As the weather gets chillier, you might start eating more hot cereal like oatmeal. If you don’t, maybe you should start, because you can use those tall, round oatmeal containers to make home planetariums with your kids. Oh, and oatmeal is good for you, too.
1. Remove the cover from the oatmeal box.
2. On the outside of the cover in the center, sketch some of the common constellations with a pencil. Make sure to keep the sketch in the center of the cover; otherwise it will not work.
3. Punch out the various “stars” in the system, as in illustration A.
4. Cut out the bottom of the oatmeal box.
5. Replace the cover on the box.
6. To see the planetary system, place a flashlight at a slant inside the box, and point the box at the ceiling, in a darkened room, as in illustration B. The stars will be projected on the ceiling, as in illustration C.
I would recommend using a copy of an actual star map to make the constellations, not the constellations in the above illustration. Tape the copied map onto the container’s lid, and punch out your stars. You can use items of varying diameters for star punching to mimic the varying luminosities of stars themselves. For example, a compass point (for drawing circles, not finding north) is usually thicker than a regular sewing needle, so use a compass point to punch out the brightest stars (usually drawn as larger dots on star maps) and the skinny sewing needle to punch out the other stars.
There’s a variation to this project called Make a Bedroom Planetarium! on education.com which increases the complexity a little bit, but also increases the coolness of it. This project has tips for decorating the oatmeal container–excuse me, Starfinder–itself, before making changeable constellation disks. In this project, they cut a hole in the plastic lid with scissors or an X-acto knife so the flashlight can fit through and be taped into place. (I guess you’ll want a dedicated flashlight for this project.) Now they cut out the round cardboard bottom from the oatmeal can and use it to trace a few circles onto black paper, adding a half-inch margin around each circle. Now you have several circles on which to trace constellations (or tape a copy of a map) for your pattern of stars to punch out. Tape one of the completed circles to the bottom of the oatmeal container, pop on the lid with flashlight, turn off the room lights, and voilà! Constellations. Then you can change star disks to show different constellations.
One thing bugs me about this one, though. It seems to me there should be a better way to change things up than to keep taping the circles on. The lid of my Quaker Oats container is a plastic ring with a cardboard insert. I wonder if you could instead carefully remove that cardboard insert and create circles of black construction paper that fit inside the ring exactly, all the way to the inner edge. Then you can replace circles and hold them in place with the plastic ring. You’ll have to take care that the circles fit exactly right, though, or else they will fall down and you’ll have gaps where the light can leak out, thus spoiling the starry projection. My initial testing of this idea with regular notebook paper didn’t work out too well, but then, notebook paper is quite flimsy compared to construction paper. But the ring is too flimsy to hold excess paper, if you were to create larger circles that would hang over the edge of the container. Hm! Well, I guess you could always eat more oatmeal. Then you could have a lot of container lids with which to make different star fields.
Good luck! Happy oat-eating! And if you have further thoughts, variations, or photos of doing this project, feel free to post in the comments or on my Facebook page, or e-mail them to me at my gmail, and I can share some of them here on Astronomommy.