#Let’s be careful about this “SETI” signal

Several readers have contacted me recently about reports that a group of international astronomers have detected a strong signal coming from a distant star that could be a sign of a high-technology civilization. Here’s my reaction: it’s interesting, but it’s definitely not the sign of an alien civilization—at least not yet.

Jodie Foster in the movie "Contact"

Jodie Foster in the movie “Contact”

Here’s why:

  1. The signal was first detected in May 2015 and has not repeated since. Unfortunately, although international protocols call for alerting the astronomical community to the detection of a mysterious signal, the observers chose not to do so. Sadly, their failure to observe this simple protocol likely hindered our ability to clarify exactly what caused the signal.
  2. The signal was detected by an antenna that is very complex—and one that a colleague of mine who is a radio astronomer said could have mislabeled a terrestrial signal (i.e, one from a satellite or airplane) crossing the side lobes of the beam when the observation was made. In other words, the pointing quality of this antenna is so uncertain that it may have captured what we call a false or “parasite” signal.
  3. HD 164595, the host star, is very similar to the sun (same color, size, and age). It’s ninety-one light years from Earth and has a known planet, HD164595 b, which is probably Neptune-like and orbits very close to its star every forty days. We have not yet detected an Earth-like or super-Earth-like planet around this star, and do not believe there is one. This is the case because this is what current theories on the formation of planetary systems tell us. But there is no reason why life could not exist on satellites of as-yet undetected icy giants in this system—but this moves us from fact to the realm of pure speculation.
  4. Finally, before getting too excited about a speculative and relatively old signal, we should recall the puzzle of fast radio bursts, or so called perytons. Astronomers detected and announced them in 2015, only to later conclude that they were nothing more than the signal from a nearby microwave oven which door was opened by impatient astronomers.

So how will I change my mind you may be wondering? Could we prove that this signal is a civilization which has been trying to communicate with us?

Following the mantra by Carl Sagan “Extraordinary claims require exceptional evidence” I will simply say that this signal should be first detected by another antenna somewhere else in the world. My colleagues at the SETI Institute are already working on it, and observed the star for several hours.

Then the signal should be analyzed to be certain that it is not coming from a human source. Finally, if the signal is detected repetitively, we can assume if E.T. wants to communicate with us, then the signal should have content. Whatever it could be, the digits of Pi, the first prime numbers, their encyclopedia or some images of themselves, we are quickly capable of finding out if this signal has indeed a meaning.

We are not there yet. It has happened in the past and tumultuous history of SETI that, for a few hours, astronomers thought to have discovered a signal (see “Aliens on Line 1”). As the technology evolves, and more searches are being conducted, we may discover more signals that look promising but at the end don’t pan out. But the search continues… in fact, in the scale the age of our solar system, it has just started.

Clear Skies,

Franck Marchis

from Welcome to Cosmic Diary ift.tt/2caMwQH

Leave a Reply

Your email address will not be published.

The CAPTCHA cannot be displayed. This may be a configuration or server problem. You may not be able to continue. Please visit our status page for more information or to contact us.

This site uses Akismet to reduce spam. Learn how your comment data is processed.