Earth had close brush with solar storm

BOULDER, Colo., Dec. 8 (UPI) -- A violent solar storm last October came closer than normal to causing earthbound disruptions, University of Colorado researchers said Monday.

Based on results obtained by NASA's SAMPEX satellite, the Halloween solar storm, as it was called, pushed Earth's protective Van Allen radiation belt inward, to the point where it came within 6,000 miles of the planet's surface, said Daniel Baker, director of the university's Laboratory for Atmospheric and Space Physics.

"We have been observing the Van Allen belts for over 11 years with the SAMPEX spacecraft," said Baker. "We have never seen such a powerful enhancement and distortion of the radiation belts."

He noted the center of the outer Van Allen belt is usually about 12,000 miles to 16,000 miles away from Earth's surface.

The charged particles within the Van Allen belts can threaten commercial and other satellites in near-Earth orbits, and some satellite failures and operational problems did occur during and following the Halloween storm, Baker said.