Earth dodges a huge magnetic bullet

I’d say electronic engineers have not been terribly worried about a solar event upsetting their designs. But maybe they should be worried.

According to University of California, Berkeley, and Chinese researchers, a rapid succession of coronal mass ejections sent a pulse of magnetized plasma barreling into space and through Earth's orbit on July 23, 2012. Had the eruption come nine days earlier, when the ignition spot was aimed at Earth, it would have potentially wreaked havoc with the electrical grid, disabled satellites and GPS, and disrupted our increasingly electroniclives.

The solar bursts would have enveloped Earth in magnetic fireworks matching the largest magnetic storm ever reported on Earth, the so-called Carrington event of 1859. The dominant mode of communication at that time, the telegraph system, was knocked out across the United States, literally shocking telegraph operators and the Northern Lights lit up the night sky as far south as Hawaii.

In a paper that appeared March 18 in Nature Communications , former UC Berkeley postdoctoral fellow and research physicist Ying D. Liu (now a professor at China's State Key Laboratory of Space Weather), UC Berkeley research physicist Janet G. Luhmann, and their colleagues reported analysis of themagnetic storm, which was detected by NASA's Solar Terrestria lRelations Observatory-Ahead (STEREO A) spacecraft.

A study last year estimated that the cost of a solar storm like the Carrington Event could reach $2.6 trillion worldwide. “An extreme space weather storm is a low-probability, high-consequence event that poses severe threats to critical infrastructures of the modern society,” warned Liu. “The cost, if it hits Earth, could reach trillions of dollars, with a potential recovery time of 4 to 10 years,” he said.

Fast-moving magnetic storm

The researchers concluded that the huge outburst propelled a magnetic cloud through the solar wind at a peak speed of more than 2,000 km/s, four times the typical speed of a magnetic storm. They found that it resulted from at least two nearly simultaneous coronal mass ejections (CMEs), which typically release energies equivalent to that of about a billion hydrogen bombs.

This NASA/STEREO image shows the coronal mass ejection of July 23, 2012.

“These gnarly, twisty ropes of magnetic field from coronal mass ejections come blasting from the sun through the ambient solarsystem, 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,” Luhmann said.

Detecting solar blasts

“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,” Luhmann added. All this activity would have been missed if STEREO A had not been there to record the blast.

From a UC Berkeley story by Robert Sanders