Life in the universe - Dionysis P. Simopoulos July 15, 2020 – Posted in: Magazine – Tags: editorial, space, science, magazine, technology

Introductory note of Dionysis P. Simopoulou, Honorary director Eugenidei Planetariou for the #3 issue of the magazine How it works

The issue you have in your hands includes dozens of interesting science and technology topics, but I personally singled out two pages of a topic that has been of particular interest to me in recent years. I am specifically referring to the possibility of extraterrestrial life on Saturn's moon Enceladus. Of course, the research we have done so far on the other planets and satellites of our Solar System excludes the existence of advanced forms of life on them, but it does not exclude the existence - now or in the past - of simpler forms of microbial life; and Enceladus is indeed one among the most likely places to look for such life. There are, of course, other similar possible places for the existence of life in the Solar System, such as the subsurface of Mars, the subsurface seas on Jupiter's moon Europa, as well as on another moon of Saturn, Titan. The chances of life existing anywhere else in the Solar System are probably infinitesimal.

And yet, beyond our Solar System there are trillions of other planets in the Universe, since today we now know that, as the Universe evolves, the creation of planets around stars is a perfectly normal process. Already in the last 25 years we have discovered more than 4,000 exoplanets in nearby stars. And then, of course, continuity. How, then, would it be possible for life to arise on a single planet among the billions upon billions of planets in the Universe? And if life was created elsewhere, what could prevent its evolution into intelligent beings and the creation of extraterrestrial technologically developed civilizations?

Research has shown us that our own species of life, or life as we know it, seems to evolve on planets that exhibit a stable temperature state. Such a planet would have to be at a constant distance from its sun so that it has water that is neither frozen nor easily evaporated. Because water seems to be necessary in the process of combining the chemical elements that will lead to the creation of life. The planet that will host it should also have the appropriate size, so that the atmosphere that will hold its gravity is neither too big, like Jupiter, nor too small, like Mars.

The recipe for life, after all, is very simple: carbon, oxygen, nitrogen and hydrogen, with some phosphorus, iron, potassium and sodium for variety. Its complexity, however, is based on the almost infinite number of combinations that these simple elements form among themselves, just as the 24 letters of the alphabet form the endless litany of world literature texts. This is because, due to their structure, the atoms of the chemical elements can combine with each other relatively easily – while the carbon atom has proven to be the most skillful of all, because it can combine not only with other carbon atoms but also with atoms of various other chemical elements, in an almost infinite variety of combinations. After all, this is why speech and life as we know it on Earth is based on carbon.

It happened here on our Earth, on a simple planet of a simple yellowish star. And if there is abundant life here, aided by the Sun, then what are the chances of life, intelligent life, anywhere else in the Universe? The stars are out there. Like the chemical components of life, they are out there, everywhere, scattered in the Universe. There is also the time required. Time to shuffle, grow, change. Time measured in billions of years. Thus, the Universe may contain 100,000 trillion races of beings who will search the void with their eyes to see what we see, to think what we think, and to wonder if they too are alone in the Universe .
Could we ever come into contact with such a space civilization? Probably not, because the number of such civilizations can vary greatly depending on how long a race of rational beings can survive as a complete technological society. Because there is a risk that it will destroy itself with a nuclear war or with the constant contamination of its environment. Therefore, with such short survival periods, the number of technological civilizations that can exist simultaneously within our Galaxy should not be all that great after all. So the average distance between them should be huge.