Washington: Earth had a near miss with a solar flare from the most powerful storm on the Sun in over 150 years that could have caused widespread power blackouts, scientists say.
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.
"If it had hit, we would still be picking up the pieces," physicist Daniel Baker of the University of Colorado said.
Baker, along with colleagues from NASA and other universities, has published a study in the journal Space Weather.
Their research describes how a powerful coronal mass ejection (CME) tore through Earth`s orbit. Fortunately Earth wasn`t there. Instead, the storm cloud hit the STEREO-A spacecraft.
"I have come away from our recent studies more convinced than ever that Earth and its inhabitants were incredibly fortunate that the 2012 eruption happened when it did," said Baker.
"If the eruption had occurred only one week earlier, Earth would have been in the line of fire," Baker said.
Extreme solar storms pose a threat to all forms of high-technology. They begin with an explosion - a "solar flare" - in the magnetic canopy of a sunspot.
X-rays and extreme UV radiation reach Earth at light speed, ionising the upper layers of our atmosphere; side-effects of this "solar EMP" include radio blackouts and GPS navigation errors.
Minutes to hours later, the energetic particles arrive. Moving only slightly slower than light itself, electrons and protons accelerated by the blast can electrify satellites and damage their electronics.
Analysts believe that a direct hit by an extreme CME such as the one that missed Earth in July 2012 could cause widespread power blackouts, disabling everything that plugs into a wall socket.