Nearly 2 Million Satellites Could Have 'Devastating Consequences for Astronomy'

The rapid expansion of satellite constellations, particularly SpaceX's Starlink, is raising alarms among astronomers who fear "devastating consequences for astronomy." Currently, around 16,000 active satellites orbit Earth, with SpaceX's Starlink making up a significant portion. However, companies are planning to deploy over 1.7 million more satellites in the coming years, including exceptionally bright ones.

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the proposal to launch such a huge number of satellites would have 'devastating consequences for astronomy.'

A study by the European Southern Observatory (ESO), which operates major telescopes in Chile, warns that such a massive deployment could severely impact astronomical observations. The study suggests that a maximum of 100,000 "weak satellites" are permissible to maintain the ability to observe the night sky with modern telescopes. While companies like SpaceX have taken steps to reduce satellite brightness, current proposals "exceed the limits" of what astronomy can withstand, according to astronomer Olivier Hainaut, a co-author of the study.

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a maximum of 100,000 weak satellites, visible to the naked eye, could orbit the Earth to preserve our ability to observe the night sky with modern telescopes.

Several companies are contributing to this potential saturation. SpaceX plans to launch a million more satellites for space data centers. Other constellations, such as E-Space's Cinnamon and China's CTC-1 and 2, will add hundreds of thousands more. This influx means hundreds, and at times thousands, of satellites could be visible each night, comparable to the number of stars seen with the naked eye.

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current proposals for satellites 'exceed the limits' of what astronomy can withstand.

Adding to the concern are proposals like Reflect Orbital's plan to launch very large, mirror-like satellites designed to illuminate parts of Earth on demand. A prototype is slated for launch this year, with a goal of 50,000 such satellites by 2035. These could be the brightest objects ever in orbit, potentially destroying humanity's view of the dark night sky. Hainaut calculates that a single mirror satellite could appear four times brighter than the full moon, and even if not aimed directly, would be as bright as Venus. ESO notes that from a light-polluted city, these satellites could become the only "stars" visible, rendering the night sky too bright for observing faint celestial objects like distant galaxies or planets.

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hundreds of satellites would be visible on any given night, and up to a few thousand at certain times, similar to the number of stars visible to the naked eye under good conditions.