How to Make a Planetarium Out of a Light

A homemade planetarium transforms your ceiling into a starry night.

Having the ability to display star constellations at home is a fun way to learn about the larger universe when live in. In urban areas where a lot of manmade light makes it difficult to see common constellations, a home planetarium is an enjoyable way to “see” the various stars and planets regardless of the weather outside. You can create your own planetarium at home using simple household items, a few art supplies and a darkened room with the ceiling as the dome to display the stars on.

Things You'll Need

• Tabletop lamp
• Cardboard sheet 2 x 3 feet
• Several cardboard sheets 12 to 16 inches square
• Printed star maps
• Tape
• Pen, awl or ice pick

Instructions

1. 

   Different stars and planets appear as the seasons change.

   Print a copy of a star map for the constellations you wish to display from one of the available astronomy websites such as Skymaps.

2. 

   Carefully make holes where the stars appear on the chart.

   Tape a star map to a square sheet of cardboard. Use a pen, awl or ice pick to punch holes in the cardboard where the stars are located.

3. Remove the lampshade from a stable tabletop lamp.

4. Measure the height from the tabletop to 2 or 3 inches above the lamp bulb. This will be the needed height of the cardboard cylinder that you will make next.

5. Wrap the rectangular sheet of cardboard into a cylinder tall enough and large enough to safely go around the tabletop lamp. Tape the ends together.

6. Lower the cardboard cylinder around the lamp and turn the lamp on.

7. Place the cardboard sheet with the punched star map on top of the cylinder and position it to show the various stars and planets.

Tips & Warnings

• Different planets and star constellations will be visible in the evening sky depending on the time of year and time of night. You can create several sheets of constellations for your planetarium matching your time of year. Then, using binoculars at night, go outside to identify the same stars and planets.

• Do not leave the cardboard planetarium unattended or let the cardboard get too hot from the bulb.

References

• International Planetarium Society: So You Want to Build a Planetarium
• Contra Costa County Office of Education: Making a Projector Cylinder
• Skymaps.com: The Evening Sky Map

Resources

• Education.com: Make a Bedroom Planetarium!
• Space.com: Skywatching
• Sky & Telescope: Getting Started in Astronomy
• Stardate: Stargazing Information