NASA
Last year, astronomers recorded a mysterious, powerful burst of radio waves from our galaxy. According to astronomers, the source of the radio waves was disabled more than 60 years ago, the NASA Relay 2 satellite was launched.
Relay 2 was launched in 1964 and was taken out of service in 1967 after two onboard transponders failed. Almost 60 years later, in June 2024, Relay 2 unexpectedly emitted an incredibly powerful radio pulse. However, astronomers do not know exactly why this happened.
The pulse lasted about 30 nanoseconds, which does not correspond to any of the systems of a disabled satellite. According to a scientist from the Institute of Radio Astronomy at Curtin University in Australia Clancy James and his colleagues, this signal could be caused either by a satellite collision with a small meteorite or by the accumulation of electricity.
The researchers discovered the unusual pulse by scanning the sky for radio pulses using the Australian Square Kilometer Array Pathfinder (ASKAP) — radio telescope in Western Australia, consisting of 36 identical dish antennas.
Radio bursts are intense emissions of radio waves that can release almost instantly the amount of energy that our Sun produces in a few days. Typically, such radio pulses come from distant galaxies. However, the intercepted signal came from our galaxy. The source of the pulse was so close to Earth that the radio telescope ASKAP was not immediately able to focus on it.
Clancy James noted that at first astronomers were very worried because they thought they had detected a signal, probably from some new pulsar, but after investigating the origin of the signal, they were convinced that it could only come from old satellite NASA Relay 2. Astronomers have ruled out the possibility that the pulse could have come from the satellite’s onboard systems.
In this regard, scientists have proposed two alternative versions. According to them, the satellite could have been hit by a micrometeorite. The impact could have created plasma clouds that could increase the conductivity of the space environment or create an electric field on the satellite’s surface. However, the most likely version is that of an electrostatic discharge, which resulted in a sudden flow of electric current occurs between two adjacent surfaces or materials on a spacecraft that have different electrical charges.
«As a very early spacecraft, Relay 2 could have been built with materials capable of holding more charge and therefore producing stronger electrostatic discharges that cause powerful radio frequency pulses», — the researchers explain.
The results of the study were published on the preprint server arXiv
Source: LiveScience