Auroras tint the clouds green in a picture of the night sky over Breivikeidet, Norway, taken September 9. The northern lights display was most likely a product of charged particles hurled off the sun a few days earlier. On September 6 sunspot 1283 produced two major eruptions, including an X2-class solar flare. Such flares are often associated with coronal mass ejections, huge clouds of particles that—when they careen toward Earth—can spark aurora-inducing geomagnetic storms. Photograph by Thilo Bubek, via National Geographic
Pop-upView Separately

Auroras tint the clouds green in a picture of the night sky over Breivikeidet, Norway, taken September 9. The northern lights display was most likely a product of charged particles hurled off the sun a few days earlier.

On September 6 sunspot 1283 produced two major eruptions, including an X2-class solar flare. Such flares are often associated with coronal mass ejections, huge clouds of particles that—when they careen toward Earth—can spark aurora-inducing geomagnetic storms.

Photograph by Thilo Bubek, via National Geographic