Arizona's big city lights are damaging astronomy


As Malcolm Smith points out in his Commentary 'Time to turn off the lights' (Nature 457, 27; 2009), significant economic benefits are to be had in the form of reduced electricity bills once efficient, astronomy-friendly outdoor lighting is adopted.

In locations such as Arizona, Hawaii and Chile, which are particularly suited to ground-based observational astronomy, the failure of governments to enact and enforce appropriate light-pollution controls could eventually lead to great economic losses. A study conducted by the University of Arizona's Eller College of Management, and sponsored by the Arizona Arts, Sciences and Technology Academy, showed that in financial year 2005–06 the total economic impact in Arizona of astronomical and space-science research was over US$250 million. More than 3,300 jobs were supported directly or indirectly by the flow of these dollars into the state ( Although I am not aware of comparable studies of the economic impact of astronomy and space science in Hawaii and Chile, it is evidently significant.

Cities in Arizona, such as Flagstaff and Tucson, and the surrounding Coconino and Pima counties, long ago enacted lighting ordinances designed to protect the nearby observatories, and these are enforced. However, our dark skies continue to be degraded by light pollution originating from more distant, larger and rapidly growing regions, such as the greater Phoenix metropolitan area and Pinal County between Phoenix and Tucson, where lighting ordinances are typically less stringent. Unless better lighting controls are enacted in these areas, the competitiveness of Arizona's observatories will be harmed and the state, instead of benefiting from further growth of this clean and green enterprise, could experience a serious decline in astronomy's contribution to the state's economy.

I do not know whether observatories in Hawaii and Chile are vulnerable to a threat of similar magnitude, but I very much doubt they are immune.

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Millis, R. Arizona's big city lights are damaging astronomy. Nature 457, 657 (2009).

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