Satellite Constellations and their Impact on Astronomy

19 December 2019

Several space companies are developing plans for constellations of satellites to put in relatively low Earth orbits, for a variety of communication purposes. The recent launches of multiple batches of satellites for Space X’s Starlink project have drawn public and media attention, particularly as a result of the satellites’ high visibility immediately after launch. The astronomy community has raised concerns about the impact of these constellations on scientific research. 

In coordination with the International Astronomical Union (IAU), the American Astronomical Society (AAS), and the Royal Astronomical Society (RAS), ESO and other observatories are evaluating the effects that these satellite constellations will have on ground-based optical and infrared astronomical observations. The calculations will soon be made public after undergoing independent peer review.  

Satellite constellations will have an impact on radio, millimetre and submillimetre observatories, including the Atacama Large Millimeter/submillimeter Array (ALMA) and the Atacama Pathfinder Experiment (APEX). ESO has an observer status in the Committee of Radio Astronomy Frequencies (CRAF), an independent European expert committee that liaises with the International Telecommunications Union and national administrations responsible for spectrum management in order to protect the interests of radio astronomy. ESO is following up the topic of these satellite constellations with CRAF together with our ALMA partners in North America and East Asia. 

ESO in coordination with the AAS and IAU is taking measures to raise the awareness of this issue in global fora such as the United Nations Committee on the Peaceful Uses of Outer Space, while exploring practical solutions with space companies that can safeguard the large-scale investments made in cutting-edge ground-based astronomy facilities. 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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