The bizarre blue spots that "float" in the Earth's atmosphere. What is the explanation

Credit image: NASA/ESA
Credit image: NASA/ESA

Article by: Andacs Robert Eugen, on 26 October 2022, at 09:08 am Los Angeles time

An astronaut aboard the ISS recently captured a strange image of Earth, with two patches of blue light shining through the planet's atmosphere. 

They are the result of two unrelated natural phenomena that coincidentally happened at the same time. The first spot of light, which is visible at the bottom of the image, is a very large lightning bolt that struck somewhere in the Gulf of Thailand. 

Lightning is usually hard to see from the ISS because it is usually covered by clouds. But this time the lightning lit up the surrounding clouds, creating a brilliant halo of light. 

The second blue spot, which can be seen in the upper right of the image, is the result of warped light from the Moon. The orientation of Earth's natural satellite relative to the ISS means that the light it reflects from the Sun passes straight through the planet's atmosphere, turning it into a bright blue blob with a fuzzy outline. 

This effect is caused by the fact that some of the moonlight is scattered among the small particles in the Earth's atmosphere. Also visible in the photo is a network of artificial lights coming from Thailand. 

The other prominent sources of light pollution in the image are emitted from Vietnam and Hainan Island, China's southernmost region, although these are largely obscured by clouds. The orange halo parallel to the curvature of the Earth represents the "edge of the atmosphere" or "edge of the Earth". 

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