Starlink and radio astronomy: the noise from the sky

The satellites of SpaceX's Starlink network emit radio noise they should not emit, and that noise reaches radio telescopes. In September 2024, Dutch astronomers showed that the second generation of these satellites leaks up to 32 times more unintended radiation than the first. In July 2025, an Australian team published what it describes as the largest survey of its kind: more than 112,000 detections from 1,806 satellites, with interference in up to 30% of the images analyzed. Some of it fell in bands reserved for science.

What happened

The first study was led by Cees Bassa, of ASTRON, the Netherlands Institute for Radio Astronomy, and published in the journal Astronomy & Astrophysics in September 2024. Using the LOFAR radio telescope, the team observed the V2-mini satellites and measured a radio leak that does not come from the communication antennas but from the onboard electronics. Compared with the faintest sources LOFAR studies, this noise is about 10 million times brighter. Federico Di Vruno, of the SKA Observatory, said at the time that humanity is approaching a tipping point in preserving the sky as a window onto the universe.

The second study came from Curtin University, in Australia, led by doctoral student Dylan Grigg and published in the same journal in July 2025. The team analyzed about 76 million images of the sky taken by an SKA-Low prototype station. It found 112,534 detections from 1,806 Starlink satellites. In 703 of them, the emission appeared at 150.8 MHz, a frequency that should be protected for radio astronomy. During the study period, the company launched 477 more satellites.

The research center's director, Steven Tingay, pointed to the gap: current International Telecommunication Union rules deal with intentional transmissions and do not cover this kind of unintended emission.

Why it matters

Radio astronomy depends on silence. Signals from the sky are so faint that any human source drowns them out. For decades, protection came from two sides: telescopes in remote locations and international agreements that reserve entire bands of the spectrum for listening, such as 1,400 to 1,427 MHz, home to the hydrogen line, where all emissions are prohibited.

Satellites change this equation. There is no remote place when the source is in orbit: a constellation of thousands of satellites passes over every observatory. And the emission they leak is not a signal transmitted on purpose, so it escapes the rules designed for transmitters.

The 2024 and 2025 studies mainly measured low frequencies, below 200 MHz. Even so, they reveal a problem that applies to the whole spectrum: the sky people wanted to hear now has noise of its own, and regulation is still catching up. The international response is under way at the ITU, heading toward the 2027 conference.

In Bairo's view

For Bairo, this case shows how fragile a good silence is. Countries took decades to agree on where not to speak, and a useful technology, satellite internet, started making noise without meaning to. In his reading, it is not a matter of choosing between progress and science, but of building responsibly over what one occupies.

The 1420 is, for him, the symbol of that listening agreement, the 21 cm yardstick that humanity decided to keep clean. No one transmits on 1420 MHz, and his project only pays tribute to the band.

Bairo also reads a lesson about leaks here. The satellites' noise does not come from what they transmit; it comes from what escapes. For him, personal data works the same way: the risk usually lies in what leaks without anyone noticing. That is the benefit he proposes with qrqbits: keeping what is intimate protected, with post-quantum cryptography designed to withstand quantum computers as well.

Where this meets the ecosystem

1420mhz, created by CLAIN, carries the name of the protected band and, with it, the responsibility to respect it. The project's tribute is digital, written on the BTZ Chain, without touching the spectrum.

None of Bairo's fronts operates satellites or takes part in the studies cited.

Sources

• Bassa et al., Astronomy & Astrophysics, unintended radiation from second-generation Starlink satellites, September 2024.
• ASTRON, Starlink satellites leak 32 times more interference, 09/18/2024.
• Curtin University, interference to astronomy, July 2025.
• Phys.org, the unintended consequence of faster internet, 07/23/2025.
• Grigg et al., Starlink emission in the SKA-Low band (arXiv), 2025.

Read also

• Why 1420 MHz is a protected frequency
• ITU and satellites: protecting radio astronomy on the road to 2027
• The frequency of silence