Radio waves generated by music radio stations on Earth can be used to accurately detect space debris in Earth orbit, Australian researchers have proved.
The team led by Australian astronomer Professor Steven Tingay used the newly built Murchinson Widefield Array (MWA), one of the most powerful telescopes of its kind, to detect radio waves reflected from objects orbiting the planet and generated by radio music stations. The study paves the way for potential improvements in space junk detection.
“We have shown that we are able to detect approximately 10 pieces of space junk simultaneously. Over time this means we are in a position to monitor a significant fraction of the space junk that is in Earth orbits,” said Professor Tingay.
Space debris is currently one of the greatest concerns of the international space community, as the growing number of various fragments and dead satellites circling the Earth puts operational satellites at risk, possibly causing communication disruption and millions of pounds of damage.
“An early warning system has the potential to protect billions of dollars’ worth of vital infrastructure orbiting the Earth but also prevent collisions that will result in even more space debris being generated, such as what happened in the case of the Iridium 33 satellite in 2009,” Tingay said, taking the collision between the functioning American satellite and an already dead and out-of-control Russian spacecraft Cosmos as an example. The collision not only destroyed both satellites but also generated thousands of dangerous fragments.
The current study is one of the first conducted at the $51m (£31m) Murchinson Widefield Array (MWA), one of the precursors of the planned $2bn Square Kilometre Array project.
“The MWA was designed to be the most powerful low frequency radio telescope in the Southern Hemisphere and this was our chance to test its capabilities,” Professor Tingay said.
The idea to use the MWA for tracking space debris came from an earlier study by Ben McKinley, an astrophysics PhD student at the Australian National University, who was able to image the Moon using reflected FM signals and calculate the likelihood that alien civilisations were listening in on us.