In late October 2003, a series of large solar flares occurred. A X17.2-class flare ejected on 28 October 2003 resulted in auroras visible as far south as Florida and Texas. A G5 level geomagnetic storm blasted the Earth's magnetosphere the next two days. [9] A few days later, the largest solar flare ever measured with instruments occurred on 4 November 2003; initially measured at X28, it was later upgraded to an X45-class.[10][11] This flare was not Earth-oriented and thus only resulted in high-latitude auroras. The whole sequence of events occurred from 28 October to 4 November is known as the Halloween Solar Storm. Other very large solar flares occurred on 7 September 2005 (X17), 15 April 2001 (X14.4) and 29 October 2003 (X10), with auroras visible in mid-latitudes.
Driving back from Dundee I watched the big one. Filled the whole sky.
