their telescopes to see what stars they can find.
The sky we see at night is full of different things, from stars and planets to satellites and asteroid showers. To be able to see more, people and astronomers use telescopes of all different sizes. How did your team work together to make a telescope to help you look at the stars? You needed a delicate touch to glue in the lenses and shape the inner tube, and a creative approach to come up with a design.
The naked eye has a limit to what it can see. But also, depending on where you live, other elements can reduce what you’re able to see, such as urban lights. How does your telescope help you see more? What could you change about your telescope to see even further? Think about other lenses and materials you could use.
Supervise young people appropriately when they’re using scissors. Store all sharp objects securely, out of the reach of young people
- Rubbish and recycling
All items should be clean and suitable for this activity.
- Glue and solvents
Supervise young people appropriately when they’re using glue and solvent products. Make sure there’s plenty of ventilation. Be aware of any medical conditions which could be affected by glue or solvent use and make adjustments as needed.
- Sharp objects
Teach young people how to use sharp objects safely. Supervise them appropriately throughout. Store all sharp objects securely, out of the reach of young people.
Provide some light, so the environment isn’t completely dark. Everyone must be able to see others and move around the area safely.