Aurora Borealis Is Not Related to Sunspots, Satellites Show

New satellite findings contradict the long-held idea that the aurora borealis (northern lights) is caused by sunspots. That belief originated because the so-called great auroras, which are visible in the mid-latitudes, usually occur after a period of high sunspot activity.

But researchers from the Applied Physics Laboratory at Johns Hopkins University report in today’s Nature that, contrary to expectations, the number of intense auroras occurring at night is independent of the sunspot cycle, and during sunlight there are actually fewer auroras in periods of sunspot activity. They conclude that auroras represent a discharge phenomenon similar to lightning.

Compiled by Times medical writer Thomas H. Maugh II