The dark sky character of archaeological landscapes: Cultural meaning and conservation strategies

Light pollution degrades our ability to see faint stars and dramatically reduces the spectacle of the observed night sky. Relatedly, scientific studies of night-sky radiance relative to the natural background level in Ireland have revealed a more-than 20% increase in artificial light levels over the last 25 years. The consequence of this is that in light polluted areas we may see no more than 300 stars in comparison to the estimated 5,000–6,000 visible in pristine dark-sky regions. This chapter presents the first investigation of light pollution of the dark sky at key Irish landscapes of archaeological and cultural importance. Neolithic passage-tomb clusters, identified by geostatistical density analysis, are used as a prime indicator of prehistoric social territories and ancient cultural landscapes. It is argued that at such locations the dark sky in prehistory would have figured prominently in the cosmology of those societies. Ten passage-tomb landscapes are overlaid on a geo-referenced light-at-night map of Ireland and this approach uniquely discovers the proximity and extent of the threat from light pollution to these regions. Having quantified the magnitude of the problem, the chapter concludes with a discussion of statutory and planning conservation remedies that could assist in the minimisation of further light pollution of these culturally special places.