Astronomers are once again concerned about the impact satellites like those used by SpaceX for its Starlink service will have on scientific research. A recent study examined the impact of such satellites on Hubble Space Telescope observations and found that the observations were already affected by the number of satellites nearby.
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 surface, this region is prime land for both scientific projects such as Hubble and the International Space Station and commercial projects such as satellite megaconstellations. While there have been satellites in this region for many years, recently the number of satellites has increased dramatically, particularly due to projects like Starlink that rely on having thousands of satellites in orbit.
When these satellites pass telescopes like Hubble, they can leave bright streaks in the images due to reflected sunlight, rendering the data scientifically unusable. The researchers found that only a small fraction of Hubble images are currently affected, less than 1%, but they revealed a multitude of images with ruinous streaks like the one above. And the biggest concern is for the future, with more and more satellites set to be launched over the next few years.
“The fraction of HST imagery traversed by satellites is currently small and has a negligible impact on science. However, the number of satellites and space debris will continue to increase in the future,” the authors write.
To illustrate the potential scale of the problem, they provide data on the current number of satellites versus estimates for the number of satellites that will be launched over the next decade. “As of the date of this analysis, there were 1562 Starlink and 320 One Web satellites in orbit, increasing the population of satellites near orbit [Hubble],” they write. “Nevertheless, the number of satellites in LEO will continue to increase in the future, with the number of satellites in LEO being estimated at between 60,000 and 100,000 by the 2030s.”
SpaceX has made efforts to reduce the impact of its satellites on astronomical observations by painting them a darker color and adjusting their orbits to reflect less sunlight. But as this study shows, the question of who gets to use space and whether scientific research or private enterprise should be prioritized is not going away anytime soon.
The research results were published in the journal Nature Astronomy.