Aliens communicating with humans? A question that arises in the field of the improbable but not the impossible and if the atmosphere is that of the scientific saga, in reality there is little invented here. It is pure science and the answer to the question could arrive as early as 2029.
The secret is in the “radio”
We humans have been making use of radio waves for a hundred years: even if we don’t hear them, they are everywhere, they travel around us and even out of our reach, in space. But how to know if they have arrived within the reach of someone able to answer us? The astrophysicists Howard Isaacson of Berkeley e Reilly Derrick of UCLA started by analyzing the signals of Deep Space Network (Dns) of NASA, the international network of radio telescopes that we have been using since 1972 to communicate with deep space missions such as Voyager, Pioneer, New Horizons. The goal is to find out if the radio signals sent from Earth have encountered any exoplanet (i.e. an exoplanet) that could host life.
The star map
Like space navigators, the scholars have crossed the path taken by the signals sent by the DSN with the map drawn by the European Space Agency’s Gaia mission, the most precise in our galaxy, to understand which stars could have been invested by them and above all at what distance they are. The response was surprising. Four stars they should have encountered the signals and the closest of them is a white dwarf that it is “only” 27 light-years away from Earth. Now, the star is unlikely to host intelligent life — white dwarfs form when a star dies — but there may be some habitable planets around that we haven’t discovered yet. And this is the point: if the inhabitants of those planets had sent us an answer as soon as they intercepted our waves, this will reach us in the 2029. The answers from the most distant stars, hit by radio exchanges with the Voyager 2 probe, could instead arrive between 2031 and 2033.
Many doubts
All this obviously assuming that there really are planets around those stars (statistically rather common possibility), that they are not only habitable but also inhabited, that the extraterrestrials in question are not only «intelligent» but so evolved as to pick up the signals and answer you. And maybe they even want to do it. It is hardly said.