Satellites keep photobombing the Hubble telescope, and it’s getting worse
The increasing number of satellites in Earth’s orbit is creating significant challenges for astronomical observations, particularly for renowned telescopes like Hubble. A recent study by NASA researchers, published in the journal *Nature*, reveals that satellite trails could severely compromise the quality of images captured by Hubble and other telescopes. The study indicates that nearly 40% of Hubble’s images could be affected by satellite interference, with numbers soaring to 96% for three other telescopes within the next decade. This surge in satellite launches, driven by the decreasing costs of space access and the rise of megaconstellations like SpaceX’s Starlink, threatens to obscure critical observations of celestial phenomena, including the detection of potentially hazardous asteroids and the discovery of new exoplanets.
The scale of this issue is alarming. Since 2019, the number of satellites orbiting Earth has skyrocketed from 5,000 to over 15,800, with projections suggesting that this could balloon to as many as 560,000 in the coming decade if all planned launches proceed. Alejandro Borlaff, the lead author of the study, emphasizes the unprecedented nature of this problem, stating, “For the first time, we found something that may actually be worse in the future.” The researchers simulated the potential impact on four different telescopes, predicting that Hubble could capture an average of 2.14 satellites per exposure, while the upcoming Chinese Space Station Telescope Xuntian could see an astonishing 92 satellites in the same scenario. The light pollution from these satellites, which reflect sunlight and other sources, can obscure crucial details in astronomical images, hindering scientists’ ability to detect changes that might indicate the presence of exoplanets or other important celestial events.
To address this growing concern, Borlaff advocates for immediate action to devise solutions that balance the needs of satellite operators with those of astronomers. This could involve designing less reflective satellites, adjusting their orbital placements, or coordinating launch schedules to minimize overlap with telescope observations. As the cosmos becomes increasingly crowded with artificial satellites, finding a sustainable coexistence strategy is essential to preserve the integrity of astronomical research. Borlaff concludes, “There has to be an optimal way to place constellations and space telescopes… so we can coexist in a sustainable way.” The time to act is now, as the clarity of our view into the cosmos hangs in the balance.
A simulated image representing the projected contamination by satellite trails in one of the future space telescopes. The stripes of light reflected from artificial telecommunication satellites outshine the otherwise pristine image of two galaxies interacting in the background. | Image: NASA / Borlaff, Marcum, Howell (Nature, 2025)
It’s getting harder and harder for the Hubble and other telescopes orbiting Earth to capture pristine images thanks to the sudden surge in satellite launches. Satellite trails could mess up nearly 40 percent of images the Hubble takes and up to 96 percent of those taken by three other telescopes over the next decade, according to a
study
by NASA researchers published today in the journal
Nature
.
That could jeopardize scientists’ ability to spot worrisome asteroids or discover new planets, they warn. Our view of space just gets fuzzier without efforts to limit light pollution from new megaconstellations of satellites.
The scale of the problem is astounding
“My career has been focused on trying to make telescopes see better … try to make the telescopes more sensitive, more precise, getting better images,” says Alejandro Borlaff, a NASA research scientist and lead author of the study. “For the first time, we found something that may actually be worse in the future.”
The scale of the problem is astounding. Cheaper launch costs and the proliferation of telecommunications satellites like Starlink’s have opened up a Pandora’s box of new challenges in space. Satellite trails, which look like streaks of light, were already detected in 4.3 percent of images taken by the Hubble between 2018 and 2021. The number of satellites orbiting Earth has grown from
5,000 in 2019
to more than 15,800 today,
according to the European Space Agency
. That number could reach as high as 560,000 if currently planned satellite launches proceed over the next 10 years or so.
Borlaff and his colleagues simulated the view that four telescopes are likely to have after all those launches. With that much crowding in space, they project that the Hubble telescope could inadvertently capture an average of 2.14 satellites per exposure. The Chinese Space Station Telescope Xuntian, one of the other telescopes included in the study that’s expected to launch next year, could see an average of 92 satellites per exposure. The Hubble is less likely to catch as many satellites in its images because of its narrower field of view. Fortunately, other powerful telescopes, including the
James Webb
, orbit far enough from Earth to avoid light contamination from satellites.
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The issue goes beyond accidentally including a satellite (or many) among the visions of swirling nebulae, stars, and distant planets these telescopes capture. The satellites reflect light from the Sun, Moon, or Earth, which can be bright enough to obscure details that might otherwise be captured in an image were it not for that light pollution. Researchers might not be able to detect a change in the brightness of a star that could indicate that there’s an exoplanet there, Borlaff explains. “You will lose that information because a satellite passed in front of you.”
Now’s the time to find solutions, he says, before there are so many satellites in orbit. Efforts to design darker, less reflective satellites have posed new problems because they tend to get hotter and shed more infrared light as a result. Researchers have also tried strategizing to take images at times and locations with a lower likelihood of satellites crossing their path, an endeavor that’s harder to do the more crowded it gets out there. It’ll take more coordination on the ground with companies and governments launching satellites, maybe by placing them in orbit lower than where the telescopes are to avoid obstructing their view or regulating where they can be deployed.
“There has to be an optimal way to place constellations and space telescopes … so we can coexist in a sustainable way,” Borlaff says.
Eric
Eric is a seasoned journalist covering US Tech & AI news.
