

The increase in our knowledge of the solar system during the five years since the author last revised this book (1963) greatly exceeds that in the previous two decades. The program of the U.S. National Aeronautics and Space Administration and the space program of the U.S.S.R...






This book has been revised it has the most extensive revisions in the chapters on the Moon, Mars, and Venus - the members of the solar system on which the various space programs have concentrated.