On May 23, 1967, a powerful solar flare could have caused World War III. At the time, the U.S. Air Force considered jamming communication equipment to be an act of war. That day, radar equipment at three early warning stations high in the northern hemisphere was disrupted. Air Force commanders, thinking Russia was behind the jamming, prepared aircraft loaded with nuclear weapons for launch. But it wasn’t Russia. A massive solar flare had fired a tremendous blast of radiation on all wavelengths, including radio, that battered military communications. “This is a grave situation,” said Delores Knipp, the lead author of a study about the solar event, in a release. “But here’s where the story turns: things were going horribly wrong, and then something goes commendably right.” Space forecasters from the military’s Solar Forecasting Center saw the solar flare and sent word that the sun was behind the jamming. The provocative launch was canceled while the planes were on the ground. A huge Coronal Mass Ejection (CME), a cannonball of charged particles that followed the solar flare, created a geomagnetic storm that kept radio communication in the northern hemisphere scrambled for almost a week afterward. Skywatchers in states as far south as New Mexico saw Northern Lights, which are usually visible only near the Arctic Circle. According to the study, the same flare today could disrupt U.S. Global Positioning System (GPS) communication, though perhaps not significantly. Unless you’re lost, who cares about GPS? Cell phone providers and 911 control centers, for a start. Cell phones communicate with towers nearest their GPS coordinates. Emergency calls get routed to a public safety facility based on the GPS coordinates of the caller. Let’s say a solar flare caused GPS coverage to collapse. “Loss of GPS timing signals of greater than two hours may force some cellular and public safety radio base stations into ‘island mode’ … unable to hand off calls to another base station,” said a study about space weather impacts on emergency management. “Users near the edge of coverage areas may experience interference from adjacent base stations or loss of service.” [caption id="attachment_21774" align="alignright" width="300"] NASA image of the geomagnetic storm that took out power in Quebec, Canada back in 1989.[/caption] Space weather also causes electromagnetic spikes that can overload utilities. A 1989 geomagnetic storm took only 90 seconds to collapse a northeastern Canada power grid. Millions of people lost power for up to nine hours. The storm also caused minor damage throughout the U.S. Nine hours is plenty of time for refrigerated food to spoil, cell phones to go dead, and transportation to stall. And that’s a best-case scenario. Some researchers suggest power outages could go on for months if power spikes destroy utilities’ transformers. A burned-out, multi-ton transformer might take up to two years to be rebuilt. Think about everything that would go down in a solar storm-caused blackout. Water and wastewater distribution systems would collapse because they’re electricity-powered. We couldn’t use the computers that we rely on for communication, transportation, finance, and health care. Solar storm-caused blackouts could cost the U.S. economy tens of billions of dollars per day, according to a study in January’s Space Weather journal. Half the loss would come from areas outside the blackout as transportation and manufacturing hubs halt. The worst-case scenario indicated the entire daily U.S. Gross Domestic Product (GDP) could be lost. A couple pieces of good news. First, a 2013 report by insurer Lloyd’s said that the likelihood of an extremely powerful solar storm is “relatively low at any given time,” though it added “it is almost inevitable that one will occur eventually.” In other good news, Ready.gov has tips for space weather before, during, and after. Before Make an emergency kit and a family communication plan with contact information. Keep your gas tank at least half full. Electricity powers gas station pumps. If you’ve got a powered garage door, know how to open it manually and keep a house key handy. Talk to a pharmacist about medication that requires refrigeration to see how long it can last in an unpowered, closed refrigerator. Get a solar-powered or hand-cranked charger for electronic devices like phones and laptops. If you have a traditional phone landline, consider keeping it active, because it will work in a power outage. Frequently back up digital data. During Listen for emergency alerts to learn when a solar storm is coming and what to do. When directed, conserve power to help power companies avoid rolling blackouts. Disconnect appliances if local officials direct to do so. Don’t use the telephone unless absolutely necessary to keep lines open for emergency responders. After Discard refrigerated food that has been kept at 40 degrees for more than two hours. If frozen food is colder than 40 degrees and still has ice crystals on it, you can refreeze it. For the most part, space weather is just fun. Auroras are amazing. Spaceweather.com sends email alerts about solar events from mild to major, so consider subscribing.