Dark and Quiet Skies for Science and Society

Online workshop 5-9 October 2020  (Registrations CLOSED)            

5, 6, 7, 9 October  (Zoom, 15:00-17:00 UTC/ 17:00-19:00 CEST)

8 October              (Zoom, 15:00-18:00 UTC/ 17:00-20:00 CEST) 

Conference at Santa Cruz de La Palma, Canary Islands, Spain, October 2021 (Details to be announced)

Following the online workshop and the comments received, the working groups of the Scientific Organising Committee (SOC) produced a report in January 2021.


Since millennia the silent and ordered beauty of the night sky has inspired humankind in all its intellectual and emotional expressions: poetry, philosophy, religion and science. In particular, modern science is deeply indebted to the observation of  astronomical phenomena as all its major progresses, from the theory of universal gravitation to general relativity, were stimulated and verified by careful observation of the sky.

Today, technological progress, in particular artificial illumination of urban areas, has made it more and more difficult to observe the night sky in its pristine magnificence. Also, remote sites chosen to host the most sophisticated astronomical observatories because of their favourable location, are becoming gradually endangered by light pollution, radio signals interference and artificially induced climatic modifications. More recently, an additional negative impact on the observation of the night sky emerged from visual interference of the mega constellations of artificial satellites in low earth orbit.

Access to the electromagnetic signals emitted by all objects in the universe is not only  instrumental for understanding the cosmos and the overall progress of Science, but the visibility of the starred sky is a fundamental human heritage that must be preserved with painstaking care and love for future generations. Losing it, would disconnect us forever from the Cosmos and Nature.


The United Nations Office for Outer Space Affairs and Spain, jointly with the International Astronomical Union (IAU) are organizing an online workshop on the topic of "Dark and Quiet Skies for Science and Society". This online event is replacing the Conference initially foreseen in October. The Conference is postponed to 19-23 April 2021 and will be hosted by the Instituto de Astrofísica de Canarias (IAC) at Santa Cruz de La Palma, Canary Islands, Spain. 

In the recent past, several similar events have been organised with the aim of analysing the threat of light and radio pollution on astronomy and on the visibility of the pristine night sky. In particular, the conference organized in 2017 in La Palma, on the 10th anniversary of the "Starlight Declaration", approved a number of recommended resolutions. The online event will result in a document that describes what measures Governments and private enterprises can adopt to mitigate the negative impact of technological implementations on astronomy (e.g. urban lighting, radio broadcasting and satellite constellations' deployment) without diminishing the effectiveness of the services they offer to citizens. The final outcome document, intended to become a reference for further analysis of the situation, will be presented to the intergovernmental Committee on the Peaceful Uses of Outer Space (COPUOS) for consideration. 

The involvement of COPUOS is particularly important since it is the natural international forum where these matters should be brought to the attention of the space community.


Rewatch each day's full session on our UN Office for Outer Space Affairs YouTube Channel (https://www.youtube.com/playlist?list=PLaOqa4cng0GFqc1epTy3XTInKqoLjVqlS)

The online workshop was supported by NOIRLab, USA, and recorded for later viewing. The online workshop presented initial findings from 5 working groups of the Scientific Organising Committee (SOC), for discussion. Each day of the workshop focused on a different topic.

Monday 5 October: protection of dark sky oases - Download all presentations from Day 1 (PDF 12MB)
The creation and protection from light pollution of areas from which people can enjoy the clear visibility of the starry sky aims to solve the widest and most general incidences of light pollution.

15:00  Nathalie Ricard                                 Welcome & Introduction 
  Simonetta Di Pippo Welcome from UNOOSA Director Download statement (PDF 100KB)
  Kathy Nield (Moderator) Introductions for the Dark Skies Oases presenters
  John Hearnshaw  An introduction to skyglow from artificial light at night
  John Barentine Dark Sky Oasis classifications and the International Dark Sky Places Programme
  Antonia Varela Perez The Starlight Foundation: the commitment with the Starlight Declaration
  Costis Bouroussis The evolution of light sources and luminaire technology
  Antonia Varela Perez The values of dark sky oases. Starlight Tourist Destinations.
  John Hearnshaw  Recommendations 
17:00 End of Session  


Tuesday 6 October: light pollution impact on the bio-environment - Download all presentations from Day 2 (PDF 2MB)
While this aspect is not directly related to astronomy, it is a consequence of the global effects of new illumination technologies. By protecting the night sky from light pollution, negative effects on the bio-environment can also be mitigated without affecting the needed illumination and provide a substantial saving in energy consumption.

15:00 Connie Walker Welcome & Introduction 
  Pat McCarthy Welcome from NOIRLab Director
  James Lowenthal (Moderator) Introductions for the Bio-Environment presenters
  Luc Schlangen The effect of light on circadian rhythms and melatonin
  Mario Motta Human health effects of light at night
  Sibylle Shroer Effects of anthropogenic light at night on flora and fauna
  Annika Jägerbrand Protecting humans and ecoystems from anthropogenic light at night
17:00 End of Session  


Wednesday 7 October: protection of existing and future astronomical observatories - Download all presentations from Day 3 (PDF 8MB)
Several Countries and International Organisations have made very large financial investments in building and operating large astronomical facilities. Most of these facilities are open to astronomers of any Country. In the interest of the world community, these sites need to be protected from light pollution and from artificial local climate alterations.

15:00 José Miguel Rodriguez Espinosa Welcome & Introduction 
  Rafael Rebolo Welcome from IAC Director
  Casiana Muñoz-Tuñon (Moderator) Introductions for the Optical Astronomy presenters
  Richard Green Dark Sky Protection for Optical Observatories
  Dionýz Gašparovský Outdoor lighting recommendations and protection of observatories
  Martin Aubé Dark sky protection measures near optical observatories
17:00 End of Session  


Thursday 8 October: impact of satellite constellations - Download all presentations from Day 4 (PDF 19MB)
The impact of the tenths of thousands of communication satellites that are being placed in LEO (Low Earth Orbit) has only recently raised the attention of the astronomical community and of the general public. Their real impact has now been carefully established on the basis of sound simulations and initial observational data.

15:00 Piero Benvenuti Welcome & Introduction 
  Ewine van Dishoeck Welcome from IAU President
  Oli Hainaut (Moderator)   Introductions for the Observations presenters
  Jeremy Tregloan-Reed Results from the Universidad de Antofagasta LEO satellites Observations Team
  Harrison Krantz Results from the POMENIS Telescope (University of Arizona, Steward Observatory) LEO satellites Observations Team
  Angel Otarola Lessons Learned & Recommendations
  Oli Hainaut (Moderator) Introductions for Simulations presenters
  David Galadí  Simulating the impact of large satellite constellations on optical astronomy
  Sara Lucatello (Moderator) Introductions for Mitigations presenters
  Genoveva Micheva Introduction to Mitigations: purpose and aims
  Meredith Rawls and Genoveva Micheva Mitigating the impacts of satellite constellations on astronomy
  Sara Lucatello (Moderator) Introductions for Recommendations presenters
  Patricia Cooper Industry perspectives
  Andrew Williams Astronomy community, industry and policymaker recommendations
18:00 End of Session  


Friday 9 October: protection of radio astronomy - Download all presentations from Day 5 (PDF 16MB)
Similar to the impact of satellite constellations on optical astronomy, radio interferences can also be geographically wide-ranging. Radio astronomy has a long history of successful international agreements on the protection of radio interests from anthropic ground-based radio broadcastings. However, the large number of additional communication satellites will make regulatory action even more important.

15:00 Casiana Muñoz Tuñon Welcome & Introduction 
  Pedro Duque Welcome from Spain Minister of Science
  Harvey Liszt (Moderator) Introductions for the Radio Astronomy presenters
  Harvey Liszt Radio Astronomy As a Discipline
  Harvey Liszt Radio Spectrum is for everyone
  Liese Van Zee Regulations for spectrum for radio astronomy
  Federico di Vruno Risks to radio astronomy
  Harvey Liszt The way forward in practices and recommendations
  Conclusions and way forward  
17:00 End of Workshop  


Registration CLOSED

Interested parties are requested to apply for the online workshop through this link.

Working Language

The working language will be English.

Expected Participants

The online workshop addresses astronomers, urban planners, and private industry involved in technology development that potentially emits light or radio signals interfering with astronomy. The Office of Outer Space Affairs strives to support gender mainstreaming in its programmes and is also committed to ensure a balanced representation from different perspectives. Applications from female applicants are particularly encouraged.

Contact Information

For additional information, please contact: unoosa-events@un.org

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