SpaceX’s Starlink and other satellite Internet providers make light pollution worse for astronomers

The rapid growth of Internet satellites, the formation of mega-constellations, and the accumulation of space debris are already beginning to disrupt astronomers’ research. The problem is growing exponentially, scientists warn in a series of papers published recently. magazine Astronomy of nature. And they want regulators to do something about it.

The flock of satellites operating in low Earth orbit has more than doubled since 2019, when space-based Internet initiatives really took off. That year, SpaceX and OneWeb launched their first batch of satellites with the goal of providing global Internet coverage. Orbiting the planet at a closer distance than other satellites is expected to make those services faster by reducing the distance for signals to and from Earth. The trade-off is that at such close range, companies need many more satellites to cover the entire planet.

All that equipment makes light pollution worse, which then makes it difficult for astronomers to peer deep into our universe. Satellite tracks also photobomb telescope observations.

“In just three years, satellite mega-constellations have become an increasingly serious threat to astronomy,” says A. perspective paper is published Astronomy of nature yesterday “We are witnessing a dramatic, fundamental, and perhaps biannual transformation of the night sky without historical precedent and under limited control.”

The numbers are quite staggering. There are several 9800 satellites in orbit around the Earth today, of which about 7,200 are still operational. By 2030, the number of satellites in low Earth orbit may increase to 75,000, according to the European Southern Observatory. SpaceX alone plans to launch 42,000 satellites for its Starlink internet service.

Astronomers were already sounding the alarm when SpaceX launched its first 60 Starlink satellites in 2019. Satellites and spacecraft debris reflect and scatter sunlight, making the night sky brighter. according to 2021. And unlike the sources of light pollution on Earth, which tend to be concentrated around brightly lit cities, light pollution from space can affect the entire planet’s view of space.

The authors of the perspective paper calculated the effect of this increased brightness big question The night sky was scheduled to begin in 2024 at the Vera Rubin Observatory in Chile. Data from the survey is expected to provide new insights into how the Milky Way formed, the properties of dark matter and dark energy, and even the trajectories of asteroids that may be heading toward Earth. But the observatory’s discoveries could be hampered by the proliferation of satellites, according to the paper. In particular, brighter night skies result in a significant loss of efficiency and can cost a project millions of dollars.

Light reflected by objects in low Earth orbit will increase the brightness of the background for research by 7.5 percent by 2030 compared to the unpolluted night sky. The researchers found that the intervention could have ballooned the program’s costs by about $22 million. That’s because with brighter night skies, researchers need to increase exposure time to spot distant objects. And scientists may miss more faint objects in brighter skies, the paper warns. Rising costs and competition for telescope time can also make it difficult for smaller institutions and astronomers from underrepresented backgrounds to do their research.

Photobombarding satellites are another growing problem for astronomers. Satellite tracks appeared in 2.7 percent of Hubble images taken between 2002 and 2021 during 11 minutes of exposure, according to another report. article: was published in the same journal earlier this month. By the 2030s, that number could reach 50 percent of pictures. Similarly, 30 percent of the images taken by the Vera Ruby Observatory survey could contain satellite tracks if SpaceX succeeds in sending 42,000 satellites into space.

SpaceX did not respond to a request for comment The Verge. But in January, the National Science Foundation announced agreement Working with SpaceX to limit the company’s influence on astronomy included proposals to reduce the optical brightness of satellites. The company has published its own paper last year, describing its efforts to design satellites that reflect less light.

Design tweaks to the satellites haven’t completely alleviated the researchers’ concerns. These types of changes can make satellites less visible in images by reducing the brightness of the bands. But they may present new problems, as darker objects may appear brighter at infrared and submillimeter wavelengths, according to the prospective authors. The new designs also won’t fix the problems caused by small pieces of debris, which are responsible for increasing the brightness of the night sky. Crowding low-Earth orbit with satellites only increases the risk of accidental collisions, which create more debris.

For all these reasons, governments should start cracking down on satellite launches, the researchers argue. a interpretation paper The same magazine published yesterday goes so far. “Now is the time to think about banning mega constellations.”

One more paper magazine defends space as a shared environment like humans can on Earth. That could include mandatory environmental assessments for satellites and coordinated international regulation, the paper said. Without thinking about ways to mitigate risks early, University of San Francisco professor Aparna Venkatesan writes: Astronomy of nature“Who will be left to foot the bill for such damage in unregulated terrain?”