Thought in the Middle Ages to be reflections of heavenly warriors, and often accompanied by cracking sounds, no one knows exactly why they form in the various patterns that they do, including diffuse, pulsating, curtains, and arcs.
Thought in the Middle Ages to be reflections of heavenly warriors, and often accompanied by cracking sounds, no one knows exactly why they form in the various patterns that they do, including diffuse, pulsating, curtains, and arcs. Of course, the immediate cause is known: excitation of oxygen atoms caused by the solar wind. It's not surprising, then, that their activity correlates strongly with sunspot activity. For ten points, what is the scientific name for these "northern lights"?
Thought in the Middle Ages to be reflections of heavenly warriors, and often accompanied by cracking sounds, no one knows exactly why they form in the various patterns that they do, including diffuse, pulsating, curtains, and arcs.
{AURORA BOREALIS} (prompt on "northern lights")