A solar superstorm could have ended 'life as we know it' in 2012 if it hadn't narrowly missed Earth.
Experts have revealed that two Coronal Mass Ejections -- in which the Sun throws off huge amounts of plasma and energy in one 'belch' -- occurred on July 23, 2012 at four times the usual speed.
The rare event resulted in a solar storm rushing out from the Sun at speeds exceeding 3,000 kilometres per second.
Had it struck the Earth, it would have resulted in damage to power lines and communications that could have had a catastrophic effect on civilisation. It would have also cancelled the London Olympics.
Daniel Baker of the University of Colorado said at the NOAA's Space Weather Workshop that had the storm hit, "we would still be picking up the pieces".
Everything from food and banking networks to essential services, medicine production and agriculture would have been affected - and would still be struggling to recover.
The reason that this event was particularly troubling is that there were two storms instead of one, and that the region of space through which it travelled had already been 'cleared out' by another CME days earlier.
Baker said that had the CME intercepted Earth's orbit, the impact would have been even greater than the 'Carrington Event' - a massive solar storm that struck the Earth in 1859, and caused 'Northern Lights' phenomena as far south as Cuba.
Luckily back then modern technology was not advanced enough to be badly affected - indeed some telegraph operators reported at the time that their transmissions were moving faster than normal.
These days we are more vulnerable - and governments are starting to plan for the worst. The UK published its outline report on how to deal with space weather and solar storms in 2012, resulting in some changes to design requirements for the National Grid. But there are still massive flaws in the network, and for now we simply have to hope we keep dodging solar bullets.
At the time NASA said that it was glad the storm occurred, because while it missed Earth it happened to intercept its STEREO solar-studying spacecraft.
"Seeing a CME this fast, really is so unusual," said Rebekah Evans at the Goddard Space Weather Lab.
"And now we have this great chance to study this powerful space weather, to better understand what causes these great explosions, and to improve our models to incorporate what happens during events as rare as these."