Pin Hole Planetariums

At our next Bear den meeting we are going to focus on Bear Elective 1: Space. So I want to try to do the pinhole planetariums with them. I think they will enjoy this because it involves hammers, nails, and flashlights.

Printable copy of   Pinhole Planetarium


  • Clean, empty 15 oz cans (1 for each constellation)
  • Scissors
  • Glue
  • Hammer
  • Nail
  • Constellation patterns (see printable copy)


  1. Cut out the patterns. (See the printable version to get the patterns.)
  2. Glue the patterns to the ends of the cans and let the glue dry.
  3. Using the hammer and nail, punch holes through the patterns into the can where the dark black dots are locate.
  4. Turn out the lights in the room.
  5. Place a flashlight in the can and turn it on.
  6. Look at the bottom of the can. You should be able to see the pattern of the constellation through the holes.

The universe is not static. Plus, some of the placements for the nail holes had to be adjusted due to being to close together. If the accuracy of the constellation pattern is important, you must use a star chart. The pictures on the patterns are just to give the scouts an idea how the ancients used their imaginations to visualize the constellations.

11 Responses to Pin Hole Planetariums

  1. Philosoweed December 14, 2011 at 1:24 PM #

    Love the site (dad btw)

  2. MarktheScout January 5, 2012 at 8:20 AM #

    So what do you have the boys do while the glue dries?

    • Scouter Mom January 5, 2012 at 8:48 AM #

      Whatever is going on at the rest of the meeting. I usually use a fast drying tacky glue for stuff like this. If you glue them on at the beginning of the meeting, they should be dry enough after about 30 or 40 minutes.

      • Anonymous February 11, 2012 at 6:49 PM #

        Or just tape it on and skip the drying altogether…just a thought. 🙂

      • Den Mom March 11, 2012 at 4:39 PM #

        or use a glue stick

  3. Nicole January 8, 2012 at 10:29 AM #

    Hi, I’m kinda dumb when it comes to computer stuff…when I went to the printable site to get the patterns, all I got was “click to delete” wherever I put my cursor…Please help….can you send me a link to the patterns? Thanks.

    • Nicole January 8, 2012 at 10:34 AM #

      Never mind I got it thank you!

  4. Brett February 2, 2013 at 6:52 PM #

    Okay, so I have been messing around with this, but whenever I put a light to the constelation I made in the can and try to shin it on a roof or wall it just becomes mushed. Really unfocused, not little dots of light like I remember as a kid. Tried to move the flashlight back and forth to ‘focus’ but no effect. My two guess are that either the holes are to big or the light is to bright. Anyone have any ideas on the exact size of nail (everything i read just says small) or about how bright a flashlight should be (big billyclub maglite or cheap dinky one.)

    • Scouter Mom February 4, 2013 at 4:44 PM #

      Try shining it on something closer, like a wall, but only a foot or two away. A really bright flashlight and a really dark room helps also.

  5. Jessica May 31, 2013 at 3:51 PM #

    Thank you! This will be great fun. We’re going to do our Tall Tales story-telling requirement under our man-made “night sky.”

  6. Denise A Chaffin June 21, 2018 at 10:40 AM #

    Try hot glue???

Leave a Reply

This site uses Akismet to reduce spam. Learn how your comment data is processed.

%d bloggers like this: