A Mysterious Glitch in Space: Dead Satellite's Radio Burst

In the vast expanse of space, a dead satellite named Relay 2 made a surprising comeback. Astronomers in Australia detected a powerful radio signal in mid-June that initially sparked excitement. They thought they had stumbled upon an unknown object near Earth. However, the source of the signal turned out to be much closer than expected. Relay 2, launched by NASA in 1964, had been orbiting Earth as space junk since 1967. The signal detected was so strong that it outshone everything else in the sky. This event raised questions about the growing problem of space debris and its impact on astronomical observations. The signal was picked up by the ASKAP radio telescope, an array of 36 dish antennas in Western Australia. The team was initially searching for fast radio bursts, which are powerful explosions in radio waves from distant galaxies. However, this signal was coming from just 4, 500 kilometers away, far too close to be an astronomical object. The researchers realized the signal was from Relay 2. They were disappointed at first, but then they wondered what could have caused such a powerful spark after decades of silence. The signal was about 2, 000 to 3, 000 times brighter than other radio data detected by the instrument. There are two possible explanations for the signal. The most likely cause is a buildup of static electricity on the satellite's metal skin, which was suddenly released. This is similar to the static electricity that builds up when you rub your feet on a carpet and then spark your friend. A less likely cause is the impact of a micrometeorite, a tiny space rock that could turn into plasma and emit a short burst of radio waves. This event highlights the challenges posed by space junk. With over 22, 000 satellites launched since the dawn of the Space Age, the risk of confusion between satellite bursts and astronomical objects is increasing. As more satellites are launched, it will become more difficult to conduct experiments like this one. The study also suggests that ground-based radio observations could reveal unusual events happening to satellites. This could be done with a cheaper, easier-to-build device rather than a sprawling telescope. The study illustrates the need for careful analysis to distinguish between radio bursts from astrophysical sources and those from man-made objects close to Earth.