Extraterrestrial intelligence or interference: scientists study a signal from space

Chinese astronomers using the FAST radio telescope have detected a narrowband radio signal from the K2-155 system, home to the potentially habitable planet K2-155 d. The signal retains characteristics of an artificial transmitter even after filtering out interference, but scientists urge caution in drawing conclusions.

Chinese astronomers working with the world's largest radio telescope, FAST, have detected an intriguing radio signal from the star system K2-155, located 238 light-years away. This system hosts three super-Earths orbiting a red dwarf, one of which—K2-155 d, 1.6 times larger than Earth—lies in the habitable zone where liquid water could theoretically exist. The signal at 1148.4167 MHz is narrowband, a trait typical of artificial transmitters rather than natural cosmic sources. Even after thorough filtering of terrestrial interference and noise, the pulse retained these properties. The researchers, who published their findings in ScienceAlert, emphasize that the signal's nature remains a mystery and requires further observation. The article is popular science in tone, presenting facts without speculation.