Hemisferium Rojas´ Universal Astrolabe 20 øHemisferium developed this unique piece to celebrate the International Astronomical Year in 2009. The astrolabe reached the peak of its popularity in the 16th century. The Spanish astronomer and mathematician Juan de Rojas presented the Orthographic Projection to the European public in 1550. This projection was successfully applied in a new type of astrolabe that offered remarkable advantages over its predecessors because it could be used in any