PLANETARIUM

PROBLEM TO BE SOLVED: To realize the synchronization of a planetary projector to the movement of a fixed star projection globe while adopting the method of driving each planetary projection barrel not by a train of gears but by biaxial control based on computed values. SOLUTION: The projector is composed of a rotary stage 10 which is concentrically disposed with the precession axis 1A of a fixed star projection globe 1 and performs the movement along the X axis, and of a planetary projection barrel 20 which is disposed in a deviated position from the X axis on the rotary stage and performs the movement along the Y axis to vertically vary the projection direction with respect to the rotary stage. The motion of planets are projected by controlling the movement along the X axis and the movement along the Y axis on the values computed by a planetary motion computing device to which the data of the date and time is sent.