NASA has shared an image of Earth’s “air glow” captured from the International Space Station (ISS), showing the planet draped in bright orange hues created by the atmospheric phenomenon.In a post on Instagram, the space agency shared the photo taken by French astronaut Sophie Adenot. As seen from orbit, the image shows a glowing orange band encircling the Earth.“In this image of Earth from @ISS, Earth appears bathed in orange light,” NASA wrote. “This is caused by a phenomenon called airglow, where molecules in the upper atmosphere release energy after being excited by radiation from the Sun. This glow can be of a variety of colors, including red, green, purple and yellow.Further explaining this phenomenon, NASA said that airglow is constantly present throughout Earth’s atmosphere, but is usually too faint to be visible to the naked eye from the ground. It says, “Airglow is glowing continuously throughout Earth’s atmosphere, but it is so dim that it can only be seen by a sensitive camera from orbit or from the ground in dark skies.”What is airglow?This phenomenon occurs when atoms and molecules in Earth’s upper atmosphere release energy that they absorb from the Sun’s radiation.Primarily, this occurs when molecules (mostly nitrogen and oxygen) are activated by ultraviolet (UV) radiation from sunlight.As they release that energy, atoms in the lower atmosphere collide with each other and lose energy in the collision. The result is a colorful airglow. This is different from Aurora.Airglow performs functions such as carrying information on the temperature, density and composition of the upper atmosphere. Additionally, it helps to find out how those particles move in the field.