The shapes of the aurora borealis appear differently depending on the angle from which they are viewed, much the way curtains hanging in a window look different if viewed from an oblique angle or from underneath. These shapes have descriptive names, whether they be a homogenous arc, rayed arc, or corona. Coronal rays look like they are coming out of a single point in the sky because they are centered on a magnetic field line. The outer edges of these rays are 60 miles (100 km) above Earth. When you follow each ray to the center, it’s the same optical illusion as looking at railroad tracks that seem to narrow as they disappear into the distance.
Printed in Alaska on matte paper that meets the Sustainable Forest Initiative guidelines that promote responsible management of the world’s forest.