MANY MINDEDStudy puts a number on how satellite swarms would damage astronomy
A European Southern Observatory study has tried to quantify how planned satellite constellations would degrade ground-based astronomy. Published in Astronomy & Astrophysics by ESO astronomer Olivier Hainaut, the paper argues that no more than 100,000 faint satellites, capped at visual magnitude 7, should be allowed in orbit. Existing proposals point to more than 1.7 million satellites. Today around 14,000 orbit Earth, mostly Starlink.
The simulations found ESO's Very Large Telescope at Paranal could lose up to 28% of its field of view from SpaceX's planned satellites, and the Vera C. Rubin Observatory could lose several hours of observation each night. The study also flags Reflect Orbital, which aims to launch up to 50,000 mirror-like satellites by 2035 to beam solar power to the ground at night. Its beams would span at least 5 km, appear four times brighter than a full Moon inside them, and shine as bright as Venus outside. Amazon plans more than 3,000 internet satellites of its own.
The night sky and the data drawn from it are a shared resource. Crowding low orbit trades one form of access, connectivity and orbital services, against another: the ability to observe the universe from the ground. That is a friction point for the scientific commons, harder to reverse once constellations are launched.
Hainaut says 100,000 is not a hard threshold; he would prefer 50,000. The findings rest on his simulations, and the environmental impact of satellites burning up on re-entry remains poorly understood.
Source: New Atlas