A coronal mass ejection (CME) hit Earth on Oct. 24th at approximately 1800 UT (2:00 pm EDT). The impact strongly compressed Earth’s magnetic field, directly exposing geosynchronous satellites to solar wind plasma, and sparked an intense geomagnetic storm. As night fell over North America, auroras spilled across the Canadian border into the contiguous United States. The display spread all the way down to Arkansas.
Auroras were seen or photographed in more than half of all US states including Alabama, Wisconsin, New Mexico, Tennessee, Missouri, Illinois, Nebraska, Kentucky, North Carolina, Indiana, Oklahoma, Kansas, Iowa, Maryland, New York, Montana, Ohio, Colorado, Pennsylvania, Washington, Virginia, Texas, Arizona, Minnesota, Maine, Michigan, Oregon, Arkansas and California. Many observers, especially in the deep south, commented on the pure red color of the lights they saw. These rare all-red auroras sometimes appear during intense geomagnetic storms. They occur some 300 to 500 km above Earth’s surface and are not yet fully understood.