By now many of you have heard the preliminary reports from the astronomy community that a team of researchers has detected an interesting signal from a distant star. At this point it is impossible to know what generated this signal, but one possibility is that it could be a product of an advanced alien civilization. However it is far more likely that it is a natural astrophysical phenomena, which would be just as interesting for the scientific community but less newsworthy.

The SETI program in its current form dates back to 1995, when in response to government funding cuts in related astronomy research a non-profit institute was setup to search for evidence of extraterrestrial civilizations. Using spare time on a series of different radio telescopes, the team behind SETI collected radio signals from different regions of the sky. For the first four years the scientists used their own computer systems to analyze the data looking for signals that did not have a natural origin. Then in the spring of 1999 they launched the first distributed science project with SETI@Home, which asked volunteers around the world to donate processing time on their home computers to do this analysis. (And I am proud to say that I was one of the first to sign on)

For twenty years they have been searching and have found no indications of alien life. But now that may have changed with the announcement that a team of Russian astronomers have identified an as yet unexplained signal that appears to originate from a star nearly 94 lightyears away. The HD 164595 star system is a few billion years older than our own sun, but is otherwise very similar to the solar system. The central star is of comparable size and temperature to our sun, and it is known that the system contains at least one exoplanet and probably more. 

The signal appears weak to our telescopes, but a few simple calculations show that if it was indeed generated in HD 164595 then it must have been a very energetic signal. If the signal was transmitted in all directions, then it would need to be powered by 1020 watts, which is several hundred times more power than the Earth receives from the Sun. At present we have no technology that comes close to generating this much power, which would suggest if the signal is artificially generated then it comes from a very advanced civilization.

The other possibility is that they know we are here and pointed their transmitter directly at our solar system. However that still requires a few trillion watts of power, which is comparable to the total energy consumption of our own planet. While this might be possible for a civilization such as ours to manage, it would be very difficult.

However there are also a lot of doubts about this data. For one thing, the radio telescope that detected it is of an unusual design and as such the effects of terrestrial interference or other natural phenomena in the galaxy are not well understood. Furthermore, the astronomers who found the signal were measuring a wide range of frequencies and are unable to say what frequency the signal appeared at. It also only appeared once in a set of 39 different measurements of that patch of sky.

Since the announcement, other radio telescopes have been directed to the same star system and have not detected a signal. Unfortunately the interesting data set was collected in May 2015, and the team running the telescope did not think to let either the SETI team or any other astronomers know that there might be something interesting. As such their data set is the only one that was collected in that direction during that period of time, and confirmation is impossible.

So is this the first sign of alien life? It is possible, but I would doubt it. At this point it is far more likely to be an error in the data collection or some more mundane source of radio noise.

For now it is just an interesting glimmer of something more.