Update 70, Mega-constellations vs. Astronomers

Wishing upon a star has taken on a whole new meaning with the advent of Earth-orbiting mega-constellations that now punctuate the night sky. Astronomers worldwide are raising concerns about the impact of initiatives like Starlink, OneWeb, and Amazon’s Project Kuiper, which collectively plan to deploy around 400,000 satellites in low Earth orbit in the near future. As these mega-constellations grow, astronomers fear that their observations will be hindered by the overwhelming presence of artificial light.

Proponents of mega-constellations argue that Earth-based instruments should not be hindered since space-based observatories like the Hubble Space Telescope and the James Webb Space Telescope already exist for in-depth celestial study. However, Andrew Williams from the European Southern Observatory and the International Astronomical Union’s Center for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference, emphasizes the urgent need for space governance solutions to address the impact of these satellite swarms on astronomy and the night sky’s pristine view.

Simonetta Di Pippo, former director of the United Nations Office for Outer Space Affairs, echoes the need for a balance between global internet coverage and protecting astronomical research. The challenge lies in fostering international discussions among stakeholders to propose recommendations that can be implemented at the local or international level.

Despite the allure of conducting astronomy from space, Richard Green from the University of Arizona’s Steward Observatory emphasizes that duplicating ground-based capabilities is impractical. Industry efforts are showing some promise, with SpaceX being a leader in developing an optical coating to reduce satellite brightness. They have also signed coordination agreements with organizations like the National Science Foundation to minimize their impact on astronomy.

The background image shows the double star Albireo in Cygnus and was taken on 26 December 2019. Two out of ten 2.5-minute exposures recorded Starlink satellites moving across the field. 
Credits: Rafael Schmall

However, the push for direct-to-cell communications poses a new challenge, leading to larger space-based structures that further impact ground-based observations. Even the Hubble Space Telescope is not immune, as evidenced by machine learning finding over 2,400 satellite trails in its images.

John Barentine from Dark Sky Consulting highlights the significance of ground-based observatories in advancing our understanding of the cosmos, complementing space-based missions like JWST. He emphasizes that the night sky is a shared resource, affecting not only astronomers but also stargazers and Indigenous communities with cultural and religious connections to the celestial world.

Johan Eklöf, author of “The Darkness Manifesto,” points out that the increasing number of satellites could confuse animals that navigate by the stars. This rapidly changing night sky provides an opportunity for astronomers to reassess their approach to observatories and innovate for the future.

As mega-constellations continue to grow, finding a delicate balance between global connectivity and preserving the wonders of the night sky becomes ever more critical. With cooperation and innovative solutions, astronomers hope to ensure that the celestial beauty and scientific discoveries remain accessible to all.


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    • Samuel Durrance, the astronaut who built and flew with a telescope, passes away at 79.