satellite constellations invading Earth’s orbital skies they are currently polluting the wavelength bands that are supposed to be protected for radio astronomy.
According new researchelectronics on board SpaceX star link satellites are “leaking” low-frequency radio waves, separate from their assigned downlink bands, in a way that could affect our ability to conduct astronomy.
“This study represents the latest effort to better understand the impact of satellite constellations on radio astronomy,” says engineer Federico Di Vruno the SKA Observatory and the International Astronomical Union.
“Previous workshops on Dark and calm skies Theorized about this radiation, our observations confirm that it is measurable.”
As Earth’s skies become more crowded, the effect satellites have on our study of space becomes increasingly worrisome. SpaceX currently has a estimated 4,365 of its small Internet satellites in Earth orbit, with thousands more planned. And they are not the only company. OneWeb has more than 600. Amazon plans to launch thousands more from in 2024.
SpaceX listened to concerns about visible light pollution and designed a new dimmer satellite. But the visible wavelengths only represent one type of Earth-based astronomy. The other branch, possibly much larger, is radio astronomyand herein lies what could be a problem.
Radio frequencies between 10.7 and 12.7 gigahertz are used by satellites for communications downlink, at least in Europe; researchers have already expressed concern for those.
But scientists thought that the satellites might be emitting unwanted radio waves out of that band. This is what Di Vruno and his colleagues sought to investigate.
They used the low-frequency ARray (PROMISES) in Europe, a network made up of some 20,000 radio antennas distributed throughout 52 locations. With this level of sensitivity, they observed 68 satellites belonging to the Starlink constellation. Sure enough, they detected an electromagnetic leak.
“With LOFAR, we detected radiation between 110 and 188 MHz from 47 of the 68 satellites that were observed.” says astronomer Cees Bassa from ASTRON, the Netherlands Institute for Radio Astronomy.
“This frequency range includes a protected band between 150.05 and 153 MHz assigned specifically to radio astronomy by the International Telecommunication Union.”
This emission seems to be unintentional, since it comes from the electronics of the satellites. He’s also not breaking any rules. Here on Earth, the International Electrotechnical Commission It places strict restrictions on electrical devices to control electromagnetic interference, but those rules don’t apply in space.
The effect is relatively small, so far. But it will not necessarily always be so. The more satellites that emit this unintentional radio signal, the brighter it gets.
However, a solution is already in the works. Researchers have contacted SpaceX, which is working on ways to reduce or eliminate this unintentional leak. And although there are already thousands of machines up there, we are really alone at first of satellite constellation technology.
This makes satellite radio leakage a problem that was caught relatively early. Future designs may be adjusted accordingly as regulators work to fill the unexpected gap in the official rules.
“The present study highlights one example of the various channels of how technological development can have unforeseen side effects in astronomy.” says astronomer Michael Kramer from the Max Planck Institute for Radio Astronomy and the Astronomische Gesellschaft of Germany.
“With SpaceX leading by example, we now expect broad support from across the satellite industry and regulators.”
The research has been published in Astronomy and Astrophysics.