How to Make a Cardboard-Box Planetarium

Use scissors to cut a hole large enough to accommodate the flashlight in the center of one of the cardboard box's sides. Use the side opposite the side you want to use for the stars. The narrower sides usually work best.

Cut a rectangular opening in the side of the box opposite the hole you made for the flashlight. Leave one inch of space between the opening and the box's edges.

Place the box on top of black construction paper with one of the cut sides facing down.

Trace around the edges of the box.

Cut out the tracing.

Draw dots on the paper in the shape of a constellation. Use a star chart as a guide. You can also add surrounding stars if you want to.

Poke holes through the drawn dots using the tip of a pen or pencil. Make large holes for bright stars and small holes for dim stars.

Flip the paper horizontally so that the constellation is facing the opposite direction. Put the paper over the box's rectangular opening.

Tape the edges of the paper to the box with masking tape.

Tape the box shut, if necessary. If you're using a shoebox, tape the lid to the box tightly, so there are no cracks for the light to leak out.

Put the flashlight through the hole opposite the constellation.