Astronomy Picture of the Day . A Spiral Aurora over Iceland . ... The aurora resulted from a solar storm, with high energy particles bursting out from the Sun and through a crack in Earth's protective magnetosphere a few days later. ... The liveliness of the Sun -- and the resulting auroras on Earth -- is slowly diminishing as the Sun emerges from a Solar maximum of surface activity and evolves towards a historically more quite period in its 11-year cycle. ... Publications with keywords: aurora . ...