Satellites like Starlink interfere with Hubble’s observations

Astronomers are also concerned about the impact of satellites like those used by SpaceX for its Starlink service on scientific research. A recent study looked at the effect of those satellites on observations from the Hubble Space Telescope and found that the observations were already affected by the number of nearby satellites.

Telescopes like Hubble are particularly vulnerable to interference from satellites because of their location, in an area called low-Earth orbit (LEO). At less than 1,200 miles above the Earth’s surface, this region is prime ground for scientific projects such as Hubble and the International Space Station and for commercial projects such as satellite megaconstellations. While there have been satellites in this region for many years, recently the number of satellites has increased significantly, mainly due to projects such as Starlink which rely on having thousands of satellites in orbit.

The curving light streak produced by an artificial satellite distorts the image taken by the Hubble Space Telescope. S. Kruk et al./Nat. Astron.

When these satellites pass in front of telescopes like Hubble, they can leave bright streaks in the images due to reflected sunlight that renders the data useless for science. Researchers have found that only a small fraction of Hubble images are affected today, less than 1%, but they show various images with damaging streaks like the one above. And the biggest concern is for the future, with more satellites set to be launched in the next few years.

“The fraction of HST images crossed by satellites today is small with little scientific impact. However, the number of satellites and space debris will only increase in the future,” the authors wrote.

To illustrate the potential scale of the problem, they provide data on the current number of satellites compared to estimates of the number of satellites launched in the next decade. “As of the date of this analysis, there are 1562 Starlink and 320 One Web satellites in orbit, increasing the population of satellites near the orbit of [Hubble],” they wrote. “However, the number of LEO satellites will only increase in the future, with an estimated number of LEO satellites between 60,000 and 100,000 in the 2030s.”

SpaceX is trying to reduce the impact of its satellites on astronomical observations by painting them a darker color and adjusting their orbit to reflect less sunlight. But as this study shows, the issue of who gets to use space and whether priority should be given to scientific research or private companies isn’t going away anytime soon.

The research is published in the journal Nature Astronomy.

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