DURING the eighteen‐month period that will begin on July 1, 1957, and end on December 31, 1958, scientists from at least forty nations will take part in a global study of the physics of the earth and its atmosphere that will dwarf, in scope and intensity, any previous international scientific undertaking in history. Plans for the International Geophysical Year have been far advanced since the initial formulation in 1954 of a comprehensive program by the Special Committee appointed to serve as a central coordinating body by the International Council of Scientific Unions, the official sponsor of IGY. Each of the participating nations is responsible for the planning and execution of its own part of the program, and the various National Committees have by now determined the extent and structure of their projects in broad outline and many are well along in matters of organization and procedural detail.