The Auroral Oval

The Auroral Oval

. POLAR looks down on an aurora from high above the Earth's north polar region on 22 October 1999, showing the northern lights in their entirety. The glowing oval, imaged in ultra violet light, is 4.5 million meters across. The most intense aurora activity appears in bright red or yellow. It is typically produced by magnetic reconnection events in Earth's magnetotail, on the night side of the Earth. (Courtesy of the Visible Imaging System, University of Iowa and NASA.)

Copyright 2010, Professor Kenneth R. Lang, Tufts University