Starlink satellites harm space observation – 09/30/2024 – Science

The radiation emitted by the most modern models of Starlink satellites has “overshadowed” radio telescopes and made the work of astronomers more difficult, according to a study led by the Dutch Institute of Radio Astronomy (Astron).

Starlink is an arm of SpaceX, billionaire Elon Musk’s space exploration company. Its fleet is estimated to have more than 6,300 satellites in operation around the Earth – more than half of the objects in orbit –, with a third of them being made up of newer, much “shinier” models.

This “noise” is known as unintended electromagnetic radiation, or UEMR, and is generated by satellites owned by Starlink and other companies operating in space. These devices move 550 km and provide broadband internet around the world, often to remote places such as the Amazon.

According to the scientists involved in the research, the radiation emitted by Starlink’s second-generation satellites causes interference 32 times greater than that generated by first-generation satellites.

Starlink’s older satellites, which currently comprise the majority of the network, were once in the astronomical community’s crosshairs when its UEMR was first detected “polluting” research in 2022.

Benjamin Winkel, a scientist at the Max Planck Institute for Radio Astronomy who contributed to the analysis of the Starlink fleets, says the interference is literally “blinding” the work of the scientific community.

“Although generation one satellites have, in fact, gotten dimmer over the last year – so Starlink actually did something with them [para reduzir os vazamentos de radiação]– the new generation, unfortunately, seems to be brighter again,” said Winkel.

“When we say ‘blind,’ it means your eye takes in too much light for you to see something, it’s becoming saturated. That’s exactly what happens with our radio telescopes,” explains Winkel.

“If the input power of some artificial signal is much greater than what we want to observe from the sky, there is no way to detect or analyze this tiny signal amidst the enormous amount of noise that is generated by the [atividade] human.”

Astron also signaled concern about the number of satellites in orbit from all operators, which could increase to 100,000 by the end of the decade.

With Starlink satellites already visible in the night sky to the naked eye, a ninefold increase in the number of satellites in low-altitude orbit from all operators has the potential to cripple astronomers using optical and radio telescopes.

“My colleagues have told me they are really scared about the future,” Winkel said.

“There should be some improvements if they really want to observe properly.”

These latest findings, published in the journal Astronomy & Astrophysics, are particularly devastating for radio telescope observations.

High levels of radio pollution from near-Earth orbit add to interference from other sources of anthropogenic radiation on the ground, such as cell phones and transmission towers, and will lead to reduced sensitivity of radio telescopes in certain situations.

This isn’t limited to radio telescope operators either. Although large optical telescopes operate using the visible light spectrum, the presence of tens of thousands of satellites orbiting Earth risks reflecting light toward these telescopes.

The consequence may be the appearance of “spots” of light in the images obtained by these instruments. Light leaks cannot always be removed, tarnishing valuable observation data.

How to avoid an astronomical blackout?

Although cell phone networks and radio pollution from other ground-level electronic sources can interfere with space observations, these emissions are controlled by regulatory bodies such as the International Telecommunications Union.

On the space side, the story is different. With few regulations on satellite operators, the research community relies on creating good-faith interactions with companies putting technology into space.

For the most part things have been positive, Starlink itself has made modifications to its first fleet to reduce radio noise.

In August, SpaceX (owner of Starlink) said in a statement that it intends to continue its efforts to divert radio emissions from the telescope’s line of sight.

It also reported that “SpaceX maintains an open invitation to other radio astronomy organizations around the world to implement the approach to protect their important scientific research.”

DW contacted the company for comment on the latest assessment of its second-generation fleet, but did not receive a response at the time of publishing this text.

Starlink is not the only one causing astronomical interference. An emerging player in the space internet game is OneWeb, which has about 630 satellites in orbit. Amazon’s Kuiper project has only two satellites in orbit, but there are large investments to expand broadband offerings.