Celestial Halo Over the Indian Ocean: ISS Captures a Rare Lunar Phenomenon from the Edge of Space

An astronaut aboard the International Space Station (ISS) has captured a breathtaking image of a "Lunar Halo" while orbiting over the Indian Ocean. This rare optical phenomenon manifests as a delicate luminous arc surrounding the moon, created by the refraction of moonlight through microscopic ice crystals in the Earth's upper atmosphere. Specifically, these hexagonal crystals in the mesosphere—located between 30 and 54 miles above the surface—bend light at a precise 22^ angle, transforming the moon into a radiant focal point of a natural light show.

Operating at an altitude of approximately 200 nautical miles, the ISS provides a unique vantage point that eliminates atmospheric distortion caused by lower-altitude clouds. According to NASA's Earth Observatory and recent studies in "Atmospheric Chemistry and Physics," the ice crystals involved are distinct from common cloud formations due to their extreme sensitivity to temperature fluctuations in the thin mesospheric air. Such imagery serves as an invaluable scientific tool, offering researchers profound insights into the complex interactions between light, atmospheric chemistry, and global weather patterns on a planetary scale.