The 1.7 million satellites that companies are planning to launch into Earth\u2019s orbit in the coming years will have \u201cdevastating consequences for astronomy\u201d, new research has warned.<\/p>\n
The plans to deploy huge, extremely bright satellites represent an \u201cexistential threat\u201d to telescopes viewing the universe, according to the European Southern Observatory<\/a> (ESO), which conducted the research published on Wednesday.<\/p>\n To preserve humanity\u2019s ability to explore the night sky, researchers are calling for a maximum limit of 100 000 satellites orbiting Earth.<\/p>\n The study is the first to calculate how planned constellations of large and particularly bright satellites would impact astronomical observations by making the night sky brighter.<\/p>\n The number of satellites orbiting Earth has now reached 14 000 after surging in recent years, many of them part of Elon Musk\u2019s Starlink<\/a> internet constellation.<\/p>\n However, that is just the beginning.<\/p>\n Musk\u2019s SpaceX company has announced plans to launch more than one million satellites by 2028 to serve as data centres powering the artificial intelligence boom.<\/p>\n Other projects such as the \u201cCinnamon\u201d plans of start-up E-Space and Chinese constellations CTC-1 and CTC-2 would add hundreds of thousands more satellites orbiting the planet.<\/p>\n US start-up Reflect Orbital hopes to launch 50 000 huge satellites that use giant mirrors to point sunlight back down to Earth, aiming to provide light during the night.<\/p>\n In total, more than 1.7 million satellites could soon be lighting up the night sky, obscuring or blocking the view of ground-based telescopes.<\/p>\n Night sky four times brighter<\/p>\n \u201cWhen a satellite crosses what we observe, it makes a bright streak on our image, zapping whatever is behind it,\u201d said ESO astronomer Olivier Hainaut, who led the study published in Astronomy & Astrophysics.<\/p>\n \u201cFor the past few years, this has been happening, but it is still manageable,\u201d Hainaut told AFP.<\/p>\n \u201cBut if we go from 14 000 to 1.7 million, we are really going to have problems.\u201d<\/p>\n The Reflect Orbital satellites pose a particularly significant threat to dark skies.<\/p>\n Even when their mirrors are not pointed at the observer, the light they scatter will make each one as bright as Venus, known as the \u201cmorning star\u201d, Hainaut said.<\/p>\n The researchers determined that almost all images captured by the largest camera ever built, part of the new Vera C. Rubin Observatory in Chile, would be rendered unusable.<\/p>\n Whether in France, the Sahara Desert or Chile, the sky \u201cwould no longer be clear, resembling instead the sky seen in the suburbs of a city\u201d, he warned.<\/p>\n In light-polluted cities, the satellites \u201cwould be the only \u2018stars\u2019 visible in the night sky\u201d, according to the ESO.<\/p>\n All 50 000 Reflect Orbital satellites would also make the entire night sky up to four times brighter.<\/p>\n Regulators face decision<\/p>\n Hainaut called for the number of orbiting satellites to be limited to 100 000, and that they be made dim enough to be invisible to the naked eye.<\/p>\n