This invention pertains to an educational toy called a comet ball which may be utilized in many games involving both skill and chance. The comet ball comprises a plastic ball having a source of interior illumination and having designed on its surface small areas through which light shines brightly. These areas are designed in patterns representing constellations of celestial bodies. The remaining surface of the comet ball may be of different colors of plastic having some light permeability. Games utilizing the comet ball may be based upon the astronomical models incorporated in the ball or the illuminated colors of a set of comet balls. The ball is formed of two hemisphere secured together. A hollow cylindrical tube is attached internally to each of the sphere. The tubes are threaded and can be screwed together to tightly secure the hemispheres. Inside the tube is placed a battery which supplies power to light a bulb also located interiorly of the sphere.