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Northern lights glow over trees in Xilingol League in northern China's Inner Mongolia region early Sunday, May 12.
Joshua Mellin
Aurora borealis shines above the Chicago skyline on Saturday, May 11.
Alastair Johnstone/Story Picture/Shutterstock
A person watches the northern lights from atop a rock formation near Sheffield, England, on May 11.
Andrew Chin/Getty Images
Aurora borealis is reflected in water at Manning Park in British Columbia, on May 11.
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People look at the aurora australis on the outskirts of Christchurch, New Zealand, on May 11.
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In this long exposure photo, the blinking lights of a plane streak through the aurora borealis over Lake Berryessa, California, on May 11.
Josh Walet/EPA-EFE/Shutterstock
The northern lights shine in the night sky above the Molenviergang in Aarlanderveen, the Netherlands, early May 11.
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The northern lights illuminate the sky in Debrad, Slovakia, on May 11.
Jean-Christophe Bott/Keystone/AP
The aurora borealis glows in the night sky over the mountains in Le Col des Mosses pass, Ormont-Dessous, Switzerland, during the early hours of May 11.
Alexey Malgavko/Reuters
The aurora borealis illuminates the skies over the southwestern Siberian town of Tara, in Russia's Omsk region, on May 11.
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The aurora borealis glows over Vienna on May 11.
Courtesy Luke Culver
The northern lights are seen in a rural area west of Fort Lauderdale, Florida, on Friday, May 10.
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People photograph the northern lights from Whitley Bay, England, on May 10.
Robert F. Bukaty/AP
The northern lights flare in the sky over a farmhouse in Brunswick, Maine, on May 10.
Cristobal Saavedra Escobar/Reuters
Aurora australis, or the southern lights, glow over Villarrica volcano in Pucón, Chile, on May 10.
Geoff Robins/AFP/Getty Images
People stop along a country road near London, Ontario, to view the aurora borealis on May 10. Auroras are often observed in Canada's northern regions, but rarely in southern Ontario.
CNN
The aurora borealis lights are seen over western Tennessee out the window of a flight from Washington, DC, to Memphis, Tennessee, on May 10.
Courtesy Jan Reed
The northern lights are seen in the sky over Rich Hill, Missouri, on May 10.
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The northern lights glow in the night sky in Brandenburg, Germany, on May 10.
Jenny Kane/AP
In this long exposure photo, cars pass by as people look at the night sky towards the northern lights in Estacada, Oregon, on May 10.
CNN
The northern lights seen over Cumming, Georgia, on May 10.
Adam Vaughan/EPA-EFE/Shutterstock
People pose for a photograph with the aurora borealis in Crosby, England, on May 10.
Courtesy Jacob Anderson
The aurora borealis glows over Edinburgh, Scotland, on May 10.
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The aurora borealis is seen at Crosby Beach in Liverpool, England, on May 10.