Starlink satellites blind astronomers’ view of space – DW – 20.09.2024

Efforts to explore the universe are being hampered by radio waves emitted by Starlink’s extensive network of satellites, according to a new study.

The Starlink “constellation” consists of more than 6,300 active satellites orbiting the planet at an altitude of 550 km, making up more than half of all satellites orbiting the Earth.

All of these satellites generate radio noise, called unintended electromagnetic radiation (UEMR).

While the Starlink network enables the delivery of high-speed internet services around the world – a service that benefits communities without reliable internet infrastructure – there is a risk that satellite noise could interfere with astronomers’ work.

A study led by the Netherlands Institute for Radio Astronomy (ASTRON) found that second-generation Starlink satellites “V2” – which make up about a third of the company’s network – emit UEMR at a level 32 times brighter than the brand’s V1 infrastructure.

Starlink’s first-edition satellites, which currently make up the majority of the network, were already in the crosshairs of the astronomy community when their UEMRs were first discovered to be polluting research in 2022.

Benjamin Winkel, a scientist at the Max Planck Institute for Radio Astronomy who participated in the analysis, said the disturbances would “blind” the research community’s work.

“While the Generation 1 satellites actually got weaker last year – so Starlink actually did something to them [to reduce radio leaks] – the new generation unfortunately seems to be brighter again,” says Winkel.

“When we say ‘blinded,’ it means that your eye takes in too much light to see anything. You become saturated. That’s exactly what happens with our radio telescopes,” he added.

Interference from low-Earth satellites blocks our view of space

By 2030, the number of satellites in space operated by all operators could rise to 100,000.

Since some satellites are already visible to the naked eye in the night sky, there is a risk that this huge increase in the number of low-Earth orbiters by all operators will result in even greater blinding for astronomers using both optical and radio telescopes.

“My colleagues told me that they are very afraid of the future,” says Winkel.

“There needs to be some improvements if they really want to do the monitoring properly.”

These latest findings are particularly devastating for observations with radio telescopes.

The result could be that light spots appear in the images from these powerful instruments. These light leaks cannot always be removed and distort valuable observation data.

New satellite regulations may be needed

Cellular networks and radio pollution from other ground-level electronic sources can also interfere with space observations, but these emissions are strictly controlled by regulatory bodies such as the International Telecommunication Union.

In space, things are very different. Since there are few regulations for satellite operators, the research community has to build trusting relationships with companies that will bring their technology into space.

The development was largely positive: Starlink had already made acceptable changes to its V1 fleet to reduce radio noise.

In August, Elon Musk’s SpaceX (owner of Starlink) detailed its efforts to keep radio emissions out of the line of sight of telescopes, a technique known as the “telescope boresight avoidance method.”

In a statement, it said: “SpaceX openly invites other radio astronomy organizations around the world to implement this approach to protect their important scientific research.”

However, Starlink is not the only culprit when it comes to future astronomical disruptions.

A new player in space internet is OneWeb, which has around 630 satellites in orbit. Amazon’s Kuiper project may only have two satellites in orbit, but it is expected to grow as it stakes its claim on consumers’ broadband dollars.

It’s big business, but together these companies are taking away important real estate from space explorers. Regulation is essential, but that takes time, and so a good-faith commitment from satellite operators to continually plug their radio leaks seems to be the best short-term solution.

“There is no way to manufacture electrical or electronic devices without such leaks,” Winkel said. “The question is always: How much leakage is there?”

“Consumer devices are subject to some form of regulation with regard to these leaks, also for health and safety reasons. [and] not to interfere with other devices. But that’s not the case with satellites, so it’s a grey area,” he said.

Edited by: Fred Schwaller

Primary source

Bright unintended electromagnetic radiation from second-generation Starlink satellites. Published by CG Bassa, F. Di Vruno, B. Winkel, GIG Józsa, MA Brentjens and X. Zhang in Astronomy & Astrophysics (2024)