A Planetarium for Every Classroom
Building and Using a Planetarium for Your Classroom Using Inexpensive Materials


for students who visit this site or who build their own planetariums


Here is a multiple-choice quiz you can use for students who visit this site. Answers are available by email.

1. A planetarium is a place where

a. domes are built.
b. stars are simulated.
c. telescopes are used to take pictures

2. A geodesic dome's frequency refers to

a. the number of feet tall it is in the center.
b. the number of different shaped triangles used.
c. the speed with which you build planetarium domes.

3. A planetarium made with a cylinder-style projector can show all of the following except

a. how the stars rise and set
b. the effect of latitude on the appearance of stars.
c. what the stars look like millions of years from now.

4. The number of triangles needed to construct a 2-frequency hemispherical dome is

a. 10
b. 30
c. 40
d. 80

5. A planetarium is painted white on the inside because

a. it reflects dim light better.
b. it makes you able to see in the dark.
c. oops! planetariums are really black on the inside.

Mathematics investigations

  1. Build a 1-frequency dome and a 2 frequency dome of the same size. Compare the surface area of the triangles to the surface area of a hemisphere of the same size. Find the relationship between area and frequency.
  2. Predict the amount of volume the dome will require. Build a small dome and fill it with packing peanuts or ping-pong balls to measure the volume.
  3. How can a cylindrical projection correctly recreate the patterns of stars on a spherical projection surface?

Science investigations

  1. How does the size of a projected constellation vary with distance of the projector to the wall?
  2. How does the size of the light bulb affect the quality of the projected star images?
  3. How can the planetarium be used to teach the concepts of lunar phases or seasons?
  4. If the sun were the size of your planetarium, how far would the earth be from it, and how large would the earth be?






NSTA Files

Building a Dome

2 Meter
5 Meter
Paint Your Project


Making a Projector

Building a Projector


Using the Planetarium




Celebration Checklist page

Send your dome building report to us!


Quick Links

Deer Valley High School Science Department

Antioch SPACE Academy

AstronomyTeacher's web site


Contact Us

Jeff Adkins

Cheryl Domenichelli



Site counter courtesy of www.digits.com

This project was supported by a County Technology Academy Grant funded by the Dean and Margaret Lesher Foundation in cooperation with the Contra Costa County Office of Education.