17. Solar Flares
(l.) Alessandro Cerruti, (r.) Paul Kintner
Paul M. Kintner Jr., Electrical and Computer Engineering, and graduate student Alessandro Cerruti discovered that strong solar flares cause Global Positioning System (GPS) receivers to fail. Solar flares—usually unpredictable—could wreak havoc for operations such as navigating passenger jets, stabilizing floating oil rigs, and locating mobile phone distress calls. The researchers discovered the failure accidentally while operating a GPS receiver at the Arecibo Observatory. They confirmed the effect through data collection from other receivers operated by the Federal Aviation Administration (FAA) and the Brazilian Air Force. The flare they observed consisted of two events about 40 minutes apart, with the first one lasting for 70 seconds and causing a 40 percent signal drop and the second one for 15 minutes and causing a 50 percent drop. During the next solar maximum, flares are expected to be 10 times as intense, last much longer, and cause 90 percent signal drops that will last much longer. Awareness that GPS systems may fail during a solar flare is the best recommendation the researchers can offer.