As the race to provide global satellite internet intensifies, astronomers are raising urgent concerns about the unintended consequences of populating Earth’s orbit with thousands of new satellites. While SpaceX’s Starlink has been at the forefront of this trend, it’s just one player in an increasingly crowded field.
OneWeb has already deployed 634 satellites, while Amazon’s Project Kuiper plans to launch over 3,000. Even more ambitious is China’s Spacesail Constellation, aiming for a staggering 15,000 satellites.
Beyond Visual Pollution
The most obvious effect of these satellite constellations has been the visible light streaks they create during astronomical observations, particularly at dusk. However, a new study reveals a more insidious threat: radio frequency interference.
Research published last year found that constellation satellites are leaking radio waves outside their designated 10.7-to-12.7 gigahertz range used for communication downlink. Alarmingly, some of this leakage falls within the 150.05-to-153 megahertz (MHz) range, which is crucial for radio astronomy.
New Evidence from LOFAR
A recent study analyzed data from the LOw Frequency ARray (LOFAR) in Europe, a network of about 20,000 radio antennas spread across 52 locations. Using two 1-hour observations from LOFAR’s six central stations, researchers observed 97 Starlink satellites emitting radio waves in the 110-to-188 MHz frequency range.
Notably, emissions from the newer v2mini versions of Starlink satellites were significantly brighter than those from the first generation.
Regulatory Vacuum
Currently, there are no regulations addressing the leakage of unintended electromagnetic radiation from constellation satellites. Researchers strongly advocate for such regulations to be implemented swiftly.
“Humanity is clearly approaching an inflexion point where we need to take action to preserve our sky as a window to explore the Universe from Earth,” says Federico Di Vruno of the SKA Observatory. “Satellite companies are not interested in producing this unintended radiation, so minimizing it should also be a priority in their sustainable space policies.”
Call for Action
The researchers urge Starlink to use their data analysis to identify and address the source of unintended electromagnetic radiation in their satellites. As the leading player in the field, Starlink has the opportunity to set industry standards.
Jessica Dempsey, ASTRON’s general and scientific director, emphasizes the broader implications: “Radio astronomy doesn’t just have implications for space research. The technological advances and discoveries made for and in the study of the cosmos have helped develop technologies that we use here on Earth, too – from Wi-Fi and GPS to medical imaging.”
She adds a stark warning: “Without mitigations, very soon the only constellations we will see will be human-made.”
As of the time of reporting, SpaceX has not responded to requests for comment on these findings.
