Aurora borealis. Time-lapse footage of the aurora borealis appearing over Kirkjufell mountain and waterfalls, Iceland, during a geomagnetic storm. Also known as the northern lights, this atmospheric phenomenon is a coloured light display visible in the night sky at high latitudes. It occurs when charged and energetic particles from the Sun (the solar wind) are drawn by Earth's magnetic field to the polar regions. Hundreds of kilometres up, the particles collide with gas molecules and atoms, causing them to emit light. Geomagnetic storms are associated with intense solar activity and result in very bright auroral displays.