Watching NLCs

The Noctilucent or night-shining clouds (NLCs) appear in a clear June evening of Sweden. While nights of June and July at this latitude (about 60 degrees) never get dark enough to see many stars, bright planet Jupiter is visible between the two observers in this mid-night twilight. NLCs lie near the edge of space, reflecting sunlight from about 80 kilometers above Earth’s surface. They are usually spotted above the Polar Regions in summer. © P-M Heden