This is an 8-frame panorama of the aurora from last month in Alaska.  Why simmering fires?  The Mandan tribe of North Dakota thought the northern lights were fires over which great medicine men of northern nations simmered their dead enemies in pots.  The Makah Indians of Washington State, on the other hand, believed the lights were fires over which a tribe of dwarfs were boiling whale blubber.  Not sure which one of them is correct, but clearly a simmering fire of some sort is involved in creating these lights.