#1Mar 8th, 2012
A strong geomagnetic storm is racing from the Sun toward Earth, and its arrival on Thursday could affect power grids, airplane routes and space-based satellite navigation systems, U.S. space weather experts said.
The storm, a big cloud of charged particles flung from the Sun at about 4.5 million miles per hour (7.2 million km per hour), was spawned by a pair of solar flares, scientists said.
This is probably the strongest such event in nearly six years, and is likely more intense than a similar storm in late January, said Joseph Kunches, a space weather specialist at the U.S. National Oceanic and Atmospheric Administration (external - login to view) (NOAA).
IN PICTURES: Solar flares and Northern Lights (external - login to view)
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Such stormy space weather is unusual in recent history, according to Harlan Spence, an astrophysicist at the University of New Hampshire (external - login to view) who is principal investigator on the Cosmic Ray Telescope for the Effects of Radiation (CRaTER) aboard NASA (external - login to view)'s Lunar Reconnaissance Orbiter (external - login to view).
"These relatively large (solar) events, which we've had maybe a couple of handfuls total in the course of a decade, we've now