Excellent? Typical? Urban? Use this nine-step scale to rate the sky conditions at any observing site.
The post Gauging Light Pollution: The Bortle Dark-Sky Scale appeared first on Sky & Telescope.
Excellent? Typical? Urban? Use this nine-step scale to rate the sky conditions at any observing site.
The post Gauging Light Pollution: The Bortle Dark-Sky Scale appeared first on Sky & Telescope.