Australian astronomers had captured in June 2024, using the Askap radioelescope, a radio signal similar to an extremely powerful flash. Scientists originally believed that it could be a rapid radio start, a phenomenon still unexplained and potentially linked to magnetars. The real explanation of this radio flash, presented Monday in The Astrophysical Journal Lettersis much more disappointing, as CNN reports.
A very close culprit
Indeed, to discover the source of this signal, the researchers must not have gone on the side of distant galaxies and magnetars. The flash had been issued less than 4,500 km away from the earth, from its average orbit.
Scientists quickly identified the culprit: the former Satellite Relay 2. Launched by NASA in 1964, this experimental communication device was used to broadcast the 1964 Tokyo Olympic Games in the United States and Europe. However, he stopped operating in 1967, becoming with his companion Relay 1 one of the many debris that orbit around the earth.
Static or micro -metering electricity?
But then, how can we explain that a satellite that was thought to be dead be able to issue such a radio signal, even for a few nanoseconds? Several hypotheses have been put forward. First, an accumulation of static electricity on the metal shell of the satellite. This accumulation of electrons would have caused a short circuit which would in turn have trained the spark responsible for the signal.
In a less likely manner, researchers also considered the hypothesis of an impact with a microméteorite which would have transformed the debris into plasma, releasing a large amount of energy. In all cases, these results recall that the many space debris can interfere with galactic observations.
