The Carrington Event^[1] was a powerful geomagnetic storm on September 1–2, 1859, during solar cycle 10 (1855–1867). A solar coronal mass ejection (CME) hit Earth’s magnetosphere and induced the largest geomagnetic storm on record. The associated “white light flare” in the solar photosphere was observed and recorded by British astronomers Richard Carrington and Richard Hodgson. The storm caused strong auroral displays and wrought havoc with telegraph systems. The now-standard unique IAU identifier for this flare is SOL1859-09-01.

A solar storm of this magnitude occurring today would cause widespread electrical disruptions, blackouts, and damage due to extended outages of the electrical grid.^[2][3] The solar storm of 2012 was of similar magnitude, but it passed Earth’s orbit without striking the planet, missing by nine days.^[4]

https://en.wikipedia.org/wiki/Carrington_Event?wprov=sfla1