Free Astronomy Magazine November-December 2020

44 NOVEMBER-DECEMBER 2020 ASTROBIOLOGY signal not directly attributable to that handful of known ex- oplanets. Tuning into the right channel, identifying the trans- mitter in space, and receiving the message are all actions that require a precise level of cognitive and technological development that the broad- caster (the alien civilization) should consider typical of the receiver (us). How could the alien civilization be certain of our ability to perform those actions? Why should anyone who takes the initiative to attempt a contact choose a path that re- quires the possible interlocu- tor to use complex techniques and processes so that the mes- sage sent is received and un- derstood? Furthermore, con- sidering the immense distance that would surely divide two galactic technological civiliza- tions, and the very long times that would then elapse be- tween each back and forth, would it even make sense to start a conversation? Each reply to a previous message could find an interlocutor with ideas and intentions dif- ferent from the original ones. They may not even know the previous contents of the con- versation or no longer be able to recognize our messages. Those who deal with these is- sues inevitably ask themselves why the members of a tech- nological civilization should seek contact (active or passive, it does not matter) with a sim- ilar civilization on a very dis- tant planet. The answer is obvious: to understand if they are alone in their galaxy or in the universe. Although we hu- mans inhabit this wonderful planet in the company of