@piggo Haha, city lights. I am not sure about this exact one, but those pics are not necessarily visible spectrum (some yes, but most not). People think it's a normal camera there, it's not 🙂.
Check the instrument spec. Depending on the satellite, here's the list: https://en.wikipedia.org/wiki/Polar_Operational_Environmental_Satellites
@piggo At least those grayish ones are probably infrared.