green and blue aurora lights

Light beam onto the illuminated sky. Two long exposure pictures stitched into one due to lens sharpness. Unless if you do a really long bulb exposure at f16 (lens does not go more and you would get startrails after 25'') its almost impossible to sharpen at 2.8 ice in the foreground and infinity of the sky in the background ;) ...to cheat a bit i illuminated the ice from the floor for a fraction of second