People across the northern United States and parts of Canada witnessed a brilliant atmospheric phenomena on Sunday into Monday morning, as the aurora borealis — known more commonly as the northern lights — appeared in night skies from California to Maine and beyond.

The uncharacteristically large viewing area stretched as far south as North Carolina and Washington, D.C., where aurora borealis sightings are especially rare, and touched a number of other areas in the West, Midwest, Southwest and Great Plains regions. Reports of northern lights sightings emerged alongside stunning images and time lapse videos out of Wyoming and Illinois.  

The National Weather Service branch in Riverton shared multiple photos of colorful light displays over their office in central Wyoming.

“The #NorthernLights are here are our office, although a bit muted by twilight and some clouds on the horizon. We will try to get some pictures as it gets completely dark,” the Riverton office wrote in the first of several tweets shared throughout Sunday night, which showed the sky colored with green and purple hues traditionally associated with the aurora borealis.

Nick Albers, a Twitter user in Illinois, shared a handful of images and a time lapse video of the aurora borealis seen in skies north of Macomb.

“Man tonight took me on an emotional journey…I am speechless!” Albers wrote.

The northern lights shone vibrantly over other parts of Illinois, too. Landon Moeller, another Twitter user, posted a dazzling image of the sky near Apple River, which appeared to show a meteor zooming through the aurora borealis.

“WOW!! INCREDIBLE meteor with smoke trail just fell through the northern lights near Apple River, Illinois!” Moeller tweeted.

People also reported seeing the northern lights in Arkansas, South Dakota, Nevada, Arizona, Oklahoma, Texas, Iowa, Colorado, Utah and Wisconsin. Outside of the U.S., the aurora was reportedly visible in skies over Toronto and in the United Kingdom over Stonehenge. They may be visible again on Monday night, according to EarthSky.

What causes Aurora Borealis?

Sunday’s light show over the northern hemisphere was caused by a “severe” solar storm impacting Earth, Space Weather Watch said. That storm followed a solar flare, or coronal mass ejection, from the Sun on Friday directed toward our planet, according to the Space Weather Predictions Center at the National Oceanic and Atmospheric Administration.  

Although some properties of auroras and what causes them remain mysterious, scientists know that northern lights are triggered by disturbances in the Earth’s magnetosphere involving solar winds. Coronal mass ejections, which are essentially huge bursts of plasma and magnetic field particles from the sun, can cause or contribute to the formation of auroras by changing the speed of solar winds. 

Northern lights are typically seen in very high-latitude places, like Alaska, Iceland and parts of northern Canada. Officials at NOAA’s Space Weather Predictions Center suggested that the aurora borealis will very likely be visible again on Monday night in those places, as well as, potentially, other areas as far south as the U.S.-Canada border.