Back on July 23, 2012 a furious solar magnetic storm just grazed our planet. Had it erupted just nine days earlier, it would have hit us, causing extensive damage to our technological infrastructure. It would have been a geomagnetic catastrophe the likes of which we've never seen. Scientists say the close shave should serve as an important wake-up call.
We actually have a precedent for such an event, but it happened back in the mid 19th Century. It was called the Carrington Event of 1859, and it damaged the few electronic devices that existed at the time, namely telegraph systems. The solar blast managed to shock some telegraph operators and set fire to their offices. It even caused the Northern Lights to shine so bright and so far south that people could read newspapers by its red and green glow as far as Mexico.
More recently, a severe magnetic storm in 1989 wreaked havoc on Canada's Hydro-Quebec power grid, resulting in a power-out that kept six-million people without electricity for nine hours.
Back To The Dark Ages
Several years ago, the National Academy of Sciences estimated that, if a Carrington-like event occurred today, it could cause $1- to $2-trillion in damages to our civilization's high-tech infrastructure and require four to ten years for complete recovery. Last year, Lloyds put out a study showing that geomagnetic storms could cause upwards of $2.6 trillion in damages across the globe.
And what a headache it would be. An event like this would damage everything from satellites, emergency services' systems, hospital equipment, banking systems, and air traffic control devices, through to everyday items such as home computers, iPods and GPSs. Because of our heavy reliance on electronic devices, which are sensitive to magnetic energy, the storm could leave a multi-billion dollar damage bill and cataclysmic-scale problems for governments.
Worse than this, however, would be the potential length of blackouts. According to a Metatech Corporation study, an event like the 1921 geomagnetic storm would result in large-scale blackouts affecting more than 130 million people and would expose more than 350 transformers to the risk of permanent damage. It could take months—if not years—to put everybody back on the grid.
And as a new analysis from UC Berkeley's Ying D. Liu and Janet Luhmann show, it almost happened two years ago.
A Perfect Solar Storm
Using data detected by NASA's STEREO A spacecraft, the researchers concluded that a huge outburst on the sun on July 22, 2012 propelled a magnetic cloud through the solar wind at a speed of more than 2,000 kilometers per second — nearly four times the typical speed of a magnetic storm. It violated our orbit, but Earth and all the other planets were on the other side of the sun at the time.
When the storm hit STEREO A it was about 120 degrees ahead of the Earth (west of the Earth). Had it occurred nine days earlier — one third of the rotation period of the Sun (which takes 27 days to complete one rotation) — it would have propagated directly towards the Earth.
Here's what it looked like from STEREO's perspective:
The outburst was generated by two nearly simultaneous coronal mass ejections (separated by about 10 to 15 minutes), releasing energies equal to about a billion hydrogen bombs. But that alone wasn't enough to create the intensity observed. According to the analysis, the incredible speed of the magnetic cloud was possible because of another mass ejection four days earlier which had cleared the path of material that would have slowed it down.
The storm also produced a long-duration, southward-oriented magnetic field, which made it all the more dangerous. This is a nasty orientation owing to Earth's northward field. This causes a process called reconnection, resulting in a violent merger.
"These gnarly, twisty ropes of magnetic field from coronal mass ejections come blasting from the sun through the ambient solar system, piling up material in front of them, and when this double whammy hits Earth, it skews the Earth's magnetic field to odd directions, dumping energy all around the planet," explained Luhmann in a statement.
Predicting the Weather
According to the researchers, this event is not as rare as it might seem. It could have easily been missed if STEREO A (the spacecraft ahead of us in Earth's orbit) had not been there to record it.
"People keep saying that these are rare natural hazards, but they are happening in the solar system even though we don't always see them," noted Luhmann. "It's like with earthquakes — it is hard to impress upon people the importance of preparing unless you suffer a magnitude 9 earthquake."
Indeed, preparation is possible. Further study of solar superstorms and the sun's 11 year cycle should help our predictive abilities. But we also need to create more robust technologies to protect ourselves for this eventuality. NASA, for example, has proposed a solar shield to protect power grids from geomagnetic storms. We certainly need to start thinking along these lines to prevent a world-changing catastrophe.
Source: io9
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