The northern lights are in stunning display over a frozen lake in northern Sweden in this skywatching photo.
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 northern lights. The lights over the South Pole are dubbed the aurora australis, or southern lights.
In the image, the aurora seems to burst from the sky in a flash of red and green appearing near the zenith (directly overhead). When the aurora is most active, it creates a beautiful display of bright colors called the aurora corona.
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