NASA is reporting its spacecraft has detected high-altitude clouds over Antarctica.
According to a press release by the agency, "Data from NASA's Aeronomy of Ice in the Mesosphere, or AIM, spacecraft shows the sky over Antarctica is glowing electric blue due to the start of noctilucent, or night-shining, cloud season in the Southern Hemisphere – and an early one at that."
As to what these clouds are, NASA explains, "Noctilucent clouds are Earth's highest clouds, sandwiched between Earth and space 50 miles above the ground in a layer of the atmosphere called the mesosphere. Seeded by fine debris from disintegrating meteors, these clouds of ice crystals glow a bright, shocking blue when they reflect sunlight."
Noctilucent clouds or NLCs have been appearing at more southerly latitudes, with sightings as far down as Northern California.
Computer models suggest that as greenhouses gasses warm the lower levels in the atmosphere, the upper layers cool. That scenario is conducive to these high clouds forming.
NASA further notes, "This year, AIM saw the start of noctilucent cloud season on Nov. 17, 2016 – tying with the earliest start yet in the AIM record of the Southern Hemisphere."