As our closest neighbor in the Universe, the Moon is a natural place for humans to explore. Before the telescope was invented, people usually envisioned the Moon with a smooth surface. In 1610, Galileo’s lunar drawings showed another world to be discovered and charted. Seventeenth century lunar cartography beautifully illustrates the flurry of discovery after the invention of the telescope.
Polish astronomer and scientific instrument-maker Johannes Hevelius published the first lunar atlas, Selenographia in 1647. To prepare the publication, Hevelius systematically observed the Moon through every phase of the lunar cycle. For two years, he plotted the Moon from an upstairs room in his home and, later, a roofed tower added to the house. Hevelius engraved most of the plates himself, revealing his artistic talent.
Selenographia included more than forty engravings of lunar phases, observations of eclipses, notes on lunar librations, and Moon maps. This map shows the Moon’s features with a full set of lunar nomenclature that was ultimately not adopted. Hevelius carefully considered his plan before introducing his proposed lunar naming system. He specifically avoided using his contemporaries’ names for fear of jealous arguments. Instead, Hevelius opted for classical names of geographical features on Earth, reflecting his belief that the Moon’s dark regions consisted of water and the brighter regions areas of land. For example, on the left side of Hevelius’ map, Sicilia is an island in the Mediterranean Sea. Only four of Hevelius’ 285 names remain in use as he intended and six are used in different locations. The Alpes and Appennius mountains, both on the right side of Hevelius’ Mediterranean, are still used today.
Around the same time, Italian astronomer Giovanni Battista Riccioli also meticulously developed lunar nomenclature. Francesco Grimaldi drew the Moon maps for Riccioli’s two-volume Almagestum Novum (1651), basing them on the work of Hevelius and Michiel Van Langren. Riccioli’s names provide the basis of our lunar nomenclature system today.
Riccioli divided the Moon into eight regions (“Octans”), marked by pie-shaped lines. He named large areas for terrestrial weather, reflecting a belief in the Moon’s influence on the Earth’s conditions. Riccioli also honored significant astronomers, grouping them according to their philosophies and time periods. Ancient astronomers appear toward the top, while more recent observers (such as Tycho Brahe) are near the bottom. Riccioli, a Jesuit compelled to adhere to Church teaching, claimed to punish Nicholas Copernicus and Johannes Kepler by tossing them into Oceanus Procellarum, a stormy sea. As a result, however, two of the Moon’s most prominent craters are named after proponents of a Sun-centered Universe.
Written by Jodi Lacy, archivist & digital projects manager at the Adler Planetarium.