Thermal Characteristics of the Moon

During the middle part of the decade of the 1960's the United States Ranger spacecraft series produced a quantum jump in our knowledge; the later Surveyor spacecraft landings on the moon and the series of Lunar Orbiter spacecraft added larger quantum jumps. Two immediate uses for the information obtained from these spacecraft projects were to increase our scientific knowledge and to generate engineering information for utilization in spacecraft design and in operational planning of subsequent missions. The 1969-1971 Apollo flights resulted in still greater contributions to lunar knowledge, and these recently reached a peak with the very promising Apollo 15 landing. The USSR space effort also has produced major contributions to lunar knowledge, especially from the still-continuing Luna and Zond spacecraft series and from the Lunokhod rover that was first landed in 1970. Russian contributions included the first photographs of the far side of the moon, the return of a lunar soil sample, soil analyses with the rover, and microwave measurements of the lunar surface.

During these periods many techniques were employed to study the moon. Earth-based methods of observing the moon were greatly extended and refined, spacecraft-borne experiments made direct measurements on the lunar surface, and simulated and actual lunar materials were subjected to tests in terrestrial laboratories. Finally, stimulated by all of these findings, theories of the origin of the moon and of its surface features were developed.

The purpose of this volume is to bring together in one place results obtained during the first decade of space exploration that bear on the thermal characteristics of the moon. The successive chapters show the way in which many pieces of information can be put together and used by different investigators from different disciplines to provide a coherent and reasonably accurate explanation of the moon's thermal characteristics. The characteristics include thermal properties of lunar surface material, surface and interior temperatures, heat flow patterns, and related physical properties. It is hoped that assembling the varied information together in one place in this volume will encourage further multidisciplinary studies and thus have a synergistic effect on future research.