New Science Reveals Secrets of Night-Shining Crystal Clouds
National Geographic Your Shot photographs depict the haunting beauty of noctilucent clouds. New observations reveal their secrets.
Electric-blue wisps streaking the sky, noctilucent clouds shine after sunset, gleaming with icy crystals. (See: "Pictures: First Night-Shining Clouds of 2012.")
After first noting them in 1885, scientists have long tracked these "night-shining" clouds hanging on the edge of space some 51 miles (83 kilometers) high in the sky. (Regular clouds top out at around 10 miles [16 kilometers] high.) They glow in the night sky after sunset.
Now, scientists led by Michael Gerding of the Leibniz Institute of Atmospheric Physics in Kuehlungsborn, Germany, report on 100 hours of LIDAR (light detection and ranging) observations of the clouds at temperate latitudes. The three-year observations explain the sky-high schedules of the clouds, as detailed in a report in