On September of 1770, the skies above China turned blood red, and for over a week each night these glowing red auroras lingered. This mysterious event was lost to history for nearly three centuries before scientists began to research the cause behind this phenomenon.
Researchers have been poring through palace diaries and other historical documents from East Asia and have proposed a likely cause: A giant magnetic storm that rivaled the most powerful one on record, the so-called Carrington Event of 1859.
Geomagnetic storms occur when solar eruptions hit Earth's magnetosphere, the shell of electrically charged particles trapped by Earth's magnetic field.
When looking around we see how dependent on electricity the world has become since this Carrington Event, if as powerful geomagnetic storm would hit us now the damage it causes would be significant.
A 2013 study from Lloyd's of London estimated a $2.6 trillion cost for North America if a Carrington-level storm happened now, and predicted "a Carrington-level, extreme geomagnetic storm is almost inevitable in the future
For instance, in 1989, a geomagnetic storm hit and blacked out Quebec in just 90 seconds and left 6 million customers in the dark for 9 hours, damaging transformers as far away as New Jersey, and nearly taking down U.S. power grids from the Eastern Seaboard to the Pacific Northwest. And when considering that the Quebec event may have packed just one-tenth the power of the Carrington Event it is not hard to think what ten times more powerful magnetic storm would do.
More information about this case can be found from the original article on the Livescience's page below:
https://www.livescience.com/61120-massive-geomagnetic-storm-discovered-from-1770.html