Night-shining clouds. This poetic phrase describes noctilucent clouds that dwell in the mesophere, a layer of Earth's upper atmosphere located above the stratosphere. NASA describes the enchanting formations as "ice blue" and "brilliant." They're so high up, they shine even after the sun hides away.
In a release Thursday, NASA scientists heralded the arrival of noctilucent cloud season in the Arctic. NASA's Aeronomy of Ice in the Mesosphere (AIM) spacecraft spotted signs of these clouds on May 17 and watched as they expanded.
Night-shining clouds are a bit different from the fluffy cumulus and filament-like cirrus formations we're used to. They develop around dust particles in the mesosphere. "The icy clouds, reflecting sunlight, shine bright blue and white," NASA said.
The space agency animated AIM observations to show the growth of the clouds from May 17 through May 25. AIM principal investigator Jim Russell called the cloud season kickoff "a big event for us." This year's start is the second earliest on record for the Arctic.
"The reason we're excited is we're trying to find out what the causes of the season's starting are and what does it really mean with regard to the larger picture in the atmosphere," Russell said. Researchers will be watching to see if the clouds move far south like they did in 2019 when they were visible in California, New Mexico and Oklahoma in the US:
Noctilucent clouds aren't a purely Earth phenomenon.on Mars in 2019. They're beautiful to behold no matter what planet they're on.