There is a claim that habitable-zone orbits are stable around both components of the Alpha Centauri binary, and at least one planet has been detected (though not in the habitable zone). Both stars appear to be about as old as the Sun or older. There is now some serious effort to look for an "Earth Proxima" (Mission Centaur) in the Alpha Centauri system. Seems like a lot more to go on than SETI has had with other places they've been listening to. With that in mind, has there ever been any effort to listen for artificial signals from Alpha Centauri or to send something like an "Arecibo message"?

Since Alpha Centauri is only about 4 light years away, it would be reasonable to expect that if there is an intelligence present with the means and desire to listen and reply (admittedly a whole lot of "ifs"), we shouldn't have to wait more than 10 years to get a result if one is at all forthcoming, and it would be a relatively inexpensive exercise to undertake, even if nothing comes of it.

  • $\begingroup$ Have you seen this: seti.org/weeky-lecture/… ? I can't watch right now, but it looks promising. $\endgroup$
    – called2voyage
    Aug 5, 2016 at 20:22
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    $\begingroup$ Though an official announcement isn't expected until late August, it now appears that there's an Earth-like planet orbiting Proxima Centauri. Proxima is about 0.24 light-years from Alpha Centauri A and B, with a separation as seen from Earth of 2.18°. Proxima is a flare star, which might limit the possibilities for life. $\endgroup$ Aug 14, 2016 at 22:47
  • $\begingroup$ @KeithThompson I was watching some of the SETI videos at/associated with the link mentioned above. Proxima is apparently a very un-promising candidate for life. $\endgroup$
    – Anthony X
    Aug 14, 2016 at 23:04
  • $\begingroup$ The videos predate the recent discovery. But yes, the x-ray flares could be a bit of an inconvenience. It's also worth mentioning that studies aimed at Alpha Centauri A and B likely wouldn't cover Proxima. $\endgroup$ Aug 14, 2016 at 23:12

1 Answer 1


Yes, SETI has listened to Alpha Centauri. Here's a 2003 list of targets for SETI, which includes all of the 100 closest stars.

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    $\begingroup$ Considering the recent news about Proxima Centari (possibly) having a rocky planet in the habitable region - I wonder if this question and answer should just be updated to include both stars. They are both #1 in the list in your link - I think because Alpha CEN and Proxima CEN are physically close together and within the beam width of the measurement. I was about to ask the question about Proxima when i found this - no need for a separate question? $\endgroup$
    – uhoh
    Aug 25, 2016 at 3:06

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