[Comment on “New Moon”] “New” Lunar knowledge not so new



The December 13, 1995, Eos “In Brief” column refers to the “new” establishment of knowledge of the geometrical dependence of the Moon's diffuse reflectivity for phase angles under 1.5°, normally inaccessible to Earth-based observation because of lunar eclipse, as derived by Bonnie Buratti using Clementine data. This knowledge was first “new” 26 years ago when my colleagues and I derived it as members of the Apollo Orbital Photographic Reconnaissance Team [Pohn et al., 1969; Wildey and Pohn, 1969]. Although a good deal larger than Clementine and in a lower lunar orbit, the Apollo Command Module was also a negligible source of shadow as seen from the lunar surface against a 1/2° wide Sun and thus permitted the derivation without worry of eclipse by the 2° wide Earth.