Star Wheels

…and Sky Challengers

Starwheels are inexpensive star maps, adjustable for any time of night in any month of the year.  Such maps are also called planispheres. 

Sky Challengers

In the 1980s, 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) 

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

Deriving from the original Sky Challenger design, there are now many interchangeable disks (wheels), available for free on this page that can supplement the original 6 disks of Sky Challengers.   These supplementary wheels are sometimes referred to as Uncle Al’s Starwheels or Sky Wheels, created for the Hands-On Universe project.

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.

Download Starwheels:

Northern Hemisphere 

• English – Northern Hemisphere Starwheel (1.7 Mb, PDF; Apr 2011) includes holder and 2 wheels (basic constellations and coordinates wheels)
• Higher Latitude Starwheel (60°+; Alaska; 1.7 Mb, Nov 2014)
• Kepler Star Wheel (has Kepler target field marked and naked eye stars known to have exoplanets)
• Japanese Star Wheel (1.6 Mb, PDF; prepared by Kaoru Kimura, updated September 2015)
• Icelandic Star Wheel (64°N; 1.4 Mb, PDF; courtesy Sverrir Gudmundsson for the Stjörnufræðivefurinn website)
• Blank Star Wheel (no lines or labels)

Southern Hemisphere

• English – Uncle Al’s Starwheel – Southern Hemisphere (1.2 Mb PDF; Nov 2014)
• Español – Planisferio del Tío Al – Hemisferio Sur (1.2 Mb PDF; Nov 2014)
• Português – Planisfério Celeste do Tio Al (1.2 Mb PDF; Nov 2014)
• Pulsar Starwheels (1.2 Mb PDF; Aug 2011; in English) – pulsar target objects from Parkes Radio Telescope

See also the Lawrence Hall of Science Starwheels page.

Download Messier Catalog Excel File

[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. ]

This is a photo of the original Sky Challenger product. Packaged in the back of each Sky Challenger was the premier (and only) issue of the Stargazers’ Gazette.