A solar "perfect storm" nearly hit the Earth in 2012, missing our planet by just nine days.
On the 18th of July that year, the Sun released the first of three large solar flares. Four days later, a pair of coronal mass ejections (CME's) erupted just ten minutes apart from each other. The third flare left the Sun at the highest speed ever recorded by the Solar Terrestrial Relations Observatory (STEREO) for this type of event - more than 1,800 miles a second. Astronomers believe the first two flares created an "expressway," allowing the last two flares to gain speed, as they raced away from the Sun.
A new report from researchers at the University of California Berkeley states that if the CME's happened on July 13, the mass of solar energy could have collided with our home world.
If the solar storm had hit the Earth, it would have traveled completely around the Earth in a minute, wiping out electronics aboard satellites and on the ground. Even the electrical grid, supplying energy to homes and businesses worldwide, could have been blacked out. Costs to repair the damage could have exceeded two trillion dollars, according to some estimates. It may have taken four to ten years for communications and electronic systems to recover from the disaster.
A similar solar storm struck the Earth in 1859. That storm became known as the Carrington Event. It wiped out telegraph communication throughout the United States, and caused northern lights so dramatic, they were in Cuba and Hawaii.
The new analysis of the storm reveals how solar storms can make it easier for successive storms to travel, increasing their velocity. They found the earlier ejections cleared particles away from the area where they erupted, and straightened magnetic fields, making travel easier for the later flares.
"A key finding is that it's not just the initial conditions on the sun that can produce an extreme space weather storm," said Gurman. "The interactions between successive coronal mass ejections farther out in interplanetary space need to be considered as well," said Joe Gurman, project scientist for STEREO at NASA's Goddard Space Flight Center.
In addition to the pair of spacecraft that make up the STEREO observatory, the event was also witnessed by the Solar and Heliospheric Observatory (SOHO). A video of the third eruption is available on YouTube.
Coronal mass ejections rise from the Sun with energies equal to a billion hydrogen bombs exploding at once. Astronomers are referring to these three storms traveling together as a "perfect storm," after the historic Atlantic tempest in 1991.
Study of the solar "perfect storm" that nearly devastated communications on Earth was detailed in the journal Nature Communications.
