Alexander's Star is a mechanical puzzle invented by Adam Alexander in 1982. It is a great dodecahedron with 30 moving pieces, which rotate in star-shaped groups of five around the outermost vertices. The challenge of the puzzle is to get it to a state in which each star is surrounded by five faces of the same color, and opposite stars are surrounded by the same color; this is equivalent to solving just the edges of a six-color Megaminx.