A study of images taken by the Hubble Space Telescope has shown that the influence of satellites on our understanding of the universe is deteriorating.
The findings may confirm the fears of astronomers who claim that satellite constellations, such as SpaceX’s fleet of more than 3,500 Starlink spacecraft, could seriously impact astronomy.
Initially, these fears were associated with astronomers working with ground-based observatories, but as humanity actively used the space around our planet and plans were developed to create the so-called “mega-constellations” of satellites, these fears spread to colleagues working with space-based instruments.
To come to their conclusions, a team of researchers, including more than 11,000 civilian scientists from the Hubble Asteroid Hunter Project, studied images taken by the Hubble Space Telescope between 2002 and 2021.
The team found that 2.7% of the Hubble images, with a typical exposure time of 11 minutes, were intersected by satellites. In addition, the probability of detecting satellite trails in Hubble images has increased over time from 3.7% in 2002 to 5.9% in 2021.
Related: Megaconstellations like SpaceX’s Starlink could interfere with the world’s largest radio telescope’s search for life
Hubble’s orbit has decreased since its launch in 1990, bringing the telescope up to about 334 miles (538 kilometers) above Earth. In this lower orbit, the telescope becomes increasingly sensitive to satellites in higher orbits. These spacecraft affect Hubble’s images, appearing as bright steaks as they hurtle past the space telescope when its lens is open to collect light from the universe.
“With the increase in the number of artificial satellites currently planned, the proportion of Hubble Space Telescope images traversed by satellites will increase in the next decade and will require further scrutiny and monitoring,” the authors write in a study published in the journal Nature Astronomy. (will open in a new tab)
Volunteer citizen scientists scanned Hubble images and picked out those that were obscured by the bright bands of satellites. Two machine learning algorithms were then used to learn the classification of volunteers, one for an 11-minute exposure and the other for a 35-minute exposure. The study found that the trails matched between images taken by Hubble during the two exposures.
Surprisingly, the stripes were even found in images taken before the deployment of the Starlink megaconstellation. Astronomers are concerned that the problem will only get worse as only a small fraction of the planned satellites are currently in orbit; Eventually, SpaceX hopes to have up to 42,000 Starlink satellites in low Earth orbit. British firm OneWeb has permission to launch a constellation of 648 broadband satellites and has expressed a desire to add up to 7,000 to that with future upgraded versions of the spacecraft. The European Southern Observatory (ESO) predicted in 2020 that there could be up to 75,000 low-orbit satellites around the Earth by 2030.
We hope that the new results, obtained before swarms of artificial satellites reach orbit, will help establish the basis for future research that will help astronomers better assess the impact of megaconstellations on astronomy.
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