© Image generated by DALL-E AI for Presse-Citron
Extraterrestrial life is one of the fundamental questions that humanity has been asking since Antiquity. Already, our distant ancestors imagined the sky populated by celestial beings, or gods residing in the stars. However, the modern approach to research into extraterrestrial life really took root in the second half of the 20th century, with developments such as the SETI (Search for Extraterrestrial Intelligence) project. A project launched in 1960, which aimed to detect artificial signals from space.
The exploration of this question has accelerated with technological progress, in particular through the search for exoplanets, the study of extreme environments on Earth and advances in astrobiology. Advances that have allowed us to understand more precisely the question of life on Mars, for example. However, a new study published in May in the journal Astrobiology using the Drake equation may well put an end to all this speculation: we would be alone and isolated in the Universe.
A nuanced perspective on the Drake equation
The Drake equation, formulated by the famous American astronomer Frank Drake during the 1960s, aims to estimate the number of intelligent civilizations populating our galaxy, the Milky Way. This equation takes into account a plurality of factors.
The rate of star formation (R*), the proportion of these stars with planets (fp), the number of planets likely to harbor life (ne), the fraction of planets with the appearance of life ( fl), the fraction of planets harboring intelligent life (fi), the fraction of intelligent civilizations with technology to communicate (fc) and the average lifespan of a technological civilization (L). Thanks to the multiplication of these values, we therefore obtain this equation: N = R × fp × ne × fl × fi × fc × L*.
Note, this equation is a rough estimate, as the values of each factor are still largely uncertain.< strong> It must be seen as a framework for reflection. The results obtained by applying this equation vary considerably, ranging from a few dozen to several million potential civilizations. To establish their new theory, the researchers added new factors to the Drake equation. Enough to turn everything upside down!
Plate tectonics: the great forgotten one
Des Researchers have recently drawn on the reservoir of newly acquired data on exoplanets in order to refine their estimates. Their attention focused on plate tectonics, an element considered crucial for the development of complex life forms. What is plate tectonics?? It is a scientific model explaining the movement of the rigid plates that make up the earth's crust, and responsible for the formation of continents, mountains , volcanoes and earthquakes.
This tectonics plays, in fact, several essential roles: it exposes freshly exhumed rocks at regular intervals, releasing essential nutrients such as phosphorus, or carbon, fundamental components of biological molecules that are l’ DNA (deoxyribonucleic acid) and RNA (ribonucleic acid). Without DNA or RNA, no life! At least as we know it. The latter carry the genetic information necessary for the reproduction, development and functioning of living organisms.
Furthermore, these geological movements contribute to an increase in levels of &# 8217;oxygen, necessary for the respiration of complex organisms, while contributing to climate regulation through several processes: volcanoes release CO2 into the atmosphere (warming), trapping of CO2 in sediments and rocks (cooling), formation of marine currents, etc.
These researchers therefore combined these geological factors with the parameters of the Drake equation, in order to estimate the number of planets likely to see the development of intelligent civilizations.
Their conclusions are striking: taking into account the need for plate tectonics and other favorable conditions, they estimate that our galaxy could be home to between 0 and 100,000 planets capable of supporting intelligent civilizations. When the risks of mass extinctions and societal collapses are factored into the equation, this figure drops further, now sitting between 0 and 20%. 000. Although these numbers may seem high, compared to the hundreds of billions of stars in the Milky Way, they don't actually amount to much.
A pessimistic but realistic perspective
These estimates suggest that intelligent and communicative life could prove to be an extremely rare phenomenon. However widespread primitive life, such as bacteria, may be, it appears that the specific conditions required for the evolution of complex and advanced life forms are only rarely met. This brings a somewhat austere perspective on the possibility of one day establishing contact with other civilizations.
Despite these results, which are discouraging to say the least, we must keep in mind that all hope is not lost. Detection techniques continue to progress, and it is not excluded that we will one day discover planets similar to ours, capable of supporting life. In the meantime, this study reinforces the idea according to which our own existence could well be of greater preciousness and singularity than we know ;#8217;imagine.
Regardless, the quest to understand our place within the world #8217;Universe will take its course. Curiosity is inherent to the human species, and we have an innate desire: to discover and interpret what surrounds us. This same desire that will push scientists to continue to probe and explore the mysteries of space. Remember that this new theory also remains a probability. About this, the French-Canadian astrophysicist Hubert Reeves very rightly said: “ The word “probable” suppose that we know how it happened, that we can decompose the actions that happened to have the appearance of life on Earth. As long as we do not have a suitable and acceptable theory concerning the set of phenomena which led to life appearing on Earth, we cannot calculate probabilities. I believe that we must exclude the word “probability” as long as we do not have this possibility of calculation.” This is what keeps us dreaming a little longer.
- A new study has brought Drake's theory up to date to estimate our chances of one day encountering a planet hosting extraterrestrial life.
- The researchers added to the factors already existing factors of the plate tectonics model.
- Their results: the chances of other intelligent creatures living in our galaxy are extremely low .
📍 To not miss any news from Presse-citron, follow us on Google News and WhatsApp.
[ ]