On the increasing number of satellite constellations

7 June 2019

Several initiatives around the world are developing constellations of satellites to be put in relatively low Earth orbits, with the aim of providing communication services, most notably in areas poorly served by other means. Recent public and media attention has brought focus on the possible impacts to astronomy from these constellations, which may eventually reach numbers of tens of thousands of individual satellites.  

The 16 Member States of ESO, as well as other states and organisations around the world, are making substantial investments in the construction and operation of ground-based facilities to carry out fundamental scientific research advancing knowledge for humanity. The superb sky conditions required for the optimal performance of these facilities may be compromised by the passage of bright satellites across the field of view of the telescopes. Observing strategies are being considered by ESO and other observatories to minimise the impact of these constellations in astronomical observations.

ESO supports the statements made by the International Astronomical Union and other organisations calling for consultation with experts from the astronomical community at the time of designing satellite constellations to be deployed in low Earth orbits that may interfere with astronomical observations. ESO has discussed the issue with its governing Council of Member States and is prepared to collaborate with relevant national and international agencies to study and mitigate the impacts. ESO supports the development of regulatory frameworks that will ultimately ensure the harmonious coexistence of highly promising technological advancements in low Earth orbit with the conditions that enable humankind to continue its observation and understanding of the Universe.



Andrew Williams
ESO External Relations Officer
Office of the Director General
Tel: +49 89 320 062 78

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Flare at Paranal
Flare at Paranal