In March 1989, six million Quebecers lost power for nine hours after a massive solar flare—an explosion of magnetic energy from the sun—created electric ground currents here on Earth, collapsing the power grid. Another geomagnetic storm, in 1921, brought ground currents 10 times as strong. But the fiercest one ever recorded, called the Carrington Event of 1859, electrified telegraph lines—even setting telegraph papers on fire—and created northern lights visible as far south as Cuba and Hawaii. If such a storm were to strike today, the consequences would be devastating. But NASA researchers say severe space weather could be on the way.
Every 11 years, for reasons that aren’t completely understood, our sun hits what’s called its solar maximum: an especially active period when sun spots, solar flares and “coronal mass ejections—these clouds of plasma that flow out of the sun at millions of kilometres an hour,” as astronomer Sten Odenwald puts it, are more likely to occur. The resulting streams of particles and pulses of electromagnetic energy create what’s called space weather, which can have all sorts of impacts here, throwing the Earth’s magnetic field into disarray and disrupting everything from GPS systems to the power grid. We’re now coming out of a quiet period for the sun, as it wakes up and moves toward the next solar maximum, expected in 2013, and experts say we should be preparing for the worst.
If the 1921 storm were to repeat itself today, massive blackouts would affect more than 130 million people, according to a 2009 NASA report on space weather, and over 350 transformers would risk permanent damage. Water distribution would be “affected within several hours; perishable foods and medications lost in 12-24 hours; loss of heating/air conditioning, sewage disposal, phone service, fuel re-supply and so on.” The social and economic impact might last for years. A repeat of the Carrington Event (thought to be at least 50 per cent stronger than the 1921 superstorm) could cripple banking systems, air travel and satellites; in the first year alone, the report warns, it could cost $2 trillion, 20 times more than hurricane Katrina.
Whether we’ll actually get such a superstorm is hard to predict, since the science doesn’t yet exist to accurately forecast it, says Richard Fisher, head of NASA’s heliophysics division. However, in the report, researchers noted that the electronic power grid, “modern society’s cornerstone technology,” is especially vulnerable to solar activity. Coronal mass ejections temporarily compress the Earth’s magnetic field, “stretching it out on the midnight side, opposite the sun,” Odenwald says, generating currents in the ground powerful enough to melt copper windings in transformers. At the solar maximum, he adds, there might be 10 coronal mass ejections in a week.
While we’d be more affected by a solar storm than ever before, we’re slowly becoming better prepared for it, too. “To a degree, we can see [storms] coming,” Fisher says, thanks to remote sensing in space. NASA recently launched the Solar Dynamics Observatory (SDO), which shows material streaming off the sun in previously impossible detail. Another device, called ACE, is “like a wind sock for solar wind,” Fisher says, and can give some advance warning of impending storms. That way, power grid operators can reserve capacity to counteract their effects, a lesson learned after the Quebec disaster; operators can switch satellites off-line, reroute flights, or warn people to put off “hunt[ing] an oil pipeline on the bottom of the ocean by GPS navigation,” Fisher says. Whether there’s a superstorm coming from space or not, it’s best to be prepared.