A new NASA satellite has recorded the first detailed images from space of a mysterious type of cloud called "night-shining" or "noctilucent."
The clouds are on the move, brightening and creeping out of polar regions, and researchers don't know why.
"It is clear that these clouds are changing, a sign that a part of our atmosphere is changing and we do not understand how, why or what it means," said atmospheric scientists James Russell III of Hampton University in Hampton, Va. "These observations suggest a connection with global change in the lower atmosphere and could represent an early warning that our Earth environment is being changed."
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The "Aeronomy of Ice in the Mesosphere" (AIM) satellite first imaged the noctilucent clouds May 25. People on the ground began seeing them June 6 over Northern Europe.
The clouds form 50 miles above the Earth's surface, in an upper layer of the atmosphere called the mesosphere.
The puffs of water vapor and crystals appear during summer months above the Northern Hemisphere's pole as well the Southern Hemisphere's pole in summer.
AIM will record two complete cloud seasons over both regions, effectively documenting an entire life cycle of the shiny clouds for the first time.
Researchers hope to figure out why noctilucent clouds form and how they might be related to global climate change.