This edition reviews the results of Apollos 11, 12, 14, and 15. Included are approximately sixty new pages of text and forty new photographs and pictures. Thomas A. Mutch has written this book for students of lunar geology and scientists in diverse fields related to astrogeology as well as for the interested layman. Originally published in 1973. The Princeton Legacy Library uses the latest print-on-demand technology to again make available previously out-of-print books from the distinguished backlist of Princeton University Press. These editions preserve the original texts of these important books while presenting them in durable paperback and hardcover editions. The goal of the Princeton Legacy Library is to vastly increase access to the rich scholarly heritage found in the thousands of books published by Princeton University Press since its founding in 1905.