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Planispheres are star maps that are adjustable for any time of night in any month of the year. They are like little “paper planetariums.”

Sky Challengers

The original sky challenger, with 6 disks, holder, and star clock
The original Sky Challenger product. Packaged in the back of each Sky Challenger was the premier (and only) issue of the Stargazers’ Gazette.

In the 1970s, Budd Wentz at the Lawrence Hall of Science with NSF funding developed Sky Challengers, a unique planisphere (adjustable star map) with 6 interchangeable disks:

  • Introductory Wheel (basic constellation finder)
  • Native American Constellations
  • Binocular Sky Treasure Hunt (favorite deep sky objects)
  • Test Your Eyes-Test the Skies (a few star magnitudes marked)
  • Where Are the Planets? (ecliptic zone marked)
  • Invent Your Own Constellations (stars, no constellations)
Sky Challenger planisphere

The original Sky Challenger is no longer in print, but the 6 disks plus holder are now available as a Do-It-Yourself product reduced to allow print on 8.5″x11″ cardstock or paper.


See DIY Sky Challengers.

Star Wheels

Derived from the original Sky Challenger design, there are now many interchangeable disks (wheels), available for free that can supplement the original 6 disks of Sky Challengers. These supplementary wheels (at times called Uncle Al’s Starwheels or Sky Wheels), were created for the Hands-On Universe project and the NASA Kepler Mission.

Young woman cutting out and making a star wheel

The latest Starwheel is the Messier Starwheel (created Nov 2024 and updated Feb 2026). If you do telescope star parties and have ever wanted to quickly know which Messier objects are well positioned on a given night, the Messier Starwheel is especially for you! Starwheels are sized to fit on 8½”x11″ paper by default. Printed or copy on to the heaviest cardstock available, e.g. 110 lb. Although the default size may be good for students with decent eyesight, the print is rather small. You can make a larger version for teachers, senior stargazers, or anyone by printing or copying the master enlarged 130% to fit on 11″x17″ cardstock.

It’s customary to use a red light to illuminate the starwheel when reading at a star party to preserve good night vision. You can make your phone into a red flashlight with an app such as  Color Flashlight (android) or the iOS apps NightVision Light,  jLight, and Flashlight.

Download Starwheels

Instructions for making them are included on the PDFs (all under 2Mb).

Northern Hemisphere

Southern Hemisphere

Download Messier Catalog Excel File.

To Use the Star Wheels

  1. Set date and time
  2. Note which horizon the constellation is closest to and put that horizon near the bottom.
  3. Constellations higher in the sky are closer to the center of the map.

You may find more details and ways to use Star Wheels in the “Making and Using Star Wheels” section of Investigation 2.1 Using Star Maps from the Global Systems Science book A Changing Cosmos.

See also the Lawrence Hall of Science Star Wheels page.

[Historical note: Along with Sky Challengers, Lawrence Hall of Science once sold the Star Maker Planetarium Kit, a build-it-yourself mini-planetarium. It included a geodesic pinhole projector and a 6-foot-diameter dome that suspended from a ceiling. The revolving geodesic globe projected stars onto the dome and re-created the heavens as seen from anywhere in the Northern Hemisphere. Assembly, which included punching holes in the globe for the stars, took four to eight hours. Star Maker is no longer available.]