questionedithistorytranslationsCurrent version This is the accepted version. added by Ninjai March 16, 2018, 4:24 p.m. What does the Bortle scale refer to? spectrum of the starstypes of nebulaebrightness of the night skysize of the planetsThe Bortle scale is a nine-level numeric scale that measures the night sky's brightness of a particular location. It quantifies the astronomical observability of celestial objects and the interference caused by light pollution. It was created by John E. Bortle in 2001.NinjaiShare and bring new players to the game!0Very uninterestingToo difficultPoorly writtenIncorrect or questionableCorrect this questionwikipedia → Bortle scale0Very interesting! wikipedia → Bortle scalereach: rather globalastronomyskyspaceunitsVotes Acceptable Piper Perabo Acceptable th3pizgat0r Acceptable olorion