Technological advancements in low Earth orbit are disabling observation and understanding of the Universe. SpaceX, Amazon, and OneWeb are the guilty party for both the improvements and the disability. Their 18 representative satellite constellations under development are polluting the twilight sky with light overspill, and the International Astronomical Union started fighting it some time ago. Now, the European Southern Observatory is making a call.
The study from the astronomers
ESO sustaining IAU’s concerns recently released a paper. The research proves that astronomical observations are and will continue to be more and more impaired, especially during twilight.
Recently, 240 satellites were launched to space by SpaceX. Its goal is to launch a total of 42,000. Internet service for the Northern U.S. and Canada is the beneficiary, but the intent is to expand to near-global coverage of the populated world by 2021. Amazon and OneWeb have similar grandiose goals.
The threat of satellite constellations
Two hundred fifty constellation satellites at any given time, all illuminated by the Sun at twilight, will endanger the accuracy of astronomical observations. They get into the shadow of the Earth toward the middle of the night.
When combined with space debris, satellite mega-constellations become an essential reason for concern. Along with the IAU, other societies such as the American Astronomical Society and the UK Royal Astronomical Society are trying to make global fora such as the United Nations Committee on the Peaceful Uses of Outer Space and the European Committee on Radio Astronomy Frequencies to become aware and find measures to contain the repercussions.
Nearly 20,000 artificial objects are in orbit above the Earth, the operational satellites. However, these are just objects, large enough to be tracked. As of January 2019, more than 128 million pieces of debris smaller than 1 cm, about 900,000 pieces of debris 1–10 cm, and around 34,000 pieces larger than 10 cm were estimated to be in orbit around the Earth.
The solution to the recent problems
ESO’s Very Large Telescope and ESO’s upcoming Extremely Large Telescope will be moderately affected. US National Science Foundation’s Vera C. Rubin Observatory would be severely affected due to its wide-field survey. Data about supernovae or potentially dangerous asteroids will be impaired.
Further studies are expected. Studies about the satellites’ impact on the radio, millimeter, and submillimeter observatories, such as the Atacama Large Millimeter/submillimeter Array and the Atacama Pathfinder Experiment.
There are effective steps to mitigate impacts: either the companies darken the satellites, or the observatories make changes to the operating schedules of the telescopes. Both of the solutions come at a cost.