Biggest solar storm in years races toward Earth

The largest solar storm in five years was due to arrive on Earth early Thursday, promising to shake the globe's magnetic field while expanding the Northern Lights.       

The storm started with a massive solar flare earlier in the week and grew as it raced outward from the sun, expanding like a giant soap bubble, scientists said. When it strikes, the particles will be moving at 4 million mph (6.4 million kph).       

"It's hitting us right in the nose," said Joe Kunches, a scientist for the National Oceanic and Atmospheric Administration.       

The massive cloud of charged particles could disrupt utility grids, airline flights, satellite networks and GPS services, especially in northern areas. But the same blast could also paint colorful auroras farther from the poles than normal.       

Astronomers say the sun has been relatively quiet for some time. And this storm, while strong, may seem fiercer because Earth has been lulled by several years of weak solar activity.       

The storm is part of the sun's normal 11-year cycle, which is supposed to reach peak storminess next year. Solar storms do not harm people, but they do disrupt technology. And during the last peak around 2002, experts learned that global positioning systems were vulnerable to solar outbursts.       

Because new technology has flourished since then, scientists could discover that some new systems are also at risk, said Jeffrey Hughes, director of the Center for Integrated Space Weather Modeling at Boston University.       

A decade ago, this type of solar storm happened a couple of times a year, Hughes said.       

"This is a good-size event, but not the extreme type," said Bill Murtagh, program coordinator for the federal government's Space Weather Prediction Center.      

The sun erupted Tuesday evening, and the most noticeable effects should arrive here between 1 a.m. and 5 a.m. EST Thursday (0600GMT and 1000GMT), according to forecasters at the space weather center. The effects could linger through Friday morning.       

Center forecaster Rob Steenburgh said shortly before 5 a.m. EST Thursday (1000 GMT that there still had been no noticeable effects on Earth or on a satellite geared to monitor the storm's impact.  

"We haven't seen the shock arrive at the satellite yet," Steenburgh said. "We're keeping an eye on it."       

The region of the sun that erupted can still send more blasts our way, Kunches said. He said another set of active sunspots is ready to aim at Earth right after this.       

"This is a big sun spot group, particularly nasty," NASA solar physicist David Hathaway said. "Things are really twisted up and mixed up. It keeps flaring."       

Storms like this start with sun spots, Hathaway said.         

AP