

The geomagnetic storm was triggered by a huge solar flare that erupted on Jan. 22.
A subsequent surge of charged particles rushed toward Earth at 1,400 miles per second, threatening to disrupt satellite communications and knock out power.
Solar physicists say the planet was dealt only a “glancing blow” by the particles.
But it was enough to ignite the upper atmosphere into vivid and colorful ribbons of the aurora borealis and australis around the polar regions.
As a precaution to protect passengers and crew, Delta Air Lines diverted some flights between Detroit and Asia to avoid possible disruptions to aircraft communications and exposure to unusually high radiation levels aloft.
United Airlines said it diverted one flight for the same reasons.
In 1972, a much stronger geomagnetic storm knocked out long-distance telephone communication across the US state of Illinois.
An even more powerful event in 1859 caused parts of the then-fledgling telegraphic network to spark, and even function once batteries were removed.
Photo: Børge Wahl Flickr
