The solar-terrestrial event of 23 February 1956

The solar flare of 23 February 1956 and the resulting geophysical disturbance ranks as one of the most remarkable solar-terrestrial events of the twentieth century. It sparked many papers and has seldom been equalled. Fifty years after the International Geophysical Year, it seems timely to review the observations of the event from today’s perspective, and to draw on the recollections of scientists who were active at the time.