Jason Steffen of the University of Nevada and Li Gongjie of the Harvard-Smithsonian Center for Astrophysics argue that even if there are two planets in a star system that are suitable for life, then it is extremely unlikely that intelligent life exists simultaneously independently on each them, reports The Conversation.
The number of known exoplanets is growing every year, and researchers are increasingly concerned with the question of how likely it is to find among them a planet on which intelligent life exists.
Jason Stephen and Li Gongjie, inspired by the discovery of the Kepler 36 system, which has several planets, the orbits of two of them are very close to each other and therefore the conditions on their surface are very close, tried to predict how likely it is that each of these planets exists intelligent life that develops independently of each other.
Modeling led to a disappointing conclusion - the existence of brothers in mind in the same system is almost impossible. First, it is rather difficult to assume the very fact of the independent emergence of life at such a close distance - it is much more likely that when life arises on one of the planets, it will be brought to the neighboring one as a result of either the so-called. "Panspermia" - when microorganisms move by themselves between celestial bodies, - or "lithopanspermia" when they do the same on stones or other solid particles.
According to scientists, at small distances by space standards, this is quite likely, since, for example, 30% of terrestrial bacteria that spent 6 years in outer space survived.
But even if life got to the second planet in this way, it has rather little chances that it and life on another planet will simultaneously reach the level of civilization. Indeed, according to scientists, it took 2 billion years for bacteria to form multicellular organisms, and another billion was needed for a human civilization to appear.
And according to scientists, the likelihood that two evolutions in this regard will take place at an identical speed up to thousands of years is extremely small. Thus, even if there is life on two planets of one star system, intelligent beings from one of the planets, having flown to the other, will find substances suitable for their nutrition at best.
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And accordingly, the "attack of intelligent beings from Mars", which H. Wells once wrote about, is extremely unlikely in any star system.