Mysterious signal from a Sun-like star
In May 2015, a strange signal was detected that later sent the Internet abuzz. It was found by the RATAN-600 radio telescope in Zelenchukskaya, Russia, coming from a star 94-light-years away called HD 164595.
The radio signal was interesting because it was extremely powerful, suggesting it was not a natural phenomenon. Such was the strength that it would have needed to been caused by an advanced civilisation, a Type II on the Kardashev scale, which is a hypothetical scale for measuring the technological process of a civilisation. This strength was equivalent to the total energy consumption of all humankind being sent directly at us.
The star was subsequently monitored by a suite of telescopes, including those run by the SETI (Search for Extraterrestrial Intelligence) Institute. There was some confusion, however, as the
Russians had been slow to announce the discovery of the signal – making follow-up observations difficult. In the following year, no further spikes were seen from the star.
Sadly for alien hunters, a team in Russia investigating the signal said it had almost certainly come from a satellite in Earth orbit. Usually when searching for signals, astronomers take care to remove other interference from terrestrial objects. In this case, it seems one slipped through.