Glowing Clouds Shine in Electric Blue Over Antarctica (Photos)

These magnificent clouds — also known as noctilucent clouds, or NLCs — form in an upper layer of the Earth's atmosphere called the mesosphere, and can be seen in summer night skies from high latitudes. Data collected from AIM on Nov. 17 shows an early start to this year's noctilucent, or night-shining, cloud season in the Southern Hemisphere, according to a statement from NASA. "This year, AIM saw the start of noctilucent cloud season on Nov. 17, 2016 — tying with the earliest