Roger Culver, professor of physics and longtime astronomy instructor at CSU, with Eric Craine of Tucson’s STEM Laboratory Inc., and Brian Craine of Western Research Co., have created a first-of-its-kind index that ranks communities according to their observed lighting efficiency, which affects the quality of their dark skies. A paper describing their work is titled “An Approach to Objectively Defining and Ranking Dark Night Communities,” and was presented June 13 at the annual meeting of the American Astronomical Society, in San Diego. Eric Craine is an affiliate faculty member at CSU.