11 February 1958 Synoptic Auroral Map
By early 1958, under the auspices of the International Geophysical Year, the National Research Council had compiled a list of amateur contributors to an auroral research program. The period of maximum solar activity in an 11-year cycle had peaked in late 1957, and Helen Sawyer Hogg reported in her Toronto Star column of June 7th, 1958 that the relative sunspot number for December 24th and 25th was 355. This was the highest value ever observed, exceeding the value of 353 on May 17th 1778.