Good Article on Solar Flares From Nat Geo | Emergency Preparedness | Forums

The space-weather forecast for the next few years: solar storms, with a chance of catastrophic blackouts on Earth. Are we prepared?

By Timothy Ferris

Video courtesy NASA Solar Dynamics Observatory (SDO)

On Thursday, September 1, 1859, a 33-year-old brewer and amateur astronomer named Richard Carrington climbed the stairs to his private observatory near London, opened the dome slit, and as was his habit on a sunny morning, adjusted his telescope to project an 11-inch image of the sun onto a screen. He was tracing sunspots on a piece of paper when, before his eyes, “two patches of intensely bright and white light” suddenly appeared amid one large sunspot group. At the same time the magnetometer needle dangling from a silk thread at London’s Kew Observatory began dancing wildly. Before dawn the next day enormous auroral displays of red, green, and purple illuminated the skies as far south as Hawaii and Panama. Campers in the Rocky Mountains, mistaking the aurora for sunrise, got up and started cooking breakfast.

The flare Carrington had observed heralded a solar superstorm—an enormous electromagnetic outburst that sent billions of tons of charged particles hurtling toward Earth. (Another amateur English astronomer named Richard Hodgson also witnessed the flare.) When the invisible wave collided with the planet’s magnetic field, it caused electrical currents to surge through telegraph lines. The blast knocked out service at several stations, but telegraphers elsewhere found that they could disconnect their batteries and resume operations using the geomagnetic electricity alone. “We are working with the current from the Aurora Borealis alone,” a Boston telegrapher messaged an operator in Portland, Maine. “How do you receive my writing?”

“Much better than with the batteries on,” Portland replied.

Operators of today’s communication systems and power grids would be less sanguine. No solar superstorm as powerful as the 1859 event has occurred since, so it is difficult to calculate what impact a comparable storm might have on today’s more wired world. A hint came with the Quebec blackout of March 13, 1989, when a solar storm roughly a third less powerful than the Carrington event knocked out the power grid serving more than six million customers in less than two minutes’ time. A Carrington-class storm could fry more transformers than the power companies keep stockpiled, leaving millions without light, potable water, sewage treatment, heating, air-conditioning, fuel, telephone service, or perishable food and medications during the months it would take to manufacture and install new transformers. A recent National Academy of Sciences report estimates that such a storm could wreak the economic disruption of 20 Katrina-class hurricanes, costing one to two trillion dollars in the first year alone and taking a decade to recover from.

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