EMERALD DYNAMITE: On Oct. 18th, Earth passed through multiple folds in the heliospheric current sheet--a phenomenon known as "solar sector boundary crossings." This sparked a veritable explosion of bright auroras around the Arctic Circle. Ole Salomonsen of Tromso, Norway, captured the outburst in this photo, which he calls Emerald Dynamite:
"This is one of many spectacular auroral DISPLAYS I captured tonight," says Salomonsen. "There were red auroras, green auroras, coronas, fast moving purple bands... It was the most amazing display I have witnessed in a long time."