Scientists Propose New Explanation That We Haven't Found ETs Yet

With the discovery of new exoplanets practically every day - some of which are even considered potentially habitable - not to mention that in the Milky Way alone it is estimated that there are 100 billion planets (of which 1 billion would be habitable), you are already Asked how we could never, ever get in touch with any alien civilization?

We at Mega Curioso have already talked about this issue in detail in one of our stories - which you can check through this link - and explain that this incongruity is called Fermi's Paradox. In the article (which is very interesting and worth reading), we also tell that several theories have already been proposed to justify this absence of signs of life, and one of the most popular is the “Great Filter”.

Where is everybody?

Basically, the great filter states that while life may be incredibly common in the universe at some point between its emergence and its development - until this life form reaches the highest level of evolution as civilization - a kind of obstacle presents itself and prevents life from advancing.

This could be, for example, a cataclysmic event, such as a geological catastrophe, an asteroid collision, exposure to a supernova, or a nuclear war or environmental apocalypse. For now, according to David Szondy of the Gizmag portal, a pair of astrobiology specialists from the National University of Australia have suggested an "addendum" to the big filter theory.

The researchers - Charley Lineweaver and Aditya Chopra - suggest a new hypothesis, called the 'Gaia Filter', which is based on the idea that, as conditions on newly formed planets are very volatile, if life does not evolve fast enough. stabilize the environment, it can be quickly extinguished before it "avenges."

They believe that the emergence of life on a young rocky planet requires more than just heat and water in its liquid state. In addition to these ingredients, there needs to be a certain level of stability that life itself helps to establish.

Taming the environment

As you know, when the earth formed, the environment was incredibly inhospitable to the most advanced life forms. However, the simplest organisms were able to survive the harsh conditions of the day, and their biological activity - such as transforming carbon dioxide into oxygen in the atmosphere and absorbing methane - gave rise to a dynamic system capable of regulating the environment and sustain the most varied forms of life.

For, according to Lineweaver and Chopra, most young planets have the same kind of unstable environment that existed in Earth's early days. And in order to turn these worlds into habitable places, the simplest life forms need to regulate conditions - especially greenhouse gases and water - in order to keep the surface temperature under control.

Evolution

Astrobiologists use as examples the cases of Venus and Mars, whose environments were very similar to Earth's 4 billion years ago. Today, however, Venus has become a world where it rains sulfuric acid and whose temperatures are high enough to melt lead, while Mars has become a red desert almost entirely devoid of atmosphere.

They believe something must have happened in the past of these planets to make their evolution so different from ours - and Lineweaver and Chopra hypothesize that life has developed fast enough around here, contributing to a more stable environment. quickly and became habitable.

On the other hand, it is possible that on Venus and Mars the emergence of life was slower, and therefore it disappeared before it had a chance to settle. On top of that, the pair's proposal predicts that if we find fossils of alien beings across the universe, they will probably be from extinct microbes - and if we find them on Mars, the discovery will indicate that humanity has already survived the great filter.

On the other hand, if we ever find fossils of complex organisms, it means that there is a possibility that the Terrans have not yet faced the great obstacle to the evolution of life - and that our end is yet to come.

Do you believe that humanity will ever be extinguished? How do you think this will happen? Comment on the Mega Curious Forum