Satellites contribute significantly to nocturnal light pollution

Image: Strip of light trails in the sky from Starlink satellites. The shorter paths of light are the stars. (Andreas Mueller)

New research, to be published soon, shows that the brightness of the night sky could increase by more than 10 percent due to large-scale launches of satellites. This form of “light pollution” could also become a problem for astronomical observations outside densely populated areas.

The research, led by Miroslav Kosevag of the Slovak Academy of Sciences and Comenius University, is the first to calculate the global impact of objects in space rather than the influence of individual satellites and space debris.

Using a computer model and the known dimensions and brightness of multiple objects, Kocifaj and colleagues calculated how much they contributed to the brightness of the sky background. Unlike “normal” light pollution, this contribution can be observed over a large portion of the Earth – so remote observatories are affected as well.

The main causes are large configurations of communication satellites, such as SpaceX, which are also called massive constellations. This technology also increases the number of collisions between satellites and between satellites and other objects, increasing the amount of space debris. This is not only a nuisance to space travel, but also astronomy.