Fig. 5 Change in lighting technology in Milan, Italy, observed from space. Change in lighting technology in Milan, Italy, observed from space. Color astronaut photographs from 2012 (A) and 2015 (B) courtesy of the Earth Science and Remote Sensing Unit, NASA Johnson Space Center, with identification and georeferencing by the European Space Agency, the International Astronomical Union, and Cities at Night (48). (C) Change from 2012 to 2016 in the DNB radiance band. Christopher C. M. Kyba et al. Sci Adv 2017;3:e1701528 Copyright © 2017 The Authors, some rights reserved; exclusive licensee American Association for the Advancement of Science. No claim to original U.S. Government Works. Distributed under a Creative Commons Attribution NonCommercial License 4.0 (CC BY-NC).