The development of the projection planetarium is under the century-old influence of various models of the starry sky in the form of celestial globes (e.g. Gottorp Globe (1664), Atwood Celestial (1913)) and mechanical models of the solar system, which primarily demonstrated the motion sequences among each other (e.g. Huygens Planetarium (1682), Eisinga Planetarium (1774)). Both model variants are combined in the star projector and thus allow a geocentric view of the motion sequences in the night sky.