Make an upside down telescope

Make an upside down telescope

Look up to the night sky

Astronomers use telescopes to see the stars. You can build your own telescope to find out how they work.

What you need:

  • Scissors
  • Pencil
  • Corrugated card - 24 inches in length
  • Strong glue
  • 2 magnifying glasses - same size
  • Marker pens or felt tips (optional)

How to:

These step-by-step videos will show you how to make your own telescope.

Wrap the corrugated paper around the edge of the magnifying glass. Draw a line on the corrugated paper to mark the diameter of the magnifying glass.

Measure an inch and a half from your first mark and make a second mark. Cut straight along the length of the corrugated paper from this mark.

Cut the piece of corrugated paper in half widthways.

Wrap the first piece of corrugated card around a magnifying glass and glue securely.

Glue the edges of the corrugated card together.

Repeat for the second piece of corrugated card and magnifying glass. Make the second tube of corrugated card slightly wider than the first tube, so the first tube can move in and out of the second tube.

Put the first tube inside the second tube. You should have a magnifying glass at either end.

Decorate your telescope with marker pens or felt tips.

If you want, you can put markings on the telescope to show where each distance comes into focus. Put an object a foot away from the telescope. Move the inner tube out and in until the object comes into focus.  Make a mark around the inner tube where it meets the outer tube.

This line shows you that when an object is a foot away it will come into focus when the two tubes are in this position. Repeat for objects at different distances from the telescope.

What's happening?

All the images you see in the telescope are upside down, because you're using two magnifying glasses. This doesn't matter very much to astronomers. In space there is no up or down!

Your telescope might not be powerful enough to view the stars clearly. If you'd like to build a more powerful telescope to look at the stars, have a look online. You can buy kits to help you build your own telescope.

Curriculum information