Yukon Aurora with Star Trails . ... But at high latitudes during March and April, it can also capture an aurora shimmering in the night. ... To compose the picture, many short exposures were digitally combined to follow the concentric star trail arcs while including the greenish auroral curtains also known as the northern lights . ... NASA Web Site Statements, Warnings, and Disclaimers . NASA Official: Jay Norris. ... A service of: LHEA at NASA / GSFC . ... U. Based on Astronomy Picture Of the Day ...