Published by UNESCO in 1957 in the series "UNESCO and Its Programme" (No. XV), this booklet was issued to mark the launch of the International Geophysical Year (IGY, 1957–1958). The author, a German science journalist, outlines the programme's goals as coordinated by CSAGI, the eleven scientific disciplines involved (from meteorology and glaciology to ionospheric research) and devotes a chapter to the planned Vanguard satellite project, written before the launch of Sputnik (October 1957). Prefaced by UNESCO Director-General Luther H. Evans, the work provides a general-audience introduction to the largest postwar international scientific campaign.