To make one of the tubes smaller, cut it open along it’s length. Press it back together with a 1cm overlap and tape back together. Check it fits neatly inside the other tube, if not, adjust the tape until it does.
Measure a 5mm x 8cm slit on the taped tube, 1cm from the bottom. Use a craft knife to carefully cut it out.
Paint both tubes blue and leave to dry. Use the knife to poke a hole in the bigger tube, 1cm from the end. Place the smaller tube inside and line up the cut out strip with the hole. Insert a brad through the hole and slit to hold in place – you should now be able to extend the telescope (it might take a little wiggling before it runs smoothly!)
Decorate the telescope using gold paint and stars. We decorated one with constellations created with dots of gold paint. For the other we created a graduated effect using gold stars and paint.
Draw around the larger end of the tube onto a piece of acetate. Fill the circle in with a space scene, such as planets or a rocket. Colour in with Sharpies and cut out.
Add a line of glue using a glue gun inside the wider tube, about 2cm from the end. Leave to dry to create a ledge. Place the acetate circle on top and glue in place.