
A batch of Starlink satellites launched on a Falcon 9 rocket
SpaceX
SpaceX’s Starlink satellites are emitting radio waves at a level that poses a threat to the study and understanding of the early universe, according to astronomers.
Astronomers have been concerned about the interference caused by the thousands of Starlink satellites in orbit, which provide global internet service. The radio emissions from these satellites could impact sensitive telescopes that observe distant and faint radio sources. Although SpaceX has collaborated with astronomers to minimize interference by deactivating internet-transmitting beams when passing over key telescopes, recent findings suggest that these measures are insufficient.
Researchers led by Steven Tingay at Curtin University in Australia have monitored signals from nearly 2000 Starlink satellites using a prototype telescope from the Square Kilometre Array-Low observatory (SKA-Low) in Australia. This observatory, which consists of over 100,000 interconnected telescopes, is designed to explore the early universe. The team discovered that Starlink signals could impact up to a third of the data collected at certain frequencies, potentially jeopardizing the observatory’s scientific goals.
The study also revealed that the satellites were emitting signals in two frequency ranges protected for radio astronomy by the International Telecommunication Union (ITU), indicating a violation of regulations. However, these emissions are believed to be unintentional, originating from onboard electronics transmitting signals through the satellites’ antennas. The leaked emissions are significantly stronger than faint radio signals from neutral hydrogen clouds present during the formation of the first stars, which astronomers aim to detect to enhance their understanding of the early universe.
According to Tingay, the unintentional emissions are not technically illegal as ITU regulations only cover deliberate emissions. He emphasized the need for discussions within the ITU to introduce regulations addressing this type of emission. In response, SpaceX has expressed openness to dialogue on reducing emissions, although they have not provided a formal comment.
Efforts to mitigate the impact of these emissions may involve enhancing satellite technology to minimize leakage. The researchers have suggested that SpaceX could implement measures similar to those taken to reduce light interference in optical astronomy. While these findings align with previous studies, further research is required to fully assess the impact on low-frequency observations.
Should SpaceX fail to address the issue, researchers may need to develop algorithmic solutions to filter out interfering radio waves, though this approach is still in its early stages and may require substantial computing power. Tingay emphasized the importance of finding a resolution to preserve the integrity of astronomical observations amidst increasing satellite deployments.