The International Quiet Sun Year (IQSY) was a cooperative international effort to study the effects of the sun during the quiet period of the 11 year solar activity cycle (Dec. 1964 – Dec. 1965). The IQSY was organized by the International Council of Scientific Unions to study solar events that are easier to observe during periods of lower solar activity. Observations were made using terrestrial observatories and various spacecraft.
Set of 6 stamps issued by Togo for the IQSY |