Recently the news announced the discovery of a planet with characteristics similar in size to earth with the possibility for liquid water, 4.2 light years away.

Now, if there was a civilisation of human beings, pretty much identical to our own civilisation, with the same population, radio output, distribution, etc then, could we detect them now?

If not, assuming the progression of radio/telescope technology here on earth continues at the same pace, how long would it be before we were aware something artificial was happening on that planet ( disregarding communications, language, etc etc )

If it helps, assume the planet is an identical clone of earth in every way. I'm more interested in if our civilisation was on our closest star would we know?

  • 2
    $\begingroup$ The planet is Proxima Cen b, not Alpha Cen B (which is a star). $\endgroup$
    – ProfRob
    Aug 28, 2016 at 14:34
  • $\begingroup$ A fun article here on the James Webb telescope, which should be launched in a couple years. Related to your question. Atmospheric analysis should tell us quite a bit more than we're currently able to work out. earthsky.org/space/will-james-webb-telescope-find-new-earths $\endgroup$
    – userLTK
    Aug 28, 2016 at 16:50


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