SpaceX's Starlink internet satellites 'leak' so much radiation that it's hurting radio astronomy, scientists say

An artist's illustration of Starlink satellites above the LOFAR array.
The LOFAR radio astronomy array in the Netherlands can detect electronic hum from Starlink satellites, raising concerns about the megaconstellation's impact on radio astronomy. (Image credit: ASTRON/ Danielle Futts)

Hum from onboard electronics that power SpaceX's internet-beaming Starlink satellites may disturb radio astronomy observations, a new study has found.

Experts have long warned about how astronomy is being impacted by megaconstellations  of low Earth orbit satellites such as SpaceX's Starlink. The streaks those satellites leave in astronomical images mar observations of telescopes even in the most remote locations. The reflection of sunlight from these satellites might lead to an unwanted brightening of the night sky even in areas far away from urban light pollution. And the radio waves these satellites use to carry out their communications could hamper the observations of sensitive radio telescopes. 

But a new, unexpected source of scientific disturbance has now emerged thanks to a new study conducted by researchers using the Low Frequency Array (LOFAR) telescope in the Netherlands: Radiation from the onboard electronics inside Starlink satellites. 

Related: Megaconstellations like SpaceX's Starlink may interfere with search for life by world's largest radio telescope

LOFAR is a network of over 40 radio antennas spread across the Netherlands, Germany and a few other European countries. The telescope is capable of detecting the longest wavelengths of radiation emitted by objects in the cosmos. However, as it transpires, radio frequencies similar to those LOFAR is designed to detect are also unintentionally emitted by Starlink satellites. In the new study, the researchers described detecting this unwanted low-frequency radio hum from nearly 50 Starlink spacecraft. 

"With LOFAR, we detected radiation between 110 and 188 MHz from 47 out of the 68 satellites that were observed," Cees Bassa, an astronomer at the Netherlands Institute for Radio Astronomy (ASTRON), which manages the LOFAR array, and a co-author of the recent paper said in a statement. "This frequency range includes a protected band between 150.05 and 153 MHz specifically allocated to radio astronomy by the International Telecommunications Union."

The finding is of concern to next-generation large-scale radio observatories, such as the Square Kilometer Array Observatory (SKAO), which is currently being built on two remote sites in Australia and South Africa. To maximize the telescope's ability to detect even the faintest signals, regulators have placed radio-quiet zones around the sites where no cellular telephony, terrestrial TV or radio use is allowed. Starlink (and other internet-beaming) satellite constellations, however, can freely travel over those locations and due to their low altitude disturb observations. 

The ASTRON team added in their statement that SpaceX is not in breach of any rules as this kind of radiation from satellites is not regulated by any guidelines, unlike that of the terrestrial devices. 

"This study represents the latest effort to better understand satellite constellations' impact on radio astronomy," the study's lead author and SKAO spectrum manager Federico Di Vruno, said in the statement. "Previous workshops on Dark and Quiet Skies theorized about this radiation, our observations confirm it is measurable." 

The researchers further modeled the impact of this "unintended" radiation from a larger number of satellites. The simulations showed that the unwanted effects would become more pronounced with the constellation's size. 

"Our simulations show that the larger the constellation, the more important this effect becomes as the radiation from all satellites adds up," said co-author Benjamin Winkel from the Max-Planck-Institute for Radio Astronomy (MPIfR) in Germany. "This makes us not only worried about the existing constellations but even more about the planned ones. And also about the absence of clear regulation that protects the radio astronomy bands from unintended radiation." 

The authors added that SpaceX is collaborating with the astronomers in search for solutions that would enable the constellation and astronomy to coexist without negative impacts.

SpaceX has already launched well over 4,000 Starlink satellites, according to astrophysicist and satellite tracker Jonathan McDowell.  The company already has regulatory approval to deploy 12,000 of the broadband communications satellites and has filed for approval to launch another 30,000 Starlink craft.

The study was published in the journal Astronomy & Astrophysics on Wednesday, July 5.

Join our Space Forums to keep talking space on the latest missions, night sky and more! And if you have a news tip, correction or comment, let us know at:

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.

  • EarthShattering
    Interesting that you single out SpaceX satellites. Is there a valid reason or was that just an opportunity to smear Elon Musk? If the latter, I beg you to keep ideology out of science.
  • CheckRide
    I'm 100% confident it was not a starlink sat. Starlinks transmit at 2000 MHz which would be the sat downlink to the user terminal and 500 MHz which is the uplink from user terminal to sat. No radio telescopes operating in that range would be able to see interference from a starlink sat.
  • Classical Motion
    For those who understand radio this could become a real problem. It's comparable to using spark gap transmitters. In context with the sensitive equipment we use today. One of the reasons our modern sensitive equipment works so because we have standards, conditions and restrictions on the emissions we can legally manufacture. There are no spark gap transmitters permitted today.......except in orbit and space, it now appears from the article. What I mean by that is that international emission treaties apparently are not valid in space/orbit. This is real bad juju.

    There are many multiples of, and sub multiples of, plus un-related frequencies, that are used to manufacture the RX and the TX frequencies. In the U.S. and other countries, only the licensed frequency can be emitted. All other frequencies have to be suppressed to a certain ratio of the TX signal power. Some restrictions apply to limit these spurious matter what the TX power. There are many other restrictions also. We would need a textbook to go thru them.

    Anyhow, if this is not suppressed and controlled, the far side of the moon might be the only place left to listen to the stars. This is terrible news about the filthiness of our sat emissions. And there is no excuse for it with today's tech, except for cost. So now we not only have space debris clutter, we have a RF clutter zone along with it. An antenna array can track and nail down an interference source in a heartbeat. It's not a probability.
  • Harry Costas
    It's just amazing how far man has come from 50 - 60 years ago.

    I still remember my Log Tables.
  • Classical Motion
    And a slide rule. My roommate in college told me he caught me using an invisible slide rule in my sleep. And I didn't doubt him. Some classes were very slide rule intensive. I used to have several but they've all disappeared now.
  • Unclear Engineer
    Classical Motion said:
    Some classes were very slide rule intensive. I used to have several but they've all disappeared now.
    Yes, some tests were very "intensive" with a slide rule. We used to joke about making water cooling jackets for them to use in a couple of our engineering courses.

    But, now with all the wiz-bang calculators, test time is not taken up by mechanical manipulations, and you are expected to be able to answer more questions.

    I still have a few slide rules sitting around - just in case one of those apocalyptic scenarios actually happens. And they do help explain logarithms to people who need to think of things physically.
  • Harry Costas
    I remember where my slide rule is.
    Got it out
    And my son said what's that.
  • blazeww420
    Really. Can say they can see atmospheres light years away. Planets from the wobble of its parent star, dimming light from planets passing by a star.. even tell what gases are in an atmosphere light years away.... but no... satellites that have a set frequency mess up the radio telescopes... As those satellites aren't even in frequency range the RT picks up. Like what can't tell human made from natural even tho the energies and process to make each are vastly different.

    Like um... how do they see anything then if radiation that's not like what is being looked for blocks the view? How do they see past all the other stuff then?

    Can't even see past man made stuff... so are they full of crap?
  • Classical Motion
    When you look closely at starlight not with your eyes, but with an amplifier(collector) and a prism(spectrometer) will see a rainbow........with black slots in it. A pattern of black lines.

    If you shine white light thru elements of the periodic will see a partial rainbow and black slots there too. All the stars, and all the elements have a different pattern of those black slots.

    First they look at the star black slot pattern. Then they watch for a change in that pattern when the planet crosses the star. A new slot pattern indicates the elements(and molecules) on that planet crossing.

    It's not perfect, but it gets better all the time. And not being an astronomer, I'm quite sure there are other methods. Or will be.

    When there's a demand, we improve our instruments and methods. These reports are not fairy tales.

    There is probably lot's more information and data than published......waiting for some confirmation. Or procedures these people go thru.

    This is the new big thing. We will be hearing about these discoveries for years to come. And they will get better and better at it.

    We will have to wait and see if there is any benefit. But it keeps our instruments sharp.
  • Harry Costas
    Man has come so far, scratching the surface.
    And yet
    Some scientists think they have cracked the ways of the universe.
    I Quess we all fall into that path.