Unexplained radio bursts have once again been detected by astronomers searching for evidence of alien life, and science is still no closer to coming up with a solid explanation for why they exist or what (or who) may have caused them. The newest batch, which were heard on August 26th, is the latest in what is becoming a fairly regular occurrence.

The signals, called fast radio bursts (or FRBs for short), have puzzled scientists for years. FRBs were first discovered about 15 years ago, and in the years since they’ve been detected a couple dozen times. This most recent event came courtesy of one of the usual suspects, FRB 121102, which has been heard on and off for years. The August 26 burst of radio signals repeated 15 times before going silent.

FRB 121102 has been traced to a small galaxy some 3 billion light years away from Earth. That’s an incredibly long distance, which means that whatever is causing the radio signals would have to be extremely powerful. Theories put forth to explain FRBs range from black holes sucking up stars to, you guessed it, alien life. Of course, we would still have no way to explain how an alien civilization might produce such powerful signals either, so whatever causes FRBs is something humanity simply has no knowledge of — yet.

Ultra-powerful telescopes have allowed humanity to gaze deeper into the cosmos than ancient astronomers could have ever dreamed, but we still really have no idea why lies beyond our comparatively tiny scope. Are aliens trying to hail us from afar? Probably not… but maybe.