Though a banker by profession, Wilhelm Beer, who was born Jan. 4, 1797, in Germany, dedicated his life to astronomy, establishing a private observatory in Berlin and acting as a patron and collaborator to professional astronomer Johann Madler. Between 1834 and 1836, Beer and Madler created and published Mappa Selenographica, the most complete and correct map of the Moon of its time. The work would be unparalleled for four decades. Illustrations were created using lithography, a new printing process that allowed for unprecedented accuracy, and the volume was noted for having images that could fold out and be viewed while the user read the text.
Beer and Madler followed the map work up with Das Mond, which gave the measurements for the key features of the Moon, the diameters of 148 craters and heights of 830 mountains. And after their lunar book was complete, their next project was Fragmentes sur les corps celestes du system solaire, in which they produced the first high-quality illustrations of the surface of Mars.
