A really powerful CME known as the ‘Carrington Event’, after English astronomer Richard C. Carrington, hit in 1859 and was the first one to effect modern technology, knocking out the world telegraph network, which was a kind of ‘internet’ of the time. For several days before it hit, Carrington and other observers were noting unusually intense white light flare activity in the photosphere of the Sun, as well as auroras here on Earth – in Australia the ‘Southern Aurora’ was observed as far north as the state of Queensland[i], while the Northern Lights were reported as far south as Cuba and Honolulu. With the energy of 10 billion atomic bombs, it reached Earth in less than eighteen hours, instead of the several days they normally take. A telegraph manager in the USA reported that “the resulting currents flowing through the wires were so powerful that platinum contacts were in danger of melting and ‘streams of fire’ were pouring forth from the circuits.[ii]”
A solar storm in 2012 was of similar magnitude, but fortunately it passed Earth's orbit without striking the planet. If another one occurred now it could cause extensive social and economic disruptions due to its impact on power grids, satellite communications, GPS systems and airline flights, with a price tag in the trillions of dollars – so ESA’s Solar Orbiter will be a valuable tool of the future.
Credit for Image at top of Page: http://www.ieap.uni-kiel.de/et/solar-orbiter/Images/solar_orbiter_RGB.png
[i] "SOUTHERN AURORA.". The Moreton Bay Courier (Brisbane: National Library of Australia). September 7, 1859. p.2. Retrieved by en.wikipedia.org/wiki/Solar_storm_of_1859