Noun
airglow (usually uncountable, plural airglows)
A faint illumination in the sky due to photochemical luminescence in the upper atmosphere, now rarely observed by earthbound humans without the assistance of instruments.
At first he mistook airglow as the real horizon when trying to make some fixes on stars. Source: Internet
The amount of airglow and zodiacal light is quite variable (depending, amongst other things on sunspot activity and the Solar cycle ) but given optimal conditions the darkest possible sky has a brightness of about 22 magnitude/square arcsecond. Source: Internet
HST actually observed airglow of atomic oxygen in the far-ultraviolet at the wavelengths 130.4 nm and 135.6 nm. Source: Internet
This is caused by two main sources: airglow and scattered light. Source: Internet