National Geographic’s cover story
Solar storms disrupt the ionosphere—the layer of Earth’s atmosphere where auroras occur, more than 60 miles above the Earth’s surface. The pilots of the nearly 11,000 commercial flights routed over the north polar region each year rely on shortwave radio signals bouncing off the ionosphere to communicate above 80 degrees of latitude, beyond the range of communications satellites orbiting over the Equator. When space weather disrupts the ionosphere and interrupts shortwave communications, pilots are obliged to change course, which can cost $100,000 a flight. A flustered ionosphere deranges GPS signals as well, resulting in positioning errors that can be more than 150 feet. This means that surveyors must pack up and go home, floating oil-drilling rigs have trouble remaining on station, and pilots cannot rely on the increasingly popular GPS-based systems employed for landing at many airfields.
UV light emitted during solar flares can also disturb satellite orbits by heating up the atmosphere, which increases drag. NASA estimates that the International Space Station descends more than a thousand feet a day when the sun is acting up. Solar storms could also affect the electronics on communications satellites, turning them into “zombiesats,” adrift in orbit and dead to the world.
Unlike satellites in space, most power grids have no built-in protection against the onslaught of a powerful geomagnetic storm. Since large transformers are grounded to the Earth, geomagnetic storms can induce currents that could cause them to overheat, catch fire, or explode. The damage could be catastrophic. According to John Kappenman of Storm Analysis Consultants, who studies the impact of space weather on the electrical grid, a solar storm like one that took place in May 1921 would today turn out the lights over half of North America. One on the order of the 1859 event could take out the entire grid, sending hundreds of millions of people back to a preelectric way of life for weeks or perhaps months on end. In Kappenman’s words, we’re “playing Russian roulette with the sun.”
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