The heliophysics community is buzzing
today in response to
an
article in
Nature Communications, which describes an
intense solar storm that narrowly missed Earth almost two years ago.
On July 23, 2012, a CME rocketed away from the sun at 2000 km/s,
almost four times faster than a typical eruption. The storm tore
through Earth orbit, but fortunately Earth wasn't there. Instead it
hit the STEREO-A spacecraft, which experienced the most intense solar
proton storm since 1976. Researchers have been analyzing the data
ever since, and they have concluded that the storm was akin to the
Carrington
Event of 1859.
"Had it hit Earth, it probably would have been
like the big one in 1859," says Janet Luhmann of UC Berkeley, a
co-author of the paper. "The effect today [on] our modern
technologies would have been tremendous."
The Carrington Event was a series of powerful CMEs
(corneal mass ejections) that hit Earth head-on, sparking Northern
Lights as far south as Tahiti. Intense geomagnetic storms caused
global telegraph lines to spark, setting fire to some telegraph
offices and disabling the 'Victorian Internet." A similar storm
today would have a catastrophic effect on modern power grids and
telecommunication networks. According to
a
study by the National Academy of Sciences, the total economic
impact could exceed
$2 trillion or 20 times greater than the costs of
a Hurricane Katrina. Multi-ton transformers fried by such a storm
could take years to repair.
The paper in Nature Communications describes
what gave the July 2012 storm Carrington-like potency. For one thing,
the CME was actually two CMEs separated by only 10 to 15 minutes.
Plus the CMEs traveled through a region of space that had been
cleared out by another CME four days earlier. As a result, they were
not decelerated as much as usual by their transit through the
interplanetary medium.
The storm clouds crossed Earth's orbit in a place where
Earth itself would be about 1 week later, so it was a relatively
narrow escape. The whole episode highlights the perils of space
weather. Many observers have noted that the current solar cycle is
weak, perhaps the weakest in 100 years. Now we see that even a weak
solar cycle can produce a very strong storm. Earth is not safe from
these kind of events, so it's time to be prepared.
My Thoughts: While we're all busy, looking for a
lost airplane and as we try to come to terms with a sadistic Russian
leader, off in the wings may lurk a real game changer! Massive solar
flares, known as Class X CME's, can easily plunge our little world
instantly into the Dark Ages virtually overnight!
