To detect radio emissions and signals sent by hypothetical devices of extraterrestrial civilizations, the choice of the search point plays an important role. After all, space is huge, and the likelihood of accidentally stumbling on a television radio signal of extraterrestrial origin is extremely low. However, now, with the help of data obtained by NASA's Kepler space telescope, astronomers can focus on finding radio signals coming from certain star systems, those where planets are located, suitable for the emergence and development of life on their surface. This search strategy yielded successful results almost immediately, with a radio signal recently detected as the most likely candidate for an extraterrestrial signal.
Naturally, uncork the champagne and shout "we found aliens!" a bit early. There is a fairly high probability that the captured signal is actually of terrestrial origin, it may well be our own, reflected from some cosmic body. According to a press release by a group of astronomers from the University of California at Berkeley, the use of the SETI program in conjunction with the Kepler telescope began only recently, but candidates for the right to be called a signal of extraterrestrial origin appeared almost immediately. Unfortunately, however, most of the first detected radio transmissions turned out to be only traces of radio frequency signals and interference sent from Earth.
But the fact was also noted that among the many recorded signals there are some that, according to scientists, may be sent by extraterrestrial technologies. These signals are very narrow in frequency, much narrower than most signals generated by any of the known astrophysical phenomena. It was also noted that they constantly drift in frequency, which can be easily explained by the Doppler effect, arising from the superposition of the movements of the transmitter and the radio telescope.
Naturally, the fact that the SETI program now selects star systems with exoplanets similar to Earth for the search will significantly increase the chances of finding an extraterrestrial civilization that has reached a stage of technological development, which allows transmission of powerful radio signals. However, one should take into account the infinity of space and the huge number of star systems, which, according to astronomers, are discovered "in batches a day" using the Kepler telescope. Therefore, the likelihood of detecting aliens remains quite low.