Free Astronomy Magazine May-June 2024

24 MAY-JUNE 2024 ASTRO PUBLISHING tion of radio waves or through de- tection of an excess of infrared radi- ation resulting from the dispersion of heat produced by its technologi- cal activities. These means are, as often happens in the ETC field, from a vision with an anthropocentric fla- vor: these are in fact the ways in which an ETC could, in our opinion, discover today's Earthlings and those of the next decades or cen- turies. Admitting but not granting that a possible ETC may have expe- rienced an initial technological evo- lution completely comparable to ours, it could now find itself at a level of development enormously superior to ours, considering that the Milky Way could have been hab- itable already for a few billion years earlier than the formation of our solar system. Presumably, an ETC hundreds of thousands or millions by Michele Ferrara revised by Damian G. Allis NASA Solar System Ambassador S ome astrobiologists are opti- mistic about the possibility of discovering extraterrestrial technosignatures within a few decades, that is, the collection of ir- refutable evidence of the existence of another technological civilization somewhere in our galaxy. The rapid progress of the instrumentation available to researchers seems to be taking us towards that epochal goal. But is this optimism shareable across both space and time? Only in part, because in order to make that dis- covery, the more-or-less voluntary, but by no means certain, complicity of at least one other technological civilization (ETC for short) would be indispensable. In the scientific com- munity, the idea is quite widespread that, regardless of the desire of an ETC to not reveal its existence, we could still find it through the recep- Zoo hypothesis − as intriguing as it is unlikely