Pop music finally put to good use tracking space junk
Australia's Murchison Widefield Array was built to probe intergalactic gas, but it can also use FM radio waves to determine the orbits of space junk.
Australian broadcaster Triple J plays a mix of pop and alternative tunes that are being recruited to serve science -- by helping track orbiting above us.
The station is among FM broadcasters whose signals are bouncing off decaying satellites and other debris and into the giant "ear" that is the Murchison Widefield Array in Western Australia.
The high sensitivity of the radio telescope launched earlier this year allows it to detect objects smaller than 1 meter (3.2 feet), according to its director Steven Tingay of Curtin University. Tingay wants to use the array to improve knowledge of the thousands of bits of scrap that may threaten working satellites.
FM radio transmitters send waves over the Earth but also into space, where they bounce off satellites and space junk. Some of those waves get reflected back to Earth.
The array, which consists of 2,048 dual-polarization dipole antennas arranged in 128 formations of four-by-four tiles, is a precursor to the international Square Kilometre Array radio telescope. It can pick up reflected waves from objects up to 620 miles away.
In 2009, an Iridium communications satellite collided with a defunct Russian satellite, creating an unprecedented cloud of more than 2,000 bits of debris, which worried operators of other satellites as well as the International Space Station.
Earlier this month, the European Space Agency's 1-ton Gravity field and steady-state Ocean Circulation Explorer, mostly burning up in the atmosphere with bits hitting the southern Atlantic.
In a study in The Astronomical Journal, Tingay and collaborators showed how they used the Murchison Widefield Array to track the ISS based on how it reflected FM radio broadcast signals originating in southwestern Australia.
"Because the telescope has such a large field of view, monitoring vast patches of the sky at any given time, we can simultaneously image hundreds of these objects every day and track them for long enough to determine their orbits," Tingay says in a recent video.
"We can do all this at the same time as our primary mission. That is, to look way back into cosmic time."
Check out the slideshow below on the persistent threat posed by the junkyard above our heads.