More than 1900 Starlink satellites are now in low earth orbit. And Elon Musk’s space company SpaceX has permission to launch more than 11,000 more. However, astronomers fear that such megaconstellations will affect the work of observatories on Earth. Researchers led by Przemek Mróz from the University of Warsaw have now examined for the Zwicky Transient Facility (ZTF) at the Palomar Observatory in San Diego whether and to what extent the SpaceX satellite network has clouded the view into space since 2019: the number of disruptions is true significantly increased, but the recordings themselves are only slightly affected. Still, astronomers could miss important observations.
Every two days, the ZTF records the entire night sky accessible from the observation site in the visible and in the infrared range. As the scientists around Mróz report in the specialist magazine “The Astrophysical Journal Letters”, they are now looking through images that the telescope recorded between November 2019 and September 2021. The satellites appear as stripes on the scans. The researchers discovered a total of 5,301 such stripes. However, these did not occur evenly over the entire period. The amount of corrupted images has increased with the number of Starlink satellites SpaceX has launched into near-Earth orbit. At the end of 2019, stripes were only found on 0.5 percent of the recordings, in August 2021 it was around 18 percent. At the latest when SpaceX has launched a large part of its Starlink satellites into space, every recording should be impaired, the researchers suspect.
At the moment, the satellites have mainly left traces on images that were taken during twilight. Such recordings are used to detect asteroids not far from Earth. According to co-author Thomas A. Prince from Caltech in Pasadena, there is a low probability that the researchers would miss an asteroid as a result, “but compared to the influence of the weather, for example when the sky is cloudy, these are rather small effects for the ZTF «.