Astronomers concerned

Light pollution from satellites is increasing sharply

In the past five years alone, around 7000 so-called constellation satellites have been launched into orbit - and the trend is rising.

(Bild: Umweltdachverband)

More and more satellites are reflecting more and more light, brightening the night sky and interfering with astronomical measurements. The "Centre for the Protection of the Dark and Quiet Sky from Satellite Constellation Interference" (IAU CPS) is therefore now working on reducing the influence of satellites on measurements.

One of the board members of the scientific association, which is part of the International Astronomical Union (IAU), is the Austrian astrophysicist Siegfried Eggl from the University of Illinois in the USA. One of his tasks is to determine the brightness of newly launched satellites independently of the manufacturer's specifications, which are not always accurate. The problems with reflected sunlight from satellites have recently increased rapidly: in the past five years alone, around 7000 so-called constellation satellites have been launched into orbit - and the trend is rising.

By comparison, this is almost as many as were previously launched into space during the entire space age, according to a statement from the IAU. The combined radiant power of the devices is now causing problems for both high-tech research with highly sensitive detectors and amateur stargazers.

Worrying effects
In order to understand and mitigate the impact of these effects on astronomical research, which experts find worrying, the US National Science Foundation has now awarded the group a grant of 750,000 dollars (around 687,000 euros). The research project involves the development of a system called "SatChecker", which aims to predict with high precision when and where reflective satellites will move across the night sky and what effects this may have on measurements.

This should ultimately help observatories to understand how frequently satellite overflights "interfere with observations", reduce their disruptive effects "and thus improve scientific results", IAU CPS co-director Connie Walker is quoted as saying.

According to CPS Interim Director Richard Green, awareness of the growing problem has now also increased on the part of the UN and some countries: What is needed now is "more financial support and lobbying at national level to make decision-makers aware of the need for further action and to get industry to work with astronomy to mitigate the effects."