For the second night in a row, Chicagoans gathered along the city’s lakefront to see an array of colors light up the night sky.
The northern lights, or aurora borealis, were visible in intervals throughout Saturday night and into Sunday morning in Illinois. The lights were visible because of a strong geomagnetic storm, according to the National Oceanic and Atmospheric Space Weather Prediction Center.
Kevin Doom, a meteorologist at the National Weather Service, said coronal mass ejections, a large expulsion of plasma and magnetic field from the sun’s corona, allowed the lights to be visible this weekend.
“They ejected from the sun and are hurtling toward Earth,” Doom said. “They come in sequences. The past few nights we’ve had very strong solar activity, and that’s what brought this really vibrant, widespread aurora across the globe.”
The northern lights are caused when those particles interact with Earth’s magnetic field.
Saturday’s northern lights were weaker in Chicago than Friday night’s display, according to Doom.
“They weren’t expected to be as vibrant or to extend as far south, and I think that’s what we saw,” Doom said. “A lot of areas that saw the Northern lights on Friday night it was more difficult to see them Saturday, including here in Chicagoland.”
The lights could be seen as far south as Alabama Saturday evening, with the best viewing across the Ohio River Valley. Experts said the further north, the better the view, although it’s most important to get away from light pollution.
Doom said that people in the Chicago area should not expect to be able to see the Northern Lights again during this geomagnetic storm.
“The northern lights won’t be visible from most of the Midwest tonight,” Doom said. “Maybe in the far northern Midwest, up by the Great Lakes, but in Chicagoland, we’re done.”