The growing number of satellites in orbit could soon make telescopes obsolete. 'For astronomy, this would obviously be catastrophic'

If the number of satellites in Earth's orbit exceeds 100,000, humanity may lose its ability to study the universe from the planet's surface. That's the conclusion of a study conducted by astronomers from the European Southern Observatory (ESO) which warns that if existing plans to deploy a million orbiting data centers and tens of thousands sun-reflecting mirrors were to come to fruition, the world's most cutting-edge astronomical telescopes may as well be mothballed. "We can reach conditions where basically, there is no point in operating the telescopes anymore because all the data will be corrupted. All. 100 percent," Olivier Hainaut, the director of operations at ESO and lead author of the study, told Space.com. Hainaut used computer modelling to understand the effect of varying numbers of satellites of different brightness levels on astronomical observations. The modelling showed that if 100,000 satellites were to orbit the planet and all were barely visible to the naked eye, astronomy could cope. If those satellites were brighter, however, around magnitude 7 or below in astronomical terms, astronomical research would become more difficult and costly. Satellites affect the sky in two ways. Firstly, the sunlight they reflect increases the overall brightness of the sky , creating light pollution. Second, brighter satellites also create streaks in telescope images that mar observations. …