The bright satellites have affected a notable portion of Hubble’s imagery, with studies indicating distortions in a meaningful share of long-exposure frames. A detailed article on this issue appeared in Natural Astronomy.
Today there are thousands of objects circling Earth, many of which are inactive relics or decommissioned probes. Some moons can be seen as streaks across the night sky with the naked eye, but they become even more conspicuous through a telescope. This visual interference worries astronomers because persistent bright trails can map across a telescope’s field of view and, in some cases, resemble solar system objects. The phenomenon has drawn particular attention to constellations of satellites like Starlink, whose growing numbers have sparked debate about their impact on ground- and space-based astronomy.
Researchers compiled the full set of Hubble long-exposure photographs taken over nearly two decades, from 2002 to 2021. Long exposure times heighten the probability that a satellite will cross the frame, leaving a trace in the image. To identify these traces, the team employed a neural network designed to detect motion within static-looking frames. The analysis found that more than 2.7 percent of Hubble’s long-exposure images were compromised by satellites passing through the telescope’s view. The researchers note that this rate is likely to climb as the orbital population grows, driven by new launches and ongoing solar system projects. Their assessment underscores a trend that is expected to continue in the near future, given the current pace of satellite deployment.
A striking finding from the study is that the frequency of distorted imagery nearly doubled in the period between 2009 and 2021. This acceleration points to a widening challenge for the astronomy community, as more satellites share the same celestial playground. The implications extend beyond individual frames: persistent interference can complicate the calibration of long-term surveys, affect measurements of faint distant objects, and require more sophisticated data-processing strategies. Though some mitigation steps exist, including scheduling observations to avoid known satellite passes and developing improved tracking models, the sheer growth in orbital traffic presents a persistent hurdle for high-precision astronomy. The research team emphasizes the need for coordinated policy discussions among satellite operators and the space science community to balance the commercial and scientific value of satellite networks with the preservation of astronomical data. The findings contribute to the broader debate about how to maintain the integrity of celestial observations in an increasingly crowded sky .