Solar bursts could threaten Global Positioning System

The Global Positioning System, relied on for everything from navigating cars and airplanes to transferring money between banks, may be threatened by powerful solar flares, a panel of scientists warned recently "Our increasingly technologically dependent society is becoming increasingly vulnerable to space weather," David L. Johnson, director of the National Weather Service, said at a briefing. GPS receivers have become widely used in recent years, for satellite signals that navigate airplanes, ships, and automobiles and for cellphones, mining, surveying, and many other commercial uses. Indeed, banks use the system to synchronize money transfers, "so space weather can affect all of us, right down to our wallet," said Anthea J. Coster, an atmospheric scientist at the Haystack Observatory of the Massachusetts Institute of Technology. The cause for their concern, Johnson said, was an unexpected solar radio burst on Dec. 6 that affected virtually every GPS receiver on the lighted half of earth. Some receivers had a reduction in accuracy while others completely lost the ability to determine position, he said.