Northern Lights creep south

Last Sunday, the dancing lights of the aurora borealis were visible as far south as Oklahoma, the Seattle Times reports.

The light show was caused by an “extreme geomagnetic storm,” said John Sahr, an associate professor of electrical engineering at the University of Washington.

Cosmic weather causing such a storm is not unusual. Solar activity takes place on an 11-year cycle. The most recent cycle peaked last year, bringing unusual magnetic activity with it.

High solar winds can force charged particles from space into the atmosphere. The northern lights appear when these particles oxygen and nitrogen molecules 20 to 200 miles above the planet.

The northern lights are visible in Seattle several times a year, but are usually hidden by clouds.