Starlink & Co. will contaminate almost all images of future space telescopes
The rapidly growing number of satellites is not only disturbing Earth-based astronomy, but also space telescopes. The consequences have now been quantified.
Simulated image of the planned European space telescope ARRAKIHS
(Image: Borlaff et.al)
If only the currently planned number of satellites are launched into space in the next ten years, the consequences for several space telescopes will be severe. This is the result of an analysis that has now been presented, which also quantifies the consequences. According to the analysis, streaky trails from these satellites will contaminate one-third of the Hubble Telescope's images; for one launched and two planned instruments, this would even be the case for 96 percent of the images. For NASA's SPHEREx space telescope, other satellites would leave an average of almost 6, for the European space telescope ARRAKIHS 69, and for China's Xuntian telescope even 92 streaks per image. The consequences for research would be far-reaching.
Astronomical images deteriorating for the first time
It has been known for years that mega-constellations like SpaceX's Starlink satellite internet not only interfere with observations of the starry sky from Earth. In early 2023, Hubble images were published showing the typical streaks. These are created because the satellites pass in front of the lens during a long exposure. At that time, a good 6 percent of all images were affected, but SpaceX only had 4,000 internet satellites in Earth orbit. Now there are more than 9,000, and other mega-constellations are planned. Two researchers from NASA have therefore calculated the consequences for astronomy from Earth orbit if the planned 560,000 satellites are in operation there.
(Image:Â Borlaff et.al)
The research group found that the consequences for future space telescopes are significantly more massive than for Hubble. Specifically, ARRAKIHS (Analysis of Resolved Remnants of Accreted galaxies as a Key Instrument for Halo Surveys) and the Xuntian telescope are two instruments that are not yet in space, while SPHEREx was launched in the spring. Two of them will image dozens of satellite streaks on each image on average. If more satellites are launched, the number of streaks will increase accordingly. The differences are explained, among other things, by the way the instruments work, but also by the altitude at which they are supposed to orbit the Earth.
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The results are "really frightening," quotes astronomer Patrick Seitzer, who was not involved in the work, the US science magazine Nature. It is a significant study for the future of space-based astronomy. In the US magazine The Verge, study leader Alejandro Borlaff of NASA laments that he has spent his whole life improving telescopes: "For the first time, we have now found something that will actually degrade their images in the future." The complete analysis is presented in Nature, where the research group also discusses possible countermeasures, but there is no simple solution.
(mho)
