ELECTRIC-BLUE CLOUDS CIRCLING ANTARCTICA: NASA's AIM spacecraft is monitoring a vast ring of electric-blue clouds circling high above Antarctica. These are noctilucent clouds (NLCs), made of ice crystals frosting specks of "meteor smoke" in the mesosphere 83 km above the frozen continent. This is the season for southern noctilucent clouds. Every year around this time, summertime water vapor billows up into the high atmosphere over Antarctica, providing moisture needed to form icy clouds at the edge of space. Sunlight shining through the high clouds produces an electric-blue glow, which AIM can observe from Earth orbit. "The current season began on...