It is worth mediately determining what the Cosmos is all about: Its appearance is the beginning of the expansion of the Universe, before which the Universe was in a singular state, that is, it had infinite density and temperature. In fact, singularity is a very contradictory concept, because having infinite density, a substance cannot have infinite temperature - and vice versa. That is why the phenomenon of cosmic singularity is one of the biggest mysteries of modern astrophysics, because the data allow scientists to guess what was AFTER the Big Bang, but not what was before.
It is now accepted that the modern Universe, including the cosmos, was formed approximately 13.77 ± 0.059 billion years ago. According to the theory, the earliest moment that can be described is the moment of the Planck era (the earliest era in the history of the Universe we are observing about which there are any theoretical assumptions. It lasted for Planck time from zero to 10 to -43 degrees seconds.
Approximately 10 to -35 degrees seconds after the onset of the Planck era, the phase transition caused an exponential expansion of the Universe. That is, our Universe began to expand at an incredibly high speed. This is followed by several phases of the development of the Universe with the participation of quarks, gluons, baryons, protons and neutrons, which are difficult to describe, and this is not important to us. So, soon we need the phase of nucleosynthesis, when the usual chemical elements are formed, and some of the lightest nuclei, except for primary nucleosynthesis, are formed in stars.
About 380 thousand years after the Big Bang, the temperature dropped so that the existence of hydrogen atoms became possible, and gravity became the dominant force - the Universe began to cool, and matter formed and strengthened.
There are countless distant worlds, and this has become apparent even to skeptics. The first celestial body near a distant star was discovered in 1992 - since then, planet hunters have already discovered more than 4,000 exoplanets, and their number is constantly growing. And the biggest problem is no longer the discovery of new celestial bodies, but the identification of particularly interesting candidates and the disclosure of their characteristics. At the same time, the most exciting specimens are those that could provide favorable living conditions. In this context, the emphasis is on the so-called habitable zones - areas around distant stars in which water can exist on planets in liquid form. It is with respect to such distant worlds that it seems most likely that extraterrestrial life forms could arise there.
By confirming certain signatures in the emission spectrum of the atmospheres of such planets, it seems quite likely that someday we will be able to confirm the existence of extraterrestrial life on at least one of them. And to increase this chance, astronomers should concentrate as much as possible on the most promising candidates using modern telescopes. A study by a research team led by Stephanie Olson of the University of Chicago now offers more information on which exoplanets could provide a particularly high level for a diverse life. They reported on the results of the work at the Goldschmidt Geochemical Congress in Barcelona.
As part of their study, scientists simulated probable conditions on various types of exoplanets using a special computer program developed by NASA. It is designed to simulate the climate and habitat of the oceans with various planetary features. “NASA, in search of life in the universe, is targeting planets in habitable zones that oceans can possess. Our work is currently aimed at identifying candidates among these planets whose oceans have the greatest potential for a vibrant and active life in them, ”says Olson.
Key factor - ocean circulation
As she explains, life in the Earth’s oceans depends on ascending currents that deliver nutrients from the depths to the sunlit parts of the ocean, where certain living things are photosynthesizing, laying the foundation for the food chain. It follows: more mixing means more nutrients and more biological activity. “These are exactly the conditions we need to search for exoplanets,” Olson explains. “We used the ocean circulation model to find out which planets have a particularly efficient mixing of water and therefore can have particularly viable oceans.”
According to scientists, the simulation clearly shows that a higher density of the atmosphere, lower planet rotation speeds and the presence of continents definitely contribute to mixing. But if you look at the Earth from this point of view, the researchers are sure that it is not optimal. And this means the following: in the universe, planets are quite possible that could offer living organisms even better conditions than our planet, alive with life.
As Olson points out, we do not yet have systems that could identify all the features of the planets identified in the study - but everything could change. “Our work can influence the development of telescopes so that they are equipped with the appropriate capabilities. And now, when we know more and more precisely what to look for, we must begin to search in practice, ”says the scientist.