Astronomers ask UN committee to protect night skies from megaconstellations

The image shows diagonal lines caused by the light reflected by a group of 25 Starlink satellites passing through the field of view of a telescope at Lowell Observatory in Arizona during observations of the NGC 5353/4 galaxy group on May 25, 2019.
(Image credit: Victoria Girgis/Lowell Observatory)

The International Astronomical Union is calling for the pristine night sky to be protected by the United Nations as astronomers struggle with exposures ruined by trains of Elon Musk's Starlink satellites.

At first, they provided a new type of heavenly spectacle. But Space's Starlink internet satellite trains traveling across the sky in neat formations after the launch of each batch of the megaconstellation's spacecraft have long annoyed astronomers.

The IAU has now decided to take the issue to the United Nations Committee on the Peaceful Uses of Outer Space (UN COPUOS), according to Thomas Schildknecht, the deputy director of the Astronomical Institute of the University of Bern, Switzerland, who represents Switzerland in the IAU. The organization of astronomers is requesting that UN COPUOS protect the sky's darkness for the sake of future advancements in astronomy.

"These trains are nice and impressive, but do we really want to see them everywhere?" Schildknecht said on April 20 in a news conference organized by the European Space Agency (ESA) during the 8th European Space Debris Conference held virtually from Darmstadt, Germany, April 20 to 23. "Do we want to see them in the Australian outback? In Antarctica? Or in the very dark regions of Chile? Probably not."

Related: No, they're not aliens — SpaceX's Starlink satellites surprise skywatchers

Astronomers have complained about the streaks ruining their observations ever since SpaceX, Starlink's operator, started lofting the Internet-beaming megaconstellation into low Earth orbit in 2019. SpaceX currently has approval to launch 12,000 satellites, but the company's plans call for launching as many as 30,000 spacecraft. The launches are coming thick and fast, up to four a month, each injecting up to 60 satellites into orbit.

"It's not just the streaks but also the diffuse background light and the radio noise from these satellites that may prevent us from accessing the sky," Schildknecht said. "It may cut us off from accessing knowledge about our universe."

SpaceX has acknowledged the problem and tried to reduce the amount of light reflected by the satellites. Astronomers, however, said the mitigation measures so far have been insufficient.

The IAU, Schildknecht said, asks UN COPUOS to create regulations that would restrict the brightness of the satellites in megaconstellations and request operators to share data about their satellites' orbits with astronomers so that they could more easily avoid streaks in their observations. 

Report: Satellite megaconstellations could have 'extreme' impact on astronomy

The efforts of SpaceX, as well as other aspiring megaconstellation developers like Amazon and OneWeb, which launched 36 new satellites for its own constellation on Sunday, concern the global space community not only because of the impact on astronomical observations but also because of the hazards these satellites pose to the already cluttered orbital environment. 

Operators at the European Space Operations Centre in Darmstadt, Germany, have to conduct avoidance maneuvers on average every two weeks over the fleet of 20 ESA spacecraft controlled from the center, said Holger Krag, the head of ESA Space Safety Program, during the news conference. But many more events generate alerts and have to be evaluated, even though an avoidance maneuver is at the end not conducted.

Nearly half of all of these alerts involve objects in large constellations or small satellites, the agency added in a written statement to "These two classes are those that increased most in the past few years and are forecast to continue increasing," ESA said.

Related: This is what SpaceX's Starlink satellites first looked like in the sky

Space debris experts have long warned about the deteriorating orbital environment. Regulations, they say, were drawn up long ago when there were far fewer satellites hurtling around the Earth. What is worse, the guidelines, such as the requirement to deorbit a spacecraft within 25 years of a mission's end, are not always observed. According to ESA, only about 20% of satellites in low Earth orbit are successfully deorbited at the end of their mission.

According to ESA, about 11,370 satellites have been launched since 1957, when the Soviet Union successfully orbited a beeping ball called Sputnik. About 6,900 of these satellites remain in orbit, but only 4,000 are still functioning. 

Starlink, with its monthly rate of over a hundred launched satellites, might wreak havoc in the already perilous orbital environment. 

"Within one month, hundreds of satellites are being launched, and that is much more than we used to launch during an entire year," Schildknecht said. "Even with post-mission disposal, if we want to ensure long-term sustainable use of space, we will come to a point in certain orbital regions when we have to decide about the maximum capacity. We will need to decide whether we can safely launch another 10,000 new satellites."

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Tereza Pultarova
Senior Writer

Tereza is a London-based science and technology journalist, aspiring fiction writer and amateur gymnast. Originally from Prague, the Czech Republic, she spent the first seven years of her career working as a reporter, script-writer and presenter for various TV programmes of the Czech Public Service Television. She later took a career break to pursue further education and added a Master's in Science from the International Space University, France, to her Bachelor's in Journalism and Master's in Cultural Anthropology from Prague's Charles University. She worked as a reporter at the Engineering and Technology magazine, freelanced for a range of publications including Live Science,, Professional Engineering, Via Satellite and Space News and served as a maternity cover science editor at the European Space Agency.