This image of the aurora borealis reminds astrophotographer John Chumack of another cosmic beauty – a barred spiral galaxy. Chumack took the image on a 2016 trip to Alaska, an annual event for him and a group of skywatchers.
"Aurora borealis spiral in Alaska! Sure looks like a barred spiral [galaxy] in the sky," Chumack wrote in an email to Space.com. [The 100 Greatest Night Sky Photos of 2016]
Auroras occur when charged particles from the sun's solar wind interact with Earth's upper atmosphere (at altitudes above 50 miles, or 80 km), causing a glow. The particles are funneled to Earth's polar regions by the planet's magnetic field. The auroras over the North Pole are known as the aurora borealis, or the northern lights. The lights over the South Pole are dubbed the aurora australis, or southern lights.
You can see more amazing night sky photos by our readers in our astrophotography archive here.
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