The sound of aurora borealis

By B.T.

WHAT SOUND does the solar system make? Usually only children, scientists and philosophers ask that sort of question. A whole branch of Renaissance thought speculated about the unheard “music of the spheres” that the planets in their orbits supposedly played; the notion obsessed the great astronomer Johannes Kepler. Now listeners have the chance to hear at least one song from the music of the spheres with mortal ears—helped a little by extreme low-frequency recordings and computer-aided electronic music.

To capture this celestial soundtrack, “Songs of the Sky”, an episode from BBC Radio 3’s “Between the Ears” strand, takes a winter journey through central Alaska. Within a crisply atmospheric soundscape of crunching snow, splitting ice and howling wolves, the programme, produced by Kate Bissell, shows how a wildlife ranger and a hi-tech composer collaborated to create otherworldly music out of the Northern Lights, or aurora borealis. The lights make the Arctic and subarctic skies glow with spectacular colours when charged particles carried from the sun on solar winds interact with gaseous particles in the upper atmosphere at latitudes with a weaker electromagnetic field.