1. Istituto di Scienza e Tecnologia dell’Inquinamento Luminoso (Light Pollution Science and Technology Institute), 36016 Thiene, Italy.
2. National Park Service, U.S. Department of Interior, Natural Sounds and Night Skies Division, Fort Collins, CO 80525, USA.
3. Deutsches GeoForschungsZentrum GFZ, Potsdam, Germany.
4. Leibniz–Institute of Freshwater Ecology and Inland Fisheries, Berlin, Germany.
5. Earth Observation Group, National Oceanic and Atmospheric Administration’s National Centers for Environmental Information, Boulder, CO 80305, USA.
6. Cooperative Institute for Research in Environmental Sciences, University of Colorado, Boulder, CO 80309, USA.
7. Department of Natural Resources and Environmental Management, Faculty of Management, University of Haifa, 3498838 Haifa, Israel.
8. American Association of Variable Star Observers, Cambridge, MA, USA.