D. Kalmančok, M. Šebeň [CC BY-SA 3.0 (https://creativecommons.org/licenses/by-sa/3.0) or GFDL (http://www.gnu.org/copyleft/fdl.html)], via Wikimedia Commons
https://commons.wikimedia.org/wiki/Category:Aurora_Borealis#/media/File:AGOModra_aurora.jpg