GLOBE at Night: An update and look ahead to IYA2009

The ongoing loss of a dark night sky as a natural resource for much of the world’s population is a growing, serious issue that not only impacts astronomical research, but also human health, ecol-ogy, safety, security, economics and energy conservation. “Star hunts ” or “star counts ” provide “citizen-scientists ” with a fun, fast and no-frills way to acquire heightened awareness about light pollution through firsthand observations of the night sky. Over the last two years, the GLOBE at Night programme has enabled citizen-scientists around the world to contribute measurements on sky-brightness to a growing global database in two ways: simple unaided-eye observations that anyone can do and quantitative digital measurements through a handheld, well-calibrated sky-brightness meter. As discussed in this article, the GLOBE at Night programme will serve as a basis for the IYA2009 global Cornerstone Project on Dark Skies Awareness, as well as the central programme for the US IYA2009 Dark Skies are a Universal Resource theme. Introduction: the challenge We live in a world of urban constellations, unable to see the stellar constellations a moderately dark sky would provide. We should ask ourselves whether this is the legacy that we wish to leav