Starship Asterisk*

Airglow Ripples over Tibet

Explanation: Why would the sky look like a giant target? Airglow. Following a giant thunderstorm over Bangladesh in late April, giant circular ripples of glowing air appeared over Tibet, China, as pictured here. The unusual pattern is created by atmospheric gravity waves, waves of alternating air pressure that can grow with height as the air thins, in this case about 90-kilometers up. Unlike auroras powered by collisions with energetic charged particles and seen at high latitudes, airglow is due to chemiluminescence, the production of light in a chemical reaction. More typically seen near the horizon, airglow keeps the night sky from ever being completely dark.

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posted link chemiluminescence is in fact about the afterglow and is informative but with little infographics

Beautiful; Gravity waves create circular rings in the atmosphere!

Be advised that Tibet should not be shown as part of China. It was illegally taken over and annexed. It should alsways be listed as an independent country.

Sometimes the APOD information isn't 100% accurate. Here they say the giant thunderstorm over Bangladesh we assume happened in late April, 2022. However the Flickr link says that the photo was taken on April 27, 2014. So most likely the Bangladesh storm also took place in 2014 rather than in April this year.

De58te wrote: ↑Sun Nov 20, 2022 4:27 pm Sometimes the APOD information isn't 100% accurate. Here they say the giant thunderstorm over Bangladesh we assume happened in late April, 2022. However the Flickr link says that the photo was taken on April 27, 2014. So most likely the Bangladesh storm also took place in 2014 rather than in April this year.

Actually, it never said April, 2022. It just said April. They probably should have said 2014,
but as per usual for a Sunday, this APOD is a repeat. This one is from 2014 Sept 01.