The chances of the emergence of intelligent life on twin Earth was equal to about 3:2, reported in a new study in the journal Proceeding of the National Academy of Sciences. SATO primitive organisms on planets like ours, can meet more often. This is the conclusion the author came to build a probabilistic model that takes into account the evolution of life on earth.
The question of how common life in the Universe is one of the fundamental for modern science. Today, scientists have no direct evidence of the existence of even primitive organisms beyond the Earth, and remote detection of chemical biomarkers (e.g. methane or carbon dioxide) outside the Solar system yet does not allow us to say unequivocally that they are associated with the presence of life. Nevertheless, astronomers today continue to develop projects to search for extraterrestrial civilisations and sending signals to space, and the development of probabilistic models can help them choose the best candidates for their research.
David Kipping (David Kipping) at Columbia University have suggested to use Bayesian analysis to determine probability of intelligent life on Earth, if we went back in time to the moment of its inception. In his work, the researcher took into account three main factors: the time of appearance of the first living organisms, the time of appearance of intelligent life and the window size of the habitability of our planet.
Life on Earth on a cosmic scale, arose quite early. The carbon of organic origin, found in tiny crystals, shows that primitive microbes on the planet could exist, after 400 million years after its formation. But intelligent life appeared much later, with the emergence of human civilization a few million years ago (Kipping notes that the starting point may be the emergence of hominids, and the separation of Homo sapiens, as the scope of the study this does not create significant error). As this event had at a fairly late time window of the habitability of Earth, the amount of which the researcher was estimated at 5.3 billion years, Kipping concludes that the process of the emergence of intelligent life was neither easy nor guaranteed.
Numerous runs of the simulation showed that the chances of life on twin Earth is equal to at least 9:1, which, in the opinion of the astronomer, suggests that the existence of primitive organisms outside the Solar system should not be too rare. However, the situation with intelligent life was somewhat different: the probability that the processes similar to those that occurred on our planet, its twin will appear civilization, is able to develop to our level, was equal to only 3:2. According to Kipping, if we again lose the history of the Earth, then it is unlikely there is intelligent life.
However, Kipping notes that his work cannot be regarded as proof that the cosmos extended life, as our knowledge about it is limited only by the knowledge of one world — Earth. The proposed model provides only a statistical assessment of the processes occurring on our planet, and not a definite prediction.
Today astronomers consider different methods of detecting life outside the Solar system. Recently, scientists have proposed to search for extraterrestrial civilizations not only on radio but also on space debris surrounding their planet.