The IAU Symposium No. 47 The Moon was held in the School of Physics of the University of Newcastle-upon-Tyne, England, from 22 to 26 March 1971. The Meet­ ing was sponsored by Commission 17 and co-sponsored by URSI. The Symposium was supported financially by the IAU. The Scientific Organizing Committee included Prof. S. K. Runcorn, Chairman (University of Newcastle-upon-Tyne), Prof. H. Alfven (Royal Institute of Technology, Stockholm), Prof. G. Colombo (University of Padova), Prof. A. Dollfus (Observatoire de Paris), Prof. T. Gold (Cornell University), Dr K. Koziel (Jagellonian University, Poland), Prof. G. P. Kuiper (University of Arizona), Dr B. J. Levin (U. S. S. R. Academy of Sciences), Dr A. A. Mikhailov (U. S. S. R. Academy of Sciences), Prof. A. E. Ringwood (Australian National Univer­ sity) and Prof. H. C. U rey (University of California). The Local Organizing Committee included Prof. S. K. Runcorn (Chairman), Dr G. Fielder, Prof. W. R. Hindmarsh, Prof. Z. Kopal and Prof. W. H. McCrea. This book includes the majority of papers presented at this the second IAU Sym­ posium on The Moon: comparison with the previous IAU Symposium on The Moon held in Leningrad, a decade earlier, makes clear the great advances made possible in our knowledge of the Moon and solar system by space technology. Academician A. A.