Aug. 26, 2018: Last night, a crack opened in Earth’s magnetic field. Solar wind poured in to fuel a strong G3-class geomagnetic storm. John McKinnon photographed the storm’s brilliant green glow from Four Mile Lake in Alberta, Canada:
“At 2 o’clock in the morning, the auroras were so bright I could see them through the glare of the full Moon,” he says.
At the peak of the storm, Northern Lights spilled across the Canadian border into US states such as Michigan, New York, Montana, Wisconsin, and Indiana. People in Alaska witnessed a fine display as well. At the same time, Southern Lights were photographed from several locations in New Zealand.
Forecasters did not see this coming. The stage was set for the storm when a minor CME arrived with little fanfare about 24 hours ago. First contact with the CME barely registered in solar wind data, and Earth’s magnetic field was unperturbed. The action began only after Earth entered the CME’s wake, where strong south-pointing magnetic fields opened a crack in our planet’s magnetosphere. A surprise geomagnetic storm ensued.