  Fifty years after the first mention of light pollution in Science, the
journal recently elevated this topic to the cover of its 16 June 2023 issue,
highlighting the large impact on human and ecological health, circadian
rhythms, migratory patterns, and more. We offer here the term noctalgia to
express "sky grief" for the accelerating loss of the home environment of our
shared skies - representing loss of science, heritage, millennia-old sky
traditions, place-based language, and more - and summarize next steps to
address the protection of our nighttime and daytime skies.

Physics and Society;Instrumentation and Methods for Astrophysics