For centuries, the night sky has been humanity’s window to the cosmos, an endless expanse of stars, planets, and galaxies that evoke wonder and curiosity. But with the rise of modern civilization, this once-pristine celestial tapestry is rapidly disappearing. Light pollution—an unintended consequence of urbanization—casts an artificial glow over much of the Earth, masking the stars and erasing the natural rhythms of the night.
In this battle to reclaim the skies, the Bortle scale emerged as a practical tool for measuring and describing the brightness of the night sky. The Bortle scale evaluates everything from the visibility of the Milky Way to the faintest stars, providing a structured way to classify the night sky’s quality.
So, what exactly is the scale, and how does light pollution play a crucial role? Click through to find out.