Clear skies on Thursday night gave Chicagoans, including the scores gathered at Montrose Point, a good look at the aurora borealis.
The National Oceanic and Atmospheric Administration issued a severe geomagnetic storm watch for Thursday into Friday after an outburst from the sun was detected earlier this week. Such a storm could temporarily disrupt power and radio signals.
The storm also may trigger northern lights as far south in the U.S. as the lower Midwest and Northern California, though exact locations and times are uncertain, according to NOAA. Skygazers are reminded to point their smartphones upward for photos; the devices often can capture auroras that human eyes cannot.
“Weather conditions are going to remain favorable for seeing the aurora [Thursday night],” Lee Carlaw, a meteorologist with the National Weather Service, said.
The aurora borealis might not be as visible Friday, Carlaw said.
“Cloud cover is going to start rolling overhead through the day tomorrow. It’s not going to be opaque or anything but through tomorrow night and into Saturday morning, it may get a little more opaqueness to it which may inhibit any additional viewing for parts of the area.”
The northern lights, which are happening nearly constantly at both polar regions of the planet, are caused when coronal mass ejections of solar material from the sun reach Earth’s magnetic field, causing a geomagnetic storm. The neon lights are produced by collisions between the solar material and atoms and molecules of Earth’s upper atmosphere.
It’s been a good year for seeing auroras even in lower latitudes. That’s because of increased electromagnetic activity as the sun is believed to be approaching the height of its 11-year solar cycle.
Contributing: AP