The mystery of a strange radio burst has been solved
What's the story
A mysterious and intense flash of radio waves, detected by a team of astronomers, has been traced back to its source after more than a year of investigation. The signal was first detected on June 13 last year at the Murchison Radio-astronomy Observatory in Western Australia. The team was able to trace the source of the burst to a defunct US communications satellite called Relay 2, which was launched in 1964 and went silent by 1967.
Signal details
Initial investigation of the burst
The radio burst, unlike other fast radio bursts from billions of light-years away, showed no delay between high and low frequencies. This initially indicated it had originated within a few hundred light-years of Earth, but further investigation pinpointed it to be much closer, at approximately 4,500km. The team thought the signal was an interference from human-made sources. However, they later realized it was not typical interference but was still not an astronomical event, as it was traced to a satellite.
Burst duration
About the radio burst and its characteristics
The radio burst in question was a bright pulse lasting a few billionths of a second, with two dimmer after-pulses. This total duration of 30 nanoseconds is much shorter than other known fast radio bursts. The team considered various possible sources for this short, bright burst and traced it to the Relay 2 satellite, but couldn't definitively determine the exact mechanism that caused the burst.
Potential
More such signals could be found in future
The team believes that an electrostatic discharge or a micrometeoroid strike may have caused the burst from Relay 2. With the right techniques, astronomers could find more of these signals in the future. They suggest that monitoring satellites for electrostatic discharges with ground-based radio antennas could be a viable method. This is especially necessary as the number of satellites in orbit continues to grow rapidly.