Cut out the astrolabe drawing and punch a hole as indicated.
Cut a piece of string (~ 30cm long). Knot one end to the hole on the astrolabe and attach a weight to the other end.
Tape a straw on the edge indicated.
Instruct students on its use:
Hold the astrolabe so the curved part is downwards, and the 0° mark is closest to you.
Look along the flat edge of the astrolabe with your eye looking through the straw.
Point the straw at the object that you want to measure. As you tilt the astrolabe up, the weight will move to measure the degree of your angle of observation.
Place astronomic object cut-outs on the classroom walls and have students measure the angles of observation with a partner. Invite them to find different objects and record their angles of observation.
Gather for a group discussion. Example prompts:
What happens when you hold your astrolabe and look straight up?
What happens when you look straight ahead?
Does it make a difference if you measure the angle while lying down compared to if you were sitting or standing?
Can students accurately measure angels up to 180° using the astrolabe?
Do students see the similarities and differences between using an astrolabe and a protractor?