The origin of life on Earth is one of those fascinating enigmas that we may never be able to solve. There is some consensus, based on the scientific evidence accumulated so far, that life on our planet would probably begin at least 3.8 billion years ago. In addition, one of the most accepted theories about the origin of the same assumes that in the primitive Earth the most suitable conditions were given for the first organic molecules to be synthesized, whose level of complexity would have progressively increased until forming more complex ones.
There is, however, another alternative hypothesis to that of the origin of life on Earth itself and with fascinating connotations: panspermia, which means that life would have arisen outside of our planet. Although the idea may seem far-fetched, in recent years evidence has been accumulating that shows that it would not be so complicated that certain organic molecules that are fundamental to life had been formed beyond our borders and reached Earth through of meteorites. However, the theory of panspermia is still that: a theory, and for now it seems much more plausible that life had originated on our planet.
But let’s go in parts: who came up with the idea of panspermia? It is said that in the 5th century AD. C, the Greek scientist Anaxagoras already spoke that life would have dispersed throughout the universe in the form of seeds. At the beginning of the 20th century, Swedish chemist and Nobel laureate Svanté Arrhenius proposed that resistant bacterial spores were propelled by the solar wind from one star to another. Arrhenius even calculated the time it would take for a terrestrial spore to reach Pluto: four months. Furthermore, this spore would reach Alpha Centaurus in just 7,000 years.
Biologist Lynn Margulis, to whom we owe such important advances in biology as endosymbiotic theory, was skeptical of panspermia. However, in the book What is life? , written with his son Dorion Sagan, makes an interesting reflection: “ If life began in outer space, the study of how it arose could be applied to any planet other than Earth. In fact, the Earth itself is suspended in a vacuum, so however you look at it, life originated in space. “
What the scientist comes to say is that, regardless of the place of origin, the mystery about how life was formed is still there, and the only thing we do when accepting the panspermia theory is “change the place” of the unknown.
In any case, in this gallery we want to share some recent scientific advances that would support, not only the theory of panspermia, but also the possibility that life had arisen, in addition to on Earth, outside the limits of our planet. Happy journey!
