ANCHORAGE - A solar flare erupting from an enormous sunspot hit Earth last week with the second-biggest geomagnetic storm ever measured, said scientists at the Geophysical Institute at the University of Alaska Fairbanks.
It produced fabulous red and green auroras seen throughout the Northern Hemisphere, especially in Europe.
"The material that was ejected from that (sunspot) just happened to come at the Earth in a way that caused the most possible disruption," said research professor Dirk Lummerzheim. "You could say we were extremely lucky, or extremely unlucky, depending in your point of view."
A much larger storm in 1989 triggered a power outage in Quebec, and a storm last month damaged two Japanese satellites. Lummerzheim said there were no reports of damage during Thursday's event.
The charged particles streaming from the sun originated in the same sunspot that produced a huge flare and triggered auroras in October, Lummerzheim said.
The spot passed from view for a few weeks during the sun's 27-day rotation and re-emerged somewhat smaller. Another flare has erupted from the same spot and sent more particles toward Earth.
The institute had forecast maximum auroras for all of Alaska on Saturday. Even clouds, Alaskans should not despair of missing the display, Lummerzheim said. A friend out feeding his dogs reported that the clouds seemed brighter on Thursday night.