CONSOLIDATED LUNAR ATLAS
Paul D. Spudis, Ph.D.
In the dawn of the Space Age, NASA undertook to find and assemble the very best images of the Moon it could find. In a project led by the late Gerard Kuiper of the University of Chicago (later of the University of Arizona), the best telescopic plates from observatories around the world were assembled into one compilation, the Photographic Lunar Atlas (Kuiper et al., 1960, University of Chicago Press). This atlas consisted of loose-leaf, printed (lithographed) sheets of telescopic plates of the Moon, showing the surface at a variety of illumination conditions. Widely distributed, this atlas served as the basis for many early photographic studies of the Moon.
Over the ensuing years, two supplements were issued to this atlas: an orthographic atlas (Kuiper et al., 1961, University of Chicago Press) that assigned coordinates and names to lunar features, and a rectified atlas (Whitaker et al., 1963, University of Arizona Press) in which telescopic images were projected onto a blank sphere and photographed from above, yielding a "spacecraft view" perspective. But the acme of telescopic lunar atlases came with the publication of the third and fourth supplements, the Consolidated Lunar Atlas (CLA) (Lunar and Planetary Laboratory, University of Arizona, 1967). This atlas was a collection of very high quality, loose-leaf photographic prints of all of the best images taken from Earth-based telescopes. As it was made up of photographs, and not printed, this atlas was reproduced in limited quantities and distributed to members of the space community to support the upcoming Apollo missions to the Moon. Few intact copies of the CLA have survived; it has become one of the scarcest of all lunar publications, with used copies found in some rare book stores going for thousands of dollars.
Although we have had several orbital missions that took pictures of the Moon, ranging from Lunar Orbiter to Apollo to Clementine, even today, the CLA is of great scientific value. It shows the nearside of the Moon under a wide variety of illumination conditions, from sunrise to sunset. Images from the various space missions show the Moon under whatever lighting conditions occurred during the mission. Lunar Orbiter photographed the Moon under early-morning conditions while Clementine took its images under the glare of lunar noon. Both lighting conditions give different information, and the CLA helps to bridge the information gap by showing regions on the Moon at all possible Sun illumination angles.
Amateur astronomers have known for years that the CLA is a superb resource, and knowledgeable lunar scientists and observers use the atlas to this day. Until now, its rarity has hindered its widespread use. Eric Douglass has done the astronomical and lunar scientific communities a great service by rendering the CLA images into digital form. For Eric, this labor of love has resulted in a product that we can all use and treasure for a long time to come. This atlas joins the Digital Lunar Orbiter Photographic Atlas of the Moon as an online resource that researchers, observers, and students will consult for years to come.