Year and approximate magnetic latitude of lowest latitude report of visible aurora for storms spanning 500 years (1520–2020). The 14 events are placed above and below the timeline to avoid overlap. Brackets indicate southern latitudes. All MLAT values have been rounded to the nearest whole degree. Large circles correspond to more equatorward auroral visibility. An open marker indicates a probable event. See references in Table 1. Several technology developments are listed, as are the approximate intervals of grand/secular solar minima.