Build a colorful, mechanical, rotating model of our solar system! 
The model uses a windup motor to set the planets in motion--no batteries required. 
Explore fundamental gear mechanics and discover a special type of gear called a planetary gear. 
Great for science fair projects, you'll learn about the planets' celestial orbits and tons of cool planetary facts. 
Includes a built-in expansion slot should the mysterious Planet Nine be discovered! 
Assembly time: 1-2 hours, Difficulty Level: Intermediate