National Geographic : 2012 Jun
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 dol- lars in the rst year alone and taking a decade to recover from. "We cannot predict what the sun will do more than a few days ahead of time," laments Karel Schrijver of Lockheed Martin's Solar and Astro- physics Laboratory in Palo Alto, California. With a period of maximum solar activity expected to begin this year, space-weather centers are add- ing sta and hoping for the best. "We're trying to understand how space weather percolates into society and just how bad it can get," says Schrijver. " e morally right thing to do once you've identified a threat of this magnitude is to be prepared. It's like earthquakes in San Francisco. Not preparing for it has intolerable consequences." FEW OBJECTS SEEM as familiar as the sun---there it is, up in the sky every sunny day---yet few are so strange. Look through a solar telescope, and the quotidian yellow disk is transformed into a dynamic wonderland, where planet-size prominences rise into black space like glowing jelly sh, only to loop and slither back hours or days later, as if enthralled by some unseen force. SEPTEMBER 1, 1859 Astronomer Richard Carrington was drawing sunspots--- regions of intense magnetic activity on the sun's surface---when two brilliant bursts of light (A and B, above) suddenly appeared within one large group. Hours later Earth was hit by the most powerful geomagnetic storm on record. Timothy Ferris has been covering the universe for more than 40 years. He last wrote for the magazine on the Magellanic Clouds, in December 2011. ROYAL ASTRONOMICAL SOCIETY/PHOTO RESEARCHERS, INC.