The Federal Reserve Bank of Atlanta eyed up an extreme but perhaps not unlikely hypothetical scenario this week: What would happen to the U.S. economy if a “massive geomagnetic solar storm” crippled the domestic power grid, potentially for a “long, long time”? The answer: nothing good.

“One could anticipate serious disruption of electronic payments such as [automated clearing house transactions], cards and wire transfers in the affected areas and beyond,” Steven Cordray, a payments risk expert at the Atlanta Fed, wrote in a blog post Monday. That means electronic payment systems in general – including those involving credit and debit cards – would be compromised in the event of a solar storm. No electronic money transfers, no online banking – possibly no “online,” period. READ MORE