Humanity would still have to wait between two millennia and 400,000 years before hoping to meet aliens, according to a new report from Chinese scientists.
The two Chinese scientists, working on the search for intelligent communicating extra-terrestrial civilizations (CETI), explain in their paper, published in The Astrophysical Journal, that they can study to what extent new stars in the galaxy could support life and when intelligent life could appear on a nearby habitable planet, using star formation and knowledge of the planetary system.
"Most studies on this problem are based on the Drake equation," the authors write, reports RTBF. "The obvious difficulty with this method is that it is uncertain and unpredictable to quantify the likelihood that life could appear on a suitable planet and eventually develop into an advanced communicating civilization."
The Drake equation, formulated in 1961 by American astronomer and astrophysicist Frank Drake, is a probabilistic argument used to estimate the number of active, communicative extra-terrestrial civilizations in the Milky Way Galaxy.
The equation has been used by many astronomers curious to update it with the new data collected. This was particularly the case of a study which stated that there would be many extinct civilizations in our galaxy that did not have time to contact us before intelligent life appeared on Earth.
According to the calculations of the two Chinese researchers, luck could (or may not) smile on us in 2,000 years when the first aliens come into contact with us.
Considering that a star has to wait 25% of its life to provide a viable environment and that each planet has a 0.1% chance of creating life, then 2,000 years could be plausible to meet another CETI life form in the Milky Way. In this hypothesis, there would then be 42,000 potential communicating extra-terrestrial civilizations in our galaxy.
If, on the contrary, the star that will see life bloom must cool down because it is too powerful at the beginning of its life, it will be necessary to wait for 75% of its existence, reducing the chances of the planets to 0.0001% and therefore the waiting time to 400,000 years.
According to this hypothesis, we then fall to 111 CETI in the Milky Way, which is more likely according to some.
In November 2020, a study by NASA stated that there would be no less than 300 million planets that could possibly host extra-terrestrial life in our galaxy.
Start from the Fermi paradox
However, not all astrophysicists agree with the statements released by the Chinese researchers. Professor Alain Jorissen from the Institute of Astronomy and Astrophysics at the ULB in Brussels was particularly surprised when approached by The Brussels Times for comment.
“Who would be smart enough or daredevil enough to make such an improbable statement?” he said. “It seems to me that this issue lies well beyond the field of Cartesian science.”
“Let’s start from the Fermi paradox: where are they?” he continued. “Earth is lagging behind other civilisations – were they to exist – by several billions of years. So why are we not the servant slaves of ETs? If we are not, it is because they do not exist... That is the essence of Fermi’s paradox.”
“Of course, there are many other possible solutions: they do exist, but they are not interested in travelling across the galaxy, and prefer to travel within their own mind, meditating," Jorissen said. "Or they may have decided to stay away from us, not to interfere with our culture, in order not to jeopardise our societies. Or they are here with us indeed, abducting some humans in their vessels, if one gives credit to these stories.”
“The problem with this topic is that it is way outside the reach of the Cartesian scientific approach requiring reproducibility and independence from the observer,” he concluded. “A much more promising approach is the search for biosignatures, such as methane CH4 and ozone O3, in the atmosphere of known, possibly habitable, exoplanets, within reach of the European Southern Observatory telescopes."