Johann von Madler (1794-1874), German astronomer. Johann Heinrich von Madler is most famous for his pioneering work Mappa Selenographica. This map of the moon, which he produced with Wilhelm Beer (1777-1850), was the first of its kind and was published in four volumes between 1834 and 36. He and Beer also wrote the 1837 book Der Mond, which gave a detailed description of the moon and established the facts that the features of the moon do not change and that there is no atmosphere or water. Other collaborations between von Madler and Beer included creating the first globe of Mars and calculating the rotation period for the planet.