A little over a year ago, scientists in Australia recorded a short burst of electromagnetic radiation. The pulse was so strong that it overshadowed all other signals coming from the sky, but its origin was unknown. After analyzing the data, the team discovered that the source was not a distant celestial object, but a zombie satellite left in Earth orbit with no purpose.
Relay-2 was launched by NASA on January 21, 1964, two years after its predecessor, Relay-1, was sent into orbit. These were experimental communication satellites on board which experiments were conducted to map radiation belts, otherwise known as the Van Allen radiation belts. Relay-2 continued to operate until June 9, 1967, when two of its transponders failed and it was not heard from again until it emitted a short-lived signal almost 60 years later.
On June 13, 2024, astronomers at Australia’s Patfinder Observatory detected a mysterious fast radio burst (FRB) that lasted less than 30 nanoseconds. “We were really excited, thinking we might have discovered a new pulsar or some other object,” Clancy James, a researcher at Curtin University, told New Scientist. “It was an incredibly powerful radio pulse that dwarfed everything else in the sky for a very short period of time.”
Initially, scientists assumed that the signal came from a distant object in space, but further analysis showed that the culprit behind the mysterious pulse was the long-dead Relay 2, according to the article available on the arXiv preprint site.
Fast radio bursts are short, powerful pulses of radio waves that usually come from deep space and last only a few milliseconds. According to NASA, despite their short duration, FRBs can release so much energy in this short period of time that they can darken an entire galaxy. The FRB detected in June 2024 was particularly powerful – and it coincided with a NASA satellite flying directly over it at the time, as the article notes. It was also extremely clear and well-defined.
Why Relay-2 suddenly emitted this signal remains a mystery. The scientists who made the discovery believe that the satellite could have been accumulating electricity for years and then suddenly discharged it in one powerful burst. Another possibility is that Relay-2 was struck by a micrometeorite or other object in orbit, which led to the release of a small cloud of plasma, the researchers suggest.
As more and more malfunctioning satellites appear in space, making all sorts of strange noises, it will be increasingly difficult for scientists to distinguish whether it is space talking or just some faulty machinery.
