Featured on PDR in the collection “Firelight Flickering on the Ceiling of the World”: The Aurora Borealis in Art

About fifty miles above sea level, far beyond the outer reaches of the ozone layer, there lies a huge stretch of air called the thermosphere, where temperatures soar to 2000° Centigrade. Particles in this part of the sky are so scarce that, as Lyall Watson writes, “not enough of them strike a body in orbit to transfer such awesome heat,” though there are more than enough to “combine with other charged particles thrown into the edges of our atmosphere by gusts of solar wind” and create the “awesome display of pyrotechnics” we call the Aurora Borealis and Aurora Australis, or the Northern and Southern Lights: