A solar wind stream hit Earth's magnetic field during the late hours of June 7th, sparking a
G2-class geomagnetic storm. In the United States, surprised sky watchers from Maine to Washington witnessed a rare display of summer auroras. Outside of Rochester, Minnesota, photographer Marcella Chester recorded the green glow alongside a June thunderstorm:
"I've never seen auroras and lightning visible side by side before," marvels Chester. "These photos were taken between 2 and 3 am on Monday, June 8th."
At about the same time in Hartford, Wisconsin, Jake Stehli witnessed
a similar display. "The auroras were visible to the naked eye with lightning in a thunderhead on the horizon as well," he says.
© Jake Stehli
Researchers have long known that geomagnetic storms happen most often in spring and fall. In other words,
auroras prefer equinoxes. That's why seeing them so close to the summer solstice is remarkable.
The show is subsiding, but might not be finished. NOAA forecasters estimate a 45% chance of polar geomagnetic storms on June 10th as the solar wind continues to blow.
Comment: June sure has been an active month for 'signs' in the skies:
Sun halo appears during beatification mass in El Salvador
Rare 'smile in the sky' rainbow spotted over Welsh border
England night sky lit up by rare noctilucent clouds above Newcastle, Country Durham and Northumberland
Sun halo captured in Maine skies
US: Rare auroras and lightning visible side by side