Solar StormThe most powerful solar storm to wash over Earth's magnetic field since fall 2013 slammed into us on Tuesday, producing auroras that lit up night skies around the world. These northern lights painted the heavens over Donnelly Creek, Alaska, a neon green.

Photograph by Sebastian Saarloos

Week's Best Space Pictures: Solar Storm and a Cosmic Iris

Auroras paint the night sky green for St. Patrick's Day and a thermonuclear explosion flings debris away from a star in this week's best space pictures.

March 20, 2015

The most powerful solar storm to wash over Earth's magnetic field since fall 2013 slammed into us on Tuesday, producing auroras that lit up night skies around the world. These northern lights painted the heavens over Donnelly Creek, Alaska, a neon green.