A recent study by the European Southern Observatory (ESO) outlines a staggering shift in the future of our night skies.

With new proposals from aerospace entities like SpaceX and Reflect Orbital, the number of planned satellites in low-Earth orbit has surged to over 1.7 million.

For astrophotographers and astronomers alike, this goes far beyond managing the occasional satellite trail during a long exposure. The study reveals a multi-layered impact on our ability to capture the cosmos.

Crowded Frames: In a fully realised 1-million-satellite constellation, hundreds to thousands of satellites would remain illuminated and visible to the naked eye at any given moment. Deep-sky imagers utilizing premier instruments like the Very Large Telescope (VLT) could experience field-of-view losses of up to 28% due to constant streak crossings.

Diffuse Light Pollution: Perhaps more concerning than the visible trails is the hidden pollution. Fainter, invisible satellites collectively create a "veil" of background sky brightness. This diffuse and scattered light threatens to artificially brighten even the darkest, most remote locations on Earth.

Space Mirrors: Proposals include thousands of orbital mirrors designed to redirect sunlight. From the ground, these mirrors could appear as bright as Venus or, when caught directly in the reflected beam, four times brighter than a full Moon.

The absolute madness of this last proposal is hard to overstate; we do not need daylight at night. The environmental and ecological disruption would be immense for zero genuine gain. Reflect Orbital's website offers plenty of platitudes about mitigating the impact on astronomy, but the reality of the concept is genuinely horrifying

Where do we go from here?

The study concludes that to safeguard ground-based astronomy, the global orbital population needs to be limited to a maximum of 100,000 sufficiently faint satellites. Striking a balance between global connectivity and the preservation of our natural night sky requires urgent, strict international collaboration between astronomers, engineers, and satellite operators. Without collaborative mitigation measures, the pristine, dark windows we rely on to capture the universe may soon be permanently altered.

Please read the Press Release from the ESO here.