“A NASA satellite has created a new map of so-called ‘night-shining clouds,’ which form at high altitudes on Earth and glow even after the sun sets. These mysterious clouds, also called noctilucent clouds or Polar Mesospheric Clouds (PMCs), appear about 50 miles (80 km) above Earth's surface during the summer of each hemisphere — from late May through late August in the north, and from late November to late February in the south. NASA's Aeronomy of Ice in the Mesosphere (AIM) satellite has captured five complete polar seasons of noctilucent cloud coverage, showing that they can quickly form and disperse, and that they are highly dependent on weather systems. ‘The AIM findings have altered our previous understanding of why PMCs form and vary,’ said AIM principal investigator James Russell III of Hampton University in Virginia. ‘We have captured the brightest clouds ever observed and they display large variations in size and structure signifying a great sensitivity to the environment in which the clouds form.’”