Starlink satellites disrupting astronomy research in WA's Murchison, study finds

Australia Broadcast Center

3 days ago

Global satellite internet service Starlink could interfere with the world's largest radio telescope being built in Western Australia's Murchison, a new study reveals.
The Square Kilometre Array Observatory (SKAO) is an international project that aims to provide an unparalleled view of the universe, enabling scientists to explore the first billion years after the so-called dark ages, when the first stars and galaxies formed.
Curtin University PhD researcher Dylan Grigg analysed 73 million images of the entire sky at different frequencies to examine how satellite signals were disrupting radio astronomy.
His study indicated the future of WA's SKAO telescope, known as SKA-Low, could be in jeopardy, as radio noise spilling from thousands of Starlink satellites low orbiting Earth was already interfering with signals.
Mr Grigg explored the 50—350 MHz frequency range that the SKA-Low would use during his three years of research.
"We took an image of the sky every two seconds for about a month," he said.
"In the end, we found that there were a lot of satellites, with the overwhelming majority of them being Starlink."
Mr Grigg said Starlink satellites were emitting radio noise from onboard electronics, different to the designated downlink frequencies used for the internet.
"It currently falls into a bit of a grey area of regulation," he said.
"What they're doing is completely legal and fine, but it's interference for radio astronomy."
Mr Grigg said SKA-Low aimed to seek out extremely faint signals emitting from the far reaches of the universe, but this would be challenging with "very noisy" satellites passing.
"Even if your algorithms are very good for filtering some of this … it makes it really difficult."
The ABC has contacted Starlink for comment.
SKAO spectrum manager Federico Di Vruno said Mr Grigg's findings were consistent with SKAO's previous studies, but more work was needed to develop a clearer understanding of Starlink's impact on low-frequency observations.
"Unintended electromagnetic radiation (UEMR) is an unregulated aspect of space which poses a challenge for radio astronomy," he said.
The number of human-made objects in space has soared, with the Union of Concerned Scientists reporting that a record number of satellites were launched last year.
But Mr Di Vruno said that, unlike the single station used in Mr Grigg's study, the SKA-Low would use many stations separated over a large distance, meaning the unwanted signals that satellites produced were not as much of a worry.
"The SKA-Low telescope will be made of up to 512 stations spread over 74 kilometres," he said.
"We are continuing to study the issue and raising it in international settings like the UN in collaboration with all stakeholders."
International Centre for Radio Astronomy director Steven Tingay said he hoped Mr Grigg's report would stimulate conversation.
"I characterise this particular study as, I think, the most comprehensive, unbiased study of the situation, setting down a bit of a baseline for what's going on at this particular point in time," Professor Tingay said.
"We can then revisit this in future years and then go back and compare to the baseline and see what's changed — have things improved, have things not improved? Are there more signals?
"And also, stimulate discussion, raising awareness with the general public that, yeah, there are some pretty obvious trade-offs between having global internet, which is an amazing thing, and preserving the sky for doing important science.
"It's a trade-off there that I think the public should be aware of."