Free Astronomy Magazine November-December 2020

NOVEMBER-DECEMBER 2020 seeing radio waves or microwaves emitted by everything that exists on the rocky sur- face of its planet of origin, as inanimate objects in a terrestrial-like environment do not habitually emit such radiation. In the first case, life would not exist; in the second case, it would not have the slightest aware- ness of what surrounds it (although, at most, an exception could be made for in- frared radiation). It is, therefore, not a gamble to say that the only certainty an alien civilization could have about us is that we are able to distin- guish variations in intensity (and perhaps also in color) of so-called visible light. That same alien civilization could also reason- ably assume that, if we are curious enough, we would have already invented the tele- scopes and other devices useful for record- ing starlight, and that we are therefore able to perceive small variations in the light radiation arriving at our planet. On the contrary, ET would have no certainty of our knowledge of radio waves, which are not as essential to the evolution of intelligent life. So why look for frequency modulation or in radio bands at all? The obstinacy of most SETI projects in investigating the ra- A fter seven years of de- sign and proto- typing, the Inter- national Center for Radio Astron- omy Research (ICRAR) has com- pleted prepara- tions for the con- struction of SKA, which will begin in 2021 and will give new impetus to SETI projects.