Scientists thought they found a 'zombie' in space. Turns out, it was something even stranger

Economic Times

30-06-2025

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In June last year, astronomers scanning the sky from the remote deserts of Western Australia picked up a sudden, blinding burst of radio energy. The signal was so powerful, it temporarily outshone every other radio source in the sky, according to a report of CNN.At first, the team at Curtin University believed they had discovered something extraordinary — perhaps a new type of astronomical object or an ultra-rare fast radio burst (FRB) from within our galaxy.'We were really excited,' Dr. Clancy James, associate professor at Curtin's Institute of Radio Astronomy, told CNN. 'It looked like we had found an unknown object near Earth.'The data came from the ASKAP telescope , an advanced array of 36 large antennas spread across the Wajarri Yamaji Country in Western Australia. This setup is usually used to detect FRBs — intense, millisecond-long bursts of radio energy from distant galaxies, potentially caused by exotic phenomena like magnetars, the ultra-magnetic remains of dead stars.These bursts are not only puzzling but also powerful tools for mapping the "missing" matter in the universe. But this particular signal wasn't behaving like a normal FRB.Unlike typical FRBs that originate billions of light-years away, this burst appeared to be shockingly close — just 4,500 kilometers (2,800 miles) from Earth. When the team zoomed into the data, the image became blurry — a telltale sign the source was much closer than expected.After sifting through satellite databases, the astronomers matched the source to Relay 2, a long-defunct U.S. communications satellite launched in 1964. Relay 2 had been orbiting silently since its instruments failed in 1967.But this sparked an even more bizarre question: Could a dead satellite suddenly burst back to life?The leading theory is an electrostatic discharge — a burst of energy caused by a buildup of electric charge on the satellite's surface, similar to the shock you get from touching a doorknob after walking on carpet. When the charge releases, it can emit a sharp flash of radio energy.While these discharges are common and often harmless, the intensity and brevity of this one — just 30 nanoseconds long — was unprecedented. In fact, it was 2,000 to 3,000 times brighter than any other signal the ASKAP instrument typically detects.Another possibility, though less likely, is that a micrometeorite no larger than a grain of sand slammed into Relay 2 at extreme speed, causing a burst of plasma and radio waves. However, the team estimates there's only about a 1% chance that was the cause.Although this turned out to be a human-made source, the discovery underscores a major challenge in space research: the interference of space junk with astronomical observations. With over 22,000 satellites launched since the dawn of the space age — and thousands no longer functional — Earth's orbit is becoming a crowded and unpredictable place.Signals like the one from Relay 2 could easily be mistaken for cosmic phenomena, especially as ground-based observatories like ASKAP and upcoming arrays such as SKA-Low (Square Kilometre Array) continue to scan the skies for fast, faint signals.While this unexpected 'zombie signal' turned out to be from a defunct satellite, it opens up new possibilities for using radio telescopes to monitor aging spacecraft for signs of unusual activity.