On July 23, 2012, the sun unleashed two massive clouds of plasma that barely missed a catastrophic encounter with the Earth’s atmosphere. These plasma clouds, known as coronal mass ejections (CMEs), comprised a solar storm thought to be the most powerful in at least 150 years.
Fortunately, the blast site of the CMEs was not directed at Earth. Had this event occurred a week earlier when the point of eruption was Earth-facing, a potentially disastrous outcome would have unfolded.
Analysts believe that a direct hit … could cause widespread power blackouts, disabling everything that plugs into a wall socket. Most people wouldn’t even be able to flush their toilet because urban water supplies largely rely on electric pumps.
“In my view the July 2012 storm was in all respects at least as strong as the 1859 Carrington event,” Baker tells NASA. “The only difference is, it missed.”
During the Carrington event, the northern lights were seen as far south as Cuba and Hawaii according to historical accounts. The solar eruption “caused global telegraph lines to spark, setting fire to some telegraph offices,” NASA notes. The infamous solar storm of 1921 caused “the entire signal and switching system of the New York Central Railroad below 125th Street to be put out of operation, followed by a fire in the control tower at 57th Street and Park Avenue.” global manufacturing capacity for high voltage transformers is estimated to be only about 70 units per year. A repeat of the 1921 space weather event might damage at least several hundred such units worldwide, with replacement of so many transformers taking a year or more
Though it’s impossible for scientists to predict exactly when or where the next solar storm happen, what they do know is that with more sunspots come more stoms. And the fall of 2013 is when the Sun is set to reach the crest of its 11-year sunspot cycle.
via How a solar storm two years ago nearly caused a catastrophe on Earth.