The Conference “Dark and Quiet Skies for Science and Society”, jointly organized by the United Nations Office for Outer Space Affairs (UNOOSA), the Government of Spain and the International Astronomical Union (IAU), should have taken place in October 2020, but, because of the COVID-19 pandemic, it has been postponed and is now scheduled in Santa Cruz de La Palma, Canary Islands, Spain, from 3 to 7 October 2021.

However, because of the urgency to protect the right of humankind to access an uncontaminated night sky, both for its intrinsic cultural value and for the progress of science, the organizers decided to hold an on-line Workshop, on the same theme as the originally planned Conference.

The rationale for the Workshop and Conference relates to exponential deployments of technological developments, like urban illumination by LED, the large constellations of satellites in low Earth orbit and the high power radio transmission, which are creating unprecedented threats to the visibility of the pristine night sky and call for effective and prompt mitigating measures before the damage may become irreversible.