Cosmo Leap Σ is an optical projector for mid-size, municipal planetariums operated primarily for educational purposes. It is designed to benefit all planetarium users, including the children who learn and grow through astronomy. Combining both star and planet projection, it is the smallest projector in its class worldwide, offering 80 constellation images, reference marks and more to enable a full, all-inclusive analysis of the night sky in the limited space of a mid-size planetarium dome. Quiet operation on par with that of library noise levels enables novel show types, such as projection accompanied by musical concerts. The unit's pitch-black color, which blends into the dark, and elaborate, polyhedral light-emitting projection foster an elegant harmony as they recreate the starry sky.